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Sample records for cooled superconducting power

  1. Counter flow cooling characteristics with liquid nitrogen for superconducting power cables

    NASA Astrophysics Data System (ADS)

    Furuse, Mitsuho; Fuchino, Shuichiro; Higuchi, Noboru

    2002-06-01

    Counter flow cooling is one of effective cooling systems for superconducting power transmission cables to save space. In designing of HTc superconducting power cables, investigating cooling characteristics with liquid nitrogen is important. We have conducted counter flow cooling tests of a 100-m long duplex-counter-flow tube with liquid nitrogen and obtained basic data of initial cooling and temperature distributions along the tube. Measured temperature distributions are compared with those calculated that are based on our previous study. They agree with temperature distributions of inner tube but not for outer tube. During cooling tests, mass flow rate oscillations are observed. Relation between oscillation period and tube length is discussed. Reservoir pressure dependence of measured initial cooling time is also shown and compared with analytically estimated time in this paper.

  2. Quench protection tests of a cryocooler cooled 6 T NbTi superconducting magnet by an active power method

    NASA Astrophysics Data System (ADS)

    Nanato, Nozomu; Inoue, Takahiro; Murase, Satoru; Nishijima, Gen; Tamakawa, Katsunori; Amaya, Munenori; Uemura, Yoshifumi

    2012-07-01

    When a quench occurs in a superconducting magnet, excessive joule heating may damage the magnet. We have presented the quench protection system based on an active power method. Our previous quench protection tests have been carried out for small superconducting magnets whose self inductances are less than several hundred mH to verify principles of our proposed system. In this paper, we present experimental results of quench protection tests of a cryocooler cooled 6 T NbTi superconducting magnet (self inductance 15.5 H), which is a commercial size magnet made by Tamakawa Co., Ltd. We confirmed that our proposed system could inhibit the maximum temperature of the superconducting magnet (initial temperature 4.3 K) after the quench to less than about 44 K at operation magnetic field 5.5 T. Experimental results suggest that our proposed system is useful for practical used superconducting magnets.

  3. Power superconducting power transmission cable

    DOEpatents

    Ashworth, Stephen P. (Cambridge, GB)

    2003-01-01

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  4. Power superconducting power transmission cable

    SciTech Connect

    Ashworth, Stephen P.

    2003-06-10

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  5. Superconducting magnet system for muon beam cooling

    SciTech Connect

    Andreev, N.; Johnson, R.P.; Kashikhin, V.S.; Kashikhin, V.V.; Novitski, I.; Yonehara, K.; Zlobin, A.; /Fermilab

    2006-08-01

    A helical cooling channel has been proposed to quickly reduce the six-dimensional phase space of muon beams for muon colliders, neutrino factories, and intense muon sources. A novel superconducting magnet system for a muon beam cooling experiment is being designed at Fermilab. The inner volume of the cooling channel is filled with liquid helium where passing muon beam can be decelerated and cooled in a process of ionization energy loss. The magnet parameters are optimized to match the momentum of the beam as it slows down. The results of 3D magnetic analysis for two designs of magnet system, mechanical and quench protection considerations are discussed.

  6. Superconducting Materials, Magnets and Electric Power Applications

    NASA Astrophysics Data System (ADS)

    Crabtree, George

    2011-03-01

    The surprising discovery of superconductivity a century ago launched a chain of convention-shattering innovations and discoveries in superconducting materials and applications that continues to this day. The range of large-scale applications grows with new materials discoveries - low temperature NbTi and Nb3 Sn for liquid helium cooled superconducting magnets, intermediate temperature MgB2 for inexpensive cryocooled applications including MRI magnets, and high temperature YBCO and BSSCO for high current applications cooled with inexpensive liquid nitrogen. Applications based on YBCO address critical emerging challenges for the electricity grid, including high capacity superconducting cables to distribute power in urban areas; transmission of renewable electricity over long distances from source to load; high capacity DC interconnections among the three US grids; fast, self-healing fault current limiters to increase reliability; low-weight, high capacity generators enabling off-shore wind turbines; and superconducting magnetic energy storage for smoothing the variability of renewable sources. In addition to these grid applications, coated conductors based on YBCO deposited on strong Hastelloy substrates enable a new generation of all superconducting high field magnets capable of producing fields above 30 T, approximately 50% higher than the existing all superconducting limit based on Nb3 Sn . The high fields, low power cost and the quiet electromagnetic and mechanical operation of such magnets could change the character of high field basic research on materials, enable a new generation of high-energy colliding beam experiments and extend the reach of high density superconducting magnetic energy storage.

  7. STOCHASTIC COOLING POWER REQUIREMENTS.

    SciTech Connect

    WEI,J.BLASKIEWICZ,M.BRENNAN,M.

    2004-07-05

    A practical obstacle for stochastic cooling in high-energy colliders like RHIC is the large amount of power needed for the cooling system. Based on the coasting-beam Fokker-Planck (F-P) equation, we analytically derived the optimum cooling rate and cooling power for a beam of uniform distribution and a cooling system of linear gain function. The results indicate that the usual back-of-envelope formula over-estimated the cooling power by a factor of the mixing factor M. On the other hand, the scaling laws derived from the coasting-beam Fokker-Planck approach agree with those derived from the bunched-beam Fokker-Planck approach if the peak beam intensity is used as the effective coasting-beam intensity. A longitudinal stochastic cooling system of 4-8 GHz bandwidth in RHIC can effectively counteract intrabeam scattering, preventing the beam from escaping the RF bucket becoming debunched around the ring.

  8. The integration of cryogenic cooling systems with superconducting electronic systems

    SciTech Connect

    Green, Michael A.

    2003-07-01

    The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types will be compared for vibration, efficiency, and cost. Some solutions to specific problems of integrating cryocoolers to superconducting devices are presented.

  9. Cooling system for superconducting magnet

    DOEpatents

    Gamble, Bruce B. (Wellesley, MA); Sidi-Yekhlef, Ahmed (Framingham, MA)

    1998-01-01

    A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir.

  10. Cooling system for superconducting magnet

    DOEpatents

    Gamble, B.B.; Sidi-Yekhlef, A.

    1998-12-15

    A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir. 3 figs.

  11. Power electronics cooling apparatus

    DOEpatents

    Sanger, Philip Albert (Monroeville, PA); Lindberg, Frank A. (Baltimore, MD); Garcen, Walter (Glen Burnie, MD)

    2000-01-01

    A semiconductor cooling arrangement wherein a semiconductor is affixed to a thermally and electrically conducting carrier such as by brazing. The coefficient of thermal expansion of the semiconductor and carrier are closely matched to one another so that during operation they will not be overstressed mechanically due to thermal cycling. Electrical connection is made to the semiconductor and carrier, and a porous metal heat exchanger is thermally connected to the carrier. The heat exchanger is positioned within an electrically insulating cooling assembly having cooling oil flowing therethrough. The arrangement is particularly well adapted for the cooling of high power switching elements in a power bridge.

  12. Electromagnetic launcher with cryogenic-cooled superconducting rails

    SciTech Connect

    Jasper, L.J.

    1987-06-12

    This patent application discloses railgun with superconducting rails. The device features rails made from ceramic materials capable of becoming superconducting at relatively high temperatures. Some embodiments utilize rails made entirely from superconducting ceramics, while other embodiments utilize rails with metallic cores covered by layers of superconducting ceramics. Cooling of the superconducting ceramic to a temperature below its critical temperature is accomplished by liquid nitrogen cryorefrigerator or a compressed gas cryorefrigerator.

  13. Materials research for hydrogen-cooled superconducting power transmission lines. Fifth quarterly report, January 1-March 31, 1981

    SciTech Connect

    Sletten, A.M.; Braginski, A.I.; Rosado, M.; Gavaler, J.R.

    1981-01-01

    The objectives of this three-year contract for DOE are to perform dielectric breakdown and loss measurements in liquid hydrogen and liquid-hydrogen-impregnated synthetic dielectrics, at temperatures between 14 and 20/sup 0/K and at hydrostatic pressures up to 5 atmospheres. (Effects of dissolved impurities/additives in the liquid are included); and to characterize the self-field and low-field superconducting properties of high-critical temperature materials at temperatures between approximately 14 and 20/sup 0/K. During the current reporting period, the following was accomplished: a decision was made to conduct the experiments on dielectrics outdoors, due to safety considerations; the design of the auxiliary equipment for the tests on the dielectric properties of LH/sub 2/ was finished, and all the key components were ordered; a new Safety Analysis Report (SAR) was started, to discuss the effect of the new setting on the safety aspects of this project; the design of the system of small electrodes was modified to provide individual ground connections for each ground electrode; data on Tc vs. composition was obtained for several samples of carbon-doped V/sub 3/Si; and the Nb/sub 3/ Ge chemical vapor deposition (CVD) apparatus was reactivated. Initially, it will provide Nb/sub 3/ Ge samples for various annealing experiments to be conducted during the duration of this project.

  14. Cooling of superconducting devices by liquid storage and refrigeration unit

    DOEpatents

    Laskaris, Evangelos Trifon; Urbahn, John Arthur; Steinbach, Albert Eugene

    2013-08-20

    A system is disclosed for cooling superconducting devices. The system includes a cryogen cooling system configured to be coupled to the superconducting device and to supply cryogen to the device. The system also includes a cryogen storage system configured to supply cryogen to the device. The system further includes flow control valving configured to selectively isolate the cryogen cooling system from the device, thereby directing a flow of cryogen to the device from the cryogen storage system.

  15. Compact he II Cooling System for Superconducting Cavities

    NASA Astrophysics Data System (ADS)

    Takahashi, M.; Yazawa, T.; Tosaka, T.; Kuriyama, T.; Kakutani, N.; Ota, T.; Nakayama, K.; Saito, K.

    2008-03-01

    This paper describes a compact He II cooling system for superconducting cavities. The cooling system mainly comprises a vacuum vessel, an 80 K liquid nitrogen bath, a 4 K He I bath, a He II bath, an evacuation pump, a single-stage GM cryocooler for the 80 K bath, and a 4 K GM cryocooler for the 4 K He I bath. Superfluid helium is generated and refilled into the He II bath via a heat exchanger and a JT valve by operating the evacuation pump. The refrigeration capacity attained was more than 10 W at 1.8 K. The cooling system was connected with a single-cell cavity cryostat. A superconducting cavity was immersed in superfluid helium. He II was supplied to the cavity vessel from the cooling system and evaporated helium gas was returned to it. High electric fields were obtained during superconducting cavity operations.

  16. Cooling arrangement for a superconducting coil

    DOEpatents

    Herd, K.G.; Laskaris, E.T.

    1998-06-30

    A superconducting device is disclosed, such as a superconducting rotor for a generator or motor. A vacuum enclosure has an interior wall surrounding a cavity containing a vacuum. A superconductive coil is placed in the cavity. A generally-annularly-arranged, thermally-conductive sheet has an inward-facing surface contacting generally the entire outward-facing surface of the superconductive coil. A generally-annularly-arranged coolant tube contains a cryogenic fluid and contacts a generally-circumferential portion of the outward-facing surface of the sheet. A generally-annularly-arranged, thermally-insulative coil overwrap generally circumferentially surrounds the sheet. The coolant tube and the inward-facing surface of the coil overwrap together contact generally the entire outward-facing surface of the sheet. 3 figs.

  17. System and method for cooling a superconducting rotary machine

    DOEpatents

    Ackermann, Robert Adolf; Laskaris, Evangelos Trifon; Huang, Xianrui; Bray, James William

    2011-08-09

    A system for cooling a superconducting rotary machine includes a plurality of sealed siphon tubes disposed in balanced locations around a rotor adjacent to a superconducting coil. Each of the sealed siphon tubes includes a tubular body and a heat transfer medium disposed in the tubular body that undergoes a phase change during operation of the machine to extract heat from the superconducting coil. A siphon heat exchanger is thermally coupled to the siphon tubes for extracting heat from the siphon tubes during operation of the machine.

  18. Direct cooled power electronics substrate

    DOEpatents

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W. (Kingston, TN) [Kingston, TN; Lowe, Kirk T. (Knoxville, TN) [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  19. Status of superconducting power transformer development

    SciTech Connect

    Johnson, R.C.; McConnell, B.W.; Mehta, S.P.

    1996-03-01

    Development of the superconducting transformer is arguably the most difficult of the ac power applications of superconductivity - this is because of the need for very low ac losses, adequate fault and surge performance, and the rigors of the application environment. This paper briefly summarizes the history of superconducting transformer projects, reviews the key issues for superconducting transformers, and examines the status of HTS transformer development. Both 630-kVA, three-phase and 1-MVA single phase demonstration units are expected to operate in late 1996. Both efforts will further progress toward the development of economical and performance competitive superconducting transformers.

  20. Progress on Superconducting Magnets for the MICE Cooling Channel

    SciTech Connect

    Green, Michael A; Virostek, Steve P.; Li, Derun; Zisman, Michael S.; Wang, Li; Pan, Heng; Wu, Hong; Guo, XingLong; Xu, FengYu; Liu, X. K.; Zheng, S. X.; Bradshaw, Thomas; Baynham, Elwyn; Cobb, John; Lau, Wing; Lau, Peter; Yang, Stephanie Q.

    2009-09-09

    The muon ionization cooling experiment (MICE) consists of a target, a beam line, a pion decay channel, the MICE cooling channel. Superconducting magnets are used in the pion decay channel and the MICE cooling channel. This report describes the MICE cooling channel magnets and the progress in the design and fabrication of these magnets. The MICE cooling channel consists of three types of superconducting solenoids; the spectrometer solenoids, the coupling solenoids and the focusing solenoids. The three types of magnets are being fabricated in he United States, China, and the United Kingdom respectively. The spectrometer magnets are used to analyze the muon beam before and after muon cooling. The coupling magnets couple the focusing sections and keep the muon beam contained within the iris of the RF cavities that re used to recover the muon momentum lost during ionization cooling. The focusing magnets focus the muon beam in the center of a liquid hydrogen absorber. The first of the cooling channel magnets will be operational in MICE in the spring of 2010.

  1. Progress on the superconducting magnets for the MICE cooling channel

    NASA Astrophysics Data System (ADS)

    Green, M. A.; Virostek, S. P.; Li, D.; Zisman, M. S.; Wang, L.; Pan, H.; Wu, H.; Guo, X. L.; Xu, F. Y.; Liu, X. K.; Zheng, S. X.; Bradshaw, T.; Baynham, D. E.; Cobb, J.; Lau, W.; Lau, P.; Yang, S. Q.

    2010-06-01

    The muon ionization cooling experiment (MICE) consists of a target, a beam line, a pion decay channel, the MICE cooling channel. Superconducting magnets are used in the pion decay channel and the MICE cooling channel. This report describes the MICE cooling channel magnets and the progress in the design and fabrication of these magnets. The MICE cooling channel consists of three types of superconducting solenoids; the spectrometer solenoids, the coupling solenoids and the focusing solenoids. The three types of magnets are being fabricated in the United States, China, and the UK respectively. The spectrometer magnets are used to analyze the muon beam before and after muon cooling. The coupling magnets couple the focusing sections and keep the muon beam contained within the iris of the RF cavities that are used to recover the muon momentum lost during ionization cooling. The focusing magnets focus the muon beam in the center of a liquid hydrogen absorber. The first of the cooling channel magnets will be operational in MICE in the spring of 2010.

  2. Cryogenic performance of a cryocooler-cooled superconducting undulator

    SciTech Connect

    Fuerst, J. D.; Doose, C.; Hasse, Q.; Ivanyushenkov, Y.; Kasa, M.; Shiroyanagi, Y.

    2014-01-29

    A cryocooler-cooled superconducting undulator has been installed and operated with beam at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The device consists of a dual-core 42-pole magnet structure that is cooled to 4.2 K with a system of four cryocoolers operating in a zero-boil-off configuration. This effort represents the culmination of a development program to establish concept feasibility and evaluate cryostat design and cryocooler-based refrigeration. Cryostat performance is described including cool-down/warm-up, steady-state operation, cooling margin, and the impact of beam during operation in the APS storage ring. Plans for future devices with longer magnets, which will incorporate lessons learned from the development program, are also discussed.

  3. Influence of neutron irradiation on conduction cooling superconducting magnets

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Yoshida, M.; Ogitsu, T.; Makida, Y.; Nakamoto, T.; Okamura, T.; Sasaki, K.; Sugano, M.

    2015-12-01

    The conduction-cooled superconducting magnets are now widely used in various applications due to their minimum usage of helium. In the accelerator science, they also play an increasingly important role in particle detector solenoids because they can minimize the materials needed for the magnet such that they can be more transparent against irradiated particles. For the same reason they are currently used in high radiation environments because they can reduce the heat load from the irradiation. However, the hadronic reactions, such as neutron or proton irradiation, can create degradation on the thermal conductivity of pure aluminum which is used as a cooling path. It leads to a poor cooling condition of the magnets. In Japan, there are two conduction-cooled superconducting magnets for muon production; one is already constructed and under operation, the other is now under construction. This paper briefly reports the influence of the irradiation on those magnets and discusses the possibilities of HTS based conduction-cooled magnets under high irradiation environments.

  4. Superconductivity for electric power systems: Program overview

    SciTech Connect

    Not Available

    1995-02-01

    Largely due to government and private industry partnerships, electric power applications based upon high-temperature superconductivity are now being designed and tested only seven years after the discovery of the high-temperature superconductors. These applications offer many benefits to the national electric system including: increased energy efficiency, reduced equipment size, reduced emissions, increased stability/reliability, deferred expansion, and flexible electricity dispatch/load management. All of these benefits have a common outcome: lower electricity costs and improved environmental quality. The U.S. Department of Energy (DOE) sponsors research and development through its Superconductivity Program for Electric Power Systems. This program will help develop the technology needed for U.S. industries to commercialize high-temperature superconductive electric power applications. DOE envisions that by 2010 the U.S. electric power systems equipment industry will regain a major share of the global market by offering superconducting products that outperform the competition.

  5. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C

    2013-12-24

    A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

  6. Heat pipe cooled power magnetics

    NASA Technical Reports Server (NTRS)

    Chester, M. S.

    1979-01-01

    A high frequency, high power, low specific weight (0.57 kg/kW) transformer developed for space use was redesigned with heat pipe cooling allowing both a reduction in weight and a lower internal temperature rise. The specific weight of the heat pipe cooled transformer was reduced to 0.4 kg/kW and the highest winding temperature rise was reduced from 40 C to 20 C in spite of 10 watts additional loss. The design loss/weight tradeoff was 18 W/kg. Additionally, allowing the same 40 C winding temperature rise as in the original design, the KVA rating is increased to 4.2 KVA, demonstrating a specific weight of 0.28 kg/kW with the internal loss increased by 50W. This space environment tested heat pipe cooled design performed as well electrically as the original conventional design, thus demonstrating the advantages of heat pipes integrated into a high power, high voltage magnetic. Another heat pipe cooled magnetic, a 3.7 kW, 20A input filter inductor was designed, developed, built, tested, and described. The heat pipe cooled magnetics are designed to be Earth operated in any orientation.

  7. Impact of cool-down conditions at Tc on the superconducting rf cavity quality factor

    NASA Astrophysics Data System (ADS)

    Vogt, J.-M.; Kugeler, O.; Knobloch, J.

    2013-10-01

    Many next-generation, high-gradient accelerator applications, from energy-recovery linacs to accelerator-driven systems (ADS) rely on continuous wave (CW) operation for which superconducting radio-frequency (SRF) systems are the enabling technology. However, while SRF cavities dissipate little power, they must be cooled by liquid helium and for many CW accelerators the complexity as well as the investment and operating costs of the cryoplant can prove to be prohibitive. We investigated ways to reduce the dynamic losses by improving the residual resistance (Rres) of niobium cavities. Both the material treatment and the magnetic shielding are known to have an impact. In addition, we found that Rres can be reduced significantly when the cool-down conditions during the superconducting phase transition of the niobium are optimized. We believe that not only do the cool-down conditions impact the level to which external magnetic flux is trapped in the cavity but also that thermoelectric currents are generated which in turn create additional flux that can be trapped. Therefore, we investigated the generation of flux and the dynamics of flux trapping and release in a simple model niobium-titanium system that mimics an SRF cavity in its helium tank. We indeed found that thermal gradients along the system during the superconducting transition can generate a thermoelectric current and magnetic flux, which subsequently can be trapped. These effects may explain the observed variation of the cavitys Rres with cool-down conditions.

  8. Superconductivity in the splat-cooled UMo alloys

    NASA Astrophysics Data System (ADS)

    Kim-Ngan, N.-T. H.; Sowa, S.; Krupska, M.; Paukov, M.; Tkach, I.; Havela, L.

    2015-03-01

    We have investigated the superconductivity in splat-cooled UMo alloys by low-temperature resistivity and specific-heat measurements down to 0.4 K. The ?-U materials, such as U-Mo15 (with 15 at.% Mo doping), exhibit a conventional BCS superconductivity with Tc = 2.1 K and upper critical field exceeding 5 T, much higher than that for ?-U materials. The alloys with <10 at.% Mo doping consist of a mixed ? + ?-U phase. The superconducting transition in the U-Mo6 revealed by a smooth decrease below 1.5 K and a sharp drop at 0.6 K in the resistivity indicating that ?-U grains are embedded in the ?-U matrix. The superconductivity transition was revealed by ?-type peak at Tc in the C(T) curve only for U-Mo15, while only one broad peak at Tc in the C(T) curves were observed for other UMo splats. With applying the magnetic fields, the resistivity jumps and specific-heat peaks move to lower temperatures. Invited talk at the 7th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN2014, 2-6 November, 2014, Ha Long, Vietnam.

  9. Performance test of the cryogenic cooling system for the superconducting fault current limiter

    NASA Astrophysics Data System (ADS)

    Hong, Yong-Ju; In, Sehwan; Yeom, Han-Kil; Kim, Heesun; Kim, Hye-Rim

    2015-12-01

    A Superconducting Fault Current Limiter is an electric power device which limits the fault current immediately in a power grid. The SFCL must be cooled to below the critical temperature of high temperature superconductor modules. In general, they are submerged in sub-cooled liquid nitrogen for their stable thermal characteristics. To cool and maintain the target temperature and pressure of the sub-cooled liquid nitrogen, the cryogenic cooling system should be designed well with a cryocooler and coolant circulation devices. The pressure of the cryostat for the SFCL should be pressurized to suppress the generation of nitrogen bubbles in quench mode of the SFCL. In this study, we tested the performance of the cooling system for the prototype 154 kV SFCL, which consist of a Stirling cryocooler, a subcooling cryostat, a pressure builder and a main cryostat for the SFCL module, to verify the design of the cooling system and the electric performance of the SFCL. The normal operation condition of the main cryostat is 71 K and 500 kPa. This paper presents tests results of the overall cooling system.

  10. Thermoelectric Devices Cool, Power Electronics

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Nextreme Thermal Solutions Inc., based in Research Triangle Park, North Carolina, licensed thermoelectric technology from NASA s Jet Propulsion Laboratory. This has allowed the company to develop cutting edge, thin-film thermoelectric coolers that effective remove heat generated by increasingly powerful and tightly packed microchip components. These solid-state coolers are ideal solutions for applications like microprocessors, laser diodes, LEDs, and even potentially for cooling the human body. Nextreme s NASA technology has also enabled the invention of thermoelectric generators capable of powering technologies like medical implants and wireless sensor networks.

  11. Surface Power Radiative Cooling Tests

    SciTech Connect

    Vaughn, Jason; Schneider, Todd

    2006-01-20

    Terrestrial nuclear power plants typically maintain their temperature through convective cooling, such as water and forced air. However, the space environment is a vacuum environment, typically 10-8 Torr pressure, therefore in proposed missions to the lunar surface, power plants would have to rely on radiative cooling to remove waste heat. Also, the Martian surface has a very tenuous atmosphere (e.g. {approx}5 Torr CO2), therefore, the main heat transfer method on the Martian surface is also radiative. Because of the lack of atmosphere on the Moon and the tenuous atmosphere on Mars, surface power systems on both the Lunar and Martian surface must rely heavily on radiative heat transfer. Because of the large temperature swings on both the lunar and the Martian surfaces, trying to radiate heat is inefficient. In order to increase power system efficiency, an effort is underway to test various combinations of materials with high emissivities to demonstrate their ability to survive these degrading atmospheres to maintain a constant radiator temperature improving surface power plant efficiency. An important part of this effort is the development of a unique capability that would allow the determination of a materials emissivity at high temperatures. A description of the test capability as well as initial data is presented.

  12. Surface Power Radiative Cooling Tests

    NASA Astrophysics Data System (ADS)

    Vaughn, Jason; Schneider, Todd

    2006-01-01

    Terrestrial nuclear power plants typically maintain their temperature through convective cooling, such as water and forced air. However, the space environment is a vacuum environment, typically 10-8 Torr pressure, therefore in proposed missions to the lunar surface, power plants would have to rely on radiative cooling to remove waste heat. Also, the Martian surface has a very tenuous atmosphere (e.g. ~5 Torr CO2), therefore, the main heat transfer method on the Martian surface is also radiative. Because of the lack of atmosphere on the Moon and the tenuous atmosphere on Mars, surface power systems on both the Lunar and Martian surface must rely heavily on radiative heat transfer. Because of the large temperature swings on both the lunar and the Martian surfaces, trying to radiate heat is inefficient. In order to increase power system efficiency, an effort is underway to test various combinations of materials with high emissivities to demonstrate their ability to survive these degrading atmospheres to maintain a constant radiator temperature improving surface power plant efficiency. An important part of this effort is the development of a unique capability that would allow the determination of a materials emissivity at high temperatures. A description of the test capability as well as initial data is presented.

  13. High voltage superconducting switch for power application

    SciTech Connect

    Mawardi, O.; Ferendeci, A.; Gattozzi, A.

    1983-05-01

    This paper reports the development of a novel interrupter which meets the requirements of a high voltage direct current (HVDC) power switch and at the same time doubles as a current limiter. The basic concept of the interrupter makes use of a fast superconducting, high capacity (SHIC) switch that carries the full load current while in the superconducting state and reverts to the normal resistive state when triggered. Typical design parameters are examined for the case of a HVDC transmission line handling 2.5KA at 150KVDC. The result is a power switch with superior performance and smaller size than the ones reported to date.

  14. A robust platform cooled by superconducting electronic refrigerators

    NASA Astrophysics Data System (ADS)

    Nguyen, H. Q.; Meschke, M.; Pekola, J. P.

    2015-01-01

    A biased tunnel junction between a superconductor and a normal metal can cool the latter electrode. Based on a recently developed cooler with high power and superior performance, we have integrated it with a dielectric silicon nitride membrane, and cooled phonons from 305 mK down to 200 mK. Without perforation and covered under a thin alumina layer, the membrane is rigorously transformed into a cooling platform that is robust and versatile for multiple practical purposes. We discussed our results and possibilities to further improve the device.

  15. A robust platform cooled by superconducting electronic refrigerators

    SciTech Connect

    Nguyen, H. Q.; Meschke, M.; Pekola, J. P.

    2015-01-05

    A biased tunnel junction between a superconductor and a normal metal can cool the latter electrode. Based on a recently developed cooler with high power and superior performance, we have integrated it with a dielectric silicon nitride membrane, and cooled phonons from 305?mK down to 200?mK. Without perforation and covered under a thin alumina layer, the membrane is rigorously transformed into a cooling platform that is robust and versatile for multiple practical purposes. We discussed our results and possibilities to further improve the device.

  16. Decompression cooling system operation for HTS power cable in the KEPCO power grid

    NASA Astrophysics Data System (ADS)

    Yang, H. S.; Sohn, S. H.; Lim, J. H.; Yim, S. W.; Jeon, H. J.; Jung, S. Y.; Han, S. C.; Hwang, S. D.

    2014-01-01

    A 3-phase 22.9 kV/50 MVA 410 m HTS power cable system was installed at power grid of KEPCO and had been operated for 20 months. In the HTS cable system, an open type cooling system was constructed for cooling LN2 using as coolant for superconducting cable. The cooling capacity of the cooling system was 6 kW at 69 K. Subcooled LN2 flew thorough 410 m HTS cable, maintaining 69 K of operating temperature for HTS cable. The electric load had fluctuated continuously with the load status so that the cooling state was also controlled to keep stable operating condition. The consumed LN2 used for making subcooled state was refilled periodically, and the amount was 3 tons in average. During all the operating period, the HTS cable system supplied electric power stably without any problem.

  17. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  18. Superconducting helical solenoid systems for muon cooling experiment at Fermilab

    SciTech Connect

    Kashikhin, Vladimir S.; Andreev, Nikolai; Johnson, Rolland P.; Kashikhin, Vadim V.; Lamm, Michael J.; Romanov, Gennady; Yonehara, Katsuya; Zlobin, Alexander V.; /Fermilab

    2007-08-01

    Novel configurations of superconducting magnet system for Muon Beam Cooling Experiment is under design at Fermilab. The magnet system has to generate longitudinal and transverse dipole and quadrupole helical magnetic fields providing a muon beam motion along helical orbit. It was found that such complicated field configuration can be formed by a set of circular coils shifted in transverse directions in such a way that their centers lay on the center of the helical beam orbit. Closed beam orbit configurations were also proposed and investigated. This paper describes the magnetic and mechanical designs and parameters of such magnetic system based on a NbTi Rutherford type cable. The helical solenoid fabrication, assembly and quench protection issues are presented.

  19. Design Issues for Cryogenic Cooling of Short Period Superconducting Undulators

    SciTech Connect

    Green, M.A.; Dietderich, D.R.; Marks, S.; Prestemon, S.O.; Schlueter, R.D.

    2004-06-23

    Superconducting insertion devices, which produce periodic magnetic fields, have been built and installed in a number of synchrotron-light source storage-rings. For the most part, these devices have been wigglers, which have relatively long period lengths. This report concerns itself with the special cryogenic issues associated with short period undulators. The motivation for considering the incorporation of superconducting technology in insertion device designs is to achieve higher magnetic fields than can be achieved with more conventional permanent magnet technology. Since the peak field decreases sharply with increased magnet gap to period ratio, the cryogenic design of the magnet system is crucial. In particular, the insulation required for a warm vacuum bore device is impractical for short period undulators. This report describes the issues that are related to a cold bore ({approx}4 K) and an intermediate temperature bore (30 to 70 K) designs. The criteria for the use of small cryocoolers for cooling a short period undulator are presented. The problems associated with connecting small coolers to an undulator at 4.2 K are discussed.

  20. Bent Superconducting Solenoids for the Muon Cooling Experiment

    SciTech Connect

    Green, M.A.; Eyssa, Y.; Kenney, S.; Miller, J. R.; Prestemon, S.; Wang, S.T.

    1999-03-18

    This report describes some solenoid design work done for the cooling experiment for the muon collider collaboration. This report describes an analysis section of superconducting solenoids that have a center line induction of 3.0 T. The section is bent in the shape of an S. Each bend in the S bends the muon beam one radian (57.3 degrees). The warm bore diameter of the solenoid bent solenoid is 300 to 320 mm. The radius of the bend at the solenoid center line is 1000 mm. This report shows the results of three dimensional field calculations and presents a solenoid design that will include four TPC detectors that are 240 mm in diameter and 550 mm long as well as a 1300 mm long section of 1300 MHz RF cavities. The TPC sections need a solenoid wann bore diameter of about 300 320 mm while RF cavities require a warm bore diameter of 440 mm. The superconducting solenoid design must take into account the varying warm bore diameter requirements for the magnet string yet meet the stringent solenoidal field uniformity requirements within the active volume of the four TPCs.

  1. The design and fabrication of a reverse Brayton cycle cryocooler system for the high temperature superconductivity cable cooling

    NASA Astrophysics Data System (ADS)

    Park, Jae Hong; Kwon, Yong Ha; Kim, Young Soo

    2005-01-01

    A high temperature superconductivity cable must be cooled below the nitrogen liquefaction temperature to apply the cable to power generation and transmission systems under superconducting state. To maintain the superconducting state, a reliable cryocooler system is also required. The design and fabrication of a cryocooler system have been performed with a reverse Brayton cycle using neon gas as a refrigerant. The system consists of a compressor, a recuperator, a cold-box, and control valves. The design of the system is made to have 1 kW cooling capacity. The heat loss through multilayer insulators is calculated. Conduction heat loss is about 7 W through valves and access ports and radiation heat loss is about 18 W on the surface of a cryocooler. The design factors are discussed in detail.

  2. Superconducting cable cooling system by helium gas at two pressures

    DOEpatents

    Dean, John W.

    1977-01-01

    Thermally contacting, oppositely streaming, cryogenic fluid streams in the same enclosure in a closed cycle that changes the fluid from a cool high pressure helium gas to a cooler reduced pressure helium gas in an expander so as to be at different temperature ranges and pressures respectively in go and return legs that are in thermal contact with each other and in thermal contact with a longitudinally extending superconducting transmission line enclosed in the same cable enclosure that insulates the line from the ambient at a temperature T.sub.1. By first circulating the fluid from a refrigerator at one end of the line as a cool gas at a temperature range T.sub.2 to T.sub.3 in the go leg, then circulating the gas through an expander at the other end of the line where the gas becomes a cooler gas at a reduced pressure and at a reduced temperature T.sub.4 and finally by circulating the cooler gas back again to the refrigerator in a return leg at a temperature range T.sub.4 to T.sub.5, while in thermal contact with the gas in the go leg, and in the same enclosure therewith for compression into a higher pressure gas at T.sub.2 in a closed cycle, where T.sub.2 >T.sub.3 and T.sub.5 >T.sub.4, the fluid leaves the enclosure in the go leg as a gas at its coldest point in the go leg, and the temperature distribution is such that the line temperature decreases along its length from the refrigerator due to the cooling from the gas in the return leg.

  3. Development of superconducting power devices in Europe

    NASA Astrophysics Data System (ADS)

    Tixador, Pascal

    2010-11-01

    Europe celebrated last year (2008) the 100-year anniversary of the first liquefaction of helium by H. Kammerling Onnes in Leiden. It led to the discovery of superconductivity in 1911. Europe is still active in the development of superconducting (SC) devices. The discovery of high critical temperature materials in 1986, again in Europe, has opened a lot of opportunities for SC devices by broking the 4 K cryogenic bottleneck. Electric networks experience deep changes due to the emergence of dispersed generation (renewable among other) and to the advances in ICT (Information Communication Technologies). The networks of the future will be “smart grids”. Superconductivity will offer “smart” devices for these grids like FCL (Fault Current Limiter) or VLI (Very Low Inductance) cable and would certainly play an important part. Superconductivity also will participate to the required sustainable development by lowering the losses and enhancing the mass specific powers. Different SC projects in Europe will be presented (Cable, FCL, SMES, Flywheel and Electrical Machine) but the description is not exhaustive. Nexans has commercialized the first two FCLs without public funds in the European grid (UK and Germany). The Amsterdam HTS cable is an exciting challenge in term of losses for long SC cables. European companies (Nexans, Air Liquide, Siemens, Converteam, …) are also very active for projects outside Europe (LIPA, DOE FCL, …).

  4. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    NASA Astrophysics Data System (ADS)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-01

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  5. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    SciTech Connect

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-29

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  6. Design of a conduction-cooled 4 T superconducting racetrack for a multi-field coupling measurement system

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Quan; Ma, Li-Zhen; Wu, Wei; Guan, Ming-Zhi; Wu, Bei-Min; Mei, En-Ming; Xin, Can-Jie

    2015-12-01

    A conduction-cooled superconducting magnet producing a transverse field of 4 T has been designed for a new generation multi-field coupling measurement system, which will be used to study the mechanical behavior of superconducting samples at cryogenic temperatures and intense magnetic fields. A compact cryostat with a two-stage GM cryocooler is designed and manufactured for the superconducting magnet. The magnet is composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational former and two Bi2Sr2CaCu2Oy superconducting current leads. The two coils are connected in series and can be powered with a single power supply. In order to support the high stress and attain uniform thermal distribution in the superconducting magnet, a detailed finite element (FE) analysis has been performed. The results indicate that in the operating status the designed magnet system can sufficiently bear the electromagnetic forces and has a uniform temperature distribution. Supported by National Natural Science Foundation of China (11327802, 11302225), China Postdoctoral Science Foundation (2014M560820) and National Scholarship Foundation of China (201404910172)

  7. Fundamental Power Couplers for Superconducting Cavities

    SciTech Connect

    Isidoro E. Campisi

    2001-09-01

    Fundamental power couplers (FPC's) for superconducting cavities must meet very strict requirements to perform at high power levels (hundreds of kilowatts) and in a variety of conditions (CS, pulsed, travelling wave, standing wave) without adversely affecting the performance of the cavities they are powering. Producing good coupler designs and achieving operational performances in accelerator environments are challenging tasks that have traditionally involved large resources from many laboratories. The designs involve state-of-the-art activities in RF, cryogenic and mechanical engineering, materials science, vacuum technology, and electromagnetic field modeling. Handling, assembly and conditioning procedures have been developed to achieve ever-increasing power levels and more reliable operation. In this paper, the technical issues associated with the design, construction, assembly, processing, and operation of FPC's will be reviewed, together with the progress in FPC activities in several laboratories during the past few years.

  8. Development of superconducting power transmission technology

    NASA Astrophysics Data System (ADS)

    Forsyth, E. B.

    Superconducting power transmission cables are the latest innovation in a technology which is as old as electric power engineering. Distribution of power by means of wires suspended from poles was tried briefly but the densely populated areas chosen as sites for the early generators soon forced the distribution system underground. Edison's low voltage dc system was a technological dead-end but by 1890 Ferranti had built a 7 mile-long underground cable system which operated at the then unprecedented level of 10,000 V, alternating current. Ferranti was remarkably prescient in his choice of wrapped brown paper for the cable insulation, a material which has continued to be used in this application until the present day. Paper was chosen for the insulation because it gave good operating performance at low cost compared to other insulating materials then available, such as rubber and gutta percha. Economic considerations must be weighed carefully in the design of underground power transmission systems and they have been a compelling factor in the pattern of development from the turn of the century to the advanced superconducting systems under test in the 1980's.

  9. Development of superconducting power transmission technology

    SciTech Connect

    Forsyth, E.B.

    1985-01-01

    Superconducting power transmission cables are the latest innovation in a technology which is as old as electric power engineering. The construction of central electricity generating stations by Thomas Edison in the USA and Sebastian Ferranti in England in the 1880's immediately posed the problem of how customers could be connected to the power source. Distribution by means of wires suspended from poles was tried briefly but the densely populated areas chosen as sites for the early generators soon forced the distribution system underground. Edison's low voltage dc system was a technological dead-end but by 1890 Ferranti had built a 7 mile-long underground cable system from the generating plant at Deptford to central London which operated at the then unprecedented level of 10,000 V, alternating current. Ferranti was remarkably prescient in his choice of wrapped brown paper for the cable insulation, a material which has continued to be used in this application until the present day. Paper was chosen for the insulation because it gave good operating performance at low cost compared to other insulating materials then available, such as rubber and gutta percha. Economic considerations must be weighed carefully in the design of underground power transmission systems and they have been a compelling factor in the pattern of development from the turn of the century to the advanced superconducting systems under test in the 1980's.

  10. Sub-cooled nitrogen cryogenic cooling system for superconducting fault current limiter by using GM-cryocooler

    NASA Astrophysics Data System (ADS)

    Kang, Hyoungku; Kim, Hyung Jin; Bae, Duck Kweon; Ahn, Min Cheol; Chang, Ho-Myung; Ko, Tae Kuk

    2005-01-01

    The 21st Century Frontier R&D Program was planned to develop and commercialize the inductive Superconducting Fault Current Limiter (SFCL) in Korea until 2011. The 1.2 kV/80 A inductive SFCL was planned to develop at the first year in the first phase (2001-2002) and the 6.6 kV/200 A inductive SFCL for short run operation test was planned to develop at the second and third year in the first phase (2002-2004). The experimental characteristics of conduction-cooled cooling system developed in the first year was very weak from the sudden large thermal disturbance. Therefore, the conduction-cooled cooling system was concluded not appropriate for the cryogenic technology of the application of superconducting fault current limiter. In the third year research, the improved sub-cooled nitrogen cooling system was adopted and investigated. In this paper, the characteristics of each cooling type was compared and the basic deign of ameliorated cooling system was introduced and the total heat load of the cooling system was calculated and compared with the heat load of the cooling system developed at 2nd year research.

  11. Small high cooling power space cooler

    NASA Astrophysics Data System (ADS)

    Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E.

    2014-01-01

    The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

  12. Small high cooling power space cooler

    SciTech Connect

    Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E.

    2014-01-29

    The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

  13. Cooling of Compact Stars with Quark-Hadron Mixed Phase in the Colour Superconductive State

    SciTech Connect

    Noda, Tsuneo; Hashimoto, Masa-aki; Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka; Fujimoto, Masayuki

    2010-08-12

    Recently, the central source of Cassiopeia A (Cas A) has been observed, which indicates that the star has large mass and high effective temperature. We suspect that the compact object cools by the standard neutrino emission. We assume that the compact object contains quark matter with colour superconductivity and calculate cooling curves. Considering the Quark-Hadron Mixed Phase, we obtain cooling curves which are found to be consistent with the observations.

  14. Power electronics substrate for direct substrate cooling

    DOEpatents

    Le, Khiet (Mission Viejo, CA); Ward, Terence G. (Redondo Beach, CA); Mann, Brooks S. (Redondo Beach, CA); Yankoski, Edward P. (Corona, CA); Smith, Gregory S. (Woodland Hills, CA)

    2012-05-01

    Systems and apparatus are provided for power electronics substrates adapted for direct substrate cooling. A power electronics substrate comprises a first surface configured to have electrical circuitry disposed thereon, a second surface, and a plurality of physical features on the second surface. The physical features are configured to promote a turbulent boundary layer in a coolant impinged upon the second surface.

  15. Superconductivity:

    NASA Astrophysics Data System (ADS)

    Zimmerman, George O.

    The discovery of superconductivity brought with it the promise of a miracle solution to many technological problems encountered by the electrical power industry. That discovery was at Leiden in 1911. Since then, engineering designs and prototypes have been developed for the use of superconductive materials in electric power transmission, transformers, and machinery. The development of superconducting magnetic energy storage systems also held great promise. Superconductivity was even used to build marine propulsion systems and levitated track vehicles. Despite that, and despite the financial support of governments for prototype developments, the only commercial application of the technology, outside of laboratories, is for MRI magnets. Similar experience is encountered in superconducting applications to electronics, although some success has been achieved in the communication industry. The discovery of high temperature superconductivity, despite its promise, did not significantly change the situation. The developments will be reviewed, and some of the reasons why superconductivity is still mainly confined to the laboratory will be given with the view of what we, as scientists, can do in order to enhance and hasten the commercial adoption of superconducting technology.

  16. Nuclear power plant with cooling circuit

    SciTech Connect

    Kastl, H.; Gugel, G.

    1983-11-22

    A nuclear power plant is disclosed with a metallic, circulatory cooling loop formed with welding seams and including, as components thereof, a reactor pressure vessel, a heat consumer and a pump, as well as a coolant line connecting the components to one another, and thermal insulation provided on the cooling loop, the welding seams being testable by a track-traversing testing device, including a multiplicity of fixedly installed tracks having like profile and being associated, respectively, with welding seams on the components and the cooling line, at least part of the thermal insulation being in vicinity of the tracks and being formed as removable cassettes.

  17. Cryogenic System for a High Temperature Superconducting Power Transmission Cable

    SciTech Connect

    Demko, J.A.; Gouge, M.J.; Hughey, R.L.; Lue, J.W.; Martin, R.; Sinha, U.; Stovall, J.P.

    1999-07-12

    High-temperature superconducting (HTS) cable systems for power transmission are under development that will use pressurized liquid nitrogen to provide cooling of the cable and termination hardware. Southwire Company and Oak Ridge National Laboratory have been operating a prototype HTS cable system that contains many of the typical components needed for a commercial power transmission application. It is being used to conduct research in the development of components and systems for eventual commercial deployment. The cryogenic system was built by Air Products and Chemicals, Allentown, Pennsylvania, and can circulate up to 0.35 kg/s of liquid nitrogen at temperatures as low as 67 K at pressures of 1 to 10 bars. Sufficient cooling is provided for testing a 5-m-long HTS transmission cable system that includes the terminations required for room temperature electrical connections. Testing of the 5-m HTS transmission cable has been conducted at the design ac conditions of 1250 A and 7.5 kV line to ground. This paper contains a description of the essential features of the HTS cable cryogenic system and performance results obtained during operation of the system. The salient features of the operation that are important in large commercial HTS cable applications will be discussed.

  18. Simulation of Thermal Processes in Superconducting Pancake Coils Cooled by GM Cryocooler

    NASA Astrophysics Data System (ADS)

    Lebioda, M.; Rymaszewski, J.; Korzeniewska, E.

    2014-04-01

    This article presents the thermal model of a small scale superconducting magnetic energy storage system with the closed cycle helium cryocooler. The authors propose the use of contact-cooled coils with maintaining the possibility of the system reconfiguring. The model assumes the use of the second generation superconducting tapes to make the windings in the form of flat discs (pancakes). The paper presents results for a field model of the single pancake coil and the winding system consisting of several coils.

  19. Cooling and mounting power semiconductors

    NASA Astrophysics Data System (ADS)

    Wetzel, P.

    1980-04-01

    The article examines the process of heat dissipation from power semiconductors. It is shown that for the relationship between temperature loading and dissipation it is possible to take an 'Ohm's law of heat abduction' to define the thermal impedance. The computation of the optimal size for a heatsink is demonstrated in detail. Discussion covers the types of heat dissipation such as heat radiation, heat conduction, and convection. Finally, some factors to consider during installation are examined.

  20. Potential Refrigerants for Power Electronics Cooling

    SciTech Connect

    Starke, M.R.

    2005-10-24

    In the past, automotive refrigerants have conventionally been used solely for the purpose of air conditioning. However, with the development of hybrid-electric vehicles and the incorporation of power electronics (PEs) into the automobile, automotive refrigerants are taking on a new role. Unfortunately, PEs have lifetimes and functionalities that are highly dependent on temperature and as a result thermal control plays an important role in the performance of PEs. Typically, PEs are placed in the engine compartment where the internal combustion engine (ICE) already produces substantial heat. Along with the ICE heat, the additional thermal energy produced by PEs themselves forces designers to use different cooling methods to prevent overheating. Generally, heat sinks and separate cooling loops are used to maintain the temperature. Disturbingly, the thermal control system can consume one third of the total volume and may weigh more than the PEs [1]. Hence, other avenues have been sought to cool PEs, including submerging PEs in automobile refrigerants to take advantage of two-phase cooling. The objective of this report is to explore the different automotive refrigerants presently available that could be used for PE cooling. Evaluation of the refrigerants will be done by comparing environmental effects and some thermo-physical properties important to two-phase cooling, specifically measuring the dielectric strengths of potential candidates. Results of this report will be used to assess the different candidates with good potential for future use in PE cooling.

  1. Direct-Cooled Power Electronics Substrate

    SciTech Connect

    Wiles, R.; Ayers, C.; Wereszczak, A.

    2008-12-23

    The goal of the Direct-Cooled Power Electronics Substrate project is to reduce the size and weight of the heat sink for power electronics used in hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). The concept proposed in this project was to develop an innovative power electronics mounting structure, model it, and perform both thermal and mechanical finite-element analysis (FEA). This concept involved integrating cooling channels within the direct-bonded copper (DBC) substrate and strategically locating these channels underneath the power electronic devices. This arrangement would then be directly cooled by water-ethylene glycol (WEG), essentially eliminating the conventional heat sink and associated heat flow path. The concept was evaluated to determine its manufacturability, its compatibility with WEG, and the potential to reduce size and weight while directly cooling the DBC and associated electronics with a coolant temperature of 105 C. This concept does not provide direct cooling to the electronics, only direct cooling inside the DBC substrate itself. These designs will take into account issues such as containment of the fluid (separation from the electronics) and synergy with the whole power inverter design architecture. In FY 2008, mechanical modeling of substrate and inverter core designs as well as thermal and mechanical stress FEA modeling of the substrate designs was performed, along with research into manufacturing capabilities and methods that will support the substrate designs. In FY 2009, a preferred design(s) will be fabricated and laboratory validation testing will be completed. In FY 2010, based on the previous years laboratory testing, the mechanical design will be modified and the next generation will be built and tested in an operating inverter prototype.

  2. Pressure rise during the quench of a superconducting magnet using internally cooled conductors

    SciTech Connect

    Miller, J.R.; Dresner, L.; Lue, J.W.; Shen, S.S.; Yeh, H.T.

    1980-01-01

    Superconducting magnets cooled by supercritical helium flowing through internal conductor passages are an alternative to magnets cooled in a boiling pool. This alternative involves a possible large pressure increase in the captured volume of helium during a quench. In the US Large Coil Program (LCP), three of six coils to be tested will use internally cooled conductors. This paper describes experiments performed to understand the quench behavior of the Westinghouse coil. Agreement between experiment and theory is good. Also discussed is the extension of this work to the EURATOM coil and the Swiss coil, as well as to any coils wound with internally cooled conductors.

  3. Application of Superconducting Power Cables to DC Electric Railway Systems

    NASA Astrophysics Data System (ADS)

    Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru

    For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.

  4. Hydrogen cooling options for MgB2-based superconducting systems

    NASA Astrophysics Data System (ADS)

    Stautner, W.; Xu, M.; Mine, S.; Amm, K.

    2014-01-01

    With the arrival of MgB2 for low-cost superconducting magnets, hydrogen cooling has become an interesting alternative to costly liquid helium. Hydrogen is generally regarded as the most efficient coolant in cryogenics and, in particular, is well suited for cooling superconducting magnets. Cooling methods need to take into account the specific quench propagation in the MgB2 magnet winding and facilitate a cryogenically reliable and safe cooling environment. The authors propose three different multi-coolant options for MRI scanners using helium or hydrogen within the same design framework. Furthermore, a design option for whole-body scanners which employs technology, components, fueling techniques and safety devices from the hydrogen automotive industry is presented, continuing the trend towards replacing helium with hydrogen as a safe and cost efficient coolant.

  5. An analytical approach to designing a thermosiphon cooling system for large scale superconducting magnets

    NASA Astrophysics Data System (ADS)

    Dhanaraj, N.; Tatkowski, G.; Huang, Y.; Page, T. M.; Lamm, M. J.; Schmitt, R. L.; Peterson, T. J.

    2015-12-01

    A Thermosiphon cooling scheme is a productive way of cooling large scale superconducting magnets. The absence of active pumping and the availability of the higher heat capacity parameter latent heat make this an attractive cooling method. Nevertheless, the design of such a system demands a well-organized study of the effect of various flow parameters, such as, mass flow rates, flow quality, etc., and also a robust mechanical design of the various components of the system. This paper presents an analytical approach to designing a thermosiphon cooling scheme based on homogeneous flow conditions as well as separated flow conditions. The design of the mechanical components such as the piping is also discussed. The design approach presented here has been applied to the reference design of two large superconducting solenoids, the Production Solenoid and the Detector Solenoid of the Mu2e experiment at Fermilab.

  6. Hydrogen cooling options for MgB{sub 2}-based superconducting systems

    SciTech Connect

    Stautner, W.; Xu, M.; Mine, S.; Amm, K.

    2014-01-29

    With the arrival of MgB{sub 2} for low-cost superconducting magnets, hydrogen cooling has become an interesting alternative to costly liquid helium. Hydrogen is generally regarded as the most efficient coolant in cryogenics and, in particular, is well suited for cooling superconducting magnets. Cooling methods need to take into account the specific quench propagation in the MgB{sub 2} magnet winding and facilitate a cryogenically reliable and safe cooling environment. The authors propose three different multi-coolant options for MRI scanners using helium or hydrogen within the same design framework. Furthermore, a design option for whole-body scanners which employs technology, components, fueling techniques and safety devices from the hydrogen automotive industry is presented, continuing the trend towards replacing helium with hydrogen as a safe and cost efficient coolant.

  7. Hybrid Wet/Dry Cooling for Power Plants (Presentation)

    SciTech Connect

    Kutscher, C.; Buys, A.; Gladden, C.

    2006-02-01

    This presentation includes an overview of cooling options, an analysis of evaporative enhancement of air-cooled geothermal power plants, field measurements at a geothermal plant, a preliminary analysis of trough plant, and improvements to air-cooled condensers.

  8. Theoretical analysis for the transient behaviour of radiative cooling of cavities in superconducting LINAC cryomodule

    NASA Astrophysics Data System (ADS)

    Datta, T. S.; Kar, Soumen; Chacko, Jacob; Choudhury, Anup; Antony, Joby; Babu, Suresh; Kumar, Manoj

    2014-06-01

    For the superconducting linear accelerator program, three cryomodules each houses eight superconducting cavities were successfully developed at IUAC, New Delhi. In each cryomodule, the cold mass at 4.2 K is surrounded by the liquid nitrogen cooled thermal shield maintained at 100 K. Three stages of cooling namely, radiation cooling followed by liquid nitrogen pre-cooling and finally liquid helium (LHe) cooling, are followed to reduce the temperature of cold mass from 300 to 4.2 K. The cold mass at 4.2 K consists of cavities, LHe vessel and the support structure. The temperature of cavity and helium vessel reaches to 210-220 K in 40 h of time by the natural radiation from the thermal shield. The radiative cooling rates for the cavities, helium vessel and support structure are found to be 3.0, 4.0 and 2.0 K/h respectively. A detailed analytical calculation has been done to understand the transient cool-down phenomenon for each component and compared with the experimental measured values. The experimental values are in agreement with the analytical data within 5 % variation considering the correction factor of radiation funneling. This paper presents the role of different thermal parameters like shield temperature, conduction load and radiation funneling area in the transient radiative cool-down behaviour of different components.

  9. Steam-Electric Power-Plant-Cooling Handbook

    SciTech Connect

    Sonnichsen, J.C.; Carlson, H.A.; Charles, P.D.; Jacobson, L.D.; Tadlock, L.A.

    1982-02-01

    The Steam-Electric Power Plant Cooling Handbook provides summary data on steam-electric power plant capacity, generation and number of plants for each cooling means, by Electric Regions, Water Resource Regions and National Electric Reliability Council Areas. Water consumption by once-through cooling, cooling ponds and wet evaporative towers is discussed and a methodology for computation of water consumption is provided for a typical steam-electric plant which uses a wet evaporative tower or cooling pond for cooling.

  10. Power producing dry cooling apparatus and method

    SciTech Connect

    Husain, M.; Lai, B.; Maher, J.B.

    1981-09-29

    Spent steam from a steam driven electric generating power plant is condensed by heat rejection to a refrigerant in a closed loop. The closed refrigerant loop contains an expander and a compressor, and a heat exchanger in a cooling tower. The compressor and expander are integrated so that (1) in an upper cooling cycle at the upper end of the ambient or air temperature range, only the compressor is operated within its operating range; (2) in a lower cooling cycle at the lower end of the ambient or air temperature range, only the expander is operated and; (3) in a middle cooling cycle at the middle range of the ambient or air temperatures, when the turn-down of either the compressor or the expander is a limiting factor, both of them are operated. The characteristics of the compressor and the expander are advisably matched such that when both are operated the duties on both are balanced above their respective turn-down limits thus minimizing the energy loss and enhancing the power producing capability of the system. The integrated compressor/expander operation, during the middle range of the ambient or air temperatures in which the system is designed to operate, will also provide smoother operation, as the discontinuity going to and from the compressor to the expander mode of operation is eliminated.

  11. Long term operation in 200 m class superconducting DC power transmission test facility in Chubu University

    NASA Astrophysics Data System (ADS)

    Hamabe, M.; Watanabe, H.; Sun, J.; Kawahara, T.; Yamaguchi, S.

    2014-05-01

    We constructed the 200 m class superconducting DC power transmission test facility (CASER-2) in 2010, and have carried out the cooling down and operation test. The 5th cooling down and operation test was carried out from August to November 2012. Long term current feeding was tested for a month with various currents and temperatures in the 5th test. From the long term current feeding test, the LN2 circulation was clearly affected by the operation of the cryogenic system and the atmosphere, not only by the operation DC current. It was also confirmed that the Peltier current leads worked effectively for the reduction of heat leak at the cable terminal.

  12. Electrocaloric energy efficiency and cooling power

    NASA Astrophysics Data System (ADS)

    Mathur, Neil

    2014-03-01

    How much energy is required to drive electrocaloric effects near ferroelectric phase transitions? I will compare electrocaloric ceramic and polymer films with each other, with magnetocaloric materials (exploited in over 40 prototype refrigerators), and with elastocaloric materials. I will also discuss the cooling power that could be achieved in electrocaloric heat pumps based on multilayer capacitors in which heat flow is modelled using finite element analysis.

  13. Polk power station syngas cooling system

    SciTech Connect

    Jenkins, S.D.

    1995-01-01

    Tampa Electric Company (TEC) is in the site development and construction phase of the new Polk Power Station Unit No. 1. This will be the first unit at a new site and will use Integrated Gasification Combined Cycle (IGCC) Technology. The unit will utilize Texaco`s oxygen-blown, entrained-flow coal gasification, along with combined cycle power generation, to produce nominal 260MW. Integral to the gasification process is the syngas cooling system. The design, integration, fabrication, transportation, and erection of this equipment have provided and continue to provide major challenges for this project.

  14. Cooling of Compact Stars with Color Superconducting Phase in Quark-hadron Mixed Phase

    NASA Astrophysics Data System (ADS)

    Noda, Tsuneo; Hashimoto, Masa-aki; Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka; Fujimoto, Masayuki

    2013-03-01

    We present a new scenario for the cooling of compact stars considering the central source of Cassiopeia A (Cas A). The Cas A observation shows that the central source is a compact star that has high effective temperature, and it is consistent with the cooling without exotic phases. The observation also gives the mass range of M >= 1.5 M ⊙, which may conflict with the current plausible cooling scenario of compact stars. There are some cooled compact stars such as Vela or 3C58, which can barely be explained by the minimal cooling scenario, which includes the neutrino emission by nucleon superfluidity (PBF). Therefore, we invoke the exotic cooling processes, where a heavier star cools faster than lighter one. However, the scenario seems to be inconsistent with the observation of Cas A. Therefore, we present a new cooling scenario to explain the observation of Cas A by constructing models that include a quark color superconducting (CSC) phase with a large energy gap; this phase appears at ultrahigh density regions and reduces neutrino emissivity. In our model, a compact star has a CSC quark core with a low neutrino emissivity surrounded by high emissivity region made by normal quarks. We present cooling curves obtained from the evolutionary calculations of compact stars: while heavier stars cool slowly, and lighter ones indicate the opposite tendency without considering nucleon superfluidity. Furthermore, we show that our scenario is consistent with the recent observations of the effective temperature of Cas A during the last 10 years, including nucleon superfluidity.

  15. Study of high field superconducting solenoids for muon beam cooling

    SciTech Connect

    Kashikhin, V.V.; Barzi, E.; Kashikhin, V.S.; Lamm, Michael J.; Sadovskiy, Y.; Zlobin, Alexander V; /Fermilab

    2007-08-01

    The final beam cooling stages of a possible Muon Collider may require DC solenoid magnets with magnetic fields of 40-50 T in an aperture of 40-50 mm. In this paper we study possible solutions towards creating DC fields of that order using available superconductors. Several magnetic and mechanical designs, optimized for the maximum performance are presented and compared in terms of cost and size.

  16. Numerical analysis of thermal stability of an immersion-cooled, pancake type superconducting coil

    NASA Astrophysics Data System (ADS)

    Okada, S.; Kim, J.-K.; Aihara, T.; Kuroda, K.

    A numerical analysis of the thermal stability of an immersion-cooled, single pancake type superconducting coil has been carried out, taking into account transient boiling heat transfer and the temperature dependence of the physical properties of the superconducting composite. The unsteady heat conduction equation, with source terms allowing for heat conduction through an electric insulation film, thermal disturbance, heat transfer and Joule heat generation, has been solved by a control volume finite method. The stability limit of the variable property solution (VPS) is compared with that of the constant property solution (CPS). The result shows that the VPS is 1.5 times as large as the CPS. Also, the effects of the transport current density and the magnetic flux density on the stability of the superconducting coil are clarified.

  17. Lessons learned from the cool down of a superconducting magnet using a thermal-siphon cooling-loop

    NASA Astrophysics Data System (ADS)

    Green, M. A.; Bollen, G.; Chouhan, S.; Magsig, C.; Morrissey, D.; Schwarz, S.; Zeller, A. F.

    2015-12-01

    The two Michigan State University (MSU) cyclotron gas-stopper magnet superconducting-coils were designed to be cooled down and to be kept cold using three pulse-tube coolers per coil cryostat. These coolers are designed to produce from 1.3 to 1.7 W per cooler when the cooler first-stage is at 40 K. The cyclotron gas stopper coils can be separated while cold, but unpowered. The two coil cryostats were cooled down separately in 2014, and room temperature helium gas was liquefied into the coil cryostats. The magnet temperature at the end of the cool-down was 4.55 K for one coil and 4.25 K for the other with and added 1.6 W of heat. The coil-down time for the coils was three and a half times longer than expected. The time to liquefy the helium was also much longer. The reasons for the disparity between the calculated cool-down time and measured cool-down time are discussed in the paper.

  18. Cryogenic Thermal Studies on Terminations for Helium Gas Cooled Superconducting Cables

    NASA Astrophysics Data System (ADS)

    Kim, Chul Han; Kim, Sung-Kyu; Graber, Lukas; Pamidi, Sastry V.

    Details of the design of terminations for testing a superconducting DC monopole cable cooled with gaseous helium are presented. The termination design includes a liquid nitrogen chamber to reduce heat influx into the helium section through current leads. Thermal studies on the assembly of the two terminations and a 1 m or 30 m cable cryostat were performed at variable mass flow rates of helium gas. Measurements of temperature profile for the test system without the superconducting cable showed temperature rise between 5 K and 20 K depending on the mass flow rate. The temperature profile across the test system was used to estimate the heat load from different components of the system. Results with and without the liquid nitrogen in current lead section were compared to estimate the savings provided by the liquid nitrogen on the head of the helium circulation system. Suggestions for improving the design to enable fully gas cooled terminations are presented.

  19. Numerical Simulations for the Cool-Down of the XFEL and TTF Superconducting Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Jensch, K.; Lange, R.; Petersen, B.

    2004-06-01

    The alignment of the superconducting RF-cavities and the magnet packages of the cryomodules of the future XFEL linear accelerator and the existing TTF linear accelerator at DESY can be affected by the mechanical stress caused by thermal gradients during the cool-down and warm-up. Also the design of the XFEL cryogenic system has to include the cool-down and warm-up procedures. An object-oriented software concept is applied to analyze the cool-down procedures for the TTF and the XFEL linear accelerators by numerical simulations. The numerical results are compared to measurements taken during the first cool-down of the TTF linear accelerator. Some results for the XFEL cryogenic system are presented.

  20. Power converter having improved fluid cooling

    DOEpatents

    Meyer, Andreas A.; Radosevich, Lawrence D.; Beihoff, Bruce C.; Kehl, Dennis L.; Kannenberg, Daniel G.

    2007-03-06

    A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support, which may be controlled in a closed-loop manner. Interfacing between circuits, circuit mounting structure, and the support provide for greatly enhanced cooling. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  1. Venus Surface Power and Cooling System Design

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Mellott, Kenneth D.

    2004-01-01

    A radioisotope power and cooling system is designed to provide electrical power for the a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors simply cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep certain components at a temperature below ambient. The fundamental cooling requirements are comprised of the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus. Assuming 5 cm radial thickness of ceramic blanket insulation, the ambient heat load was estimated at approximately 77 watts. With an estimated quantity of 10 watts of heat generation from electronics and sensors, and to accommodate some level of uncertainty, the total heat load requirement was rounded up to an even 100 watts. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. The maximum theoretically obtainable efficiency is 47.52 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500 watt power class, laboratory-tested Stirling engines at GRC. The overall efficiency is calculated to be 23.36 %. The mass of the power converter is estimated at approximately 21.6 kg.

  2. Liquid Metal Cooled Reactor for Space Power

    NASA Astrophysics Data System (ADS)

    Weitzberg, Abraham

    2003-01-01

    The conceptual design is for a liquid metal (LM) cooled nuclear reactor that would provide heat to a closed Brayton cycle (CBC) power conversion subsystem to provide electricity for electric propulsion thrusters and spacecraft power. The baseline power level is 100 kWe to the user. For long term power generation, UN pin fuel with Nb1Zr alloy cladding was selected. As part of the SP-100 Program this fuel demonstrated lifetime with greater than six atom percent burnup, at temperatures in the range of 1400-1500 K. The CBC subsystem was selected because of the performance and lifetime database from commercial and aircraft applications and from prior NASA and DOE space programs. The high efficiency of the CBC also allows the reactor to operate at relatively low power levels over its 15-year life, minimizing the long-term power density and temperature of the fuel. The scope of this paper is limited to only the nuclear components that provide heated helium-xenon gas to the CBC subsystem. The principal challenge for the LM reactor concept was to design the reactor core, shield and primary heat transport subsystems to meet mission requirements in a low mass configuration. The LM concept design approach was to assemble components from prior programs and, with minimum change, determine if the system met the objective of the study. All of the components are based on technologies having substantial data bases. Nuclear, thermalhydraulic, stress, and shielding analyses were performed using available computer codes. Neutronics issues included maintaining adequate operating and shutdown reactivities, even under accident conditions. Thermalhydraulic and stress analyses calculated fuel and material temperatures, coolant flows and temperatures, and thermal stresses in the fuel pins, components and structures. Using conservative design assumptions and practices, consistent with the detailed design work performed during the SP-100 Program, the mass of the reactor, shield, primary heat transport, reactor instrument and control, and additional structure totaled approximately 1100 kg.

  3. COOLING OF COMPACT STARS WITH COLOR SUPERCONDUCTING PHASE IN QUARK-HADRON MIXED PHASE

    SciTech Connect

    Noda, Tsuneo; Hashimoto, Masa-aki; Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka; Fujimoto, Masayuki E-mail: hashimoto@phys.kyushu-u.ac.jp

    2013-03-01

    We present a new scenario for the cooling of compact stars considering the central source of Cassiopeia A (Cas A). The Cas A observation shows that the central source is a compact star that has high effective temperature, and it is consistent with the cooling without exotic phases. The observation also gives the mass range of M {>=} 1.5 M {sub Sun }, which may conflict with the current plausible cooling scenario of compact stars. There are some cooled compact stars such as Vela or 3C58, which can barely be explained by the minimal cooling scenario, which includes the neutrino emission by nucleon superfluidity (PBF). Therefore, we invoke the exotic cooling processes, where a heavier star cools faster than lighter one. However, the scenario seems to be inconsistent with the observation of Cas A. Therefore, we present a new cooling scenario to explain the observation of Cas A by constructing models that include a quark color superconducting (CSC) phase with a large energy gap; this phase appears at ultrahigh density regions and reduces neutrino emissivity. In our model, a compact star has a CSC quark core with a low neutrino emissivity surrounded by high emissivity region made by normal quarks. We present cooling curves obtained from the evolutionary calculations of compact stars: while heavier stars cool slowly, and lighter ones indicate the opposite tendency without considering nucleon superfluidity. Furthermore, we show that our scenario is consistent with the recent observations of the effective temperature of Cas A during the last 10 years, including nucleon superfluidity.

  4. Cooling profiles of laser induced temperature fields for superconducting vanadium nitrate products

    NASA Astrophysics Data System (ADS)

    Emetere, Moses Eterigho

    2016-01-01

    The flexibility of vanadium nitrate makes it a good constituent for emerging superconductors. Its thermal instability engenders a disordered structure when doped by insulating constituents. The physics of the heat source i.e. the probe laser was theoretical derived to avoid deficiency of the superconducting material at low laser energy density. The mathematical experimentation was accomplished by queering the energy balance and heat conductivity of the individual constituents of the reagent. In-depth analysis of the layered distribution of laser induced temperature fields was carried out by cooling the compound via the forced convective cooling technique to about 150 C. The material was gradual heated via the laser probe to its superconducting state. The structural defect which explained different state of the thermal outcomes were explained and proven to correspond with experimental outcomes. The temperature distribution under the irradiating laser intensity (0.45 W) shows an effective decay rate probability density function which is peculiar to the concept of photoluminescence. The dynamics of the electronic structure of thermally-excited superconducting materials is hinged on the complementary stoichiometry signatures, thermal properties amongst others. The maximum possible critical temperatures of the inter-layer were calculated to be about 206 K.

  5. Cooling profiles of laser induced temperature fields for superconducting vanadium nitrate products

    NASA Astrophysics Data System (ADS)

    Emetere, Moses Eterigho

    2015-05-01

    The flexibility of vanadium nitrate makes it a good constituent for emerging superconductors. Its thermal instability engenders a disordered structure when doped by insulating constituents. The physics of the heat source i.e. the probe laser was theoretical derived to avoid deficiency of the superconducting material at low laser energy density. The mathematical experimentation was accomplished by queering the energy balance and heat conductivity of the individual constituents of the reagent. In-depth analysis of the layered distribution of laser induced temperature fields was carried out by cooling the compound via the forced convective cooling technique to about 150 C. The material was gradual heated via the laser probe to its superconducting state. The structural defect which explained different state of the thermal outcomes were explained and proven to correspond with experimental outcomes. The temperature distribution under the irradiating laser intensity (0.45 W) shows an effective decay rate probability density function which is peculiar to the concept of photoluminescence. The dynamics of the electronic structure of thermally-excited superconducting materials is hinged on the complementary stoichiometry signatures, thermal properties amongst others. The maximum possible critical temperatures of the inter-layer were calculated to be about 206 K.

  6. Large cooling power hybrid Gifford mac Mahon / Joule Thomson refrigerator andliquefier

    NASA Astrophysics Data System (ADS)

    Poncet, Jean-Marc; Claudet, Grard; Lagnier, Robert; Ravex, Alain

    In this paper, we present two refrigerators using Joule Thomson cycle providing cooling powers of 4.5 W at 4.4 K and using Gifford Mac Mahon cryocoolers for the precooling. Several smaller machines have been developped in our laboratory with refrigeration capacity ranging from 100 mW up to 1.5 W in the temperature range 3 K to 4.4 K. In the present case, to increase the cooling power, we introduced a three stage precooling scheme using a liquid nitrogen vessel plus the two stages of a Gifford Mac Mahon cryocooler. Cooldown and operation of the system are fully automatic. The first refrigerator is used to cool two Nb 3Sn superconducting coils having a maximum field of 11.8 T. The second system is an helium liquefier, designed to produce more than 1 liter per hour.

  7. Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors.

    PubMed

    Chiuchiolo, Antonella; Palmieri, Luca; Consales, Marco; Giordano, Michele; Borriello, Anna; Bajas, Hugues; Galtarossa, Andrea; Bajko, Marta; Cusano, Andrea

    2015-10-01

    This contribution presents distributed and multipoint fiber-optic monitoring of cryogenic temperatures along a superconducting power transmission line down to 30 K and over 20 m distance. Multipoint measurements were conducted using fiber Bragg gratings sensors coated with two different functional overlays (epoxy and poly methyl methacrylate (PMMA)) demonstrating cryogenic operation in the range 300-4.2 K. Distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimide). The integrated system has been placed along the 20 m long cryostat of a superconducting power transmission line, which is currently being tested at the European Organization for Nuclear Research (CERN). Cool-down events from 300-30 K have been successfully measured in space and time, confirming the viability of these approaches to the monitoring of cryogenic temperatures along a superconducting transmission line. PMID:26421547

  8. Hybrid Cooling Systems for Low-Temperature Geothermal Power Production

    SciTech Connect

    Ashwood, A.; Bharathan, D.

    2011-03-01

    This paper describes the identification and evaluation of methods by which the net power output of an air-cooled geothermal power plant can be enhanced during hot ambient conditions with a minimal amount of water use.

  9. Case study on the US superconducting power transmission program

    SciTech Connect

    Hammel, E.F.

    1996-02-01

    After the 1911 discovery of superconductivity (the abrupt loss of electrical resistance in certain materials at very low temperatures), attempts were made to make practical use of this phenomenon. Initially these attempts failed, but in the early 1960s (after 50 years of research) they succeeded. By then, the projected growth in the production and consumption of electrical energy required much higher capacity power transmission capabilities than were available or likely to become available from incremental improvements in existing transmission technology. Since superconductors were capable in principle of transmitting huge amounts of power, research programs to develop and demonstrate superconducting transmission lines were initiated in the US and abroad. The history of the US program, including the participants, their objectives, funding and progress made, is outlined. Since the R&D program was terminated before the technology was completely demonstrated, the reasons for and consequences of this action are discussed in a final section.

  10. 10-kA pulsed power supply for superconducting coils

    SciTech Connect

    Ehsani, M.; Fuja, R.E.; Kustom, R.L.

    1981-01-01

    A new 4-MW inductor-converter bridge (ICB) for supplying power to pulsed superconducting magnets is under construction at Argonne National Laoratory. This is a second-generation ICB built at Argonne Lab. The analytical, design, and control techniques developed for the first prototype have been used in the design of the new system. The paper presents the important considerations in the design of the new ICB. A brief description of the operation of the circuit is also given.

  11. Superconducting electromechanical rotating device having a liquid-cooled, potted, one layer stator winding

    DOEpatents

    Dombrovski, Viatcheslav V. (Willoughby Hills, OH); Driscoll, David I. (South Euclid, OH); Shovkhet, Boris A. (Beachwood, OH)

    2001-01-01

    A superconducting electromechanical rotating (SER) device, such as a synchronous AC motor, includes a superconducting field winding and a one-layer stator winding that may be water-cooled. The stator winding is potted to a support such as the inner radial surface of a support structure and, accordingly, lacks hangers or other mechanical fasteners that otherwise would complicate stator assembly and require the provision of an unnecessarily large gap between adjacent stator coil sections. The one-layer winding topology, resulting in the number of coils being equal to half the number of slots or other mounting locations on the support structure, allows one to minimize or eliminate the gap between the inner radial ends of adjacent straight sections of the stator coilswhile maintaining the gap between the coil knuckles equal to at least the coil width, providing sufficient room for electrical and cooling element configurations and connections. The stator winding may be potted to the support structure or other support, for example, by a one-step VPI process relying on saturation of an absorbent material to fill large gaps in the stator winding or by a two-step process in which small gaps are first filled via a VPI or similar operation and larger gaps are then filled via an operation that utilizes the stator as a portion of an on-site mold.

  12. Inverter power module with distributed support for direct substrate cooling

    DOEpatents

    Miller, David Harold (San Pedro, CA); Korich, Mark D. (Chino Hills, CA); Ward, Terence G. (Redondo Beach, CA); Mann, Brooks S. (Redondo Beach, CA)

    2012-08-21

    Systems and/or methods are provided for an inverter power module with distributed support for direct substrate cooling. An inverter module comprises a power electronic substrate. A first support frame is adapted to house the power electronic substrate and has a first region adapted to allow direct cooling of the power electronic substrate. A gasket is interposed between the power electronic substrate and the first support frame. The gasket is configured to provide a seal between the first region and the power electronic substrate. A second support frame is adapted to house the power electronic substrate and joined to the first support frame to form the seal.

  13. High-Tc superconducting materials for electric power applications.

    PubMed

    Larbalestier, D; Gurevich, A; Feldmann, D M; Polyanskii, A

    2001-11-15

    Large-scale superconducting electric devices for power industry depend critically on wires with high critical current densities at temperatures where cryogenic losses are tolerable. This restricts choice to two high-temperature cuprate superconductors, (Bi,Pb)2Sr2Ca2Cu3Ox and YBa2Cu3Ox, and possibly to MgB2, recently discovered to superconduct at 39 K. Crystal structure and material anisotropy place fundamental restrictions on their properties, especially in polycrystalline form. So far, power applications have followed a largely empirical, twin-track approach of conductor development and construction of prototype devices. The feasibility of superconducting power cables, magnetic energy-storage devices, transformers, fault current limiters and motors, largely using (Bi,Pb)2Sr2Ca2Cu3Ox conductor, is proven. Widespread applications now depend significantly on cost-effective resolution of fundamental materials and fabrication issues, which control the production of low-cost, high-performance conductors of these remarkable compounds. PMID:11713544

  14. The economics of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1978-01-01

    Analytic procedure evaluates cost of combining absorption-cycle chiller with solar-energy system in residential or commercial application. Procedure assumes that solar-energy system already exists to heat building and that cooling system must be added. Decision is whether to cool building with conventional vapor-compression-cycle chiller or to use solar-energy system to provide heat input to absorption chiller.

  15. Purification of condenser water in thermal power station by superconducting magnetic separation

    NASA Astrophysics Data System (ADS)

    Ha, D. W.; Kwon, J. M.; Baik, S. K.; Lee, Y. J.; Han, K. S.; Ko, R. K.; Sohn, M. H.; Seong, K. C.

    2011-11-01

    Thermal power station is made up of a steam turbine and a steam condenser which need a lot of water. The water of steam condenser should be replaced, since scales consisting of iron oxide mainly are accumulated on the surface of condenser pipes as it goes. Superconducting high gradient magnetic separation (HGMS) system has merits to remove paramagnetic substance like iron oxides because it can generate higher magnetic field strength than electromagnet or permanent magnet. In this paper, cryo-cooled Nb-Ti superconducting magnet that can generate up to 6 T was used for HGMS systems. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The result of X-ray analysis showed contaminants were mostly ?-Fe 2O 3 (hematite) and ?-Fe 2O 3 (maghemite). The higher magnetic field was applied up to 6 T, the more iron oxides were removed. As the wire diameter of magnetic filter decreased, the turbidity removal of the sample was enhanced.

  16. Superconductivity

    SciTech Connect

    Langone, J.

    1989-01-01

    This book explains the theoretical background of superconductivity. Includes discussion of electricity, material fabrication, maglev trains, the superconducting supercollider, and Japanese-US competition. The authors reports the latest discoveries.

  17. Minimization of power consumption during charging of superconducting accelerating cavities

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Anirban Krishna; Ziemann, Volker; Ruber, Roger; Goryashko, Vitaliy

    2015-11-01

    The radio frequency cavities, used to accelerate charged particle beams, need to be charged to their nominal voltage after which the beam can be injected into them. The standard procedure for such cavity filling is to use a step charging profile. However, during initial stages of such a filling process a substantial amount of the total energy is wasted in reflection for superconducting cavities because of their extremely narrow bandwidth. The paper presents a novel strategy to charge cavities, which reduces total energy reflection. We use variational calculus to obtain analytical expression for the optimal charging profile. Energies, reflected and required, and generator peak power are also compared between the charging schemes and practical aspects (saturation, efficiency and gain characteristics) of power sources (tetrodes, IOTs and solid state power amplifiers) are also considered and analysed. The paper presents a methodology to successfully identify the optimal charging scheme for different power sources to minimize total energy requirement.

  18. Emerging Two-Phase Cooling Technologies for Power Electronic Inverters

    SciTech Connect

    Hsu, J.S.

    2005-08-17

    In order to meet the Department of Energy's (DOE's) FreedomCAR and Vehicle Technologies (FVCT) goals for volume, weight, efficiency, reliability, and cost, the cooling of the power electronic devices, traction motors, and generators is critical. Currently the power electronic devices, traction motors, and generators in a hybrid electric vehicle (HEV) are primarily cooled by water-ethylene glycol (WEG) mixture. The cooling fluid operates as a single-phase coolant as the liquid phase of the WEG does not change to its vapor phase during the cooling process. In these single-phase systems, two cooling loops of WEG produce a low temperature (around 70 C) cooling loop for the power electronics and motor/generator, and higher temperature loop (around 105 C) for the internal combustion engine. There is another coolant option currently available in automobiles. It is possible to use the transmission oil as a coolant. The oil temperature exists at approximately 85 C which can be utilized to cool the power electronic and electrical devices. Because heat flux is proportional to the temperature difference between the device's hot surface and the coolant, a device that can tolerate higher temperatures enables the device to be smaller while dissipating the same amount of heat. Presently, new silicon carbide (SiC) devices and high temperature direct current (dc)-link capacitors, such as Teflon capacitors, are available but at significantly higher costs. Higher junction temperature (175 C) silicon (Si) dies are gradually emerging in the market, which will eventually help to lower hardware costs for cooling. The development of high-temperature devices is not the only way to reduce device size. Two-phase cooling that utilizes the vaporization of the liquid to dissipate heat is expected to be a very effective cooling method. Among two-phase cooling methods, different technologies such as spray, jet impingement, pool boiling and submersion, etc. are being developed. The Oak Ridge National Laboratory (ORNL) is leading the research on a novel floating refrigerant loop that cools high-power electronic devices and the motor/generator with very low cooling energy. The loop can be operated independently or attached to the air conditioning system of the vehicle to share the condenser and other mutually needed components. The ability to achieve low cooling energy in the floating loop is attributable to the liquid refrigerant operating at its hot saturated temperature (around 50 C+). In an air conditioning system, the liquid refrigerant is sub-cooled for producing cool air to the passenger compartment. The ORNL floating loop avoids the sub-cooling of the liquid refrigerant and saves significant cooling energy. It can raise the coefficient of performance (COP) more than 10 fold from that of the existing air-conditioning system, where the COP is the ratio of the cooled power and the input power for dissipating the cooled power. In order to thoroughly investigate emerging two-phase cooling technologies, ORNL subcontracted three university/companies to look into three leading two-phase cooling technologies. ORNL's assessments on these technologies are summarized in Section I. Detailed descriptions of the reports by the three university/companies (subcontractors) are in Section II.

  19. Thermoacoustic Duplex Technology for Cooling and Powering a Venus Lander

    NASA Astrophysics Data System (ADS)

    Walker, A. R.; Haberbusch, M. S.; Sasson, J.

    2015-04-01

    A Thermoacoustic Stirling Heat Engine (TASHE) is directly coupled to a Pulse Tube Refrigerator (PTR) in a duplex configuration, providing simultaneous cooling and electrical power, thereby suiting the needs of a long-lived Venus lander.

  20. Cryogenic analysis of forced-cooled, superconducting TF magnets for compact tokamak reactors

    SciTech Connect

    Kerns, J.A.; Slack, D.S.; Miller, J.R.

    1988-10-25

    Current designs for compact tokamak reactors require the toroidal- field (TF) superconducting magnets to produce fields from 10 to 15 T at the winding pack, using high-current densities to high nuclear heat loads (greater than 1 kW/coil in some instances), which are significantly greater than the conduction and radiation heat loads for which cryogenic systems are usually designed. A cryogenic system for the TF winding pack for two such tokamak designs has been verified by performing a detailed, steady-state heat-removal analysis. Helium properties along the forced-cooled conductor flow path for a range of nuclear heat loads have been calculated. The results and implications of this analysis are presented. 12 refs., 6 figs.

  1. Convective Array Cooling for a Solar Powered Aircraft

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Dolce, James (Technical Monitor)

    2003-01-01

    A general characteristic of photovoltaics is that they increase in efficiency as their operating temperature decreases. Based on this principal, the ability to increase a solar aircraft's performance by cooling the solar cells was examined. The solar cells were cooled by channeling some air underneath the cells and providing a convective cooling path to the back side of the array. A full energy balance and flow analysis of the air within the cooling passage was performed. The analysis was first performed on a preliminary level to estimate the benefits of the cooling passage. This analysis established a clear benefit to the cooling passage. Based on these results a more detailed analysis was performed. From this cell temperatures were calculated and array output power throughout a day period were determined with and without the cooling passage. The results showed that if the flow through the cooling passage remained laminar then the benefit in increased output power more than offset the drag induced by the cooling passage.

  2. Naegleria fowleri in cooling waters of power plants.

    PubMed

    Cerva, L; Kasprzak, W; Mazur, T

    1982-01-01

    Six strains of nonvirulent and three strains of virulent variants of Naegleria fowleri amoebae were isolated from the examined cooling water samples from 9 power plants. The virulent variants were obtained solely from effluents discharged from power plants with a closed-circuit cooling N. fowleri was not detected outside the reach of the thermal pollution. A disinfection of out-flowing cooling water seems to be an unnecessary investment in our climate. Warm discharge water should under no conditions be used directly for sports and recreational purposes. PMID:7119430

  3. Dependence of the residual surface resistance of superconducting radio frequency cavities on the cooling dynamics around T{sub c}

    SciTech Connect

    Romanenko, A. Grassellino, A. Melnychuk, O.; Sergatskov, D. A.

    2014-05-14

    We report a strong effect of the cooling dynamics through T{sub c} on the amount of trapped external magnetic flux in superconducting niobium cavities. The effect is similar for fine grain and single crystal niobium and all surface treatments including electropolishing with and without 120 °C baking and nitrogen doping. Direct magnetic field measurements on the cavity walls show that the effect stems from changes in the flux trapping efficiency: slow cooling leads to almost complete flux trapping and higher residual resistance, while fast cooling leads to the much more efficient flux expulsion and lower residual resistance.

  4. Helium-cooling in fusion power plants

    SciTech Connect

    Wong, C.P.C.; Baxi, C.B.; Hamilton, C.J.; Schleicher, R.W.; Streckert, H.

    1994-11-01

    This paper reviews different helium-cooled first wall and blanket designs; and compares the selection of structural materials. The authors found that the solid breeder, SiC-composite material option generates the lowest amount of induced radioactivity and afterheat and has the highest temperature capability. When combined with the direct cycle gas turbine system, it has the potential to be the most economical fusion system and can compete with advanced fission reactors. When compared to martensitic steel and V-alloy, SiC-composite is the least developed of these three structural materials, a focused development effort will be needed. Fundamental research has begun in addressing the issues of optimized composite materials, irradiation effects, leak tightness and low activation braze materials. Development of helium-cooled high heat flux components and further development of the direct cycle gas turbine system will also be needed.

  5. A Cool-down and Fault Study of a Long Length HTS Power Transmission Cable

    NASA Astrophysics Data System (ADS)

    Yuan, J.; Maguire, J.; Allais, A.; Schmidt, F.

    2006-04-01

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. Currently the US Department of Energy is funding the design, development, and demonstration of the first long length, transmission level voltage, cold dielectric, underground high temperature superconductor power cable. The cable is 620 meters long and is designed for permanent installation in the Long Island Power Authority (LIPA) grid. The cable is specified to carry 574 MVA at a voltage of 138 kV and is designed to withstand a 69 kA fault current for a duration of 200ms. The superconducting state of the cable conductors is maintained by circulating sub-cooled liquid nitrogen, which flows through one phase conductor of the cable and returns through the other two. As HTS cables develop and lengths increase to what may be considered commercial, it is critical to study the cable thermal behavior during cool-down process and fault condition to avoid any possible damage to the cable core due to the thermal stress, over heating or bubble formation. This paper reviews the efforts that have been made to study the cool-down process and fault condition. Descriptions of the transient thermal and fluid model are provided. A discussion of the simulation results is also included.

  6. Passive Two-Phase Cooling of Automotive Power Electronics: Preprint

    SciTech Connect

    Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

    2014-08-01

    Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

  7. Arrangement for cooling a superconducting field winding and a damper shield of the rotor of an electric machine

    SciTech Connect

    Weghaupt, E.; Intichar, L.; Schnapper, C.

    1983-08-02

    A cooling arrangement is disclosed for a superconducting field winding of an electric machine, especially a turbo-generator. It has a coolant space which contains a cryogenic coolant fed into it via a feed line, for cooling the field winding, and a coolant supply chamber which contains liquid coolant for cooling a damper shield. So that no separate feed and discharge lines are required for cooling the damper shield independently of the cooling of the field winding, the coolant supply chamber is connected directly to the coolant feed line via a radial connecting line, and the flow cross sections of the connecting line and of the section of the coolant feed line between the connecting head and the connecting point of the connecting line are made large.

  8. Diamond cooling of high power diode pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Tzuk, Yitshak; Tal, Alon; Goldring, Sharone; Glick, Yaakov; Lebiush, Eyal; Kaufman, Guy; Lavi, Raphael

    2003-06-01

    We have demonstrated the feasibility of cooling high power solid-stae lasers with diamond windows, whose thermal conductivity is about two orders of magnitude higher than sapphire's. An output power of 200Watt was achieved froma single Nd:YVO4 slab in a zigzag configuration when pumped with 600Watt diodes at 808nm. The maximum output power reported in the literature with conventional cooling schemes is about 50W. A 2.3x4x24mm3 slab was pumped from its broad side (4x24 mm2) through a 0.3mm thick optical diamond window placed in close contact with the lasing crystal. The diamond window, held in a water-cooled copper housing acted as a heat conductor. The other broad side of the crystal was cooled directly by its water-cooled copper housing. Since pumping and cooling were along the same axis, a Cartesian thermal gradient was achieved, while the zigzag scheme was used to minimize thermal lensing. By using a BBO Q-switch, 70Watt average power was obtained at 20kHz with a pulse width of 19msec and with a beam quality of 3 and 12 times diffraction limit in the zigzag and transverse directions respectively. The output of a two-head configuration was 295Watt.

  9. Evacuation time of cryogenic pipes for superconducting power transmission

    NASA Astrophysics Data System (ADS)

    Watanabe, Hirofumi; Sun, Jian; Yamamoto, Norimasa; Hamabe, Makoto; Kawahara, Toshio; Yamaguchi, Satarou

    2013-11-01

    The vacuum insulation has been used for the thermal insulation of cryogenic pipes for the superconducting power transmission to reduce the heat leak from the environment at the room temperature to the low temperature parts. Since the cryogenic pipes, in particular, those for long distance power transmission, are considered to be thin long pipes, it might take a long time for evacuation. To estimate the evacuation time of the long cryogenic pipes, model calculations have been performed. According to the calculations, it is found that there is an optimum condition between the pumping speed, the diameter of the outer pipe and the length of the cryogenic pipe for efficient evacuation. It is also found that, if the outgassing is suppressed enough, the evacuation can be possible within 1 week even for the long cryogenic pipe with the length of 10 km. The reduction of outgassing is particularly important for the efficient evacuation.

  10. Resistance and Cooling Power of Various Radiators

    NASA Technical Reports Server (NTRS)

    Smith, R H

    1928-01-01

    This reports combines the wind tunnel results of radiator tests made at the Navy Aerodynamical Laboratory in Washington during the summers of 1921, 1925, and 1926. In all, 13 radiators of various types and capacities were given complete tests for figure of merit. Twelve of these were tested for resistance to water flow and a fourteenth radiator was tested for air resistance alone, its heat dissipating capacity being known. All the tests were conducted in the 8 by 8 foot tunnel, or in its 4 by 8 foot restriction, by the writer and under conditions as nearly the same as possible. That is to say, as far as possible, the general arrangement and condition of the apparatus, the observation intervals, the ratio of water flow per unit of cooling surface, the differential temperatures, and the air speeds were the same for all.

  11. 4 K pulse tube refrigerator and excess cooling power

    NASA Astrophysics Data System (ADS)

    Zhu, Shaowei; Ichikawa, Masahiro; Nogawa, Masafumi; Inoue, Tatsuo

    2002-05-01

    In this paper, a pre-cooled two-stage 4 K pulse tube refrigerator is presented. The phase shifter of the first stage is two-middle buffer type, that of the second stage is double inlet type. There are four 1.5 meter long connecting tubes between the rotary valve and the cold head for reducing the vibration. The cooling power of 0.62 W and 0.72 W at 4.2 K were obtained with 5.5 kW and 6.5 kW of compressor input power, respectively. A simple method for partially solving the intrinsic low efficiency problem of 4 K regenerative refrigerator is proposed. A heat exchanger, which is called inter-heat exchanger, is installed near the center of the second stage regenerator to get excess cooling power around 10-16 K without any influence to the cooling power of the second stage. Theoretical analysis and numerical simulation shows that significant excess cooling power can be produced.

  12. Liquid metal cooled reactors for space power applications

    NASA Technical Reports Server (NTRS)

    Bailey, S.; Vaidyanathan, S.; Van Hoomissen, J.

    1985-01-01

    The technology basis for evaluation of liquid metal cooled space reactors is summarized. Requirements for space nuclear power which are relevant to selection of the reactor subsystem are then reviewed. The attributes of liquid metal cooled reactors are considered in relation to these requirements in the areas of liquid metal properties, neutron spectrum characteristics, and fuel form. Key features of typical reactor designs are illustrated. It is concluded that liquid metal cooled fast spectrum reactors provide a high confidence, flexible option for meeting requirements for SP-100 and beyond.

  13. Superconductivity

    NASA Astrophysics Data System (ADS)

    Cyrot, Michel

    Superconductiviy is a quantum phenomenon. It shows up through strange physical properties which arouse curiosity but also lead to interesting applications. The presence of superconductivity in a book on magnetism is justified: first, because superconductor substances are generally strongly diamagnetic, but also because superconductors are used both to generate relatively intense magnetic fields (superconducting magnets), and to detect very weak magnetic inductions (SQUIDs).

  14. High temperature superconductivity technology for advanced space power systems

    NASA Technical Reports Server (NTRS)

    Faymon, Karl A.; Myers, Ira T.; Connolly, Denis J.

    1990-01-01

    In 1987, the Lewis Research center of the NASA and the Argonne National Laboratory of the Department of Energy joined in a cooperative program to identify and assess high payoff space and aeronautical applications of high temperature superconductivity (HTSC). The initial emphasis of this effort was limited, and those space power related applications which were considered included microwave power transmission and magnetic energy storage. The results of these initial studies were encouraging and indicated the need of further studies. A continuing collaborative program with Argonne National Laboratory has been formulated and the Lewis Research Center is presently structuring a program to further evaluate HTSC, identify applications and define the requisite technology development programs for space power systems. This paper discusses some preliminary results of the previous evaluations in the area of space power applications of HTSC which were carried out under the joint NASA-DOE program, the future NASA-Lewis proposed program, its thrusts, and its intended outputs and give general insights on the anticipated impact of HTSC for space power applications of the future.

  15. Convection of Paramagnetic Fluid in a Cube Heated and Cooled from Side Walls and Placed below a Superconducting Magnet

    NASA Astrophysics Data System (ADS)

    Bednarz, Tomasz; Fornalik, Elzbieta; Tagawa, Toshio; Ozoe, Hiroyuki; Szmyd, Janusz S.

    The magnetic convection of paramagnetic fluid is studied in a strong magnetic field. The fluid in a cubic enclosure is heated from one vertical wall and cooled from the opposite one. The fluid is the 80% mass aqueous solution of glycerol with 0.8 mol/kg concentration of gadolinium nitrate hexahydrate to make the working fluid paramagnetic. The small amount of liquid crystal slurry is added to the fluid in order to visualize the temperature profiles in a vertical cross-section. This system is placed directly below the solenoid of the superconducting magnet which is oriented vertically. The temperature of cold wall is constantly controlled by the water flowing from a thermostating bath. On the other hand, the hot wall is heated by a nichrome wire from a DC power supply. In the numerical computations, the configuration of the system is modeled to be as close as possible to the real system. The physical properties of the working fluid are used to compute dimensionless parameters in the numerical model and the computations are carried out for corresponding cases. Later, the numerical and experimental results are compared with each other.

  16. Investigation into the use of solid nitrogen to create a ''Thermal Battery'' for cooling a portable high-temperature superconducting magnet

    NASA Astrophysics Data System (ADS)

    Hales, P.; Jones, H.; Milward, S.; Harrison, S.

    2005-02-01

    The design of a portable, "stand-alone" cooling system, for use with a high-temperature superconducting (HTS) magnet, is discussed. The HTS magnet is used to propel a magnetohydrodynamically powered model boat (approximately 120 cm × 60 cm). The aim of this investigation was to establish the suitability of solid nitrogen for use in the stand-alone cooling system, and determine the optimum method for exploiting its cooling power. It was found that obtaining good thermal contact between solid nitrogen and its container is very difficult if the nitrogen is frozen under vacuum, due to the formation of a thermal barrier between the nitrogen and its container. This problem is overcome if the nitrogen is frozen via conduction cooling from cold helium gas (at ˜4.2 K); and the design for a near isothermal "thermal battery" based on this principle is presented. This thermal battery has been constructed and integrated into the HTS magnet system onboard the model boat, and the results from the first trials of this system are presented here.

  17. Thermally matched fluid cooled power converter

    DOEpatents

    Radosevich, Lawrence D.; Kannenberg, Daniel G.; Kaishian, Steven C.; Beihoff, Bruce C.

    2005-06-21

    A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. Power electronic circuits are thermally matched, such as between component layers and between the circuits and the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  18. Thermal and magnetic behaviors of a melt-textured superconducting bulk magnet in the zero-field-cooling magnetizing process

    NASA Astrophysics Data System (ADS)

    Oka, T.; Yokoyama, K.; Fujishiro, H.; Noto, K.

    2009-06-01

    The heat generation and magnetic field trapping behaviors of the melt-textured single-domain Sm-Ba-Cu-O bulk superconductor have been precisely investigated in the zero-field-cooling magnetizing processes (ZFC). The temperature and magnetic flux density were simultaneously measured in the temperature range of 50-60 K. Since the invasion of magnetic flux is suppressed by the superconducting pinning effect, the applied magnetic field is not supplied to the whole of the sample. Therefore, the trapped field distributions consequently exhibit trapezoid shapes. According to the balance of heat generation and draining, the temperature profiles show us distinctive behaviors of magnetic fluxes. Both the temperature and the magnetic flux density kept increasing even after the external magnetic field has stopped growing at 5 T. This is attributed to the flux creeping phenomenon which propagates from the periphery to the center portion of the sample like a snow slide. The highest temperature rise due to the flux motion reached 7.5 K even when the sample was magnetized at a slow sweeping rate of 5.06 mT s-1. As the temperature profiles were different between the ascending and descending field processes, it is suggested that the magnetic fluxes invade in and diffuse out in different heating manners between the processes. This assists the hypothesis that the time while the moving fluxes heat the sample strongly affects the total amount of heat generation, which acts contrary to the FC case. This behavior implies that the improvements of the heat propagation property of the HTS bulk material by embedding metallic membranes and more powerful/efficient cooling systems must suppress the temperature increases and enhance the field trapping abilities.

  19. Modular power converter having fluid cooled support

    DOEpatents

    Beihoff, Bruce C.; Radosevich, Lawrence D.; Meyer, Andreas A.; Gollhardt, Neil; Kannenberg, Daniel G.

    2005-12-06

    A support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  20. Modular power converter having fluid cooled support

    DOEpatents

    Beihoff, Bruce C.; Radosevich, Lawrence D.; Meyer, Andreas A.; Gollhardt, Neil; Kannenberg, Daniel G.

    2005-09-06

    A support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  1. Concurrent Wind Cooling in Power Transmission Lines

    SciTech Connect

    Jake P Gentle

    2012-08-01

    Idaho National Laboratory and the Idaho Power Company, with collaboration from Idaho State University, have been working on a project to monitor wind and other environmental data parameters along certain electrical transmission corridors. The combination of both real-time historical weather and environmental data is being used to model, validate, and recommend possibilities for dynamic operations of the transmission lines for power and energy carrying capacity. The planned results can also be used to influence decisions about proposed design criteria for or upgrades to certain sections of the transmission lines.

  2. Gas-cooled reactor power systems for space

    SciTech Connect

    Walter, C.E.

    1987-01-01

    In this paper the characteristics of six designs for power levels of 2, 10, and 20 MWe for operating times of 1 and 7 y are described. The operating conditions for these arbitrary designs were chosen to minimize system specific mass. The designs are based on recent work which benefits from earlier analyses of nuclear space power systems conducted at our Laboratory. Both gas- and liquid-cooled reactors had been considered. Pitts and Walter (1970) reported on the results of a detailed study of a 10-MWe lithium-cooled reactor in a potassium Rankine system. Unpublished results (1966) of a computer analysis provide details of an argon-cooled reactor in an argon Brayton system. The gas-cooled reactor design was based on extensive development work on the 500-MWth reactor for the nuclear ramjet (Pluto) as described by Walter (1964). The designs discussed here draw heavily on the Pluto project experience, which culminated in a successful full-power ground test as reported by Reynolds (1964). At higher power levels gas-cooled reactors coupled with Brayton systems with advanced radiator designs become attractive.

  3. Investigation of a Stirling-type pulse tube cryocooler with 100 W-class cooling power at 77 K

    NASA Astrophysics Data System (ADS)

    Zhang, L. M.; Hu, J. Y.; Chen, Y. Y.; Luo, E. C.; Dai, W.

    2014-01-01

    High power Stirling-type pulse tube cryocoolers are considered as one of the ideal candidates for cooling high temperature superconducting devices for its high reliability and high efficiency. The inhomogeneity of flow in a large-diameter pulse tube is one of the main obstacles to develop an efficient cryocooler. In this paper, a Stirling-type pulse tube cryocooler with 100 W-class cooling power at 77 K was developed and tested. A screen-filled secondary water-cooled heat exchanger is used at the hot end of the pulse tube to suppress the jet steaming. Then, attentions were focused on the influence of the pulse tube configurations on the cooling performance. Pulse tubes with different size and taper angle were investigated. With a 100 mm-long cylindrical pulse tube, a cooling power of more than 100 W at 77 K was obtained, and with a 75 mm-long tapered pulse tube of 2.8, the relative Carnot efficiency of the cryocooler from acoustic work to cooling power reached 29.8%. If the efficiency of the compressor is 80%, the relative Carnot efficiency of the whole system could reach about 24%, showing great attraction to HTS applications.

  4. Air Cooling for High Temperature Power Electronics (Presentation)

    SciTech Connect

    Waye, S.; Musselman, M.; King, C.

    2014-09-01

    Current emphasis on developing high-temperature power electronics, including wide-bandgap materials such as silicon carbide and gallium nitride, increases the opportunity for a completely air-cooled inverter at higher powers. This removes the liquid cooling system for the inverter, saving weight and volume on the liquid-to-air heat exchanger, coolant lines, pumps, and coolant, replacing them with just a fan and air supply ducting. We investigate the potential for an air-cooled heat exchanger from a component and systems-level approach to meet specific power and power density targets. A proposed baseline air-cooled heat exchanger design that does not meet those targets was optimized using a parametric computational fluid dynamics analysis, examining the effects of heat exchanger geometry and device location, fixing the device heat dissipation and maximum junction temperature. The CFD results were extrapolated to a full inverter, including casing, capacitor, bus bar, gate driver, and control board component weights and volumes. Surrogate ducting was tested to understand the pressure drop and subsequent system parasitic load. Geometries that met targets with acceptable loads on the system were down-selected for experimentation. Nine baseline configuration modules dissipated the target heat dissipation, but fell below specific power and power density targets. Six optimized configuration modules dissipated the target heat load, exceeding the specific power and power density targets. By maintaining the same 175 degrees C maximum junction temperature, an optimized heat exchanger design and higher device heat fluxes allowed a reduction in the number of modules required, increasing specific power and power density while still maintaining the inverter power.

  5. LN 2 circulation in cryopipes of superconducting power transmission line

    NASA Astrophysics Data System (ADS)

    Sasaki, A.; Ivanov, Yu.; Yamaguchi, S.

    2011-09-01

    We propose and consider the application of superconducting power transmission lines (SC PTs) using high temperature superconductors (HTSs) for further reduction of the electricity losses. To keep HTS cable at low temperature it is usual to use liquid nitrogen (LN 2). Straight and bellows pipes used in SC PT have different hydraulic friction factors due to differences in the shape of the wall surfaces. Moreover, the decentering of the HTS cable, which is unfixed at the center of the pipeline, also influences the LN 2 flow. In the case of long SC PTs, high power must be expended to overcome hydraulic friction. There are two methods to evaluate pressure losses. One is based on empirical formulae and another is based on the algorithms of computational fluid dynamics (CFD). Empirical formulae can estimate pressure losses for long pipes, but the decentering of the cable is not considered. CFD computations describe flow behavior taking into account cable position inside the pipeline, though there is a limit to computable length due to the dependence on the number of mesh points and computation capacity. In this paper, circulation losses and pump power are estimated in straight and bellows pipes forming circulation channels by both methods. For a 40 mm diameter cable in an 80 mm diameter pipe, with the bellows pipe segments covering 2% of the length, and a heat loss of 1 W/m, the required flow rate and pump power for a circulation of 10 km are approximately 19 L/min and 10 W, respectively.

  6. Design of dechlorination units for power plant cooling streams

    SciTech Connect

    Tan, C.S.; Berker, A.; Whitaker, S.

    1980-02-01

    The design of dechlorination units using sulfur dioxide as a reducing agent for once-through power plant cooling streams is considered. The average concentration of hypochlorite ions is determined downstream from the point of injection of sulfurous acid as a function of the number of injection points and the initial sulfurous acid concentration. The results can be used for the design of sulfurous acid injection units required to reduce the hypochlorite ion concentration to a specified level. A sample design calculation is presented for a typical power plant cooling stream.

  7. Superconducting cable cooling system by helium gas and a mixture of gas and liquid helium

    DOEpatents

    Dean, John W.

    1977-01-01

    Thermally contacting, oppositely streaming cryogenic fluid streams in the same enclosure in a closed cycle that changes from a cool high pressure helium gas to a cooler reduced pressure helium fluid comprised of a mixture of gas and boiling liquid so as to be near the same temperature but at different pressures respectively in go and return legs that are in thermal contact with each other and in thermal contact with a longitudinally extending superconducting transmission line enclosed in the same cable enclosure that insulates the line from the ambient at a temperature T.sub.1. By first circulating the fluid in a go leg from a refrigerator at one end of the line as a high pressure helium gas near the normal boiling temperature of helium; then circulating the gas through an expander at the other end of the line where the gas becomes a mixture of reduced pressure gas and boiling liquid at its boiling temperature; then by circulating the mixture in a return leg that is separated from but in thermal contact with the gas in the go leg and in the same enclosure therewith; and finally returning the resulting low pressure gas to the refrigerator for compression into a high pressure gas at T.sub.2 is a closed cycle, where T.sub.1 >T.sub.2, the temperature distribution is such that the line temperature is nearly constant along its length from the refrigerator to the expander due to the boiling of the liquid in the mixture. A heat exchanger between the go and return lines removes the gas from the liquid in the return leg while cooling the go leg.

  8. Keeping Cool With Solar-Powered Refrigeration

    NASA Technical Reports Server (NTRS)

    2003-01-01

    In the midst of developing battery-free, solar-powered refrigeration and air conditioning systems for habitats in space, David Bergeron, the team leader for NASA's Advanced Refrigerator Technology Team at Johnson Space Center, acknowledged the need for a comparable solar refrigerator that could operate in conjunction with the simple lighting systems already in place on Earth. Bergeron, a 20-year veteran in the aerospace industry, founded the company Solus Refrigeration, Inc., in 1999 to take the patented advanced refrigeration technology he co-developed with his teammate, Johnson engineer Michael Ewert, to commercial markets. Now known as SunDanzer Refrigeration, Inc., Bergeron's company is producing battery-free, photovoltaic (PV) refrigeration systems under license to NASA, and selling them globally.

  9. PREFACE: Focus section on superconducting power systems Focus section on superconducting power systems

    NASA Astrophysics Data System (ADS)

    Cardwell, D. A.; Amemiya, N.; Fair, R.

    2012-01-01

    This focus section of Superconductor Science and Technology looks at the properties, technology and applications of (RE)BCO and MgB2 based superconductors for power engineering systems. Both bulk and conductor forms of material are addressed, including elements of materials fabrication and processing, and the measurement of their applied properties for various levels of system application. The areas of research include ac losses in type II materials in power devices, cables and coated conductors, the development of high current dc cables and the application of superconductors in levitation devices, motors and fault current limiters. This focus section presents a broad cross-section of contemporary issues, that represent state-of-the-art for power applications of superconductors, and highlights the areas that require further development if commercial applications of these rapidly emerging materials are to be realised. It contains papers from some of the major groups in the field, including contributions from Europe, the USA and Japan, and describes devices that are relatively close to market.

  10. A thermosyphon heat pipe cooler for high power LEDs cooling

    NASA Astrophysics Data System (ADS)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2015-09-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  11. Development of a higher power cooling system for lithium targets.

    PubMed

    Phoenix, B; Green, S; Scott, M C; Bennett, J R J; Edgecock, T R

    2015-12-01

    The accelerator based Boron Neutron Capture Therapy beam at the University of Birmingham is based around a solid thick lithium target cooled by heavy water. Significant upgrades to Birmingham's Dynamitron accelerator are planned prior to commencing a clinical trial. These upgrades will result in an increase in maximum achievable beam current to at least 3 mA. Various upgrades to the target cooling system to cope with this increased power have been investigated. Tests of a phase change coolant known as "binary ice" have been carried out using an induction heater to provide a comparable power input to the Dynamitron beam. The experimental data shows no improvement over chilled water in the submerged jet system, with both systems exhibiting the same heat input to target temperature relation for a given flow rate. The relationship between the cooling circuit pumping rate and the target temperature in the submerged jet system has also been tested. PMID:26254970

  12. Gas-cooled reactor power systems for space

    SciTech Connect

    Walter, C.E.

    1987-01-01

    Efficiency and mass characteristics for four gas-cooled reactor power system configurations in the 2- to 20-MWe power range are modeled. The configurations use direct and indirect Brayton cycles with and without regeneration in the power conversion loop. The prismatic ceramic core of the reactor consists of several thousand pencil-shaped tubes made from a homogeneous mixture of moderator and fuel. The heat rejection system is found to be the major contributor to system mass, particularly at high power levels. A direct, regenerated Brayton cycle with helium working fluid permits high efficiency and low specific mass for a 10-MWe system.

  13. SUPERCONDUCTING PHOTOINJECTOR

    SciTech Connect

    BEN-ZVI,I.; BURRILL, A.; CALAGA, R.; CHANG, X.; GROVER, R.; GUPTA, R.; HAHN, H.; HAMMONS, L.; KAYRAN, D.; KEWISCH, J.; LAMBIASE, R.; LITVINENKO, V.; MCINTYRE, G.; NAIK, D.; PATE, D.; PHILLIPS, D.; POZDEYEV, E.; RAO, T.; SMEDLEY, J.; THAN, R.; TODD, R.; WEISS, D.; WU, Q.; ZALTSMAN, A.; ET AL.

    2007-08-26

    One of the frontiers in FEL science is that of high power. In order to reach power in the megawatt range, one requires a current of the order of one ampere with a reasonably good emittance. The superconducting laser-photocathode RF gun with a high quantum efficiency photocathode is the most natural candidate to provide this performance. The development of a 1/2 cell superconducting photoinjector designed to operate at up to a current of 0.5 amperes and beam energy of 2 MeV and its photocathode system are the subjects covered in this paper. The main issues are the photocathode and its insertion mechanism, the power coupling and High Order Mode damping. This technology is being developed at BNL for DOE nuclear physics applications such as electron cooling at high energy and electron ion colliders..

  14. Characteristic Analysis of DC Electric Railway Systems with Superconducting Power Cables Connecting Power Substations

    NASA Astrophysics Data System (ADS)

    Ohsaki, H.; Matsushita, N.; Koseki, T.; Tomita, M.

    2014-05-01

    The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

  15. Reduction of helium loss from a superconducting accelerating cavity during initial cool-down and cryostat exchange by pre-cooling the re-condensing cryostat

    NASA Astrophysics Data System (ADS)

    O'Rourke, B. E.; Minehara, E. J.; Hayashizaki, N.; Oshima, N.; Suzuki, R.

    2015-03-01

    A Zero-Boil-Off (ZBO) cryostat is designed to realize a compact, stand-alone cryogenic system for the AIST superconducting accelerator (SCA). Under normal operation there is no evaporative helium loss from the cryomodule and therefore operating costs associated with the supply of liquid helium can be eliminated. The only significant loss of helium from the module occurs during the initial cavity cool-down procedure or when the re-condensing cryostat is replaced. It takes about 3 h to cool down the cryostat head from room temperature (300 K) to 4 K. During this time around 100 L of liquid helium is lost due to evaporation. By pre-cooling the cryostat inside a low heat load vacuum tube before transfer to the cryomodule, this evaporative loss could be essentially eliminated, significantly reducing the volume of liquid helium required for the initial cryomodule cool-down. The pre-cooling system also provides an efficient method to test the cryostat prior to use.

  16. Development and Test of World's First Industrial High-Temperature Superconducting (HTS) Power Cable

    SciTech Connect

    Sinha, U.K.

    2001-02-15

    Southwire Company has installed the world's first industrial high-temperature superconducting cable system to power three of its main manufacturing plants. The cable consists of three single-phase, 30-m long cables designed to carry 1250 A at 12.4 kV. The cable is cooled by a liquid nitrogen (LN) system that can supply LN at sub-cooled temperatures down to 72 K and at pressures up to 15 atmospheres. The design of the 30-m cables is based upon two 5-m cable prototypes, which were tested at a specially developed facility at ORNL. In addition to critical current and ac loss measurements, simulated fault-current tests were performed at ORNL on the 5-m cables. Cable terminations were designed to allow smooth transition from the cryogenic temperature and pressure environment of the HTS cable to ambient temperature and pressure for copper cables. A dielectric tape material, Cryoflex(trademark), was also developed for use at cryogenic temperatures.

  17. Behavior of power-limited transverse stochastic cooling systems

    SciTech Connect

    Goldberg, D.A.; Lambertson, G.R.

    1988-07-01

    Analysis of stochastic cooling systems is usually done under the assumption that the system performance is not limited by the available electronic gain. In practical systems, it may prove to be the case that cost-induced limitations on the maximum available output power restrict the maximum attainable gain, thereby restricting it to be less than its optimal value. Such is the case in the anti-proton sources at both CERN and Fermilab. The criteria that one would employ in, for example, upgrading such a power-limited system prove to be rather different from those for a system for which one can optimize the gain. In the following sections we first develop the formulas relevant to the behavior of power-limited cooling systems; we limit our treatment throughout to the case of systems which cool the transverse phase space of the beam. We then discuss the implications of our results for the upgrade of such cooling systems, contrasting this case with that for systems in which the electronic gain can be optimized. Finally, we apply our results to the specific case of the Fermilab debuncher ring. 3 refs., 1 fig., 2 tabs.

  18. Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices

    SciTech Connect

    Lowe, Kirk T; Tolbert, Leon M; Ayers, Curtis William; Ozpineci, Burak; Campbell, Jeremy B

    2007-01-01

    This paper presents a two-phase cooling method using R134a refrigerant to dissipate the heat energy (loss) generated by power electronics (PE) such as those associated with rectifiers, converters, and inverters for a specific application in hybrid-electric vehicles (HEVs). The cooling method involves submerging PE devices in an R134a bath, which limits the junction temperature of PE devices while conserving weight and volume of the heat sink without sacrificing equipment reliability. First, experimental tests that included an extended soak for more than 300 days were performed on a submerged IGBT and gate-controller card to study dielectric characteristics, deterioration effects, and heat flux capability of R134a. Results from these tests illustrate that R134a has high dielectric characteristics, no deterioration on electrical components, and a heat flux of 114 W/cm 2 for the experimental configuration. Second, experimental tests that included simultaneous operation with a mock automotive air-conditioner (A/C) system were performed on the same IGBT and gate controller card. Data extrapolation from these tests determined that a typical automotive A/C system has more than sufficient cooling capacity to cool a typical 30 kW traction inverter. Last, a discussion and simulation of active cooling of the IGBT junction layer with R134a refrigerant is given. This technique will drastically increase the forward current ratings and reliability of the PE device

  19. Specific power of liquid-metal-cooled reactors

    SciTech Connect

    Dobranich, D.

    1987-10-01

    Calculations of the core specific power for conceptual space-based liquid-metal-cooled reactors, based on heat transfer considerations, are presented for three different fuel types: (1) pin-type fuel; (2) cermet fuel; and (3) thermionic fuel. The calculations are based on simple models and are intended to provide preliminary comparative results. The specific power is of interest because it is a measure of the core mass required to produce a given amount of power. Potential problems concerning zero-g critical heat flux and loss-of-coolant accidents are also discussed because these concerns may limit the core specific power. Insufficient experimental data exists to accurately determine the critical heat flux of liquid-metal-cooled reactors in space; however, preliminary calculations indicate that it may be a concern. Results also indicate that the specific power of the pin-type fuels can be increased significantly if the gap between the fuel and the clad is eliminated. Cermet reactors offer the highest specific power because of the excellent thermal conductivity of the core matrix material. However, it may not be possible to take fuel advantage of this characteristic when loss-of-coolant accidents are considered in the final core design. The specific power of the thermionic fuels is dependent mainly on the emitter temperature. The small diameter thermionic fuels have specific powers comparable to those of pin-type fuels. 11 refs., 12 figs, 2 tabs.

  20. Hybrid Cooling for Geothermal Power Plants: Final ARRA Project Report

    SciTech Connect

    Bharathan, D.

    2013-06-01

    Many binary-cycle geothermal plants use air as the heat rejection medium. Usually this is accomplished by using an air-cooled condenser (ACC) system to condense the vapor of the working fluid in the cycle. Many air-cooled plants suffer a loss of production capacity of up to 50% during times of high ambient temperatures. Use of limited amounts of water to supplement the performance of ACCs is investigated. Deluge cooling is found to be one of the least-cost options. Limiting the use of water in such an application to less than one thousand operating hours per year can boost plant output during critical high-demand periods while minimizing water use in binary-cycle geothermal power plants.

  1. Efficient transfer of positrons from a buffer-gas-cooled accumulator into an orthogonally oriented superconducting solenoid for antihydrogen studies

    NASA Astrophysics Data System (ADS)

    Comeau, D.; Dror, A.; Fitzakerley, D. W.; George, M. C.; Hessels, E. A.; Storry, C. H.; Weel, M.; Grzonka, D.; Oelert, W.; Gabrielse, G.; Kalra, R.; Kolthammer, W. S.; McConnell, R.; Richerme, P.; Mllers, A.; Walz, J.; ATRAP Collaboration

    2012-04-01

    Positrons accumulated in a room-temperature buffer-gas-cooled positron accumulator are efficiently transferred into a superconducting solenoid which houses the ATRAP cryogenic Penning trap used in antihydrogen research. The positrons are guided along a 9 m long magnetic guide that connects the central field lines of the 0.15 T field in the positron accumulator to the central magnetic field lines of the superconducting solenoid. Seventy independently controllable electromagnets are required to overcome the fringing field of the large-bore superconducting solenoid. The guide includes both a 15 upward bend and a 105 downward bend to account for the orthogonal orientation of the positron accumulator with respect to the cryogenic Penning trap. Low-energy positrons ejected from the accumulator follow the magnetic field lines within the guide and are transferred into the superconducting solenoid with nearly 100% efficiency. A 7 m long 5 cm diameter stainless-steel tube and a 20 mm long, 1.5 mm diameter cryogenic pumping restriction ensure that the 10-2 mbar pressure in the accumulator is isolated well from the extreme vacuum required in the Penning trap to allow for long antimatter storage times.

  2. Active cooling solutions for high power laser diodes stacks

    NASA Astrophysics Data System (ADS)

    Karni, Yoram; Klumel, Genady; Levy, Moshe; Berk, Yuri; Openhaim, Yaki; Gridish, Yaakov; Elgali, Asher; Avisar, Meir; Blonder, Moshe; Sagy, Hila; Gertsenshtein, Alex

    2008-02-01

    High power water cooled diode lasers find increasing demand in biomedical, cosmetic and industrial applications, where very high brightness and power are required. The high brightness is achieved either by increasing the power of each bar or by reducing the emitting area of the stacks. Two new products will be presented: Horizontal CW stacks with output power as high as 1kW using 80 W bars with emitting area width as low as 50 ?m Vertical QCW stacks with output power as high as 1.2kW using 120 W bars. Heat removal from high power laser stacks often requires microchannel coolers operated with finely filtered deionized (DI) water. However, for certain industrial applications the reliability of this cooling method is widely considered insufficient due to leakage failures caused the highly corrosive DI water. Two solutions to the above problem will be discussed. A microchannel cooler-based package, which vastly reduces the corrosion problem, and a novel high-power laser diode stack that completely eliminates it. The latter solution is especially effective for pulsed applications in high duty cycle range.

  3. Superconductivity:

    NASA Astrophysics Data System (ADS)

    Sacchetti, N.

    In this paper a short historical account of the discovery of superconductivity and of its gradual development is given. The physical interpretation of its various aspects took about forty years (from 1911 to 1957) to reach a successful description of this phenomenon in terms of a microscopic theory At the very end it seemed that more or less everything could be reasonably interpreted even if modifications and refinements of the original theory were necessary. In 1986 the situation changed abruptly when a cautious but revolutionary paper appeared showing that superconductivity was found in certain ceramic oxides at temperatures above those up to then known. A rush of frantic experimental activity started world-wide and in less than one year it was shown that superconductivity is a much more widespread phenomenon than deemed before and can be found at temperatures well above the liquid air boiling point. The complexity and the number of the substances (mainly ceramic oxides) involved call for a sort of modern alchemy if compounds with the best superconducting properties are to be manufactured. We don't use the word alchemy in a deprecatory sense but just to emphasise that till now nobody can say why these compounds are what they are: superconductors.

  4. Cooling tower fill fouling control in a geothermal power plant

    SciTech Connect

    Yu, F.P.; Ginn, L.D.; McCoy, W.F.; Castanieto, H.

    1998-12-31

    Since its first introduction to the market in the 1970s, cooling tower film fill technology has significantly increased thermal performance and reduced the size of cooling towers. However, the narrow spaces between film fill sheets make them susceptible to fouling. Without proper chemical treatment, deposits can accumulate within the film fill resulting in reduced tower efficiency, increased fouling and plugging of the fill. These phenomena could eventually lead to collapse of the tower structure, This paper describes a new approach to remedy the high efficiency film fill fouling problem in a geothermal power plant. The plant has a long history of fill fouling problems due to a very complex make-up water chemistry and desert-related environmental conditions. In recent years, various biocide and biodispersant treatments have significantly improved fouling control by slowing down tower fill deposition rates. However, no program has been successful in reducing fill weights, especially during the summer months. Within six weeks after starting a new control program, the average weight of the tower fill deposits dropped 22% and thermal performance of the cooling tower increased 20%. The treatment resulted in significant improvements in cooling tower operation and power production efficiency.

  5. Design and comparative analysis of 10 MW class superconducting wind power generators according to different types of superconducting wires

    NASA Astrophysics Data System (ADS)

    Sung, Hae-Jin; Kim, Gyeong-Hun; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Kim, Jong-Yul

    2013-11-01

    Wind turbine concepts can be classified into the geared type and the gearless type. The gearless type wind turbine is more attractive due to advantages of simplified drive train and increased energy yield, and higher reliability because the gearbox is omitted. In addition, this type resolves the weight issue of the wind turbine with the light weight of gearbox. However, because of the low speed operation, this type has disadvantage such as the large diameter and heavy weight of generator. Super-Conducting (SC) wind power generator can reduce the weight and volume of a wind power system. Properties of superconducting wire are very different from each company. This paper considers the design and comparative analysis of 10 MW class SC wind power generators according to different types of SC wires. Super-Conducting Synchronous Generators (SCSGs) using YBCO and Bi-2223 wires are optimized by an optimal method. The magnetic characteristics of the SCSGs are investigated using the finite elements method program. The optimized specifications of the SCSGs are discussed in detail, and the optimization processes can be used effectively to develop large scale wind power generation systems.

  6. Magnetocaloric Materials and the Optimization of Cooling Power Density

    NASA Technical Reports Server (NTRS)

    Wikus, Patrick; Canavan, Edgar; Heine, Sarah Trowbridge; Matsumoto, Koichi; Numazawa, Takenori

    2014-01-01

    The magnetocaloric effect is the thermal response of a material to an external magnetic field. This manuscript focuses on the physics and the properties of materials which are commonly used for magnetic refrigeration at cryogenic temperatures. After a brief overview of the magnetocaloric effect and associated thermodynamics, typical requirements on refrigerants are discussed from a standpoint of cooling power density optimization. Finally, a compilation of the most important properties of several common magnetocaloric materials is presented.

  7. Full-power test of a string of magnets comprising a half-cell of the Superconducting Super Collider

    SciTech Connect

    Burgett, W.; Christianson, M.; Coombes, R.

    1992-10-01

    In this paper we describe the full-powered operation of a string of industrially-fabricated magnets comprising a half-cell of the Superconducting Super Collider (SSC). The completion of these tests marks the first successful operation of a major SSC subsystem. The five 15-m long dipole magnets in the string had an aperture of 50 mm and the single 5-m long quadrupole aperture was 40 mm. Power and cryogenic connections were made to the string through spool pieces that are prototypes for SSC operations. The string was cooled to cryogenic temperatures in early July, 1992, and power tests were performed at progressively higher currents up to the nominal SSC operating point above 6500 amperes achieved in mid-August. In this paper we report on the electrical and cryogenic performance of the string components and the quench protection system during these initial tests.

  8. Cooling options for high-average-power laser mirrors

    NASA Astrophysics Data System (ADS)

    Vojna, D.; Slezak, O.; Lucianetti, A.; Mocek, T.

    2015-01-01

    Thermally-induced deformations of steering mirrors reflecting 100 J/10 Hz laser pulses in vacuum have been analyzed. This deformation is caused by the thermal stress arisen due to parasitic absorption of 1 kW square-shaped flat-top laser beam in the dielectric multi-layer structure. Deformation depends on amount of absorbed power and geometry of the mirror as well as on the heat removal scheme. In our calculations, the following percentages of absorption of the incident power have been used: 1%, 0.5% and 0.1%. The absorbed power has been considered to be much higher than that expected in reality to assess the worst case scenario. Rectangular and circular mirrors made of zerodur (low thermal expansion glass) were considered for these simulations. The effect of coating layers on induced deformations has been neglected. Induced deformation of the mirror surface can significantly degrade the quality of the laser beam in the beam delivery system. Therefore, the proper design of the cooling scheme for the mirror in order to minimize the deformations is needed. Three possible cooling schemes of the mirror have been investigated. The first one takes advantage of a radiation cooling of the mirror and a copper heatsink fixed to the rear face of the mirror, the second scheme is based on additional heat conduction provided by flexible copper wires connected to the mirror holder, and the last scheme combines two above mentioned methods.

  9. Operational characteristic analysis of conduction cooling HTS SMES for Real Time Digital Simulator based power quality enhancement simulation

    NASA Astrophysics Data System (ADS)

    Kim, A. R.; Kim, G. H.; Kim, K. M.; Kim, D. W.; Park, M.; Yu, I. K.; Kim, S. H.; Sim, K.; Sohn, M. H.; Seong, K. C.

    2010-11-01

    This paper analyzes the operational characteristics of conduction cooling Superconducting Magnetic Energy Storage (SMES) through a real hardware based simulation. To analyze the operational characteristics, the authors manufactured a small-scale toroidal-type SMES and implemented a Real Time Digital Simulator (RTDS) based power quality enhancement simulation. The method can consider not only electrical characteristics such as inductance and current but also temperature characteristic by using the real SMES system. In order to prove the effectiveness of the proposed method, a voltage sag compensation simulation has been implemented using the RTDS connected with the High Temperature Superconducting (HTS) model coil and DC/DC converter system, and the simulation results are discussed in detail.

  10. Design of the fundamental power coupler and photocathode inserts for the 112MHz superconducting electron gun

    SciTech Connect

    Xin, T.; Ben-Zvi, I.; Belomestnykh, S.; Chang, X.; Rao, T.; Skaritka, J.; Wu, Q.; Wang, E.; Liang, X.

    2011-07-25

    A 112 MHz superconducting quarter-wave resonator electron gun will be used as the injector of the Coherent Electron Cooling (CEC) proof-of-principle experiment at BNL. Furthermore, this electron gun can be the testing cavity for various photocathodes. In this paper, we present the design of the cathode stalks and a Fundamental Power Coupler (FPC) designated to the future experiments. Two types of cathode stalks are discussed. Special shape of the stalk is applied in order to minimize the RF power loss. The location of cathode plane is also optimized to enable the extraction of low emittance beam. The coaxial waveguide structure FPC has the properties of tunable coupling factor and small interference to the electron beam output. The optimization of the coupling factor and the location of the FPC are discussed in detail. Based on the transmission line theory, we designed a half wavelength cathode stalk which significantly brings down the voltage drop between the cavity and the stalk from more than 5.6 kV to 0.1 kV. The transverse field distribution on cathode has been optimized by carefully choosing the position of cathode stalk inside the cavity. Moreover, in order to decrease the RF power loss, a variable diameter design of cathode stalk has been applied. Compared to the uniform shape of stalk, this design gives us much smaller power losses in important locations. Besides that, we also proposed a fundamental power coupler based on the designed beam parameters for the future proof-of-principle CEC experiment. This FPC should give a strong enough coupling which has the Q external range from 1.5e7 to 2.6e8.

  11. High power density reactors based on direct cooled particle beds

    SciTech Connect

    Powell, J.R.; Horn, F.L.

    1985-01-01

    Reactors based on direct cooled HTGR type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out long the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBR's) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed. 12 figs.

  12. Use of reclaimed water for power plant cooling.

    SciTech Connect

    Veil, J. A.; Environmental Science Division

    2007-10-16

    Freshwater demands are steadily increasing throughout the United States. As its population increases, more water is needed for domestic use (drinking, cooking, cleaning, etc.) and to supply power and food. In arid parts of the country, existing freshwater supplies are not able to meet the increasing demands for water. New water users are often forced to look to alternative sources of water to meet their needs. Over the past few years, utilities in many locations, including parts of the country not traditionally water-poor (e.g., Georgia, Maryland, Massachusetts, New York, and North Carolina) have needed to reevaluate the availability of water to meet their cooling needs. This trend will only become more extreme with time. Other trends are likely to increase pressure on freshwater supplies, too. For example, as populations increase, they will require more food. This in turn will likely increase demands for water by the agricultural sector. Another example is the recent increased interest in producing biofuels. Additional water will be required to grow more crops to serve as the raw materials for biofuels and to process the raw materials into biofuels. This report provides information about an opportunity to reuse an abundant water source -- treated municipal wastewater, also known as 'reclaimed water' -- for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Innovations for Existing Plants research program (Feeley 2005). This program initiated an energy-water research effort in 2003 that includes the availability and use of 'nontraditional sources' of water for use at power plants. This report represents a unique reference for information on the use of reclaimed water for power plant cooling. In particular, the database of reclaimed water user facilities described in Chapter 2 is the first comprehensive national effort to identify and catalog those plants that are using reclaimed water for cooling.

  13. A gas-cooled reactor surface power system

    SciTech Connect

    Lipinski, R.J.; Wright, S.A.; Lenard, R.X.; Harms, G.A.

    1999-01-01

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1{percent}Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars. {copyright} {ital 1999 American Institute of Physics.}

  14. A gas-cooled reactor surface power system

    SciTech Connect

    Lipinski, Ronald J.; Wright, Steven A.; Lenard, Roger X.; Harms, Gary A.

    1999-01-22

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.

  15. A Gas-Cooled Reactor Surface Power System

    SciTech Connect

    Harms, G.A.; Lenard, R.X.; Lipinski, R.J.; Wright, S.A.

    1998-11-09

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life- cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitide clad in Nb 1 %Zr, which has been extensively tested under the SP-I 00 program The fiel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fbel and stabilizing the geometty against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality cannot occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.

  16. A gas-cooled reactor surface power system

    NASA Astrophysics Data System (ADS)

    Lipinski, Ronald J.; Wright, Steven A.; Lenard, Roger X.; Harms, Gary A.

    1999-01-01

    A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.

  17. Ice Thermal Storage Systems for Nuclear Power Plant Supplemental Cooling and Peak Power Shifting

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2013-03-01

    Availability of cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. One potential solution is to use ice thermal storage (ITS) systems that reduce cooling water requirements and boost the plants thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses the ice for supplemental cooling during peak demand time. ITS also provides a way to shift a large amount of electricity from off peak time to peak time. For once-through cooling plants near a limited water body, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ITS systems can effectively reduce the efficiency loss during hot weather so that new plants could be considered in regions lack of cooling water. This paper will review light water reactor cooling issues and present the feasibility study results.

  18. Adopted Methodology for Cool-Down of SST-1 Superconducting Magnet System: Operational Experience with the Helium Refrigerator

    NASA Astrophysics Data System (ADS)

    Sahu, A. K.; Sarkar, B.; Panchal, P.; Tank, J.; Bhattacharya, R.; Panchal, R.; Tanna, V. L.; Patel, R.; Shukla, P.; Patel, J. C.; Singh, M.; Sonara, D.; Sharma, R.; Duggar, R.; Saxena, Y. C.

    2008-03-01

    The 1.3 kW at 4.5 K helium refrigerator / liquefier (HRL) was commissioned during the year 2003. The HRL was operated with its different modes as per the functional requirements of the experiments. The superconducting magnets system (SCMS) of SST-1 was successfully cooled down to 4.5 K. The actual loads were different from the originally predicted boundary conditions and an adjustment in the thermodynamic balance of the refrigerator was necessary. This led to enhanced capacity, which was achieved without any additional hardware. The required control system for the HRL was tuned to achieve the stable thermodynamic balance, while keeping the turbines' operating parameters at optimized conditions. An extra mass flow rate requirement was met by exploiting the margin available with the compressor station. The methodology adopted to modify the capacity of the HRL, the safety precautions and experience of SCMS cool down to 4.5 K, are discussed.

  19. Device for cooling a superconducting field winding and a damper shield of the rotor of an electric machine

    SciTech Connect

    Intichar, L.; Schnapper, C.; Weghaupt, E.

    1983-05-31

    A cooling device for a superconducting field winding of an electric machine, especially a turbo-generator, contains an exhaust gas line connected to a coolant space for cooling an end piece at the end face of a torque transmitting rotor body part as well as a coolant line extending along a damper shield arranged around the field winding. In order to utilize the liquid coolant in a particularly economical and simple manner, the coolant line of the damper shield is a section of the coolant exhaust gas line , and this section is arranged, as seen in the flow direction of the coolant exhaust gas, ahead of the line section of the torque transmitting end piece.

  20. 78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-12

    ... COMMISSION Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory Commission... revision to Regulatory Guide (RG), 1.68, ``Initial Test Programs for Water-Cooled Nuclear Power Plants... Initial Test Programs (ITPs) for light water cooled nuclear power plants. ADDRESSES: Please refer...

  1. Study on heat pipe sink for cooling high power LED

    NASA Astrophysics Data System (ADS)

    Wang, Zhibin; Zhang, Yuebin; Wang, Zhongdong; Xie, Shasha; Hao, Yang

    2012-10-01

    Considering the characteristic of energy-saving about high power LED device, a method to decrease the junction temperature greatly under the natural convection condition is studied in this article. Using the heat pipe technology, a cooling system is designed in which the target heat source is the LED module (0.025m0.025m0.005m), with 30W input power. The mechanism and routes of heat transfer are analyzed in detail, the thermal network model is established to calculate the thermal resistance of each part in the cooling system, the total thermal resistance was calculated to be 0.8964C /W and the junction temperature was 47.39C . Meanwhile, the finite element method was used to simulate this cooling system, and got that the junction temperature was 47.54C , and the error of the two means is only 0.15C , it indicates that applying heat-pipe technology can solve the problem of high junction temperature in LED devices under the natural convection conditions, which can guide the actual project in the thermal design.

  2. Power Handling Upgrade of Debuncher Stochastic Cooling Kicker Tanks

    SciTech Connect

    McGinnis, D.

    1991-06-01

    The Debuncher Stochastic Cooling Power Upgrade tripled the number of TWTs from 16 to 48. The power desired for each TWT is about 120 W. The debuncher stochastic cooling system contains 6 kicker tanks (4 short tanks, 2 long tanks) with a total number of 64 microwave feedthroughs. Thus, the power per feedthrough increased from 30W to 90 W as a result of the upgrade. The kicker array inside the vacuum tank is connected to the microwave feedthrough on the vacuum flange by means of a rigid 0.25-inch diameter coaxial cable which is 12-inch long. With 90 W flowing through the coax, the amount of power dissipated is 2.5 W. A lab test on a single debuncher kicker tank showed that this power dissipation caused the temperature of the coaxial cable to rise to greater than 175 C. At this point the Teflon dielectric of the coax and the solder joints in the coax might seriously degrade. As a temporary stop-gap solution, transistor heat sinks were placed around the outside of the coaxial cable. (The amount of heat sinks need for all the cables was 3400.) The primary function of the transistor heat sinks around the coaxial cable was to remove thermal energy generated in the coax by radiation. Lab tests showed that the with the heat sinks in place, the temperature of the coax was brought below 110 C. However, with the tanks installed, the maximum total amount of power that could be applied to the tanks and keep the ion pumps safely below their trip level (The trip level on the ion pumps is about 1 x 10{sup -6} Torr. We kept the ion pumps at about 3 x 10{sup -7} Torr.) was about 2250 W or 35 W per feedthrough. The ion pumps with the highest pressure in the kicker sector (D30) were D:IP202 and D:IP305. These pumps are mounted directly on the two long kicker tanks. These two long kicker tanks account for one half of the total microwave feedthroughs. Further bench studies showed that 2.5 W were also dissipated in the microwave vacuum feedthrough. This 2.5 W that was generated caused a large temperature rise in the vacuum feedthrough because of the poor heat sinking of the feedthrough. The poor heat sinking was the result of the stainless steel walled bellowed flange on which the feedthrough is mounted. To alleviate the vacuum problem. the two long kicker tanks were removed during the fall shutdown of 1990. The 32 bellowed flanges were replaced with solid flanges that mounted directly on the tank. The microwave feedthrough was welded into the flange and was heat sunk by means of a copper collar that screwed directly on to the feedthrough. The copper collar was cooled by chilled water. Because there are no bellows on the new flange design, the rigid 0.25-inch diam. coaxial cable was replaced by flexible, braided 0.141-inch diam. cable in order to allow a good vacuum seal. The flexible coaxial cable was heat sunk along most of its length by means of a 8-inch long copper collar. The collar itself was heat sunk to a 1-inch diameter copper bar that extended to outside the vacuum tank and was water cooled. The water cooling of the copper bar for each feedthrough was tied in series by 3/8-inch copper water line. The 3/8-inch copper water line itself was in series with the chilled water of the kicker tank. In this way, no flow was diverted from the chilled water into the kicker tank. The entire coax and flange assembly is shown in Fig. 1. As an added precaution, the elbow launcher on the array was water cooled by tapping off the kicker resistor chilled water cooling lines in side the vacuum tank. The extra lines were placed in series with the existing kicker resistor water lines so as not divert any flow from the kicker resistors. The water cooled lines were attached to the launcher elbow by means of a copper clip. With the above modifications in place, the temperature of each feedthrough coax could be kept under 60 C with an applied power of 90 W. Because of time constraints, the 4 short kicker tanks were not modified. Instead, the ratio of the power feeding the long tanks to the power feeding the short tanks was changed to 2:1. The power that could now be achieved while still keeping the ion pump pressure below 3 x 10{sup -78} Torr was now 3600 W which is 2/3 of the desired maximum power. This 3600 W corresponds to 75 W per feedthrough for the long tanks and 37.5 W per feedthrough for the short tanks. With the power to the short tanks off, a total power of 2700 W could be delivered to the 2 long tanks which corresponds to 84 W per feedthrough. Although it is difficult to separate the outgassing rates for the different tanks, it is believed that the limitation on the vacuum is now constrained by the shorter tanks. Thus, the above cooling scheme will be applied to the 4 short tanks after the fixed target run of 1991.

  3. Field cooling of a MgB2 cylinder around a permanent magnet stack: prototype for superconductive magnetic bearing

    NASA Astrophysics Data System (ADS)

    Perini, E.; Giunchi, G.

    2009-04-01

    The behaviour of bulk superconductors as levitators of permanent magnets (PMs) has been extensively studied for the textured YBCO high-temperature superconductor material, in the temperature range lower than 77 K, obtaining extremely high trapped fields but also experiencing limitations on the mechanical characteristics of the material and on the possibility to produce large objects. Alternatively, bulk MgB2, even if it is superconducting at lower temperatures, has fewer mechanical problems, when fully densified, and presents stable magnetization in the temperature range between 10 and 30 K. With the reactive Mg-liquid infiltration technique we have produced dense MgB2 bulk cylinders of up to 65 mm diameter and 100 mm height. This kind of cylinder can be consider as a prototype of a passive magnetic bearing for flywheels or other rotating electrical machines. We have conductively cooled one of these superconducting cylinders inside a specially constructed cryostat, and the levitation forces and stiffness, with respect to axial movements of various arrangements of the PM, have been measured as a function of the temperature below Tc. We verified the very stable characteristics of the induced magnetization after several cycles of relative movements of the PM and the superconducting cylinder.

  4. Solar-powered Rankine heat pump for heating and cooling

    NASA Technical Reports Server (NTRS)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  5. Analytical design of a superconducting magnetic energy storage for pulsed power peak

    SciTech Connect

    Netter, D.; Leveque, J.; Rezzoug, A.; Caron, J.P.; Sargos, F.M.

    1996-09-01

    A Superconducting Magnetic Energy Storage can be used to produce very high pulsed power peak. A superconducting coil is magnetically coupled with another coil linked to the load. During the storage phase, the current is constant. In order to transfer the energy to the load, the authors cause the quench of the superconducting coil. It is very important to know the efficiency of the transfer and how much energy is discharged in the Helium vessel. In this paper, they propose an analytical method which enables to calculate very quickly the electrical parameters of such a device.

  6. Power system stabilization by superconducting magnetic energy storage with solid-state phase shifter

    SciTech Connect

    Mitani, Y.; Uranaka, T.; Tsuji, K.

    1995-08-01

    In this paper, a new configuration of power system controller with a combination of superconducting magnetic energy storage and phase shifter, is proposed to improve the stability of a long distance bulk power transmission system. A power system stabilizing control scheme is also proposed. A related simulation shows that the proposed controller is effective for enhancement of power system stability independent of the location of controller in a long distance bulk power transmission system.

  7. NQR study of local structures and cooling rate dependent superconductivity in La sub 2 CuO sub 4+. delta

    SciTech Connect

    Reyes, A.P.; Ahrens, E.T.; Hammel, P.C.; Heffner, R.H.; Thompson, J.D.; Canfield, P.C.; Fisk, Z. ); Schirber, J.E. )

    1992-01-01

    Structural properties of oxygen-annealed polycrystals of La{sub 2}CuO{sub 4 + {delta}} ({delta}{approximately}0.03) have been studied using {sup 139}La NQR spectroscopy. Superconducting critical temperatures were found to depend on the rate of cooling through a narrow temperature range at about 195K. Preliminary analysis of the {sup 139}La NQR spectra suggest that the oxygen-rich phase-separated region is composed of two structurally distinct phases, both of which are metallic and super-conducting. One phase has a structure closely related to the stoichiometric oxygen-poor compound. The second shows a considerable amount of apical oxygen disorder, a large shift in NQR frequency {nu}{sub Q}, and a volume fraction which increases with cooling rate. The formation of the second phase below {minus}200K is indicative of the freezing Of CuO{sub 6} octahedral tilting. Abrupt shifts in {nu}{sub Q} above {Tc} were also observed for both phases, suggestive of a local structural anomaly or charge transfer to the Cu-O plane.

  8. Development of a High Field Superconducting Magnet Cooled by a 2 K Cryocooler (2) Characteristics of 2 K Cryocooler

    NASA Astrophysics Data System (ADS)

    Sato, A.; Nimori, S.; Maeda, M.; Nagai, H.; Matsumoto, F.; Takahashi, M.; Kuriyama, T.; Fujioka, T.; Ito, T.; Okamura, T.

    2004-06-01

    This paper describes the experimental results of a small 2 K Gifford-McMahon/Joule-Thomson type (GM/JT) cryocooler, which was used to cool a high-field superconducting magnet. We improved efficiency of the 2 K cryocooler by using a double Joule-Thomson (JT) valve. We also adopted a high capacity compressor to obtain over 1 W cooling capacity at 1.8 K. To reduce the cooling down time, we adopted a bypass line between the 1st stage heat exchanger and JT valve outlet. The 2 K-GM/JT cryocooler also has 4 K-operation mode, which is used for long time stand-by between 2 K-operation. Every switching between 4 K-mode and 2 K-mode needs many valve operations. To control cooling capacity of GM/JT cryocooler requires difficult manipulation of JT valves. To overcome this shortcoming, we developed an automatically controlling unit, which demonstrated easy operation.

  9. Development of a termination for the 77kV-class high Tc superconducting power cable

    SciTech Connect

    Shimonosono, T.; Nagaya, S.; Masuda, T.; Isojima, S.

    1997-01-01

    A termination for 77kV-class high Tc superconducting power cables was designed and fabricated. The termination is insulated with SF6 gas, nitrogen gas and liquid nitrogen and is cooled with liquid nitrogen. The current lead has a cross sectional area altered along its axis in order to decrease the heat inlet and to prevent SF6 gas from liquefying. The current lead is insulated with Ethylene-propylene Rubber (EPR) because it passes through nitrogen gas which has low dielectric strength in comparison with liquid nitrogen and SF6 gas. 200A AC current and 70 kV AC voltage to ground were successfully applied simultaneously for 40 hours in total. The measured heat loss of the termination, 9W is in good agreement with the calculated value. As the next step, the applied voltage was increased and the termination was confirmed to withstand the voltage up to 120 kV AC and 400kV Imp to ground.

  10. Development and demonstration of a high temperature superconducting power transmission cable system

    SciTech Connect

    Scudiere, J.D.; Buczek, D.M.; Miles, P.

    1997-06-01

    American Superconductor Corporation and its partners, Pirelli Cable Corporation and the Electric Power Research Institute, are developing a commercially viable high-temperature superconducting power transmission cable. In this phase of the program, two multistrand conductor assemblies will be made to verify the Bi-2223 HTS power transmission cable design. Six thousand meters of superconducting wire in tape form has been manufactured for the first multistrand conductor assembly (MCA). This tape has been thoroughly tested and results have exceeded the requirements for the first MCA. Some of the test results that are reported include critical current, mechanical properties, and environmental durability.

  11. Experimental study on using a high-temperature superconducting inductor for power loss reduction in an active power filter

    NASA Astrophysics Data System (ADS)

    Chao, C.; To, H. P.; Grantham, C.; Rahman, M. F.

    2006-06-01

    An active power filter improves the electric power quality through the compensation of harmonics in the power network. A current-source active power filter using a conventional copper inductor for its energy storage has a significant power loss. The loss in the copper inductor can be substantially reduced by using a high-temperature superconducting (HTS) inductor instead. Experiments have been conducted on a prototype current-source active power filter for studying the power loss reduction effect and harmonics compensation performance of the active power filter using a HTS inductor. Experimental results are analysed and discussed in this paper.

  12. Microgravity Spray Cooling Research for High Powered Laser Applications

    NASA Technical Reports Server (NTRS)

    Zivich, Chad P.

    2004-01-01

    An extremely powerful laser is being developed at Goddard Space Flight Center for use on a satellite. This laser has several potential applications. One application is to use it for upper atmosphere weather research. In this case, the laser would reflect off aerosols in the upper atmosphere and bounce back to the satellite, where the aerosol velocities could be calculated and thus the upper atmosphere weather patterns could be monitored. A second application would be for the US. Air Force, which wants to use the laser strategically as a weapon for satellite defense. The Air Force fears that in the coming years as more and more nations gain limited space capabilities that American satellites may become targets, and the laser could protect the satellites. Regardless of the ultimate application, however, a critical step along the way to putting the laser in space is finding a way to efficiently cool it. While operating the laser becomes very hot and must be cooled to prevent overheating. On earth, this is accomplished by simply running cool tap water over the laser to keep it cool. But on a satellite, this is too inefficient. This would require too much water mass to be practical. Instead, we are investigating spray cooling as a means to cool the laser in microgravity. Spray cooling requires much less volume of fluid, and thus could be suitable for use on a satellite. We have inherited a 2.2 second Drop Tower rig to conduct our research with. In our experiments, water is pressurized with a compressed air tank and sprayed through a nozzle onto our test plate. We can vary the pressure applied to the water and the temperature of the plate before an experiment trial. The whole process takes place in simulated microgravity in the 2.2 second Drop Tower, and a high speed video camera records the spray as it hits the plate. We have made much progress in the past few weeks on these experiments. The rig originally did not have the capability to heat the test plate, but I did some heat transfer calculations and picked out a heater to order for the rig. I learned QBasic programming language to change the operating code for our drops, allowing us to rapidly cycle the spray nozzle open and closed to study the effects. We have derived an equation for flow rate vs. pressure for our experiment. We have recorded several videos of drops at different pressures, some with heated test plate and some without, and have noticed substantial differences in the liquid behavior. I have also changed the computer program to write a file with temperature vs. time profiles for the test plate, and once the necessary thermocouple comes in (it was ordered last week), we will have temperature profiles to accompany the videos. Once we have these temperature profiles to go with the videos, we will be able to see how the temperature is affected by the spray at different pressures, and how the spray changes its behavior once as the plate changes from hot to cool. With quantitative temperature data, we can then mathematically model the heat transfer from the plate to the cooling spray. Finally, we can look at the differences between trials in microgravity and those in normal earth gravity.

  13. Insulation design of cryogenic bushing for superconducting electric power applications

    NASA Astrophysics Data System (ADS)

    Koo, J. Y.; Lee, Y. J.; Shin, W. J.; Kim, Y. H.; Kim, J. T.; Lee, B. W.; Lee, S. H.

    2013-01-01

    Recently, the superconductivity projects to develop commercial superconducting devices for extra high voltage transmission lines have been undergoing in many countries. One of the critical components to be developed for high voltage superconducting devices, including superconducting transformers, cables, and fault current limiters, is a high voltage bushing, to supply high current to devices without insulating difficulties, that is designed for cryogenic environments. Unfortunately, suitable bushings for HTS equipment were not fully developed for some cryogenic insulation issues. Such high voltage bushings would need to provide electrical insulation capabilities from room temperature to cryogenic temperatures. In this paper, design factors of cryogenic bushings were discussed and test results of specimen were introduced in detail. First, the dielectric strength of three kinds of metals has been measured with uniform and non-uniform electrodes by withstand voltage of impulse and AC breakdown test in LN2. Second, puncture breakdown voltage of glass fiber reinforced plastics (GFRPs) plates has been analyzed with non-uniform electrodes. Finally, creepage discharge voltages were measured according to the configuration of non-uniform and uniform electrode on the FRP plate. From the test results, we obtained the basic design factors of extra high voltage condenser bushing, which could be used in cryogenic environment.

  14. Power Conversion Study for High Temperature Gas-Cooled Reactors

    SciTech Connect

    Chang Oh; Richard Moore; Robert Barner

    2005-05-01

    The Idaho National Laboratory (INL) is investigating a Brayton cycle efficiency improvement on a high temperature gas-cooled reactor (HTGR) as part of Generation-IV nuclear engineering research initiative. There are some technical issues to be resolved before the selection of the final design of the high temperature gascooled reactor, called as a Next Generation Nuclear Plant (NGNP), which is supposed to be built at the INEEL by year 2017. The technical issues are the selection of the working fluid, direct vs. indirect cycle, power cycle type, the optimized design in terms of a number of intercoolers, and others. In this paper, we investigated a number of working fluids for the power conversion loop, direct versus indirect cycle, the effect of intercoolers, and other thermal hydraulics issues. However, in this paper, we present part of the results we have obtained. HYSYS computer code was used along with a computer model developed using Visual Basic computer language.

  15. Maximum allowable currents in YBa2Cu3O7 superconducting tapes as a function of the coating thickness, external magnetic field induction, and cooling conditions

    NASA Astrophysics Data System (ADS)

    Arkharov, A. M.; Dontsova, E. S.; Lavrov, N. A.; Romanovskii, V. R.

    2014-04-01

    Maximum allowable (ultimate) currents stably passing through an YBa2Cu3O7 superconducting current-carrying element are determined as a function of a silver (or copper) coating thickness, external magnetic field induction, and cooling conditions. It is found that if a magnetic system based on yttrium ceramics is cooled by a cryogenic coolant, currents causing instabilities (instability onset currents) are almost independent of the coating thickness. If, however, liquid helium is used as a cooling agent, the ultimate current monotonically grows with the thickness of the stabilizing copper coating. It is shown that depending on cooling conditions, the stable values of the current and electric field strength preceding the occurrence of instability may be both higher and lower than the a priori chosen critical parameters of the superconductor. These features should be taken into account in selecting the stable value of the operating current of YBa2Cu3O7 superconducting windings.

  16. Superconducting Tunnel Junction Refrigerators for Sub-Kelvin Cooling of Electrons, Phonons, and Arbitrary, User-Supplied Payloads

    NASA Astrophysics Data System (ADS)

    Lowell, Peter Joseph

    Modern science often requires measurements at sub-Kelvin temperatures. Temperatures of 300 mK can be reached by using liquid 3He, but reaching lower temperatures requires the use of adiabatic demagnetization and dilution refrigerators which are complex, large, and costly. Normal-metalInsulatorSuperconductor (NIS) tunnel junctions provide an alternative refrigeration method that is simple to use, compact, and provides continuous cooling power that has the potential to expand the accessibility of these sub-Kelvin temperatures. When properly biased, the electron system in the normal metal of an NIS junction is cooled since the hottest electrons preferentially tunnel from the normal metal to the superconductor, transferring heat in the process. When the normal metal is extended onto a thermally isolated membrane, the cold electrons cool the phonons in the membrane through electron-phonon coupling. In previous work, NIS junctions have been used to cool detectors and bulk objects that were integrated with the membrane, but could not be considered a general-purpose refrigerator since they could not cool arbitrary objects. The goal of this work has been to demonstrate a general-purpose NIS refrigerator to which a user can attach arbitrary bulk objects. First, we discuss NIS refrigeration and then develop a model to predict phonon cooling. We fabricated and tested NIS refrigerators capable of cooling bulk objects and used the model to explain the results. The devices were able to cool phonons from 300 mK to 154 mK with 100 pW of cooling power at 200 mK. With these devices, we were able to cool a 2 cm3 piece of copper from 290 mK to 256 mK with 700 pW of cooling power at 290 mK. This demonstration marks the emergence of NIS refrigerators as a true, general-purpose refrigerator since users can attach arbitrary objects. Measurements of Andreev reflections in the devices and next-generation refrigerators that cool electrons from 100 mK to below 50 mK are also presented.

  17. A coaxial HOM coupler for a superconducting RF cavity and its low-power measurement results

    NASA Astrophysics Data System (ADS)

    Sun, An; Tang, Ya-Zhe; Zhang, Li-Ping; Li, Ying-Min; Han-Sung, Kim

    2011-03-01

    A resonant buildup of beam-induced fields in a superconducting radio frequency (RF) cavity may make a beam unstable or a superconducting RF cavity quench. Higher-order mode (HOM) couplers are used for damping higher-order modes to avoid such a resonant buildup. A coaxial HOM coupler based on the TTF (TESLA Test Facility) HOM coupler has been designed for the superconducting RF cavities at the Proton Engineering Frontier Project (PEFP) in order to overcome notch frequency shift and feed-through tip melting issues. In order to confirm the HOM coupler design and finalize its structural dimensions, two prototype HOM couplers have been fabricated and tested. Low-power testing and measurement of the HOM couplers has shown that the HOM coupler has good filter properties and can fully meet the damping requirements of the PEFP low-beta superconducting RF linac.

  18. RF design and processing of a power coupler for third harmonic superconducting cavities

    SciTech Connect

    Li, Jianjian; Harms, Elvin; Kubicki, Tom; Nicklaus, Dennis; Olis, Daniel; Prieto, Peter; Reid, John; Solyak, Nikolay; Wong, Thomas; /IIT, Chicago

    2007-06-01

    The FLASH user facility providing free electron laser radiation is built based on the TTF project at DESY. Fermilab has the responsibility for the design and processing of a third harmonic, 3.9 GHz, superconducting cavity which is powered via a coaxial power coupler. Six power couplers have been manufactured at CPI after successful design of the power coupler including RF simulation, multipacting calculation, and thermal analysis. The power couplers are being tested and processed with high pulsed power in an elaborate test stand at Fermilab now. This paper presents the RF design and processing work of the power coupler.

  19. Non-Cooled Power System for Venus Lander

    NASA Technical Reports Server (NTRS)

    Salazar, Denise; Landis, Geoffrey A.; Colozza, Anthony J.

    2014-01-01

    The Planetary Science Decadal Survey of 2013-2022 stated that the exploration of Venus is of significant interest. Studying the seismic activity of the planet is of particular importance because the findings can be compared to the seismic activity of Earth. Further, the geological and atmospheric properties of Venus will shed light into the past and future of Earth. This paper presents a radioisotope power system (RPS) design for a small low-power Venus lander. The feasibility of the new power system is then compared to that of primary batteries. A requirement for the power source system is to avoid moving parts in order to not interfere with the primary objective of the mission - to collect data about the seismic activity of Venus using a seismometer. The target mission duration of the lander is 117 days, a significant leap from Venera 13, the longest-lived lander on the surface of Venus, which survived for 2 hours. One major assumption for this mission design is that the power source system will not provide cooling to the other components of the lander. This assumption is based on high-temperature electronics technology that will enable the electronics and components of the lander to operate at Venus surface temperature. For the proposed RPS, a customized General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHSRTG) is designed and analyzed. The GPHS-RTG is chosen primarily because it has no moving parts and it is capable of operating for long duration missions on the order of years. This power system is modeled as a spherical structure for a fundamental thermal analysis. The total mass and electrical output of the system are calculated to be 24 kilograms and 26 Watts, respectively. An alternative design for a battery-based power system uses Sodium Sulfur batteries. To deliver a similar electrical output for 117 days, the battery mass is calculated to be 234 kilograms. Reducing mission duration or power required will reduce the required battery mass. Finally, the advantages and disadvantages of both power systems with regard to science return, risk, and cost are briefly compared. The design of the radioisotope power system is considerably riskier because it is novel and would require additional years of further refinement, manufacturing, safety analysis, and testing that the primary batteries do not need. However, the lifetime of the radioisotope power system makes its science return more promising.

  20. THERMAL STRESS CALCULATIONS FOR HEATPIPE-COOLED REACTOR POWER SYSTEMS.

    SciTech Connect

    Kapernick, R. J.; Guffee, R. M.

    2001-01-01

    A heatpipe-cooled fast reactor concept has been under development at Los Alamos National Laboratory for the past several years, to be used as a power source for nuclear electric propulsion (NEP) or as a planetary surface power system. The reactor core consists of an array of modules that are held together by a core lateral restraint system. Each module comprises a single heatpipe surrounded by 3-6 clad fuel pins. As part of the design development and performance assessment activities for these reactors, specialized methods and models have been developed to perform thermal and stress analyses of the core modules. The methods have been automated so that trade studies can be readily performed, looking at design options such as module size, heatpipe and clad thickness, use of sleeves to contain the fuel, material type, etc. This paper describes the methods and models that have been developed, and presents thermal and stress analysis results for a Mars surface power system and a NEP power source.

  1. Low-Cost Superconducting Wire for Wind Generators: High Performance, Low Cost Superconducting Wires and Coils for High Power Wind Generators

    SciTech Connect

    2012-01-01

    REACT Project: The University of Houston will develop a low-cost, high-current superconducting wire that could be used in high-power wind generators. Superconducting wire currently transports 600 times more electric current than a similarly sized copper wire, but is significantly more expensive. The University of Houstons innovation is based on engineering nanoscale defects in the superconducting film. This could quadruple the current relative to todays superconducting wires, supporting the same amount of current using 25% of the material. This would make wind generators lighter, more powerful and more efficient. The design could result in a several-fold reduction in wire costs and enable their commercial viability of high-power wind generators for use in offshore applications.

  2. The Cost of Helium Refrigerators and Coolers for SuperconductingDevices as a Function of Cooling at 4 K

    SciTech Connect

    Green, Michael A.

    2007-08-27

    This paper is an update of papers written in 1991 and in1997 by Rod Byrns and this author concerning estimating the cost ofrefrigeration for superconducting magnets and cavities. The actual costsof helium refrigerators and coolers (escalated to 2007 dollars) areplotted and compared to a correlation function. A correlation functionbetween cost and refrigeration at 4.5 K is given. The capital cost oflarger refrigerators (greater than 10 W at 4.5 K) is plotted as afunction of 4.5-K cooling. The cost of small coolers is plotted as afunction of refrigeration available at 4.2 K. A correlation function forestimating efficiency (percent of Carnot) of both types of refrigeratorsis also given.

  3. Thermal analysis of the forced cooled conductor for the TF (toroidal field) superconducting coils in the TIBER II ETR design

    SciTech Connect

    Kerns, J.A.; Slack, D.S.; Miller, J.R.

    1987-06-11

    The Tokamak Ignition/Burn Experimental Reactor (TIBER) is being designed to provide nuclear testing capabilities for first wall and blanket design concepts. The baseline design for TIBER II is to provide steady-state nuclear burn capabilities. These objectives must be met using reactor relevant components, such as state-of-the-art current drive schemes coupled with superconducting toroidal field (TF) and poloidal field (PF) coils. The design is also constrained to be cost effective, which forces the machine to be as small as possible. This last constraint limits the nuclear shielding in TIBER. Therefore, the TF coils will have a high nuclear heat load of up to 4.5 kW per coil. The cooling scheme and the thermal analysis for this design are presented.

  4. Conceptual design of MgB2 coil for the 100 MJ SMES of advanced superconducting power conditioning system (ASPCS)

    NASA Astrophysics Data System (ADS)

    Atomura, Naoki; Takahashi, Toshinori; Amata, Hiroto; Iwasaki, Tatsuya; Son, Kyoungwoo; Miyagi, Daisuke; Tsuda, Makoto; Hamajima, Takataro; Shintomi, Takakazu; Makida, Yasuhiro; Takao, Tomoaki; Munakata, Kohe; Kajiwara, Masataka

    In order to reduce global carbon-dioxide in the world, we propose an Advanced Superconducting Power Conditioning System (ASPCS) which is composed of 5 MW renewable energy resources and 1 MW hybrid storage system. The hybrid storage system is composed of FC-H2-EL and SMES which is installed adjacent to a LH2 station for vehicles. Since the SMES can be operated at 20 K which is a saturated temperature of LH2, we can use MgB2 superconductors. In the ASPCS, 100 MJ storage capacities of the SMES should be required. This paper focuses on studies into a conceptual design of SMES toroidal coil composed of the MgB2 and indirectly cooled by LH2.

  5. Kinetic model for the chlorination of power plant cooling waters

    SciTech Connect

    Johnson, J.D.; Qualls, R.G.

    1983-01-01

    Concern over the environmental effects of chlorination has prompted efforts to minimize the amount of chlorine necessary to prevent fouling of power-plant condensers. Kinetic expressions are developed for the short-term reactions of chlorine consumption by organic substances in natural freshwater. These expressions were developed to use in a kinetic model to predict the free and total available chlorine discharged in cooling water. This model uses commonly available water-quality data. It assumes that most of the chlorine-consuming substances are: (1) NH/sub 3/, (2) chloramine-forming organic-N, and (3) humic substances. It uses the Morris-Wei model of chlorine-ammonia reactions. Chloramine formation from organic-N was represented by a model compound, glycylglycine.

  6. A role for high frequency superconducting devices in free space power transmission systems

    NASA Technical Reports Server (NTRS)

    Christian, Jose L., Jr.; Cull, Ronald C.

    1988-01-01

    Major advances in space power technology are being made in photovoltaic, solar thermal, and nuclear systems. Despite these advances, the power systems required by the energy and power intensive mission of the future will be massive due to the large collecting surfaces, large thermal management systems, and heavy shielding. Reducing this mass on board the space vehicle can result in significant benefits because of the high cost of transporting and moving mass about in space. An approach to this problem is beaming the power from a point where the massiveness of the power plant is not such a major concern. The viability of such an approach was already investigated. Efficient microwave power beam transmission at 2.45 GHz was demonstrated over short range. Higher frequencies are desired for efficient transmission over several hundred or thousand kilometers in space. Superconducting DC-RF conversion as well as RF-DC conversion offers exciting possibilities. Multivoltage power conditioning for multicavity high power RF tubes could be eliminated since only low voltages are required for Josephson junctions. Small, high efficiency receivers may be possible using the reverse Josephson effects. A conceptual receiving antenna design using superconducting devices to determine possible system operating efficiency is assessed. If realized, these preliminary assessments indicate a role for superconducting devices in millimeter and submillimeter free space power transmission systems.

  7. A role for high frequency superconducting devices in free space power transmission systems

    NASA Astrophysics Data System (ADS)

    Christian, Jose L., Jr.; Cull, Ronald C.

    1988-04-01

    Major advances in space power technology are being made in photovoltaic, solar thermal, and nuclear systems. Despite these advances, the power systems required by the energy and power intensive mission of the future will be massive due to the large collecting surfaces, large thermal management systems, and heavy shielding. Reducing this mass on board the space vehicle can result in significant benefits because of the high cost of transporting and moving mass about in space. An approach to this problem is beaming the power from a point where the massiveness of the power plant is not such a major concern. The viability of such an approach was already investigated. Efficient microwave power beam transmission at 2.45 GHz was demonstrated over short range. Higher frequencies are desired for efficient transmission over several hundred or thousand kilometers in space. Superconducting DC-RF conversion as well as RF-DC conversion offers exciting possibilities. Multivoltage power conditioning for multicavity high power RF tubes could be eliminated since only low voltages are required for Josephson junctions. Small, high efficiency receivers may be possible using the reverse Josephson effects. A conceptual receiving antenna design using superconducting devices to determine possible system operating efficiency is assessed. If realized, these preliminary assessments indicate a role for superconducting devices in millimeter and submillimeter free space power transmission systems.

  8. Introduction to progress and promise of superconductivity for energy storage in the electric power sector

    SciTech Connect

    Wolsky, A.M.

    1998-05-01

    Around the world, many groups conduct research, development and demonstration (RD and D) to make storage an economic option for the electric power sector. The progress and prospects for the application of superconductivity, with emphasis on high-temperature superconductivity, to the electric power sector has been the topic of an IEA Implementing Agreement, begun in 1990. The present Task members are Canada, Denmark, Finland, Germany, Israel, Italy, Japan, Korea, the Netherlands, Norway, Sweden, Switzerland, Turkey, the United Kingdom and the US. As a result of the Implementing Agreement, work has been done by the Operating Agent with the full participation of all the member countries. This work has facilitated the exchange of informtion among experts in all countries and has documented relevant assessments. Further, this work has reviewed the status of SMES and is now updating same, as well as investigating the progress on and prospects for flywheels with superconducting bearings. The Operating Agent and Task members find a substantially different set of opportunities for and alternatives to storage than was the case before the 1987 discovery of high-temperature superconductivity. Beside the need to level generation, there is also the need to level the load on transmission lines, increase transmission stability, and increase power quality. These needs could be addressed by high power storage that could be brought in and out of the grid in fractions of a second. Superconducting Magnetic Energy Storage and flywheels with superconducting bearings are devices that deserve continued RD and D because they promise to be the needed storage devices.

  9. Over Current Properties of HTC Superconducting Wire Cooled by Liquid Hydrogen

    NASA Astrophysics Data System (ADS)

    Shirai, Yasuyuki; Kobayashi, Hiroto; Takegami, Taiki; Hikawa, Kyosuke; Shiotsu, Masahiro; Tatsumoto, Hideki; Naruo, Yoshihiro; Kobayashi, Hiroaki; Inatani, Yoshifumi; Kinoshita, Katsuhiko

    An experimental setup which can energize superconducting wires immersed in LH2 was designed and made. Over current tests were carried out using MgB2 wire. Critical current and resistivity of a test MgB2 wire submerged in liquid hydrogen were measured for exponentially increasing heat input, while the transport current exceeded the critical current. The resistivity of the conductor was obtained as a function of current and the temperature of the conductor by using the transient heating method. The distribution ratio of the current through the superconductor and the sheath, and the resistivity of the MgB2 conductor itself were estimated.

  10. Portable self-contained power and cooling system

    SciTech Connect

    McCullough, J.E.

    1993-07-20

    A portable power and cooling system is described comprising: a drive unit including a combustion section, a scroll-type expander section, a scroll-type air compressor section, and a power output drive shaft, the expander and air compressor sections connected together for synchronousmovement via said power output drive shaft; said combustion section including a combustion air inlet and a combustion gas outlet, said scroll-type expander section including at least one pair of meshed axially extending involute spiral wrap members having involute centers and defining at least one expansion chamber between them that moves radially between an expander inlet zone, which is in fluid communicatino with the combustion gas outlet, and an outlet zone when one wrap member is orbited along a circular path about an orbit center relative to the other wrap member, said scroll type air compressor section including at least one pair of meshed axially extending involute spiral wrap members having involute centers and defining at least one compression chamber between them that moves radially between a compressor inlet zone and an outlet zone, which is in fluid communication with the combustion air inlet of the combustoin section, when one wrap member is orbited along a circular path relative to the other wrap member about an orbit radius, said drive connecting unit integrally connecting said one wrap member of each of said scroll-type expander and air compressor sections; means for causing combustion within said combustion chamber such that the products of combustion are expanded by said scroll-type expander section and exhausted out said expander outlet, air is drawn into said air compressor inlet zone, compressed within, expelled through said air compressor outlet zone, and delivered to said combustoin chamber and said power output shaft is rotated; a refrigeration system, a refrigerant condenser, a refrigerant expansion valve and a refrigerant evaporator, and a conduit.

  11. Design of an improved high cooling power 4 K GM cryocooler and helium compressor

    NASA Astrophysics Data System (ADS)

    Hao, X. H.

    2015-12-01

    High cooling power 4 K cryocoolers are in high demand given their broad applications in such fields as magnetic resonance imaging (MRI) and low temperature superconductors. ARS has recently designed and developed a high cooling power 4 K pneumatic-drive GM cryocooler which achieves a typical cooling power of 1.75 W/4.2 K. Steady input power of our newly developed helium compressor supplied to the cold head is 11.8 kW at 60 Hz. The operational speed of the cold head is 30 RPM. The effects of geometries and operational conditions on the cooling performance of this 4 K GM cryocooler are also experimentally tested.

  12. Study on Stability of Superconducting Coil Cooled by Subcooled He I and He II at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Ohya, M.; Shirai, Y.; Shiotsu, M.; Imagawa, S.

    2004-06-01

    Stability tests were performed of small test coils using two kinds of superconducting wire wound respectively on a FRP or a SUS bobbin. One wire is 0.50 mm-diameter NbTi composite wire with the copper ratio of 1.3, and with no insulation film. The other wire is a 0.80 mm-diameter NbTi composite wire with the copper ratio of 6.5, and with the PVF insulation. The stability limit was determined as the maximum direct current that could be applied to the test coil without spreading of a normal zone after giving a pulse current to a small heater located at a center part of the test coil winding. The stability limits were obtained for magnetic fields from 1.1 T to 7.6 T and bulk liquid temperatures from 1.6 K to 4.2 K at atmospheric pressure. The critical current at the stability limit under a constant magnetic field increased slightly with the decrease of liquid He temperature from 4.2 K down to near the ?-temperature. The stability limit increased dramatically by shifting to He II cooling from He I cooling. The degradation of heat transfer in the Kapitza conductance regime was observed on the wire with insulation film, and was not seen on the wire with no insulation film.

  13. Superconducting RF Cavity Measurement Formulae for an Exponential Decayed Pulse Incident Power

    SciTech Connect

    Sun An; Haipeng Wang

    2005-07-10

    Experimental method for evaluating a Superconducting RF (SRF) cavity performance is through low power and high power measurements without a beam load. The equations for square incident power pulse are the most popular formulae for the pulsed mode measurements. In practice, incident power may not be exactly square pulse. To understand cavity behavior and performance more accurately, in this paper, the SRF cavity's measurement equations for an exponential-decayed pulsed incident power are developed from a series equivalent circuit. The analytical result can be directly compared with the experimental data of SNS cavities obtained from the Cryomodule Test Facility (CMTF) at Jefferson Lab.

  14. Prospective of Applications of Superconducting Fault Current Limiters in Chinese Power Grids

    NASA Astrophysics Data System (ADS)

    Chen, Z. L.; Gong, W. Z.; Ren, A. L.; Zi, M. R.; Xiong, Z. Q.; Si, D. J.; Ye, F.

    China is home to the world's second largest electric power industry, and has plans to modernize its power network into a robust and efficient grid. Short-circuit fault current control becomes increasingly important to the power grid modernization process. Superconducting fault current limiters (SFCLs) may contribute significantly to the solution to the fault current problem. This paper discusses the demands and challenges in the application of SFCLs to Chinese power grids, from the perspective of the present situation and taking into consideration future developments of the electric power industry. Technical and economical comparisons with conventional fault current control technologies are presented

  15. Gas-cooled reactor for space power systems

    SciTech Connect

    Walter, C.E.; Pearson, J.S.

    1987-05-01

    Reactor characteristics based on extensive development work on the 500-MWt reactor for the Pluto nuclear ramjet are described for space power systems useful in the range of 2 to 20 MWe for operating times of 1 y. The modest pressure drop through the prismatic ceramic core is supported at the outlet end by a ceramic dome which also serves as a neutron reflector. Three core materials are considered which are useful at temperatures up to about 2000 K. Most of the calculations are based on a beryllium oxide with uranium dioxide core. Reactor control is accomplished by use of a burnable poison, a variable-leakage reflector, and internal control rods. Reactivity swings of 20% are obtained with a dozen internal boron-10 rods for the size cores studied. Criticality calculations were performed using the ALICE Monte Carlo code. The inherent high-temperature capability of the reactor design removes the reactor as a limiting condition on system performance. The low fuel inventories required, particularly for beryllium oxide reactors, make space power systems based on gas-cooled near-thermal reactors a lesser safeguard risk than those based on fast reactors.

  16. USE of mine pool water for power plant cooling.

    SciTech Connect

    Veil, J. A.; Kupar, J. M .; Puder, M. G.

    2006-11-27

    Water and energy production issues intersect in numerous ways. Water is produced along with oil and gas, water runs off of or accumulates in coal mines, and water is needed to operate steam electric power plants and hydropower generating facilities. However, water and energy are often not in the proper balance. For example, even if water is available in sufficient quantities, it may not have the physical and chemical characteristics suitable for energy or other uses. This report provides preliminary information about an opportunity to reuse an overabundant water source--ground water accumulated in underground coal mines--for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL), which has implemented a water/energy research program (Feeley and Ramezan 2003). Among the topics studied under that program is the availability and use of ''non-traditional sources'' of water for use at power plants. This report supports NETL's water/energy research program.

  17. 14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1045 Cooling test procedures for turbine engine...

  18. 14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1045 Cooling test procedures for turbine engine...

  19. 14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1045 Cooling test procedures for turbine engine...

  20. 14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1045 Cooling test procedures for turbine engine...

  1. 14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1045 Cooling test procedures for turbine engine...

  2. Pathogenic amoebae in power-plant cooling lakes. Final report

    SciTech Connect

    Tyndall, R.L.; Willaert, E.; Stevens, A.R.

    1981-06-01

    Cooling waters and associated algae and sediments from four northern and four southern/western electric power plants were tested for the presence of pathogenic amoebae. Unheated control waters and algae/sediments from four northern and five southern/western sites were also tested. When comparing results from the test versus control sites, a significantly higher proportion (P less than or equal to 0.05) of the samples from the test sites were positive for thermophilic amoeba, thermophilic Naegleria and pathogenic Naegleria. The difference in number of samples positive for thermophilic Naegleria between heated and unheated waters, however, was attributable predominantly to the northern waters and algae/sediments. While two of four northern test sites yielded pathogenic Naegleria, seven of the eight isolates were obtained from one site. Seasonality effects relative to the isolation of the pathogen were also noted at this site. One pathogen was isolated from a southwestern test site. Pathogens were not isolated from any control sites. Some of the pathogenic isolates were analyzed serologically and classified as pathogenic Naegleria fowleri. Salinity, pH, conductivity, and bacteriological profiles did not obviously correlate with the presence or absence of pathogenic Naegleria. While thermal addition was significantly associated with the presence of thermophilic Naegleria (P less than or equal to 0.05), the data implicate other as yet undefined parameters associated with the presence of the pathogenic thermophile. Until further delineation of these parameters is effected, generalizations cannot be made concerning the effect of thermal impact on the growth of pathogenic amoeba in a particular cooling system.

  3. One Hundred Years of Superconductivity: Superconducting Materials and Electric Power Applications (465th Brookhaven Lecture)

    SciTech Connect

    Li, Qiang

    2011-01-19

    It was one hundred years ago this year that Dutch physicist Heike Kamerlingh Onnes discovered that by lowering the temperature of mercury to a blistering cold four degrees Kelvin, the metal became a “superconductor” and allowed electricity to flow through it with very little, if any, resistance. Fast forward one hundred years: now we are looking for new ways to store and transport energy — energy we can use to get from one place to another, stay comfortable when the weather outside is not, grow enough healthy food to feed the population, and sustain our ways of life — all while trying to protect the planet. Superconductors, with their potential to be über-energy efficient, are likely to play a crucial role in solving these challenges, and researchers at Brookhaven Lab are figuring out just how it can be done. Li will begin his talk with an overview of the first one hundred years of exploring superconductivity. He will also discuss the challenges of developing new superconductors and improving their performance for real-world energy applications, and then explain how basic science researchers at BNL are addressing those challenges.

  4. At the Frontiers of Science Superconductivity and Its Electric Power Applications

    SciTech Connect

    1998-07-01

    Electricity - it is one of our modern scientific miracles, and today we could not imagine living without it. But what if we could make it better? Superconductivity has the potential to do just that, by improving the capacity, quality, and reliability of products that use electricity. There has been a great deal of discussion about superconductivity in the last 10 years, but what exactly is it? In this document you will learn the definition of superconductivity, how it works, and its present and potential uses. You will also get an inside look at the challenges that scientists around the world are working to overcome in order to fully incorporate superconductivity in our everyday lives. When you turn on a lamp at home, the electric current flows - is conducted - through a wire made of copper or aluminum. Along the way, this wire resists the flow of electricity, and this resistance is something very much like friction. The resistance causes some of the electricity to be lost in the form of heat. Which means that every time you use an appliance, from a radio to a generator, you are not getting 100% of the energy that flows through it; some of it is wasted by the conductor. Superconductivity - the ability of a material to conduct electricity without losses to resistance - is a physical property inherent to a variety of metals and ceramics, much the same way magnetism is present in a variety of materials. It is dependent on temperature; that is, a material will not exhibit superconductivity until it is sufficiently cold. The necessary temperatures to induce superconductivity are well below what we might commonly consider 'cold.' They are so low, in fact, that they are measured using the Kelvin temperature scale (K). Absolute zero, or 0 K, is equal to -459 Fahrenheit (F). It is defined as the lowest temperature theoretically possible, or the complete absence of heat. In 1911, working in a laboratory in Holland, the Dutch scientist Heike Kamerlingh Onnes cooled mercury to 4 K (-452 F), almost absolute zero; at this temperature, the motion of individual atoms nearly ceased. Scientists were unsure what effect this extremely low temperature would have on resistance; most suspected resistance would increase as atomic motion slowed. However, during routine measurements of the mercury, it appeared that there was no electrical resistance. Onnes assumed his equipment was broken, but days later he confirmed that, near absolute zero, mercury did completely lose electrical resistance. Onnes had discovered superconductivity.

  5. Modeling Single-Phase and Boiling Liquid Jet Impingement Cooling in Power Electronics

    SciTech Connect

    Narumanchi, S. V. J.; Hassani, V.; Bharathan, D.

    2005-12-01

    Jet impingement has been an attractive cooling option in a number of industries over the past few decades. Over the past 15 years, jet impingement has been explored as a cooling option in microelectronics. Recently, interest has been expressed by the automotive industry in exploring jet impingement for cooling power electronics components. This technical report explores, from a modeling perspective, both single-phase and boiling jet impingement cooling in power electronics, primarily from a heat transfer viewpoint. The discussion is from the viewpoint of the cooling of IGBTs (insulated-gate bipolar transistors), which are found in hybrid automobile inverters.

  6. RF Conditioning and Testing of Fundamental Power Couplers for SNS Superconducting Cavity Production

    SciTech Connect

    M. Stirbet; G.K. Davis; M. A. Drury; C. Grenoble; J. Henry; G. Myneni; T. Powers; K. Wilson; M. Wiseman; I.E. Campisi; Y.W. Kang; D. Stout

    2005-05-16

    The Spallation Neutron Source (SNS) makes use of 33 medium beta (0.61) and 48 high beta (0.81) superconducting cavities. Each cavity is equipped with a fundamental power coupler, which should withstand the full klystron power of 550 kW in full reflection for the duration of an RF pulse of 1.3 msec at 60 Hz repetition rate. Before assembly to a superconducting cavity, the vacuum components of the coupler are submitted to acceptance procedures consisting of preliminary quality assessments, cleaning and clean room assembly, vacuum leak checks and baking under vacuum, followed by conditioning and RF high power testing. Similar acceptance procedures (except clean room assembly and baking) were applied for the airside components of the coupler. All 81 fundamental power couplers for SNS superconducting cavity production have been RF power tested at JLAB Newport News and, beginning in April 2004 at SNS Oak Ridge. This paper gives details of coupler processing and RF high power-assessed performances.

  7. Design report for an indirectly cooled 3-m diameter superconducting solenoid for the Fermilab Collider Detector Facility

    SciTech Connect

    Fast, R.; Grimson, J.; Kephart, R.

    1982-10-01

    The Fermilab Collider Detector Facility (CDF) is a large detector system designed to study anti pp collisions at very high center of mass energies. The central detector for the CDF shown employs a large axial magnetic field volume instrumented with a central tracking chamber composed of multiple layers of cylindrical drift chambers and a pair of intermediate tracking chambers. The purpose of this system is to determine the trajectories, sign of electric charge, and momenta of charged particles produced with polar angles between 10 and 170 degrees. The magnetic field volume required for tracking is approximately 3.5 m long an 3 m in diameter. To provide the desired ..delta..p/sub T/p/sub T/ less than or equal to 1.5% at 50 GeV/c using drift chambers with approx. 200..mu.. resolution the field inside this volume should be 1.5 T. The field should be as uniform as is practical to simplify both track finding and the reconstruction of particle trajectories with the drift chambers. Such a field can be produced by a cylindrical current sheet solenoid with a uniform current density of 1.2 x 10/sup 6/ A/m (1200 A/mm) surrounded by an iron return yoke. For practical coils and return yokes, both central electromagnetic and central hadronic calorimetry must be located outside the coil of the magnet. This geometry requires that the coil and the cryostat be thin both in physical thickness and in radiation and absorption lengths. This dual requirement of high linear current density and minimal coil thickness can only be satisfied using superconducting technology. In this report we describe the design for an indirectly cooled superconducting solenoid to meet the requirements of the Fermilab CDF. The components of the magnet system are discussed in the following chapters, with a summary of parameters listed in Appendix A.

  8. The Use of a Solid State Analog Television Transmitter as a Superconducting Electron Gun Power Amplifier

    SciTech Connect

    J.G. Kulpin, K.J. Kleman, R.A. Legg

    2012-07-01

    A solid state analog television transmitter designed for 200 MHz operation is being commissioned as a radio frequency power amplifier on the Wisconsin superconducting electron gun cavity. The amplifier consists of three separate radio frequency power combiner cabinets and one monitor and control cabinet. The transmitter employs rugged field effect transistors built into one kilowatt drawers that are individually hot swappable at maximum continuous power output. The total combined power of the transmitter system is 33 kW at 200 MHz, output through a standard coaxial transmission line. A low level radio frequency system is employed to digitally synthesize the 200 MHz signal and precisely control amplitude and phase.

  9. Site-dependent factors affecting the economic feasibility of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1977-01-01

    A procedure has been developed which can be used to determine the economic feasibility of solar powered absorption cooling systems. This procedure has been used in a study to investigate the influence of the site-dependent parameters on the economic feasibility of solar absorption cooling. The purpose of this study was to make preliminary site selections for solar powered absorption cooling systems. This paper summarizes the results of that study.

  10. Simulation of cooling-water discharges from power plants.

    PubMed

    Wu, J; Buchak, E M; Edinger, J E; Kolluru, V S

    2001-01-01

    Accurate simulation of the temperature distribution in a cooling lake or reservoir is often required for feasibility studies of engineering options that increase the cooling capacity of the waterbody. A three-dimensional hydrodynamic and temperature model has been developed and applied to several cooling lakes in the south-eastern United States. In this paper, the details of the modeling system are presented, along with the application to the Flint Creek Lake. PMID:11381460

  11. Mechanical Analysis of High Power Internally Cooled Annular Fuel

    SciTech Connect

    Zhao Jiyun; No, Hee Cheon; Kazimi, Mujid S.

    2004-05-15

    Annular fuel with internal flow is proposed to allow higher power density in pressurized water reactors. The structural behavior issues arising from the higher flow rate required to cool the fuel are assessed here, including buckling, vibrations, and potential wear problems. Five flow-induced vibration mechanisms are addressed: buckling instability, vortex-induced vibration, acoustic resonance, fluid-elastic instability, and turbulence-induced vibration. The structural behavior of the 17 x 17 traditional solid fuel array is compared with that of two types of annular fuels, a 15 x 15 array, and a 13 x 13 array.It is seen that the annular fuels are superior to the reference fuel in avoiding vibration-induced damage, even at a 50% increase in flow velocity above today's reactors. The higher resistance to vibration is mainly due to their relatively larger cross section area making them more rigid. The 13 x 13 annular fuel shows better structural performance than the 15 x 15 one due to its higher rigidity. Analysis of acoustic resonance of the inner channel cladding with pump blade passing frequencies showed that the acoustic frequencies are within 120% of the pulsation frequency. The annular fuel exhibits reduced impact, sliding, and fretting wear than the solid fuel, even at 150% flow rate of today's reactors.

  12. Spray cooling characteristics of nanofluids for electronic power devices.

    PubMed

    Hsieh, Shou-Shing; Leu, Hsin-Yuan; Liu, Hao-Hsiang

    2015-01-01

    The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5mm with a definite nozzle-to-target surface distance of 25mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9??10(-4)kg/cm(2)s. PMID:25852429

  13. Spray cooling characteristics of nanofluids for electronic power devices

    NASA Astrophysics Data System (ADS)

    Hsieh, Shou-Shing; Leu, Hsin-Yuan; Liu, Hao-Hsiang

    2015-03-01

    The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm2 with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10-4 kg/cm2s.

  14. Remote Measurement of Heat Flux from Power Plant Cooling Lakes

    SciTech Connect

    Garrett, A.; Kurzeja, R.; Villa-Aleman, E.; Bollinger, J.

    2013-01-01

    Laboratory experiments have demonstrated a correlation between the rate of heat loss q″ from an experimental fluid to the air above and the standard deviation σ of the thermal variability in images of the fluid surface. These experimental results imply that q″ can be derived directly from thermal imagery by computing σ. This paper analyses thermal imagery collected over two power plant cooling lakes to determine if the same relationship exists. Turbulent boundary layer theory predicts a linear relationship between q″ and σ when both forced (wind driven) and free (buoyancy driven) convection are present. Datasets derived from ground- and helicopter-based imagery collections had correlation coefficients between σ and q″ of 0.45 and 0.76, respectively. Values of q″ computed from a function of σ and friction velocity u* derived from turbulent boundary layer theory had higher correlations with measured values of q″ (0.84 and 0.89). This research may be applicable to the problem of calculating losses of heat from the ocean to the atmosphere during high-latitude cold-air outbreaks because it does not require the information typically needed to compute sensible, evaporative, and thermal radiation energy losses to the atmosphere.

  15. The impact of high temperature superconductivity on the electric power sector

    SciTech Connect

    Wolsky, A.M.

    1996-01-01

    The progress and prospects for the application of high temperature superconductivity to the Electric Power Sector has been the topic of an IEA Implementing Agreement, begun in 1990. The present Task Members are Canada, Denmark, Finland, Germany, Israel, Italy, Japan, Netherlands, Norway, Sweden, Switzerland, Turkey, United Kingdom and the United States. As a result of the Implementing Agreement, work has been done by the Operating Agent with the full participation of all the member countries. This work has facilitated the exchange of information among experts in all countries and has documented relevant assessments. Further, this work has examined the status of high amperage conductor, fault-current limiters, superconducting magnetic energy storage, cables, rotating machines, refrigeration, and studies of the power system. The Task Members find more progress toward applications than many expected five years ago and the grounds for further international collaboration to hasten the use of superconductors in the power sector, early in the 21st century.

  16. 14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1047 Cooling test procedures for reciprocating engine powered airplanes. Compliance with 23.1041 must be shown for the climb (or, for multiengine airplanes...

  17. 14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1047 Cooling test procedures for reciprocating engine powered airplanes. Compliance with 23.1041 must be shown for the climb (or, for multiengine airplanes...

  18. 14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling 23.1047 Cooling test procedures for reciprocating engine powered airplanes. Compliance with 23.1041 must be shown for the climb (or, for multiengine airplanes...

  19. 77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ... COMMISSION Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory Commission...) is issuing for public comment draft regulatory guide (DG), DG-1259, ``Initial Test Programs for Water... considers acceptable for Initial Test Programs (ITPs) for light water cooled nuclear power plants....

  20. Noise and Bandwidth Measurements of Diffusion-Cooled Nb Hot-Electron Bolometer Mixers at Frequencies Above the Superconductive Energy Gap

    NASA Technical Reports Server (NTRS)

    Wyss, R. A.; Karasik, B. S.; McGrath, W. R.; Bumble, B.; LeDuc, H.

    1999-01-01

    Diffusion-cooled Nb hot-electron bolometer (HEB) mixers have the potential to simultaneously achieve high intermediate frequency (IF) bandwidths and low mixer noise temperatures for operation at THz frequencies (above the superconductive gap energy). We have measured the IF signal bandwidth at 630 GHz of Nb devices with lengths L = 0.3, 0.2, and 0.1 micrometer in a quasioptical mixer configuration employing twin-slot antennas. The 3-dB EF bandwidth increased from 1.2 GHz for the 0.3 gm long device to 9.2 GHz for the 0.1 gm long device. These results demonstrate the expected 1/L squared dependence of the IF bandwidth at submillimeter wave frequencies for the first time, as well as the largest EF bandwidth obtained to date. For the 0.1 gm device, which had the largest bandwidth, the double sideband (DSB) noise temperature of the receiver was 320-470 K at 630 GHz with an absorbed LO power of 35 nW, estimated using the isothermal method. A version of this mixer with the antenna length scaled for operation at 2.5 THz has also been tested. A DSB receiver noise temperature of 1800 plus or minus 100 K was achieved, which is about 1,000 K lower than our previously reported results. These results demonstrate that large EF bandwidth and low-noise operation of a diffusion-cooled HEB mixer is possible at THz frequencies with the same device geometry.

  1. Design and cost estimate of an 800 MVA superconducting power transmission

    SciTech Connect

    Alex, P.; Ernst, A. ); Forsyth, E.; Gibbs, R.; Thomas, R.; Muller, T. )

    1990-10-18

    Numerous studies involving cost estimates have been performed for superconducting power transmission systems. As these systems were usually aimed at providing transmission from large clusters of generation the base power rating of the corridor was very high; in the case of the most comprehensive study it was 10,000 MVA. The purpose of this study is to examine a system which is very closely based on the prototype 1000 MVA system which was operated at Brookhaven National Laboratory over a four year period. The purpose of the study is to provide cost estimates for the superconducting system and to compare these estimates with a design based on the use of advanced but conventional cable designs. The work is supported by funding from the Office of Energy Research's Industry/Laboratory Technology Exchange Program. This program is designed to commercialize energy technologies. The technical design of the superconducting system was prepared by the BNL staff, the design of the 800 MVA conventional cable system was done by engineers from Underground Systems Incorporated. Both institutions worked on the cost estimate of the superconducting system. The description and cost estimate of the conventional cable system is given in the Appendix. 5 refs.

  2. Self-driven cooling loop for a large superconducting magnet in space

    NASA Technical Reports Server (NTRS)

    Mord, A. J.; Snyder, H. A.

    1992-01-01

    Pressurized cooling loops in which superfluid helium circulation is driven by the heat being removed have been previously demonstrated in laboratory tests. A simpler and lighter version which eliminates a heat exchanger by mixing the returning fluid directly with the superfluid helium bath was analyzed. A carefully designed flow restriction must be used to prevent boiling in this low-pressure system. A candidate design for Astromag is shown that can keep the magnet below 2.0 K during magnet charging. This gives a greater margin against accidental quench than approaches that allow the coolant to warm above the lambda point. A detailed analysis of one candidate design is presented.

  3. Consideration of sub-cooled LN2 circulation system for HTS power machines

    NASA Astrophysics Data System (ADS)

    Yoshida, Shigeru; Hirai, Hirokazu; Nara, N.; Nagasaka, T.; Hirokawa, M.; Okamoto, H.; Hayashi, H.; Shiohara, Y.

    2012-06-01

    We consider a sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The planned circulation system consists of a sub-cool heat exchanger (subcooler) and a circulation pump. The sub-cooler will be connected to a neon turbo- Brayton cycle refrigerator with a cooling power of 2 kW at 65 K. Sub-cooled LN will be delivered into the sub-cooler by the pump and cooled within it. Sub-cooled LN is adequate fluid for cooling HTS power equipment, because its dielectric strength is high and it supports a large critical current. However, a possibility of LN solidification in the sub-cooler is a considerable issue. The refrigerator will produce cold neon gas of about 60 K, which is lower than the nitrogen freezing temperature of 63 K. Therefore, we designed two-stage heat exchangers which are based on a plate-fin type and a tube-intube type. Process simulations of those heat exchangers indicate that sub-cooled LN is not frozen in either sub-cooler. The plate-fin type sub-cooler is consequently adopted for its reliability and compactness. Furthermore, we found that a cooling system with a Brayton refrigerator has the same total cooling efficiency as a cooling system with a Stirling refrigerator.

  4. Use of Cooling Thermal Storage as a Heat Sink for Steam Power Plant

    NASA Astrophysics Data System (ADS)

    Hegazy, Ahmed Sabry

    In the present paper, a system is proposed for improving the performance of steam power plant with air-cooled condenser during peak loads. In this system, the power plant comprises two steam turbines, and the air-cooled condenser is replaced by two condensers. The first one is air-cooled (dry) and used for condensing the exhaust steam of the first turbine, while the second is water-cooled and serves to condense the steam outlet of the second turbine. The warm cooling water exiting the wet condenser is pumped to a cooling storage container, where it is cooled and re-circulated to the wet condenser. Cooling is produced by a refrigeration machine driven by the extra electric power generated by the two turbines during the time of the off-peak-loads (low electricity rates). Simple energy analyses have been developed to predict the energy characteristics of this system. The results of this paper showed that the proposed system leads to improving the plant power output at peak-loads. About 6, 16, 24 and 33% increase in generated plant power can be achieved at peak-loads (high electricity rates) when the ambient temperature is 20, 30, 40 and 50C respectively, and the whole steam exiting both turbines is cooled in a wet condenser to a design temperature of 20C. The results showed also that choice of the capacity of each turbine is essentially affected by the quality of the refrigeration machine and ambient temperature.

  5. Engineering development of superconducting RF linac for high-power applications

    SciTech Connect

    Dominic Chan, K.C.; Rusnak, B.; Gentzlinger, R.C.; Campbell, B.M.; Kelley, J.P.; Safa, H.

    1998-12-31

    High-power proton linacs are a promising source of neutrons for material processing and research applications. Superconducting radiofrequency (SCRF) Rf linac technology is preferred for such applications because of power efficiency. A multi-year engineering development program is underway at Los Alamos National Laboratory to demonstrate the required SCRF technology. The program consists of development of SC cavities, power couplers, and cryomodule integration. Prototypes will be built and operated to obtain performance and integration information, and for design improvement. This paper describes the scope and present status of the development program.

  6. Sub-cooled liquid nitrogen cryogenic system with neon turbo-refrigerator for HTS power equipment

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Hirai, H.; Nara, N.; Ozaki, S.; Hirokawa, M.; Eguchi, T.; Hayashi, H.; Iwakuma, M.; Shiohara, Y.

    2014-01-01

    We developed a prototype sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The system consists of a neon turbo-Brayton refrigerator with a LN sub-cooler and LN circulation pump unit. The neon refrigerator has more than 2 kW cooling power at 65 K. The LN sub-cooler is a plate-fin type heat exchanger and is installed in a refrigerator cold box. In order to carry out the system performance tests, a dummy cryostat having an electric heater was set instead of a HTS power equipment. Sub-cooled LN is delivered into the sub-cooler by the LN circulation pump and cooled within it. After the sub-cooler, sub-cooled LN goes out from the cold box to the dummy cryostat, and comes back to the pump unit. The system can control an outlet sub-cooled LN temperature by adjusting refrigerator cooling power. The refrigerator cooling power is automatically controlled by the turbo-compressor rotational speed. In the performance tests, we increased an electric heater power from 200 W to 1300 W abruptly. We confirmed the temperature fluctuation was about 1 K. We show the cryogenic system details and performance test results in this paper.

  7. Radiation Heat Measurement on Thermally-Isolated Double-Pipe for DC Superconducting Power Transmission

    NASA Astrophysics Data System (ADS)

    Hamabe, M.; Nasu, Y.; Ninomiya, A.; Ishiguro, Y.; Kusaka, S.; Yamaguchi, S.

    2008-03-01

    Multilayer insulator (MLI) is a strong tool for use as a radiation heat shield, though the use of MLI has disadvantages in construction and evacuation for a long superconducting power cable. We have proposed the "MLI-free" radiation heat shielding for DC superconducting power cable and have measured the radiation heat transfer for thermally-isolated double-pipes with different surfaces. Here, Zn coating, MLI, and Al-foil sheet were tested. Consequently, from the radiation heat of 9.7 W/m for bare stainless-steel pipe, Zn-coated stainless-steel surface reduced to 2.6 W/m, whereas the use of MLI reduced to 0.2 W/m. It is expected that the simultaneous use of Zn coating and MLI can reduce the number of total MLI sheets to reduce the evacuation time.

  8. Magnetic Energy Storage System: Superconducting Magnet Energy Storage System with Direct Power Electronics Interface

    SciTech Connect

    2010-10-01

    GRIDS Project: ABB is developing an advanced energy storage system using superconducting magnets that could store significantly more energy than todays best magnetic storage technologies at a fraction of the cost. This system could provide enough storage capacity to encourage more widespread use of renewable power like wind and solar. Superconducting magnetic energy storage systems have been in development for almost 3 decades; however, past devices were designed to supply power only for short durationsgenerally less than a few minutes. ABBs system would deliver the stored energy at very low cost, making it ideal for eventual use in the electricity grid as a costeffective competitor to batteries and other energy storage technologies. The device could potentially cost even less, on a per kilowatt basis, than traditional lead-acid batteries.

  9. New 50 Hz superconducting power supply for a 2 kA DC magnet

    NASA Astrophysics Data System (ADS)

    Shevchenko, Oleg A.; Ten Kate, Herman H. J.; Krooshoop, Erik J. G.; Markovsky, Nick V.

    1994-07-01

    A new superconducting power supply able to operate directly from the mains voltage at a frequency of 50-60 Hz is under development in our institutes. institutes.It will be applied to power a separator iron ore recycling. The supply consists of a full wave superconducting converter, a 'cold' protection system, and control and measuring units. Typical design values of the device are: output current of 1-2 kA, voltage of 1-0.5 V; input current of 7 A, voltage of 220 V and frequency of 50 Hz; an efficiency better than 96%. The high current part of the supply finally will be placed in the same cryostat as the separator magnet. The basic concept of the device is presented in the paper.

  10. State of the Art Power Couplers for Superconducting RF Cavities

    SciTech Connect

    Isidoro Campisi

    2002-08-01

    Simulations are now routinely performed that allow the prediction of electromagnetic, multipacting, thermal, and mechanical properties of couplers. From these studies, better designs have been conceived which can minimize potential problems ahead of construction. Judicious use of materials and the implementation of clean practices and of careful conditioning have gradually increased the power levels at which couplers can safely operate. Machine operation at hundreds of kilowatts has been achieved in CW at KEK and Cornell, and in a pulsed mode at the TESLA Test Facility (TTF). Test stand operations in CW at the megawatt level (Accelerator for the Production of Tritium) and in pulse mode at a peak power of 2 MW (Spallation Neutron Source, TTF version II) have been achieved. The recent progress indicates that the understanding of the behavior of fundamental power couplers is rapidly increasing and that optimal designs are being developed which will allow in the future to attain routine attainment of the megawatt power levels necessary for high-beam-power machines under construction and under study.

  11. Experimental Study on Active Cooling Systems Used for Thermal Management of High-Power Multichip Light-Emitting Diodes

    PubMed Central

    2014-01-01

    The objective of this study was to develop suitable cooling systems for high-power multichip LEDs. To this end, three different active cooling systems were investigated to control the heat generated by the powering of high-power multichip LEDs in two different configurations (30 and 2 15?W). The following cooling systems were used in the study: an integrated multi-fin heat sink design with a fan, a cooling system with a thermoelectric cooler (TEC), and a heat pipe cooling device. According to the results, all three systems were observed to be sufficient for cooling high-power LEDs. Furthermore, it was observed that the integrated multifin heat sink design with a fan was the most efficient cooling system for a 30?W high-power multichip LED. The cooling system with a TEC and 46?W input power was the most efficient cooling system for 2 15?W high-power multichip LEDs. PMID:25162058

  12. Experimental study on active cooling systems used for thermal management of high-power multichip light-emitting diodes.

    PubMed

    Kaya, Mehmet

    2014-01-01

    The objective of this study was to develop suitable cooling systems for high-power multichip LEDs. To this end, three different active cooling systems were investigated to control the heat generated by the powering of high-power multichip LEDs in two different configurations (30 and 2 × 15 W). The following cooling systems were used in the study: an integrated multi-fin heat sink design with a fan, a cooling system with a thermoelectric cooler (TEC), and a heat pipe cooling device. According to the results, all three systems were observed to be sufficient for cooling high-power LEDs. Furthermore, it was observed that the integrated multifin heat sink design with a fan was the most efficient cooling system for a 30 W high-power multichip LED. The cooling system with a TEC and 46 W input power was the most efficient cooling system for 2 × 15 W high-power multichip LEDs. PMID:25162058

  13. Termination for a superconducting power transmission line including a horizontal cryogenic bushing

    DOEpatents

    Minati, Kurt F. (Northport, NY); Morgan, Gerry H. (Patchogue, NY); McNerney, Andrew J. (Shoreham, NY); Schauer, Felix (Upton, NY)

    1984-01-01

    A termination for a superconducting power transmission line is disclosed which is comprised of a standard air entrance insulated vertical bushing with an elbow, a horizontal cryogenic bushing linking the pressurized cryogenic cable environment to the ambient temperature bushing and a stress cone which terminates the cable outer shield and transforms the large radial voltage gradient in the cable dielectric into a much lower radial voltage gradient in the high density helium coolant at the cold end of the cryogenic bushing.

  14. Horizontal cryogenic bushing for the termination of a superconducting power-transmission line

    DOEpatents

    Minati, K.F.; Morgan, G.H.; McNerney, A.J.; Schauer, F.

    1982-07-29

    A termination for a superconducting power transmission line is disclosed which is comprised of a standard air entrance insulated vertical bushing with an elbow, a horizontal cryogenic bushing linking the pressurized cryogenic cable environment to the ambient temperature bushing and a stress cone which terminated the cable outer shield and transforms the large radial voltage gradient in the cable dielectric into a much lower radial voltage gradient in the high density helium coolant at the cold end of the cryogenic bushing.

  15. MODEL AND BEAM BASED SETUP PROCEDURES FOR A HIGH POWER HADRON SUPERCONDUCTING LINAC

    SciTech Connect

    Shishlo, Andrei P

    2014-01-01

    This presentation will review methods for experimental determination of optimal operational set points in a multi-cavity superconducting high power hadron linac. A typical tuning process is based on comparison between measured data and the results of simulations from envelope and single-particle models. Presence of significant space charge effects requires simulation and measurement of bunch dynamics in 3 dimensions to ensure low loss beam transport. This is especially difficult in a superconducting linac where use of interceptive diagnostics is usually restricted because of the risk of SRF cavity surface contamination. The procedures discussed here are based on non-interceptive diagnostics such as beam position monitors and laser wires, and conventional diagnostics devices such as wire scanners and bunch shape monitors installed outside the superconducting linac. The longitudinal Twiss analysis based on the BPM signals will be described. The superconducting SNS linac tuning experience will be used to demonstrate problems and their solution for real world linac tune-up procedures

  16. Hybrid liquid metal-water cooling system for heat dissipation of high power density microdevices

    NASA Astrophysics Data System (ADS)

    Deng, Yueguang; Liu, Jing

    2010-12-01

    The recent decades have witnessed a remarkable advancement of very large scale integrated circuits (VLSI) and electronic equipments in micro-electronic industry. Meanwhile, the ever increasing power density of microdevices leads to the tough issue that thermal management becomes rather hard to solve. Conventional water cooling is widely used, but the convective coefficient is not high enough. Liquid metal owns much higher convective coefficient and has been identified as an effective coolant recently, but the high cost greatly precludes its large scale utilization. In this paper, a hybrid liquid metal-water cooling system which combines the advantages of both water and liquid metal cooling was proposed and demonstrated. By utilizing a liquid metal "heat spreader" in front of the water cooling module, this system not only owns more excellent cooling capability than that based on water alone, but also has much lower initial cost compared with absolute liquid metal cooling system. A series of experiments under different operation conditions have been performed to evaluate the cooling performance of this hybrid system. The compared results with absolute water cooling and liquid metal cooling system showed that the cooling capability of the new system is competitive with absolute liquid metal cooling, but the initial cost could be much lower. The theoretical thermal resistance model and economic feasibility also have been analyzed and discussed, which shows that the hybrid liquid metal-water cooling system is quite feasible and useful.

  17. Cryogenics Vision Workshop for High-Temperature Superconducting Electric Power Systems Proceedings

    SciTech Connect

    Energetics, Inc.

    2000-01-01

    The US Department of Energy's Superconductivity Program for Electric Systems sponsored the Cryogenics Vision Workshop, which was held on July 27, 1999 in Washington, D.C. This workshop was held in conjunction with the Program's Annual Peer Review meeting. Of the 175 people attending the peer review meeting, 31 were selected in advance to participate in the Cryogenics Vision Workshops discussions. The participants represented cryogenic equipment manufactures, industrial gas manufacturers and distributors, component suppliers, electric power equipment manufacturers (Superconductivity Partnership Initiative participants), electric utilities, federal agencies, national laboratories, and consulting firms. Critical factors were discussed that need to be considered in describing the successful future commercialization of cryogenic systems. Such systems will enable the widespread deployment of high-temperature superconducting (HTS) electric power equipment. Potential research, development, and demonstration (RD and D) activities and partnership opportunities for advancing suitable cryogenic systems were also discussed. The workshop agenda can be found in the following section of this report. Facilitated sessions were held to discuss the following specific focus topics: identifying Critical Factors that need to be included in a Cryogenics Vision for HTS Electric Power Systems (From the HTS equipment end-user perspective) identifying R and D Needs and Partnership Roles (From the cryogenic industry perspective) The findings of the facilitated Cryogenics Vision Workshop were then presented in a plenary session of the Annual Peer Review Meeting. Approximately 120 attendees participated in the afternoon plenary session. This large group heard summary reports from the workshop session leaders and then held a wrap-up session to discuss the findings, cross-cutting themes, and next steps. These summary reports are presented in this document. The ideas and suggestions raised during the Workshop will be used by the DOE Superconductivity Program for Electric Systems in preparing subsequent planning and strategy documents such as a Cryogenic Technology Development Roadmap.

  18. Calorimeter for measuring AC losses in HTS cables for superconducting power transmission lines

    NASA Astrophysics Data System (ADS)

    Daney, D. E.; Boenig, H. J.; Maley, M. P.; Fleshler, S.

    1999-06-01

    We have developed a calorimeter with a sensitivity of better than 1 mW/m for measuring AC losses in HTS multi-strand conductors for superconducting power transmission lines over a temperature range of 64 K to 80 K. By choosing a temperature difference technique we eliminate the need for corrections due to heating at the cable end connections. Use of a three-phase configuration allows measurement of single-phase, three-phase, and coupling losses. The 60 Hz calorimeter power supply has a capacity of 2500 A rms.

  19. Fast, low-power manipulation of spin ensembles in superconducting microresonators

    SciTech Connect

    Sigillito, A. J. Malissa, H.; Tyryshkin, A. M.; Houck, A. A.; Lyon, S. A.; Riemann, H.; Abrosimov, N. V.; Becker, P.; Pohl, H.-J.; Thewalt, M. L. W.; Itoh, K. M.; Morton, J. J. L.; Schuster, D. I.

    2014-06-02

    We demonstrate the use of high-Q superconducting coplanar waveguide (CPW) microresonators to perform rapid manipulations on a randomly distributed spin ensemble using very low microwave power (400 nW). This power is compatible with dilution refrigerators, making microwave manipulation of spin ensembles feasible for quantum computing applications. We also describe the use of adiabatic microwave pulses to overcome microwave magnetic field (B{sub 1}) inhomogeneities inherent to CPW resonators. This allows for uniform control over a randomly distributed spin ensemble. Sensitivity data are reported showing a single shot (no signal averaging) sensitivity to 10{sup 7} spins or 310{sup 4}spins/?(Hz) with averaging.

  20. Disorder-induced power-law response of a superconducting vortex on a plane

    NASA Astrophysics Data System (ADS)

    Shapira, N.; Lamhot, Y.; Shpielberg, O.; Kafri, Y.; Ramshaw, B. J.; Bonn, D. A.; Liang, Ruixing; Hardy, W. N.; Auslaender, O. M.

    2015-09-01

    We report drive-response experiments on individual superconducting vortices on a plane, a realization for a (1+1)-dimensional directed polymer in random media. For this we use magnetic force microscopy to image and manipulate individual vortices trapped on a twin boundary in YBa2Cu3O7 -? near optimal doping. We find that when we drag a vortex with the magnetic tip, it moves in a series of jumps. As theory suggests, the jump-size distribution does not depend on the applied force and is consistent with power-law behavior. The measured power is much larger than widely accepted theoretical calculations.

  1. WET/DRY COOLING SYSTEMS FOR FOSSIL-FUELED POWER PLANTS: WATER CONSERVATION AND PLUME ABATEMENT

    EPA Science Inventory

    The report gives results of a study of technical and economic feasibilities of wet/dry cooling towers for water conservation and vapor plume abatement. Results of cost optimizations of wet/dry cooling for 1000-MWe fossil-fueled power plants are presented. Five sites in the wester...

  2. Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2010-06-01

    Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be built at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic benefits and avoid forced derating and shutdown during extremely hot weather. For the new plants using dry cooling towers, adding the ice thermal storage systems can effectively reduce the efficiency loss and water consumption during hot weather so that new LWRs could be considered in regions without enough cooling water. \\ This paper presents the feasibility study of using ice thermal storage systems for LWR supplemental cooling and peak power shifting. LWR cooling issues and ITS application status will be reviewed. Two ITS application case studies will be presented and compared with alternative options: one for once-through cooling without enough cooling for short time, and the other with dry cooling. Because capital cost, especially the ice storage structure/building cost, is the major cost for ITS, two different cost estimation models are developed: one based on scaling method, and the other based on a preliminary design using Building Information Modeling (BIM), an emerging technology in Architecture/Engineering/Construction, which enables design options, performance analysis and cost estimating in the early design stage.

  3. Flux-transfer losses in helically wound superconducting power cables

    SciTech Connect

    Clem, John R.; Malozemoff, A.P.

    2013-06-25

    Minimization of ac losses is essential for economic operation of high-temperature superconductor (HTS) ac power cables. A favorable configuration for the phase conductor of such cables has two counter-wound layers of HTS tape-shaped wires lying next to each other and helically wound around a flexible cylindrical former. However, if magnetic materials such as magnetic substrates of the tapes lie between the two layers, or if the winding pitch angles are not opposite and essentially equal in magnitude to each other, current distributes unequally between the two layers. Then, if at some point in the ac cycle the current of either of the two layers exceeds its critical current, a large ac loss arises from the transfer of flux between the two layers. A detailed review of the formalism, and its application to the case of paramagnetic substrates including the calculation of this flux-transfer loss, is presented.

  4. Flux-transfer losses in helically wound superconducting power cables

    NASA Astrophysics Data System (ADS)

    Clem, John R.; Malozemoff, A. P.

    2013-08-01

    Minimization of ac losses is essential for economic operation of high-temperature superconductor (HTS) ac power cables. A favorable configuration for the phase conductor of such cables has two counter-wound layers of HTS tape-shaped wires lying next to each other and helically wound around a flexible cylindrical former. However, if magnetic materials such as magnetic substrates of the tapes lie between the two layers, or if the winding pitch angles are not opposite and essentially equal in magnitude to each other, current distributes unequally between the two layers. Then, if at some point in the ac cycle the current of either of the two layers exceeds its critical current, a large ac loss arises from the transfer of flux between the two layers. A detailed review of the formalism, and its application to the case of paramagnetic substrates including the calculation of this flux-transfer loss, is presented.

  5. Optimized use of superconducting magnetic energy storage for electromagnetic rail launcher powering

    NASA Astrophysics Data System (ADS)

    Badel, Arnaud; Tixador, Pascal; Arniet, Michel

    2012-01-01

    Electromagnetic rail launchers (EMRLs) require very high currents, from hundreds of kA to several MA. They are usually powered by capacitors. The use of superconducting magnetic energy storage (SMES) in the supply chain of an EMRL is investigated, as an energy buffer and as direct powering source. Simulations of direct powering are conducted to quantify the benefits of this method in terms of required primary energy. In order to enhance further the benefits of SMES powering, a novel integration concept is proposed, the superconducting self-supplied electromagnetic launcher (S3EL). In the S3EL, the SMES is used as a power supply for the EMRL but its coil serves also as an additional source of magnetic flux density, in order to increase the thrust (or reduce the required current for a given thrust). Optimization principles for this new concept are presented. Simulations based on the characteristics of an existing launcher demonstrate that the required current could be reduced by a factor of seven. Realizing such devices with HTS cables should be possible in the near future, especially if the S3EL concept is used in combination with the XRAM principle, allowing current multiplication.

  6. Large-scale experimental evaluation of an advanced concept for dry/wet cooling of power stations

    SciTech Connect

    Johnson, B.M.; Zaloudek, F.R.; Fricke, H.D.; Helenbrook, R.G.; Bartz, J.A.

    1980-01-01

    Recognizing the need to conserve water in power plant cooling, several programs have been undertaken to study the performance and economics of dry cooling systems. The goals of these programs for improved dry cooling system design, new processes for combined wet/dry cooling, cost savings for advanced all-day cooling systems, and plans for testing materials and components of air cooled systems are discussed. (LCL)

  7. EVALUATION OF EUROPEAN RIVERS FOR POWER PLANT COOLING - A POLISH RESEARCH PROJECT

    EPA Science Inventory

    The report describes analytical, laboratory, and field research conducted to optimize the use of rivers, specifically in Poland, for once-through cooling of steam electric power plants. Maximum discharge and receiving water temperatures, based on biological criteria, are coupled ...

  8. Sport fishery potential of power plant cooling ponds: Final report

    SciTech Connect

    Heidinger, R.C.; Lewis, W.M.

    1986-10-01

    This research was undertaken to determine if cooling ponds could serve as habitat for several coolwater fish species and also to evaluate the potential use of cooling ponds as nursery areas for receiving waters. The work was conducted on two cooling ponds in northern Illinois. Walleye (Stizostedion vitreum), muskellunge (Esox masquinongy), striped bass (Morone saxatilis) fingerlings, and adult threadfin shad (Dorosoma petenense) were stocked into both cooling ponds. The hybrids between the striped bass and white bass (M. chrysops) had been previously stocked into Collins Pond. Smallmouth bass (Micropterus dolomieui) fingerlings and larval striped bass and walleye were stocked in Dresden Pond. Several sampling techniques including seining, electrofishing, and rotenoning were used to monitor growth and survival of stocked species. In addition, escapement of stocked and indigenous species was monitored at the Dresden Pond spillway. Walleye, muskellunge, striped bass and hybrid striped bass exhibited excellent growth in Collins Pond as did smallmouth bass in Dresden Pond. One of the primary differences between an open system (such as Dresden Pond) and a closed system (such as Collins Pond) is the potential that the open system has to serve as a fish nursery area for receiving waters. The stocking of ''coolwater'' species in a closed type system such as Collins Pond is an effective way to control and maintain selected sport species. Dresden Pond was not open to public fishing during this study, but Collins Pond developed an excellent sport fishery as a result of these stockings.

  9. Impact of cool storage air-conditioning in commercial sector on power system operation in Thailand

    SciTech Connect

    Surapong, C.; Bundit, L.

    1997-05-01

    The results are presented from an investigation into the potential application for cool storage air-conditioning, and the resultant beneficial impact on power system operation in Thailand is discussed. Field assessment through interviews with decision makers in the identified customer groups produces results that show good potential for cool storage application. Results from a computer program used to calculate power production cost and other characteristics show that substantial benefits would also accrue to the generating utility.

  10. Refrigeration system for superfluid-cooled 21 T magnet and 40 T hybrid magnets at TML

    NASA Astrophysics Data System (ADS)

    Matsumoto, F.; Nagai, H.; Kiyoshi, T.; Sato, A.; Kawamura, I.; Matsumoto, K.

    1996-02-01

    A Helium refrigeration system has been constructed for a superfluid-cooled 21 T superconducting magnet and a 15 T superconducting outer magnet of 40 T class hybrid magnet. The refrigeration system was designed for the application of two refrigeration modes, that is, superfluid cooling mode, and pool boiling cooling mode. The refrigeration power of 450 W at 4.4 K was obtained successfully.

  11. Thermal-hydraulic tests of a recirculation cooling installation for the Rostov nuclear power station

    NASA Astrophysics Data System (ADS)

    Balunov, B. F.; Balashov, V. A.; Il'in, V. A.; Krayushnikov, V. V.; Lychakov, V. D.; Meshalkin, V. V.; Ustinov, A. N.; Shcheglov, A. A.

    2013-09-01

    Results obtained from thermal-hydraulic tests of the recirculation cooling installation used as part of the air cooling system under the containments of the Rostov nuclear power station Units 3 and 4 are presented. The operating modes of the installation during normal operation (air cooling on the surface of finned tubes), under the conditions of anticipated operational occurrences (air cooling and steam condensation from a steam-air mixture), and during an accident (condensation of pure steam) are considered. Agreement is obtained between the results of tests and calculations carried out according to the recommendations given in the relevant regulatory documents. A procedure of carrying out thermal calculation for the case of steam condensation from a steam-air mixture on the surface of fins is proposed. The possibility of efficient use of the recirculation cooling installation in the system for reducing emergency pressure under the containment of a nuclear power station is demonstrated.

  12. Solving LFC problem in an interconnected power system using superconducting magnetic energy storage

    NASA Astrophysics Data System (ADS)

    Farahani, Mohsen; Ganjefar, Soheil

    2013-04-01

    This paper proposes the combination of a load frequency control (LFC) with superconducting magnetic energy storage (SMES) to solve the LFC problem in interconnected power systems. By using this combination, the speed damping of frequency and tie-line power flow deviations is considerably increased. A new control strategy of SMES is proposed in this paper. The problem of determining optimal parameters of PID and SMES control loop is considered as an optimization problem and a pattern search algorithm (PS) optimization is employed to solve it. The simulation results show that if an SMES unit is installed in an interconnected power system, in addition to eliminating oscillations and deviations, the settling time in the frequency and tie-line power flow responses is considerably reduced.

  13. Operational experiences of the spallation neutron source superconducting linac and power ramp-up

    SciTech Connect

    Kim, Sang-Ho

    2009-01-01

    The spallation neutron source (SNS) is a second generation pulsed neutron source and designed to provide a 1-GeV, 1.44-MW proton beam to a mercury target for neutron production. Since the commissioning of the accelerator complex in 2006, the SNS has started its operation for neutron production and beam power ramp-up has been in progress toward the design goal. All subsystems of the SNS were designed and developed for substantial improvements compared to existing accelerators because the design beam power is almost an order of magnitude higher compared to existing neutron facilities and the achievable neutron scattering performance will exceed present sources by more than a factor of 20 to 100. In this paper, the operational experiences with the SNS Superconducting Linac (SCL), Power Ramp-up Plan to reach the design goal and the Power Upgrade Plan (PUP) will be presented including machine, subsystem and beam related issues.

  14. Implementation of superconducting fault current limiter for flexible operation in the power substation

    NASA Astrophysics Data System (ADS)

    Song, Chong Suk; Lee, Hansang; Cho, Yoon-sung; Suh, Jaewan; Jang, Gilsoo

    2014-09-01

    The concentration of large-scale power loads located in the metropolitan areas have resulted in high fault current levels during a fault thereby requiring the substation to operate in the double busbar configuration mode. However, the double busbar configuration mode results in deterioration of power system reliability and unbalanced power flow in the adjacent transmission lines which may result in issues such as overloading of lines. This paper proposes the implementation of the superconducting fault current limiter (SFCL) to be installed between the two substation busbars for a more efficient and flexible operation of the substation enabling both single and double busbar configurations depending on the system conditions for guaranteeing power system reliability as well as fault current limitations. Case studies are being performed for the effectiveness of the SFCL installation and results are compared for the cases where the substation is operating in single and double busbar mode and with and without the installation of the SFCL for fault current mitigation.

  15. High-power air-cooled SiC-clad Nd:YVO4 slab lasers.

    PubMed

    Zhang, Rui; Niu, Jinfu; Xu, Jianqiu; Xu, Jingzhong

    2011-05-15

    We demonstrate a diode-pumped, air-cooled, 100 W class SiC-clad Nd:YVO(4) active slab laser based on diffusion bonding of two SiC plates to a thin Nd:YVO(4) slab. We obtained 83 W of cw output power with a slope efficiency of 27% without water cooling. This demonstration initiates a novel (to the best of our knowledge) cooling design for efficient removal of waste heat generated from the diode edge-pumped high-power slab laser at room temperature. PMID:21593914

  16. Cost analysis of power plant cooling using aquifer thermal energy storage

    SciTech Connect

    Zimmerman, P.W.; Drost, M.K.

    1989-05-01

    Most utilities in the US experience their peak demand for electric power during periods with high ambient temperature. Unfortunately, the performance of many power plants decreases with high ambient temperature. The use of aquifer thermal energy storage (ATES) for seasonal storage of chill can be an alternative method for heat rejection. Cold water produced during the previous winter is stored in the aquifer and can be used to provide augmented cooling during peak demand periods increasing the output of many Rankine cycle power plants. This report documents an investigation of the technical and economic feasibility of using aquifer thermal energy storage for peak cooling of power plants. 9 refs., 15 figs., 5 tabs.

  17. Energy and peak power saved by passively cooled residences

    NASA Astrophysics Data System (ADS)

    Clark, G.; Loxsom, F.; Doderer, E.; Vieira, R.; Fleischhacker, P.

    1983-11-01

    The energy displacement potential of roof pond cooling in humid climates is sensitive to the type of dehumidification equipment employed and the humidity levels allowed. The simulated energy requirements of roof pond residences assisted by two high efficiency dehumidifier options are described. One dehumidifier was a vapor compression air conditioner with sensible cooling recovery by an air-to-air heat exchanger (improved mechanical dehumidification or IMD). The second option was a solar regenerated desiccant dehumidifier (SRDD). An IMD assisted roof pond house had energy savings of 30 to 65% in humid climates compared to the conventional house; an SRDD assisted roof pond house had energy savings of 70 to 75% in humid climates.

  18. Comparison of Hybrid Electric Vehicle Power Electronics Cooling Options

    SciTech Connect

    O'Keefe, M.; Bennion, K.

    2008-01-01

    This study quantifies the heat dissipation potential of three inverter package configurations over a range of control factors. These factors include coolant temperature, number of sides available for cooling, effective heat transfer coefficient, maximum semiconductor junction temperature, and interface material thermal resistance. Heat dissipation potentials are examined in contrast to a research goal to use 105..deg..C coolant and dissipate 200 W/cm2 heat across the insulated gate bipolar transistor and diode silicon area. Advanced double-sided cooling configurations with aggressive heat transfer coefficients show the possibility of meeting these targets for a 125..deg..C maximum junction temperature, but further investigation is needed. Even with maximum tolerable junction temperatures of 200..deg..C, effective heat transfer coefficients of 5,000 to 10,000 W/m2-K will be needed for coolant temperatures of 105..deg..C or higher.

  19. Use of LHP for cooling power electronic components

    NASA Astrophysics Data System (ADS)

    Smitka, M.; Malcho, M.; Nemec, P.; Kolkov, Z.

    2013-04-01

    The paper deals with use of cooling equipment build on basis two phase thermosyphon loop. This device belongs to a group of loop heat pipe (LHP). This LHP is a two-phase device with extremely high effective thermal conductivity that utilizes the thermodynamic pressure difference to circulate fluid. It was invented in Russia in the early 1980s. Thermosyphon loop is similar as LHP but it doesn't contain wick and circulation of the fluid using gravitation force instead of capillary pressure as it is in LHP. The work deals with the cooling insulated gate bipolar transistor with 370 W. The paper describes the course of the heat dissipation using ribbed cooler for natural convection and using fin for forced convection. The results are compared with heat dissipation through thermosyphon loop.

  20. Method and system for powering and cooling semiconductor lasers

    SciTech Connect

    Telford, Steven J; Ladran, Anthony S

    2014-02-25

    A semiconductor laser system includes a diode laser tile. The diode laser tile includes a mounting fixture having a first side and a second side opposing the first side and an array of semiconductor laser pumps coupled to the first side of the mounting fixture. The semiconductor laser system also includes an electrical pulse generator thermally coupled to the diode bar and a cooling member thermally coupled to the diode bar and the electrical pulse generator.

  1. Utilization of municipal wastewater for cooling in thermoelectric power plants

    SciTech Connect

    Safari, Iman; Walker, Michael E.; Hsieh, Ming-Kai; Dzombak, David A.; Liu, Wenshi; Vidic, Radisav D.; Miller, David C.; Abbasian, Javad

    2013-09-01

    A process simulation model has been developed using Aspen Plus® with the OLI (OLI System, Inc.) water chemistry model to predict water quality in the recirculating cooling loop utilizing secondary- and tertiary-treated municipal wastewater as the source of makeup water. Simulation results were compared with pilot-scale experimental data on makeup water alkalinity, loop pH, and ammonia evaporation. The effects of various parameters including makeup water quality, salt formation, NH3 and CO2 evaporation mass transfer coefficients, heat load, and operating temperatures were investigated. The results indicate that, although the simulation model can capture the general trends in the loop pH, experimental data on the rates of salt precipitation in the system are needed for more accurate prediction of the loop pH. It was also found that stripping of ammonia and carbon dioxide in the cooling tower can influence the cooling loop pH significantly. The effects of the NH3 mass transfer coefficient on cooling loop pH appear to be more significant at lower values (e.g., kNH3 < 4×10-3 m/s) when the makeup water alkalinity is low (e.g., <90 mg/L as CaCO3). The effect of the CO2 mass transfer coefficient was found to be significant only at lower alkalinity values (e.g., kCO2<4×10-6 m/s).

  2. Monolayer graphene dispersion and radiative cooling for high power LED

    NASA Astrophysics Data System (ADS)

    Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

    2013-10-01

    Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1? C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation.

  3. Monolayer graphene dispersion and radiative cooling for high power LED.

    PubMed

    Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

    2013-10-01

    Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1? C, while functioning as a dielectric layer with a high breakdown voltage (>5kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation. PMID:24008305

  4. Superconducting fault-current limiter and inductor design

    SciTech Connect

    Rogers, J.D.; Boenig, H.J.; Chowdhuri, P.; Schermer, R.I.; Wollan, J.J.; Weldon, D.M.

    1982-01-01

    A superconducting fault current limiter (SFCL) that uses a biased superconducting inductor in a diode or thyristor bridge circuit was analyzed for transmission systems in 69, 138, and 230 rms kV utility transmission systems. The limiter was evaluated for costs with all components - superconducting coil, diode and/or SCR power electronics, high voltage insulation, high voltage bushings and vapor cooled leads, dewar, and refrigerator - included. A design was undertaken for the superconducting cable and coils for both diode and SCR 69 kV limiter circuits.

  5. ORNL Superconducting Technology Program for Electric Power Systems, Annual Report for FY 1998

    SciTech Connect

    Hawsey, R.A.; Murphy, A.W.

    1999-04-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by U.S. industry for commercial development of electric power applications of high temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1998 Annual Program Review held July 20-22, 1998. Aspects of ORNL's work that were presented at the Applied Superconductivity Conference (September 1998) are included in this report, as well. This ORNL program is highly leveraged by the staff and other resources of U.S. industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with U.S. industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high temperature superconductor wire and wire-using systems.

  6. Thermal Management of Power Semiconductor Packages - Matching Cooling Technologies with Packaging Technologies (Presentation)

    SciTech Connect

    Bennion, K.; Moreno, G.

    2010-04-27

    Heat removal for power semiconductor devices is critical for robust operation. Because there are different packaging options, different thermal management technologies, and a range of applications, there is a need for a methodology to match cooling technologies and package configurations to target applications. To meet this need, a methodology was developed to compare the sensitivity of cooling technologies on the overall package thermal performance over a range of power semiconductor packaging configurations. The results provide insight into the trade-offs associated with cooling technologies and package configurations. The approach provides a method for comparing new developments in power semiconductor packages and identifying potential thermal control technologies for the package. The results can help users select the appropriate combination of packaging configuration and cooling technology for the desired application.

  7. Conceptual design study of the moderate size superconducting spherical tokamak power plant

    NASA Astrophysics Data System (ADS)

    Gi, Keii; Ono, Yasushi; Nakamura, Makoto; Someya, Youji; Utoh, Hiroyasu; Tobita, Kenji; Ono, Masayuki

    2015-06-01

    A new conceptual design of the superconducting spherical tokamak (ST) power plant was proposed as an attractive choice for tokamak fusion reactors. We reassessed a possibility of the ST as a power plant using the conservative reactor engineering constraints often used for the conventional tokamak reactor design. An extensive parameters scan which covers all ranges of feasible superconducting ST reactors was completed, and five constraints which include already achieved plasma magnetohydrodynamic (MHD) and confinement parameters in ST experiments were established for the purpose of choosing the optimum operation point. Based on comparison with the estimated future energy costs of electricity (COEs) in Japan, cost-effective ST reactors can be designed if their COEs are smaller than 120 mills kW-1 h-1 (2013). We selected the optimized design point: A = 2.0 and Rp = 5.4 m after considering the maintenance scheme and TF ripple. A self-consistent free-boundary MHD equilibrium and poloidal field coil configuration of the ST reactor were designed by modifying the neutral beam injection system and plasma profiles. The MHD stability of the equilibrium was analysed and a ramp-up scenario was considered for ensuring the new ST design. The optimized moderate-size ST power plant conceptual design realizes realistic plasma and fusion engineering parameters keeping its economic competitiveness against existing energy sources in Japan.

  8. AC Loss of Ripple Current in Superconducting DC Power Transmission Cable

    NASA Astrophysics Data System (ADS)

    Yoshitomi, K.; Otabe, E. S.; Vyatkin, V. S.; Kiuchi, M.; Matsushita, T.; Hamabe, M.; Yamaguchi, S.; Inada, R.

    As a method of largely reducing the transmission loss in the electric power grid, superconducting direct current (DC) power transmission cable has been investigated. Using superconducting DC power transmission cables, large amounts of current and energy can be transferred compared to conventional copper cables. In this case, an alternating current (AC) is converted to DC and superposed AC which is known as ripple current, and the energy loss by the ripple current is generated. Therefore it is desired to estimate the energy loss density for the case of DC current and superposed AC current for a design of DC transmission cable system. In this study, the hysteresis loss for DC current of 2 kA rectified from 60 Hz alternating current is calculated using the Bean model, and coupling loss was also estimated. The diameter of the cable was 40 mm. The ripple currents generated by multi-pulse rectifiers, 6-pulse, 12-pulse, and 24-pulse were considered. It is found that the total AC loss including the hysteresis loss and the coupling loss is considerably smaller than the supposed heat loss of 0.5 W/m which is obtained with a newly developed cable.

  9. Power system analysis of Hanlim superconducting HVDC system using real time digital simulator

    NASA Astrophysics Data System (ADS)

    Won, Y. J.; Kim, J. G.; Kim, A. R.; Kim, G. H.; Park, M.; Yu, I. K.; Sim, K. D.; Cho, J.; Lee, S.; Jeong, K. W.; Watanabe, K.

    2011-11-01

    Jeju island is located approximately 100 km south from the mainland of Korea, and had a peak load of about 553 MW in 2008. The demand increases 7.2% a year over the last 5 years. Since the wind profiles of Jeju island are more favorable than mainland of Korea, many companies have shown interest in the wind power business at the Jeju island. Moreover KEPCO has a plan for renewable energy test too whose power will be delivered by HVDC system. One kilometer length of total 8 km was designed as superconducting DC cable. Rest 7 km will be the conventional overhead line. In this paper, the authors have developed a simulation model of the power network around 8 km HVDC system using real time digital simulator (RTDS).

  10. Influence of the cooling rate on the superconducting properties of the organic solid di-tetramethyltetraselenafulvalenium-perchlorate TMTSF/sub 2/ClO/sub 4/

    SciTech Connect

    Garoche, P.; Brusetti, R.; Bechgaard, K.

    1982-11-01

    Specific-heat measurements on the organic solid di-tetramethyltetraselenafulvalenium-perchlorate TMTSF/sub 2/ClO/sub 4/ demonstrate that T/sub c/ decreases as much as 22%, when the cooling rate below 40 K is changed from 0.1 K/min (relaxed state) to 10 K/min (quenched state). The phenomenon is fully reversible as indicated by annealing experiments. The parameters of the superconducting state, the specific-heat jump, the entropy, and the upper critical fields (parallelc*) are strongly affected by the quenching process. A possible explanation is that quenching freezes out lattice disorder.

  11. Integrated three-dimensional module heat exchanger for power electronics cooling

    SciTech Connect

    Bennion, Kevin; Lustbader, Jason

    2013-09-24

    Embodiments discussed herein are directed to a power semiconductor packaging that removes heat from a semiconductor package through one or more cooling zones that are located in a laterally oriented position with respect to the semiconductor package. Additional embodiments are directed to circuit elements that are constructed from one or more modular power semiconductor packages.

  12. Temperature and oxygen conditions peculiarities of the cooling ponds of nuclear and thermal power plants

    NASA Astrophysics Data System (ADS)

    Mostova, N.

    2008-11-01

    On materials of laboratory and expeditionary researches on the cooling pond of the Zaporizhya nuclear power plant and adjoining area of the Kachovka reservoir are found out features of temperature and oxygen regime of the cooling ponds and condition and factors, that them determine. Carried out researches testify to significant thermal loading on ecosystem of the cooling pond which determines a course of hydrobiological and physico-chemical processes. Differences of the hydrochemical regime of cooling ponds from similar reservoirs in natural conditions are caused, first of all, by features of their thermal regime. Because of constant artificial heating, character of hydrobiological, physico-chemical and hydrodynamical processes in cooling ponds are formed peculiar conditions of formation of the dissolved oxygen regime.

  13. Cooling System for the Merit High-Power Target Experiment

    NASA Astrophysics Data System (ADS)

    Haug, F.; Pereira, H.; Silva, P.; Pezzetti, M.; Pavlov, O.; Pirotte, O.; Metselaar, J.; Efthymiopoulos, I.; Fabich, A.; Lettry, J.; Kirk, H. G.; McDonald, K. T.; Titus, P.; Bennett, J. R. J.

    2010-04-01

    MERIT is a proof-of-principle experiment of a target station suitable as source for future muon colliders or neutrino factories. When installed at the CERN (European Organization for Nuclear Research) PS (Proton Synchrotron) complex fast-extracted high-intensity proton beams intercepted a free mercury jet inside a normal-conducting, pulsed 15-T capture solenoid magnet cooled with liquid nitrogen. Up to 25 MJ of Joule heat was dissipated in the magnet during a pulse. The fully automated, remotely controlled cryogenic system of novel design permitted the transfer of nitrogen by the sole means of differential pressures inside the vessels. This fast cycling system permitted several hundred tests in less than three weeks during the 2007 data taking campaign.

  14. COOLING WATER ISSUES AND OPPORTUNITIES AT U.S. NUCLEAR POWER PLANTS

    SciTech Connect

    Gary Vine

    2010-12-01

    This report has been prepared for the Department of Energy, Office of Nuclear Energy (DOE-NE), for the purpose of providing a status report on the challenges and opportunities facing the U.S. commercial nuclear energy industry in the area of plant cooling water supply. The report was prompted in part by recent Second Circuit and Supreme Court decisions regarding cooling water system designs at existing thermo-electric power generating facilities in the U.S. (primarily fossil and nuclear plants). At issue in the courts have been Environmental Protection Agency regulations that define what constitutes “Best Technology Available” for intake structures that withdraw cooling water that is used to transfer and reject heat from the plant’s steam turbine via cooling water systems, while minimizing environmental impacts on aquatic life in nearby water bodies used to supply that cooling water. The report was also prompted by a growing recognition that cooling water availability and societal use conflicts are emerging as strategic energy and environmental issues, and that research and development (R&D) solutions to emerging water shortage issues are needed. In particular, cooling water availability is an important consideration in siting decisions for new nuclear power plants, and is an under-acknowledged issue in evaluating the pros and cons of retrofitting cooling towers at existing nuclear plants. Because of the significant ongoing research on water issues already being performed by industry, the national laboratories and other entities, this report relies heavily on ongoing work. In particular, this report has relied on collaboration with the Electric Power Research Institute (EPRI), including its recent work in the area of EPA regulations governing intake structures in thermoelectric cooling water systems.

  15. Subtask 5.10 - Testing of an Advanced Dry Cooling Technology for Power Plants

    SciTech Connect

    Martin, Christopher; Pavlish, John

    2013-09-30

    The University of North Dakota’s Energy & Environmental Research Center (EERC) is developing a market-focused dry cooling technology that is intended to address the key shortcomings of conventional dry cooling technologies: high capital cost and degraded cooling performance during daytime temperature peaks. The unique aspect of desiccant dry cooling (DDC) is the use of a hygroscopic working fluid—a liquid desiccant—as a heat-transfer medium between a power plant’s steam condenser and the atmosphere. This configuration enables a number of beneficial features for large-scale heat dissipation to the atmosphere, without the consumptive use of cooling water. The overall goal of this project was to accurately define the performance and cost characteristics of DDC to determine if further development of the concept is warranted. A balanced approach of modeling grounded in applied experimentation was pursued to substantiate DDC-modeling efforts and outline the potential for this technology to cool full-scale power plants. The resulting analysis shows that DDC can be a lower-cost dry cooling alternative to an air-cooled condenser (ACC) and can even be competitive with conventional wet recirculating cooling under certain circumstances. This project has also highlighted the key technological steps that must be taken in order to transfer DDC into the marketplace. To address these issues and to offer an extended demonstration of DDC technology, a next-stage project should include the opportunity for outdoor ambient testing of a small DDC cooling cell. This subtask was funded through the EERC–U.S. Department of Energy (DOE) Joint Program on Research and Development for Fossil Energy-Related Resources Cooperative Agreement No. DE-FC26-08NT43291. Nonfederal funding was provided by the Wyoming State Legislature under an award made through the Wyoming Clean Coal Technologies Research Program.

  16. The development of a solar-powered residential heating and cooling system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Efforts to demonstrate the engineering feasibility of utilizing solar power for residential heating and cooling are described. These efforts were concentrated on the analysis, design, and test of a full-scale demonstration system which is currently under construction at the National Aeronautics and Space Administration, Marshall Space Flight Center, Huntsville, Alabama. The basic solar heating and cooling system under development utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating and water heating, and an absorption cycle air conditioner for space cooling.

  17. Geographic, technologic, and economic analysis of using reclaimed water for thermoelectric power plant cooling.

    PubMed

    Stillwell, Ashlynn S; Webber, Michael E

    2014-04-15

    Use of reclaimed water-municipal wastewater treatment plant effluent-in nonpotable applications can be a sustainable and efficient water management strategy. One such nonpotable application is at thermoelectric power plants since these facilities require cooling, often using large volumes of freshwater. To evaluate the geographic, technologic, and economic feasibility of using reclaimed water to cool thermoelectric power plants, we developed a spatially resolved model of existing power plants. Our model integrates data on power plant and municipal wastewater treatment plant operations into a combined geographic information systems and optimization approach to evaluate the feasibility of cooling system retrofits. We applied this broadly applicable methodology to 125 power plants in Texas as a test case. Results show that sufficient reclaimed water resources exist within 25 miles of 92 power plants (representing 61% of capacity and 50% of generation in our sample), with most of these facilities meeting both short-term and long-term water conservation cost goals. This retrofit analysis indicates that reclaimed water could be a suitable cooling water source for thermoelectric power plants, thereby mitigating some of the freshwater impacts of electricity generation. PMID:24625241

  18. Advanced superconducting power conditioning system with SMES for effective use of renewable energy

    NASA Astrophysics Data System (ADS)

    Hamajima, T.; Tsuda, M.; Miyagi, D.; Amata, H.; Iwasaki, T.; Son, K.; Atomura, N.; Shintomi, T.; Makida, Y.; Takao, T.; Munakata, K.; Kajiwara, M.

    Since it is an urgent issue to reduce the global Carbon-dioxide in the world, renewable energy should be supplied as a large amount of the electric power. However, if a large amount of fluctuating renewable energy becomes more than adjustable amount of a utility grid capacity, instabilities such as frequency deviation might occur. We propose a system that is composed of SMES and FC-H2-Electrolyzer and also installed adjacent to Liquid Hydrogen station to cool down the SMES. Since the SMES has potentials of quick response and large I/O power, and Fuel Cell has potentials of slow response and steady power supplied from a large amount of hydrogen, we combine both storage devices and apply them to suppress the fluctuating power. We convert the fluctuating power to the constant power by using a developed prediction technology of Kalman filter to predict a trend of the fluctuating power. While the trend power should be supplied by FC or absorbed by the electrolyzer to produce hydrogen, the power difference between the renewable power and the trend power should be stored by the SMES. We simulate the power balance and analyze the required SMES capacity, design the concept of the SMES, and propose an operation algorithm for the SMES to estimate the electric efficiency of the system. It is found that the electric efficiency of the ASPCS can become greater than that of a pumped hydro-machine.

  19. The nuclear closed-cycle gas turbine /HTGR-GT/ - Dry cooled commercial power plant studies

    NASA Astrophysics Data System (ADS)

    McDonald, C. F.; Boland, C. R.

    1981-01-01

    Combining the modern and proven power conversion system of the closed-cycle gas turbine (CCGT) with an advanced high-temperature gas-cooled reactor (HTGR) results in a power plant well suited to projected utility needs into the twenty-first century. The gas turbine HTGR (HTGR-GT) power plant benefits are consistent with national energy goals, and the high power conversion efficiency potential satisfies increasingly important resource conservation demands. Established technology bases for the HTGR-GT are outlined, together with the extensive design and development program necessary to commercialize the nuclear CCGT plant for utility service in the 1990s. The most recent design studies for a dry-cooled commercial plant of 800 to 1200 MW(e) power based on both nonintercooled and intercooled cycles are outlined and various primary system aspects are discussed. Details are given of the reactor turbine system and on integrating the major power conversion components in the prestressed concrete reactor vessel.

  20. Design study of high-temperature superconducting generators for wind power systems

    NASA Astrophysics Data System (ADS)

    Maki, N.

    2008-02-01

    Design study on high-temperature superconducting machines (HTSM) for wind power systems was carried out using specially developed design program. Outline of the design program was shown and the influence of machine parameters such as pole number, rotor outer diameter and synchronous reactance on the machine performance was clarified. Three kinds of generator structure are considered for wind power systems and the HTSM operated under highly magnetic saturated conditions with conventional rotor and stator has better performance than the other types of HTSM. Furthermore, conceptual structure of 8 MW, 20 pole HTSM adopting salient-pole rotor as in the case of water turbine generators and race-truck shaped HTS field windings like Japanese Maglev was shown.

  1. Alternative power supply and dump resistor connections for similar, mutually coupled, superconducting coils

    NASA Astrophysics Data System (ADS)

    Owen, E. W.; Shimer, D. W.; Wang, S. T.

    1983-11-01

    Alternative methods of connecting similar mutually coupled coils to their power supplies and dump resistors are investigated. The circuits are evaluated for both operating and fault conditions. The factors considered are the voltage to ground during a dump, short cicuits, open circuits, quenches, and failure of the protection system to detect a quench. Of particular interest are the currents in coils that remain superconducting when one or more coils quench. The alternative connections include combined power supplies, individual dump resistors, combined resistors and series and parallel dump resistors. A new circuit that contains coupling resistors is proposed. The coupling resistors do not affect normal fast dumps but reduce the peak induced currents while also reducing the energy rating of the dump resistors. The series circuit with diodes, is discussed. The MFTFB central cell solenoids are used as an example.

  2. Compact fluid cooled power converter supporting multiple circuit boards

    DOEpatents

    Radosevich, Lawrence D.; Meyer, Andreas A.; Beihoff, Bruce C.; Kannenberg, Daniel G.

    2005-03-08

    A support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  3. Rotating Cryocooler for Superconducting Motor

    NASA Astrophysics Data System (ADS)

    Ko, Junseok; Jeong, Sangkwon; Kim, Hongseong; Jung, Jeheon; Choi, Jaeyoung; In, Sehwan; Sohn, Myunghwan; Kwon, Young-Kil

    2006-04-01

    A single-stage coaxial pulse tube refrigerator has been designed for HTS (High Temperature Superconductor) motor application. This paper discusses a practical realization of an advanced cooling method for superconducting rotor, on-board cryocooler. When a cryocooler is considered to be mounted on the superconducting rotor, the following two factors must be satisfied for practical application. First, the on-board cryocooler should not disturb the high-speed revolution of the rotor. Second, at the same time, the high-speed revolution of the rotor should not deteriorate the cooling performance of the cryocooler. These mutual technical demands restrict the type of cryocooler suitable for high-speed rotating environment. We select a Stirling-type coaxial pulse tube cryocooler and incorporate it on the 1800-rpm superconducting motor mock-up. The pulse tube cryocooler is designed with an adiabatic model and a various loss mechanism analysis. The no-load temperature is approximately 100 K with less than 150 W electric input power. The axisymmetric configuration of the fabricated cryocooler does not produce any undesirable effect at high-speed rotation. Even if the thermal performance of the rotating pulse tube cryocooler is not satisfactory, the feasibility of simple on-board cooling method for superconducting rotor is confirmed in this paper.

  4. Dynamical behaviour of superconducting resonators under readout-frequency, readout-power, and signal-power switching

    NASA Astrophysics Data System (ADS)

    Thompson, Sarah E.; Withington, Stafford; Goldie, David

    2012-09-01

    The sensitivities, saturation powers, and response times of Kinetic Inductance Detectors depend on the degree to which the quasiparticle and phonon temperatures differ when readout and signal power are applied. Previously, we proposed a model for saturation in KIDs, and found that hysteretic switching, which is seen experimentally, emerges from the model in a natural way. Here we extend our work, and show through a diagrammatic rep- resentation of operating-point trajectories that output pulse shapes can be calculated for non-hysteretic and hysteretic changes of state driven by readout-frequency, readout-power, and signal-power pulses. The work has several applications: (i) Understanding quasiparticle and phonon relaxation, and their dependence on film and substrate thickness. (ii) Recovering quasiparticle cooling functions from measurements. (iii) Understanding the relationship between optimum readout power and device and material parameters. (iv) Characterising the time-dependent behaviour of photon-counting KIDs, including nonlinearity and pile up.

  5. POWER PLANT COOLING WATER CHLORINATION IN NORTHERN CALIFORNIA

    EPA Science Inventory

    A survey was conducted of chlorination practices at five power plants owned and operated by the Pacific Gas and Electric Company. Frequency and duration of chlorination varied significantly from plant to plant and was controlled analytically by the orthotolidine and/or amperometr...

  6. High power density self-cooled lithium-vanadium blanket.

    SciTech Connect

    Gohar, Y.; Majumdar, S.; Smith, D.

    1999-07-01

    A self-cooled lithium-vanadium blanket concept capable of operating with 2 MW/m{sup 2} surface heat flux and 10 MW/m{sup 2} neutron wall loading has been developed. The blanket has liquid lithium as the tritium breeder and the coolant to alleviate issues of coolant breeder compatibility and reactivity. Vanadium alloy (V-4Cr-4Ti) is used as the structural material because it can accommodate high heat loads. Also, it has good mechanical properties at high temperatures, high neutron fluence capability, low degradation under neutron irradiation, good compatibility with the blanket materials, low decay heat, low waste disposal rating, and adequate strength to accommodate the electromagnetic loads during plasma disruption events. Self-healing electrical insulator (CaO) is utilized to reduce the MHD pressure drop. A poloidal coolant flow with high velocity at the first wall is used to reduce the peak temperature of the vanadium structure and to accommodate high surface heat flux. The blanket has a simple blanket configuration and low coolant pressure to reduce the fabrication cost, to improve the blanket reliability, and to increase confidence in the blanket performance. Spectral shifter, moderator, and reflector are utilized to improve the blanket shielding capability and energy multiplication, and to reduce the radial blanket thickness. Natural lithium is used to avoid extra cost related to the lithium enrichment process.

  7. Biocide usage in cooling towers in the electric power and petroleum refining industries

    SciTech Connect

    Veil, J.; Rice, J.K.; Raivel, M.E.S.

    1997-11-01

    Cooling towers users frequently apply biocides to the circulating cooling water to control growth of microorganisms, algae, and macroorganisms. Because of the toxic properties of biocides, there is a potential for the regulatory controls on their use and discharge to become increasingly more stringent. This report examines the types of biocides used in cooling towers by companies in the electric power and petroleum refining industries, and the experiences those companies have had in dealing with agencies that regulate cooling tower blowdown discharges. Results from a sample of 67 electric power plants indicate that the use of oxidizing biocides (particularly chlorine) is favored. Quaternary ammonia salts (quats), a type of nonoxidizing biocide, are also used in many power plant cooling towers. The experience of dealing with regulators to obtain approval to discharge biocides differs significantly between the two industries. In the electric power industry, discharges of any new biocide typically must be approved in writing by the regulatory agency. The approval process for refineries is less formal. In most cases, the refinery must notify the regulatory agency that it is planning to use a new biocide, but the refinery does not need to get written approval before using it. The conclusion of the report is that few of the surveyed facilities are having any difficulty in using and discharging the biocides they want to use.

  8. A passive cooling system proposal for multifunction and high-power displays

    NASA Astrophysics Data System (ADS)

    Tari, Ilker

    2013-03-01

    Flat panel displays are conventionally cooled by internal natural convection, which constrains the possible rate of heat transfer from the panel. On one hand, during the last few years, the power consumption and the related cooling requirement for 1080p displays have decreased mostly due to energy savings by the switch to LED backlighting and more efficient electronics. However, on the other hand, the required cooling rate recently started to increase with new directions in the industry such as 3D displays, and ultra-high-resolution displays (recent 4K announcements and planned introduction of 8K). In addition to these trends in display technology itself, there is also a trend to integrate consumer entertainment products into displays with the ultimate goal of designing a multifunction device replacing the TV, the media player, the PC, the game console and the sound system. Considering the increasing power requirement for higher fidelity in video processing, these multifunction devices tend to generate very high heat fluxes, which are impossible to dissipate with internal natural convection. In order to overcome this obstacle, instead of active cooling with forced convection that comes with drawbacks of noise, additional power consumption, and reduced reliability, a passive cooling system relying on external natural convection and radiation is proposed here. The proposed cooling system consists of a heat spreader flat heat pipe and aluminum plate-finned heat sink with anodized surfaces. For this system, the possible maximum heat dissipation rates from the standard size panels (in 26-70 inch range) are estimated by using our recently obtained heat transfer correlations for the natural convection from aluminum plate-finned heat sinks together with the surface-to-surface radiation. With the use of the proposed passive cooling system, the possibility of dissipating very high heat rates is demonstrated, hinting a promising green alternative to active cooling.

  9. 78 FR 64029 - Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... COMMISSION Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors AGENCY... Systems for Light-Water-Cooled Nuclear Power Reactors,'' in which the NRC made editorial corrections and... analysis for liquid and gaseous radwaste system components for light water nuclear power...

  10. Adaptive Environmentally Contained Power and Cooling IT Infrastructure for the Data Center

    SciTech Connect

    Mann, Ron; Chavez, Miguel, E.

    2012-06-27

    The objectives of this program were to research and develop a fully enclosed Information Technology (IT) rack system for 100 kilowatts (KW) of IT load that provides its own internal power and cooling with High Voltage Alternating Current (HVAC defined as 480 volt) and chilled water as the primary inputs into the system and accepts alternative energy power sources such as wind and solar. For maximum efficiency, internal power to the IT equipment uses distributed High Voltage Direct Current power (HVDC defined as 360-380 volt) from the power source to the IT loads. The management scheme aggressively controls energy use to insure the best utilization of available power and cooling resources. The solution incorporates internal active management controls that not only optimizes the system environment for the given dynamic IT loads and changing system conditions, but also interfaces with data center Building Management Systems (BMS) to provide a complete end-to-end view of power and cooling chain. This technology achieves the goal of a Power Usage Effectiveness (PUE) of 1.25, resulting in a 38% reduction in the total amount of energy needed to support a 100KW IT load compared to current data center designs.

  11. Manufacturing Superconducting Cables

    NASA Technical Reports Server (NTRS)

    England, Christopher

    1996-01-01

    Process proposed for manufacture of cables containing ceramic high-temperature-superconductor YBa(2)Cu(3)O(7-a). For protection, superconducting ceramic encapsulated before activation. Cables carry electrical current with little or no loss of power when cooled to or below temperatures of about minus 200 degrees C. Process accommodates brittle nature of YBa(2)Cu(3)O(7-a) and economical and readily controllable. Also flexible in sense modified to accommodate variety of precursor materials to be processed into YBa(2)Cu(3)O(7-a).

  12. Evaluation of Hybrid Air-Cooled Flash/Binary Power Cycle

    SciTech Connect

    Greg Mines

    2005-10-01

    Geothermal binary power plants reject a significant portion of the heat removed from the geothermal fluid. Because of the relatively low temperature of the heat source (geothermal fluid), the performance of these plants is quite sensitive to the sink temperature to which heat is rejected. This is particularly true of air-cooled binary plants. Recent efforts by the geothermal industry have examined the potential to evaporatively cool the air entering the air-cooled condensers during the hotter portions of a summer day. While the work has shown the benefit of this concept, air-cooled binary plants are typically located in regions that lack an adequate supply of clean water for use in this evaporative cooling. In the work presented, this water issue is addressed by pre-flashing the geothermal fluid to produce a clean condensate that can be utilized during the hotter portions of the year to evaporatively cool the air. This study examines both the impact of this pre-flash on the performance of the binary plant, and the increase in power output due to the ability to incorporate an evaporative component to the heat rejection process.

  13. ORNL superconducting technology program for electric power systems. Annual report for FY 1993

    SciTech Connect

    Hawsey, R.A.

    1994-04-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the technology base needed by US industry for commercial development of electric power applications of high-temperature superconductivity. The two major elements of this program are conductor development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from information prepared for the FY 1993 Annual Program Review held July 28--29, 1993. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to industrial competitiveness projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer to US industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire products.

  14. ORNL Superconducting Technology Program for Electric Power Systems: Annual Report for FY 1999

    SciTech Connect

    Hawsey, R.A.

    2000-06-13

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by U.S. industry for development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1999 Annual Program Review held July 26-28, 1999. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference and the Cryogenic Engineering Conference (July 1999) are included in this report, as well. This ORNL program is highly leveraged by the staff and other resources of U.S. industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with U.S. industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire-using systems.

  15. ORNL Superconducting Technology Program for electric power systems. Annual report for FY 1995

    SciTech Connect

    Hawsey, R.A.; Turner, J.W.

    1996-05-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the U.S. Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by U.S. industry for commercial development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and systems development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from information prepared for the FY 1995 Annual Program Review held August 1-2, 1995. This ORNL program is highly leveraged by the staff and other resources of U.S. industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with U.S. industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire-using systems.

  16. ORNL Superconducting Technology Program for Electric Power Systems, Annual Report for FY 1999

    SciTech Connect

    Hawsey, R.A.; Murphy, A.W

    2000-04-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by U.S. industry for development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1999 Annual Program Review held July 26--28, 1999. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference and the Cryogenic Engineering Conference (July 1999) are included in this report, as well. This ORNL program is highly leveraged by the staff and other resources of U.S. industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with U.S. industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire-using systems.

  17. ORNL Superconducting Technology Program for electric power systems. Annual report for FY 1996

    SciTech Connect

    Koncinski, W.S.; Hawsey, R.A.

    1997-05-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by US industry for commercial development of electric power applications of high temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1996 Annual Program Review held July 31 and August 1, 1996. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with US industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high temperature superconductor wire and wire-using systems.

  18. ORNL Superconducting Technology Program for electric power systems: Annual report for FY 1997

    SciTech Connect

    Koncinski, W.S.; O`Hara, L.M.; Hawsey, R.A.; Murphy, A.W.

    1998-03-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by US industry for commercial development of electric power applications of high temperature superconductivity. The two major elements of this program are wire development and applications development. This document describes the major research and developments activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 1997 Annual Program Review held July 21--23, 1997. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to cooperative projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with US industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high temperature superconductor wire and wire-using systems.

  19. ORNL Superconducting Technology Program for Electric Power Systems--Annual Report for FY 2001

    SciTech Connect

    Hawsey, RA

    2002-02-18

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy's Office of Energy Efficiency and Renewable Energy to develop the science and technology base needed by US industry for development of electric power applications of high-temperature superconductivity. The two major elements of this program are wire development and applications development. A new part of the wire research effort was the Accelerated Coated Conductor Initiative. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from recent open literature publications, presentations, and information prepared for the FY 2001 Annual Program Review held August 1-3, 2001. Aspects of ORNL's work that were presented at the International Cryogenic Materials Conference/Cryogenic Engineering Conference (July 2001) are included in this report as well. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. Interlaboratory teams are also in place on a number of industry-driven projects. Working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with US industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire-using systems.

  20. Impact of Hybrid Wet/Dry Cooling on Concentrating Solar Power Plant Performance

    SciTech Connect

    Wagner, M. J.; Kutscher, C.

    2010-01-01

    This paper examines the sensitivity of Rankine cycle plant performance to dry cooling and hybrid (parallel) wet/dry cooling combinations with the traditional wet-cooled model as a baseline. Plants with a lower temperature thermal resource are more sensitive to fluctuations in cooling conditions, and so the lower temperature parabolic trough plant is analyzed to assess the maximum impact of alternative cooling configurations. While low water-use heat rejection designs are applicable to any technology that utilizes a Rankine steam cycle for power generation, they are of special interest to concentrating solar power (CSP) technologies that are located in arid regions with limited water availability. System performance is evaluated using hourly simulations over the course of a year at Daggett, CA. The scope of the analysis in this paper is limited to the power block and the heat rejection system, excluding the solar field and thermal storage. As such, water used in mirror washing, maintenance, etc., is not included. Thermal energy produced by the solar field is modeled using NREL's Solar Advisor Model (SAM).

  1. Effect of Power Plant Cooling Water Discharge upon Water Quality in the Tokyo Bay

    NASA Astrophysics Data System (ADS)

    Kitahara, Kouichi; Wada, Akira; Uehara, Yoshikazu; Fukuoka, Ippei; Kawanaga, Mitsuhito; Takano, Tairyu

    Water quality in the Tokyo Bay is controlled by the load input from rivers, seawater currents, temperature variation, photosynthetic processes and others. On the other hand, 23.5 GJ/s of heat, as of 1995, is discharged into the Bay as cooling water effluent from thermal power plants along the coast. Low temperature water of bottom layers is pumped up and utilized as cooling water in thermal power plants. Although the intake and discharge of cooling water may influence water quality of coastal and inner bay areas where power plants are sited, few quantitative evaluations of the effects of cooling water on the water quality have been made yet. In the present study, we report a result of computations to predict the effects of cooling water discharge on the water quality of the Tokyo Bay in the summer, based on a "primary ecological model" for two thermal conditions: the current heat discharge of 23.5 GJ/s, and a heat discharge of 28.9 GJ/s which is expected in the future. Flow and water temperature distribution data, computed by Kitahara et al.(2003), were used to run the model. It was concluded that except in the vicinities of outlet points, water quality of the Tokyo Bay in the summer might be little changed by the future increase of 5.4 GJ/s of heat discharge.

  2. Injection locking of a high power ultraviolet laser diode for laser cooling of ytterbium atoms

    NASA Astrophysics Data System (ADS)

    Hosoya, Toshiyuki; Miranda, Martin; Inoue, Ryotaro; Kozuma, Mikio

    2015-07-01

    We developed a high-power laser system at a wavelength of 399 nm for laser cooling of ytterbium atoms with ultraviolet laser diodes. The system is composed of an external cavity laser diode providing frequency stabilized output at a power of 40 mW and another laser diode for amplifying the laser power up to 220 mW by injection locking. The systematic method for optimization of our injection locking can also be applied to high power light sources at any other wavelengths. Our system does not depend on complex nonlinear frequency-doubling and can be made compact, which will be useful for providing light sources for laser cooling experiments including transportable optical lattice clocks.

  3. Corrosion inhibition of closed cooling water auxiliary system for nuclear power plants

    SciTech Connect

    Burda, P.A.

    1990-11-06

    This patent describes a method of cooling nuclear power plants while providing corrosion protection. It comprises: circulating coolant in a closed water system, the coolant containing about 35 to 40 gallons of corrosion inhibitor per 10,000 gallons of water, the corrosion inhibitor being an aqueous solution of potassium molybdate, potassium nitrite, and potassium borate with not more than 160 ppm of sodium.

  4. A modular gas-cooled cermet reactor system for planetary base power

    SciTech Connect

    Jahshan, S.N.; Borkowski, J.A. )

    1993-01-15

    Fission nuclear power is foreseen as the source for electricity in planetary colonization and exploration. A six module gas-cooled, cermet-fueled reactor is proposed that can meet the design objectives. The highly enriched core is compact and can operate at high temperature for a long life. The helium coolant powers six modular Brayton cycles that compare favorably with the SP-100-based Brayton cycle.

  5. NREL Helps Cool the Power Electronics in Electric Vehicles (Fact Sheet)

    SciTech Connect

    Not Available

    2011-07-01

    Researchers at the National Renewable Energy Laboratory (NREL) are developing and demonstrating innovative heat-transfer technologies for cooling power electronics devices in hybrid and electric vehicles. In collaboration with 3M and Wolverine Tube, Inc., NREL is using surface enhancements to dissipate heat more effectively, permitting a reduction in the size of power electronic systems and potentially reducing the overall costs of electric vehicles.

  6. Cryogenic temperature monitoring in superconducting power transmission line at CERN with hybrid multi-point and distributed fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Chiuchiolo, A.; Palmieri, L.; Consales, M.; Giordano, M.; Bajas, H.; Galtarossa, A.; Bajko, M.; Cusano, A.

    2015-09-01

    Distributed and multi-point fiber-optic based measurements of cryogenic temperature down to 30 K are presented. Measurements have been performed along the cryostat of a superconducting power transmission line, which is currently being tested at CERN over a length of about 20 m. Multi-point measurements were based on two kinds of FBG with different coatings (epoxy and PMMA). In addition, distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimmide). Results confirm the viability of these approaches to monitor cryogenic temperatures along a superconducting transmission line.

  7. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    NASA Astrophysics Data System (ADS)

    Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

    2013-11-01

    This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

  8. High-power magnetron transmitter as an RF source for superconducting linear accelerators

    NASA Astrophysics Data System (ADS)

    Kazakevich, Grigory; Johnson, Rolland; Flanagan, Gene; Marhauser, Frank; Yakovlev, Vyacheslav; Chase, Brian; Lebedev, Valeri; Nagaitsev, Sergei; Pasquinelli, Ralph; Solyak, Nikolay; Quinn, Kenneth; Wolff, Daniel; Pavlov, Viatcheslav

    2014-10-01

    A concept of a high-power transmitter utilizing the Continuous Wave (CW) magnetrons, injection-locked by phase-modulated signals, and intended to operate within a wideband control feedback loop in phase and amplitude, is presented. This transmitter is proposed to drive Superconducting RF (SRF) cavities for intensity-frontier GeV-scale proton/ion linacs, such as the projected Fermilab proton linacs or linacs for Accelerator Driven System (ADS). The transmitter consists of two 2-cascade injection-locked magnetrons with outputs combined by a 3-dB hybrid. The transmitter performance was modelled using CW, S-Band, 1 kW magnetrons. A wideband dynamic control of magnetrons, required for the superconducting linacs, was realized using the magnetrons, injection-locked by the phase-modulated signals. The capabilities of the magnetrons injection-locked by the phase-modulated signals and adequateness for feeding of SRF cavities have been verified by measurements of the magnetrons phase performance, by measurements of the transfer function magnitude characteristics of single and 2-cascade magnetrons in the phase modulation domain, and by measurements of spectra of carrier frequency of the magnetron. At the ratio of power of locking signal to output power of ?-13 dB (in 2-cascade scheme per magnetron) a phase modulation bandwidth is over 1.0 MHz for injection-locked CW single magnetrons and a 2-cascade setup. The carrier frequency spectra (width of ~1 Hz at the level of -60 dBc) measured with the magnetron, injection-locked by a phase-modulated signal, did not demonstrate broadening at wide range of magnitude and frequency of the phase modulation. The wideband dynamic management of output power of the transmitter model has been first experimentally demonstrated using combined in power magnetrons, injection-locked by the phase-modulated signals. Experiments with the injection-locked magnetrons adequately emulated the wideband dynamic control with a feedback control system, which will allow to suppress all known parasitic modulation of the accelerating field in the SRF cavities. The magnetron transmitter concept, tests of the transmitter models and injection-locking of magnetrons by phase-modulated signals are discussed in this work.

  9. Long-term research in Japan: amorphous metals, metal oxide varistors, high-power semiconductors and superconducting generators

    SciTech Connect

    Hane, G.J.; Yorozu, M.; Sogabe, T.; Suzuki, S.

    1985-04-01

    The review revealed that significant activity is under way in the research of amorphous metals, but that little fundamental work is being pursued on metal oxide varistors and high-power semiconductors. Also, the investigation of long-term research program plans for superconducting generators reveals that activity is at a low level, pending the recommendations of a study currently being conducted through Japan's Central Electric Power Council.

  10. Performance analysis of radiation cooled dc transmission lines for high power space systems

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.

    1985-01-01

    As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on hte power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

  11. Development of fundamental power coupler for high-current superconducting RF cavity

    SciTech Connect

    Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

    2012-05-20

    Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.

  12. Energy penalty analysis of possible cooling water intake structurerequirements on existing coal-fired power plants.

    SciTech Connect

    Veil, J. A.; Littleton, D. J.; Gross, R. W.; Smith, D. N.; Parsons, E.L., Jr.; Shelton, W. W.; Feeley, T. J.; McGurl, G. V.

    2006-11-27

    Section 316(b) of the Clean Water Act requires that cooling water intake structures must reflect the best technology available for minimizing adverse environmental impact. Many existing power plants in the United States utilize once-through cooling systems to condense steam. Once-through systems withdraw large volumes (often hundreds of millions of gallons per day) of water from surface water bodies. As the water is withdrawn, fish and other aquatic organisms can be trapped against the screens or other parts of the intake structure (impingement) or if small enough, can pass through the intake structure and be transported through the cooling system to the condenser (entrainment). Both of these processes can injure or kill the organisms. EPA adopted 316(b) regulations for new facilities (Phase I) on December 18, 2001. Under the final rule, most new facilities could be expected to install recirculating cooling systems, primarily wet cooling towers. The EPA Administrator signed proposed 316(b) regulations for existing facilities (Phase II) on February 28, 2002. The lead option in this proposal would allow most existing facilities to achieve compliance without requiring them to convert once-through cooling systems to recirculating systems. However, one of the alternate options being proposed would require recirculating cooling in selected plants. EPA is considering various options to determine best technology available. Among the options under consideration are wet-cooling towers and dry-cooling towers. Both types of towers are considered to be part of recirculating cooling systems, in which the cooling water is continuously recycled from the condenser, where it absorbs heat by cooling and condensing steam, to the tower, where it rejects heat to the atmosphere before returning to the condenser. Some water is lost to evaporation (wet tower only) and other water is removed from the recirculating system as a blow down stream to control the building up of suspended and dissolved solids. Makeup water is withdrawn, usually from surface water bodies, to replace the lost water. The volume of makeup water is many times smaller than the volume needed to operate a once-through system. Although neither the final new facility rule nor the proposed existing facility rule require dry cooling towers as the national best technology available, the environmental community and several States have supported the use of dry-cooling technology as the appropriate technology for addressing adverse environmental impacts. It is possible that the requirements included in the new facility rule and the ongoing push for dry cooling systems by some stakeholders may have a role in shaping the rule for existing facilities. The temperature of the cooling water entering the condenser affects the performance of the turbine--the cooler the temperature, the better the performance. This is because the cooling water temperature affects the level of vacuum at the discharge of the steam turbine. As cooling water temperatures decrease, a higher vacuum can be produced and additional energy can be extracted. On an annual average, once-through cooling water has a lower temperature than recirculated water from a cooling tower. By switching a once-through cooling system to a cooling tower, less energy can be generated by the power plant from the same amount of fuel. This reduction in energy output is known as the energy penalty. If a switch away from once-through cooling is broadly implemented through a final 316(b) rule or other regulatory initiatives, the energy penalty could result in adverse effects on energy supplies. Therefore, in accordance with the recommendations of the Report of the National Energy Policy Development Group (better known as the May 2001 National Energy Policy), the U.S. Department of Energy (DOE), through its Office of Fossil Energy, National Energy Technology Laboratory (NETL), and Argonne National Laboratory (ANL), has studied the energy penalty resulting from converting plants with once-through cooling to wet towers or indirect-dry towers. Five locations--Delaware River Basin (Philadelphia), Michigan/Great Lakes (Detroit), Ohio River Valley (Indianapolis), South (Atlanta), and Southwest (Yuma)--were modeled using an ASPEN simulator model. The model evaluated the performance and energy penalty for hypothetical 400-MW coal-fired plants that were retrofitted from using once-through cooling systems to wet- and dry-recirculating systems. The modeling was initially done to simulate the hottest time of the year using temperature input values that are exceeded only 1 percent of the time between June through September at each modeled location. These are the same temperature inputs commonly used by cooling tower designers to ensure that towers perform properly under most climatic conditions.

  13. Advanced high-cooling power 2-stage Gifford-McMahon refrigerator systems

    NASA Astrophysics Data System (ADS)

    Jakob, Gerd; Lizon, Jean-Louis

    2010-07-01

    This paper describes the development of high-cooling power systems by making use of multiple cold head operation with a minimized number of compressor units. These advanced cooling systems were investigated for optimization and their Carnot efficiencies were analyzed. Test series were performed to monitor and rank some of their critical operation parameters. Operating envelopes for different cold head / compressor configurations were defined for applications in various VLT instruments. This new concept of providing high pressure helium as a service point for a large number of detached cold heads is a first step towards a new cryogenic facility concept for the E-ELT.

  14. Simulation of chip-size electrocaloric refrigerator with high cooling-power density

    NASA Astrophysics Data System (ADS)

    Gu, Haiming; Craven, Brent; Qian, Xiaoshi; Li, Xinyu; Cheng, Ailan; Zhang, Q. M.

    2013-03-01

    The large electrocaloric effect that found in ferroelectric polymers creates unique opportunity for developing high performance chip scale solid state refrigerator. This letter presents a finite volume simulation study and shows that by employing solid state regenerators and the micro-heat pumping mechanism used in the thermoacoustic cooling, a compact Electrocaloric Oscillatory Refrigeration (ECOR) device can be realized. The simulation results demonstrate that a 1 cm-long ECOR device can provide 9 W/cm3 volumetric cooling power density at 20 K temperature span. By tuning the device parameters in the model, the ECOR can reach more than 50% of the Carnot efficiency.

  15. Organohalogen products from chlorination of cooling water at nuclear power stations

    SciTech Connect

    Bean, R.M.

    1983-10-01

    Eight nuclear power units at seven locations in the US were studied to determine the effects of chlorine, added as a biocide, on the composition of cooling water discharge. Water, sediment and biota samples from the sites were analyzed for total organic halogen and for a variety of organohalogen compounds. Haloforms were discharged from all plants studied, at concentrations of a few ..mu..g/L (parts-per-billion). Evidence was obtained that power plants with cooling towers discharge a significant portion of the haloforms formed during chlorination to the atmosphere. A complex mixture of halogenated phenols was found in the cooling water discharges of the power units. Cooling towers can act to concentrate halogenated phenols to levels approaching those of the haloforms. Examination of samples by capillary gas chromatography/mass spectrometry did not result in identification of any significant concentrations of lipophilic base-neutral compounds that could be shown to be formed by the chlorination process. Total concentrations of lipophilic (Bioabsorbable) and volatile organohalogen material discharged ranged from about 2 to 4 ..mu..g/L. Analysis of sediment samples for organohalogen material suggests that certain chlorination products may accumulate in sediments, although no tissue bioaccumulation could be demonstrated from analysis of a limited number of samples. 58 references, 25 figures, 31 tables.

  16. Nano Superconducting Quantum Interference device: A powerful tool for nanoscale investigations

    NASA Astrophysics Data System (ADS)

    Granata, Carmine; Vettoliere, Antonio

    2016-02-01

    The magnetic sensing at nanoscale level is a promising and interesting research topic of nanoscience. Indeed, magnetic imaging is a powerful tool for probing biological, chemical and physical systems. The study of small spin cluster, like magnetic molecules and nanoparticles, single electron, cold atom clouds, is one of the most stimulating challenges of applied and basic research of the next years. In particular, the magnetic nanoparticle investigation plays a fundamental role for the modern material science and its relative technological applications like ferrofluids, magnetic refrigeration and biomedical applications, including drug delivery, hyper-thermia cancer treatment and magnetic resonance imaging contrast-agent. Actually, one of the most ambitious goals of the high sensitivity magnetometry is the detection of elementary magnetic moment or spin. In this framework, several efforts have been devoted to the development of a high sensitivity magnetic nanosensor pushing sensing capability to the individual spin level. Among the different magnetic sensors, Superconducting QUantum Interference Devices (SQUIDs) exhibit an ultra high sensitivity and are widely employed in numerous applications. Basically, a SQUID consists of a superconducting ring (sensitive area) interrupted by two Josephson junctions. In the recent years, it has been proved that the magnetic response of nano-objects can be effectively measured by using a SQUID with a very small sensitive area (nanoSQUID). In fact, the sensor noise, expressed in terms of the elementary magnetic moment (spin or Bohr magneton), is linearly dependent on the SQUID loop side length. For this reason, SQUIDs have been progressively miniaturized in order to improve the sensitivity up to few spin per unit of bandwidth. With respect to other techniques, nanoSQUIDs offer the advantage of direct measurement of magnetization changes in small spin systems. In this review, we focus on nanoSQUIDs and its applications. In particular, we will discuss the motivations, the theoretical aspects, the fabrication techniques, the different nanoSQUIDs and the relative nanoscale applications.

  17. Prospects for the medium- and long-term development of China`s electric power industry and analysis of the potential market for superconductivity technology

    SciTech Connect

    Li, Z.

    1998-05-01

    First of all, overall economic growth objectives in China are concisely and succinctly specified in this report. Secondly, this report presents a forecast of energy supply and demand for China`s economic growth for 2000--2050. In comparison with the capability of energy construction in China in the future, a gap between supply and demand is one of the important factors hindering the sustainable development of Chain`s economy. The electric power industry is one of China`s most important industries. To adopt energy efficiency through high technology and utilizing energy adequately is an important technological policy for the development of China`s electric power industry in the future. After briefly describing the achievements of China`s electric power industry, this report defines the target areas and policies for the development of hydroelectricity and nuclear electricity in the 2000s in China, presents the strategic position of China`s electric power industry as well as objectives and relevant plans of development for 2000--2050. This report finds that with the discovery of superconducting electricity, the discovery of new high-temperature superconducting (HTS) materials, and progress in materials techniques, the 21st century will be an era of superconductivity. Applications of superconductivity in the energy field, such as superconducting storage, superconducting transmission, superconducting transformers, superconducting motors, its application in Magneto-Hydro-Dynamics (MHD), as well as in nuclear fusion, has unique advantages. Its market prospects are quite promising. 12 figs.

  18. A gas-cooled cermet reactor system for planetary base power

    SciTech Connect

    Jahshan, S.N.; Borkowski, J.A.

    1992-01-01

    Fission nuclear power is foreseen as the source for electricity in colonization exploration. A gas-cooled, cermet-fueled reactor is proposed that can meet many of the design objectives. The highly enriched core is compact and can operate at high temperature for a long life. The helium coolant powers a Brayton cycle that compares well with the SP-100-based Brayton cycle. The power cycle can be upgraded further under certain siting-related conditions by the addition of a low temperature Rankine cycle.

  19. A gas-cooled cermet reactor system for planetary base power

    SciTech Connect

    Jahshan, S.N.; Borkowski, J.A.

    1992-08-01

    Fission nuclear power is foreseen as the source for electricity in colonization exploration. A gas-cooled, cermet-fueled reactor is proposed that can meet many of the design objectives. The highly enriched core is compact and can operate at high temperature for a long life. The helium coolant powers a Brayton cycle that compares well with the SP-100-based Brayton cycle. The power cycle can be upgraded further under certain siting-related conditions by the addition of a low temperature Rankine cycle.

  20. Environmental problems associated with decommissioning the Chernobyl Nuclear Power Plant Cooling Pond.

    PubMed

    Oskolkov, B Ya; Bondarkov, M D; Gaschak, S P; Maksymenko, A M; Maksymenko, V M; Martynenko, V I; Farfn, E B; Jannik, G T; Marra, J C

    2010-11-01

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination of their territories is an imperative issue. Significant problems may result from decommissioning of cooling ponds with residual radioactive contamination. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained water reservoirs in the Chernobyl region and Ukrainian and Belorussian Polesye region. The 1986 ChNPP Reactor Unit Number Four significantly contaminated the ChNPP Cooling Pond. The total radionuclide inventory in the ChNPP Cooling Pond bottom deposits are as follows: ?Cs: 16.28 2.59 TBq; ??Sr: 2.4 0.48 TBq; and ?+??Pu: 0.00518 0.00148 TBq. The ChNPP Cooling Pond is inhabited by over 500 algae species and subspecies, over 200 invertebrate species, and 36 fish species. The total mass of the living organisms in the ChNPP Cooling Pond is estimated to range from about 60,000 to 100,000 tons. The territory adjacent to the ChNPP Cooling Pond attracts many birds and mammals (178 bird species and 47 mammal species were recorded in the Chernobyl Exclusion Zone). This article describes several options for the ChNPP Cooling Pond decommissioning and environmental problems associated with its decommissioning. The article also provides assessments of the existing and potential exposure doses for the shoreline biota. For the 2008 conditions, the estimated total dose rate values were 11.4 40 ?Gy h? for amphibians, 6.3 ?Gy h? for birds, 15.1 ?Gy h? for mammals, and 10.3 ?Gy h? for reptiles, with the recommended maximum dose rate being equal to 40 ?Gy h?. However, drying the ChNPP Cooling Pond may increase the exposure doses to 94.5 ?Gy h? for amphibians, 95.2 ?Gy h? for birds, 284.0 ?Gy h? for mammals, and 847.0 ?Gy h? for reptiles. All of these anticipated dose rates exceed the recommended values. PMID:20938234

  1. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    SciTech Connect

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to determine if WSAC technology could cool process water at cycles of concentration considered highly scale forming for mechanical draft cooling towers. At the completion of testing, there was no visible scale on the heat transfer surfaces and cooling was sustained throughout the test period. The application of the WARMF decision framework to the San Juan Basis showed that drought and increased temperature impact water availability for all sectors (agriculture, energy, municipal, industry) and lead to critical shortages. WARMF-ZeroNet, as part of the integrated ZeroNet decision support system, offers stakeholders an integrated approach to long-term water management that balances competing needs of existing water users and economic growth under the constraints of limited supply and potential climate change.

  2. Microwave power coupler for a superconducting multiple-cell cavity for accelerator application and its testing procedures

    SciTech Connect

    Li, Jianjian

    2008-12-01

    Superconducting cavity resonators offer the advantage of high field intensity for a given input power, making them an attractive contender for particle accelerator applications. Power coupling into a superconducting cavity employed in a particle accelerator requires unique provisions to maintain high vacuum and cryogenic temperature on the cavity side, while operating with ambient conditions on the source side. Components introduced to fulfill mechanical requirements must show negligible obstruction of the propagation of the microwave with absence of critical locations that may give rise to electron multipaction, leading to a multiple section design, instead of an aperture, a probe, or a loop structure as found in conventional cavities. A coaxial power coupler for a superconducting multiple-cell cavity at 3.9 GHz has been developed. The cavity is intended to be employed as an accelerator to provide enhanced electron beam quality in a free-electron laser in Hamburg (FLASH) user facility. The design of the coupler called for two windows to sustain high vacuum in the cavity and two bellows to accommodate mechanical dimensional changes resulting from cryogenics. Suppression of multipacting was accomplished by the choice of conductor dimensions and materials with low second yield coefficients. Prior to integration with the cavity, the coupler was tested for intrinsic properties in a back-to-back configuration and conditioned for high-power operation with increasing power input. Maximum incident power was measured to be 61 kW. When integrated with the superconducting cavity, a loaded quality factor of 9 x 10{sup 5} was measured by transient method. Coupler return loss and insertion loss were estimated to be around -21 dB and -0.2 dB, respectively.

  3. Development of practical high temperature superconducting wire for electric power application

    NASA Technical Reports Server (NTRS)

    Hawsey, Robert A.; Sokolowski, Robert S.; Haldar, Pradeep; Motowidlo, Leszek R.

    1995-01-01

    The technology of high temperature superconductivity has gone from beyond mere scientific curiousity into the manufacturing environment. Single lengths of multifilamentary wire are now produced that are over 200 meters long and that carry over 13 amperes at 77 K. Short-sample critical current densities approach 5 x 104 A/sq cm at 77 K. Conductor requirements such as high critical current density in a magnetic field, strain-tolerant sheathing materials, and other engineering properties are addressed. A new process for fabricating round BSCCO-2212 wire has produced wires with critical current densities as high as 165,000 A/sq cm at 4.2 K and 53,000 A/sq cm at 40 K. This process eliminates the costly, multiple pressing and rolling steps that are commonly used to develop texture in the wires. New multifilamentary wires with strengthened sheathing materials have shown improved yield strengths up to a factor of five better than those made with pure silver. Many electric power devices require the wire to be formed into coils for production of strong magnetic fields. Requirements for coils and magnets for electric power applications are described.

  4. Progress in development of high temperature superconducting wire for electric power applications

    SciTech Connect

    Hawsey, R.A.; Sokolowski, R.S.; Haldar, P.; Motowidlo, L.R.

    1994-12-31

    The technology of high temperature superconductivity has gone beyond mere scientific curiosity and into the manufacturing environment. Single lengths of multifilamentary wire are now produced that are over 200 meters long and that carry over 13 amperes at 77 K. Short-sample critical current densities approach 5 x 10{sup 4} A/cm{sup 2} at 77 K. Conductor requirements such as high critical current density in a magnetic field, strain-tolerant sheathing materials, and other engineering properties are addressed. A new process for fabricating round BSCCO-2212 wire has produced wires with critical current densities as high as 165,000 A/cm{sup 2} at 4.2 K and 53,000 A/cm{sup 2} at 40 K. This process eliminates the costly, multiple pressing and rolling steps that are commonly used to develop texture in the wires. New multifilamentary wires with strengthened sheathing materials have shown improved yield strengths up to a factor of five better than those made with pure silver. Many electric power devices require the wire to be formed into coils for production of strong magnetic fields. Requirements for coils and magnets for electric power applications are described.

  5. Development of practical high temperature superconducting wire for electric power applications

    SciTech Connect

    Hawsey, R.A.; Sokolowski, R.S.; Haldar, P.; Motowidlo, L.R.

    1994-09-01

    The technology of high temperature superconductivity has gone from beyond mere scientific curiosity into the manufacturing environment. Single lengths of multifilamentary wire are now produced that are over 200 meters long and that carry over 13 amperes at 77 K. Short-sample critical current densities approach 5 {times} 10{sup 4} A/cm{sup 2} at 77 K. Conductor requirements such as high critical current density in a magnetic field, strain-tolerant sheathing materials, and other engineering properties are addressed. A new process for fabricating round BSCCO-2212 wire has produced wires with critical current densities as high as 165,000 A/cm{sup 2} at 4.2 K and 53,000 A/cm{sup 2} at 40 K. This process eliminates the costly, multiple pressing and rolling steps that are commonly used to develop texture in the wires. New multifilamentary wires with strengthened sheathing materials have shown improved yield strengths up to a factor of five better than those made with pure silver. Many electric power devices require the wire to be formed into coils for production of strong magnetic fields. Requirements for coils and magnets for electric power applications are described.

  6. The design and testing of a cooling system using mixed solid cryogen for a portable superconducting magnetic energy storage system

    NASA Astrophysics Data System (ADS)

    Kim, K. L.; Song, J. B.; Choi, J. H.; Kim, S. H.; Y Koh, D.; Seong, K. C.; Chang, H. M.; Lee, H. G.

    2010-12-01

    A cooling system that uses solid nitrogen (SN2) as an effective heat capacity enhancer was recently introduced to enhance the thermal stability of the HTS SMES. Since SN2 has a large enthalpy with minimal weight, it enables a portable system by increasing the recooling to recooling time period (RRTP). However, contact between the SN2 and HTS SMES magnet can be broken by repeated thermal disturbances (thermal 'dry-out' phenomena). Therefore, it is essential to improve thermal contact to allow full use of the heat capacity of SN2. This study evaluated the effect of using a mixture containing SN2 and a small amount of a liquid cryogen as a cooling system in the HTS SMES system. The performance of the cooling system was evaluated using the mixed cryogen and compared with that of SN2 alone. In addition, the role of liquid neon (Ne) as a heat exchanger between SN2 and the HTS SMES magnet is discussed.

  7. Air-Cooled Heat Exchanger for High-Temperature Power Electronics: Preprint

    SciTech Connect

    Waye, S. K.; Lustbader, J.; Musselman, M.; King, C.

    2015-05-06

    This work demonstrates a direct air-cooled heat exchanger strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.

  8. Accumulation of /sup 137/Cs in commercial fish of the Belyarsk nuclear power station cooling supply

    SciTech Connect

    Trapeznikova, V.N.; Kulikov, N.V.; Trapeznikov, A.V.

    1984-07-01

    Results are presented of a comparative study of the accumulation of /sup 137/Cs in basic species of commercial fish of the Beloyarsk reservoir which is used as the cooling supply for the Beloyarsk nuclear power station. Possible reasons for interspecies differences in accumulation of the radionuclide are indicated, and the increased accumulation of /sup 137/Cs by free-living fish in the zone of heated water effluent from the station and the reduced accumulation of the emitter in carp, which are cultivated on artificial food in cages, are noted. Levels of the content of the radionuclide are compared in roach and farm carp from the cooling supplies of the Beloyarsk station and the Reftinsk power plant in the Urals.

  9. Research of new packaging and cooling technique for high power fiber laser used pump coupler

    NASA Astrophysics Data System (ADS)

    Mu, Wei; Si, Xu; Lin, Ya-jun; Xu, Cheng-lin; Ma, Yun-liang; Xiao, Chun

    2015-10-01

    This article analyzes the advantages and disadvantages of a packaging structure for pump coupler, where common heat conduction material is used. In this study, the possibility of using new technology of thermal conductivity is discussed. We also proposes a solution that make the function and effect of package more uniform. A serial of experiments are done for research the cooling effect and the working reliability of the fiber combiners and couplers. Experiment proves that after improved method of package, the cooling speed increases significantly comparing the sample with old type of package technique. The technique discussed in this paper will make the high power fiber laser working long time with steady power output and high efficiency.

  10. Macro-channel cooled high power fiber coupled diode lasers exceeding 1.2kW of output power

    NASA Astrophysics Data System (ADS)

    Koenning, Tobias; Alegria, Kim; Wang, Zuolan; Segref, Armin; Stapleton, Dean; Fabender, Wilhelm; Flament, Marco; Rotter, Karsten; Noeske, Axel; Biesenbach, Jens

    2011-03-01

    We report on a new series of fiber coupled diode laser modules exceeding 1.2kW of single wavelength optical power from a 400um / 0.2NA fiber. The units are constructed from passively cooled laser bars as opposed to other comparably powered, commercially available modules that use micro-channel heat-sinks. Micro-channel heat sinks require cooling water to meet demanding specifications and are therefore prone to failures due to contamination and increase the overall cost to operate and maintain the laser. Dilas' new series of high power fiber coupled diode lasers are designed to eliminate micro channel coolers and their associated failure mechanisms. Low-smile soldering processes were developed to maximize the brightness available from each diode laser bar. The diode laser brightness is optimally conserved using Dilas' recently developed propriety laser bar stacking geometry and optics. A total of 24 bars are coupled into a single fiber core using a polarization multiplexing scheme. The modular design permits further power scaling through wavelength multiplexing. Other customer critical features such as industrial grade fibers, pilot beams, fiber interlocks and power monitoring are standard features on these modules. The optical design and the beam parameter calculations will be presented to explain the inherit design trade offs. Results for single and dual wavelengths modules will be presented.

  11. Thermal Insulation Test of new Designed Cryogenic Pipes for the Superconducting DC Power Transmission System in Ishikari, Japan

    NASA Astrophysics Data System (ADS)

    Watanabe, Hirofumi; Ivanov, Yury V.; Hamabe, Makoto; Chikumoto, Noriko; Takano, Hirohisa; Yamaguchi, Satarou

    New cryogenic pipes were designed for the superconducting DC power transmission systems constructed in the Ishikari area in Japan. In the designs two inner pipes, for the cable and for the return of liquid nitrogen, are installed in a single outer pipe for the circulation of liquid nitrogen. In contrast to the cryogenic pipes commonly used for the superconducting power transmission, in which corrugated pipes are used, straight pipes are adopted to reduce pressure loss of the circulation of the liquid nitrogen. A radiation shield to reduce heat leak to the inner pipe for the cable is adopted in one of the designs. Two types of test pipes with and without the radiation shield were constructed and heat leak of these pipes was measured to evaluate the effciency of the test pipes. The lowest heat leak of 0.73 W/m was measured for the test pipe with the radiation shield.

  12. Topographic power spectral density study of the effect of surface treatment processes on niobium for superconducting radio frequency accelerator cavities

    SciTech Connect

    Charles Reece, Hui Tian, Michael Kelley, Chen Xu

    2012-04-01

    Microroughness is viewed as a critical issue for attaining optimum performance of superconducting radio frequency accelerator cavities. The principal surface smoothing methods are buffered chemical polish (BCP) and electropolish (EP). The resulting topography is characterized by atomic force microscopy (AFM). The power spectral density (PSD) of AFM data provides a more thorough description of the topography than a single-value roughness measurement. In this work, one dimensional average PSD functions derived from topography of BCP and EP with different controlled starting conditions and durations have been fitted with a combination of power law, K correlation, and shifted Gaussian models to extract characteristic parameters at different spatial harmonic scales. While the simplest characterizations of these data are not new, the systematic tracking of scale-specific roughness as a function of processing is new and offers feedback for tighter process prescriptions more knowledgably targeted at beneficial niobium topography for superconducting radio frequency applications.

  13. Microwave properties of YBa2Cu3O(7-delta) high-transition-temperature superconducting thin films measured by the power transmission method

    NASA Technical Reports Server (NTRS)

    Miranda, F. A.; Gordon, W. L.; Bhasin, K. B.; Heinen, V. O.; Warner, J. D.

    1991-01-01

    The microwave response of YBa2Cu3O(7-delta) superconducting thin films deposited on LaAlO3, MgO, YSZ, and LaGaO3 substrates are studied. It is found that the microwave transmission properties are very weakly dependent on temperature in the normal state but change drastically upon transition to the superconducting state. In particular, the transmission decreases and there is a negative phase shift with respect to the phase at room temperature when the sample is cooled through its transition temperature. The magnetic penetration depth for all the films was determined from the surface reactance of the films. The microwave complex conductivity is determined in both the normal and the superconducting state. It is observed that both sigma1 and sigma2 increase in transition to the superconducting state. The surface resistivity is calculated for all the films.

  14. Design of 154 kV Extra-High-Voltage Prototype SF6 Bushing for Superconducting Electric Power Applications

    NASA Astrophysics Data System (ADS)

    Koo, Ja-yoon; Seong, Jae-gyu; Hwang, Jae-sang; Lee, Bang-wook; Lee, Sang-hwa

    2012-09-01

    One of the critical components to be developed for high-voltage superconducting devices, such as superconducting transformers, cables, and fault current limiters, is a high-voltage bushing to supply a high current to devices without insulation difficulties in cryogenic environments. Unfortunately, suitable bushings for high-temperature-superconductivity (HTS) equipment have not been fully developed to address cryogenic insulation issues. As a fundamental step towards developing the optimum design of the 154 kV prototype SF6 bushing of HTS devices, the puncture and creepage breakdown voltages of glass-fiber-reinforced-plastic (GFRP) were analyzed with a variety of configurations of electrodes and gap distances in the insulation material. And design factors of high-voltage cryogenic bushings were obtained from the result of tests. Finally, the withstand voltage tests of manufacturing a 154 kV extra-high-voltage (EHV) prototype bushing has been performed. Consequently, we verified the insulation level of the newly designed 154 kV EHV cryogenic prototype bushings for superconducting electric power applications.

  15. Heterogeneous Superconducting Low-Noise Sensing Coils

    NASA Technical Reports Server (NTRS)

    Hahn, Inseob; Penanen, Konstantin I.; Ho Eom, Byeong

    2008-01-01

    A heterogeneous material construction has been devised for sensing coils of superconducting quantum interference device (SQUID) magnetometers that are subject to a combination of requirements peculiar to some advanced applications, notably including low-field magnetic resonance imaging for medical diagnosis. The requirements in question are the following: The sensing coils must be large enough (in some cases having dimensions of as much as tens of centimeters) to afford adequate sensitivity; The sensing coils must be made electrically superconductive to eliminate Johnson noise (thermally induced noise proportional to electrical resistance); and Although the sensing coils must be cooled to below their superconducting- transition temperatures with sufficient cooling power to overcome moderate ambient radiative heat leakage, they must not be immersed in cryogenic liquid baths. For a given superconducting sensing coil, this combination of requirements can be satisfied by providing a sufficiently thermally conductive link between the coil and a cold source. However, the superconducting coil material is not suitable as such a link because electrically superconductive materials are typically poor thermal conductors. The heterogeneous material construction makes it possible to solve both the electrical- and thermal-conductivity problems. The basic idea is to construct the coil as a skeleton made of a highly thermally conductive material (typically, annealed copper), then coat the skeleton with an electrically superconductive alloy (typically, a lead-tin solder) [see figure]. In operation, the copper skeleton provides the required thermally conductive connection to the cold source, while the electrically superconductive coating material shields against Johnson noise that originates in the copper skeleton.

  16. Application of a combined superconducting fault current limiter and STATCOM to enhancement of power system transient stability

    NASA Astrophysics Data System (ADS)

    Mahdad, Belkacem; Srairi, K.

    2013-12-01

    Stable and reliable operation of the power system network is dependent on the dynamic equilibrium between energy production and power demand under large disturbance such as short circuit or important line tripping. This paper investigates the use of combined model based superconducting fault current limiter (SFCL) and shunt FACTS Controller (STATCOM) for assessing the transient stability of a power system considering the automatic voltage regulator. The combined model located at a specified branch based on voltage stability index using continuation power flow. The main role of the proposed combined model is to achieve simultaneously a flexible control of reactive power using STATCOM Controller and to reduce fault current using superconducting technology based SFCL. The proposed combined model has been successfully adapted within the transient stability program and applied to enhance the transient power system stability of the WSCC9-Bus system. Critical clearing time (CCT) has been used as an index to evaluate and validate the contribution of the proposed coordinated Controller. Simulation results confirm the effectiveness and perspective of this combined Controller to enhance the dynamic power system performances.

  17. Power flattening on modified CANDLE small long life gas-cooled fast reactor

    SciTech Connect

    Monado, Fiber; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Ariani, Menik; Sekimoto, Hiroshi

    2014-09-30

    Gas-cooled Fast Reactor (GFR) is one of the candidates of next generation Nuclear Power Plants (NPPs) that expected to be operated commercially after 2030. In this research conceptual design study of long life 350 MWt GFR with natural uranium metallic fuel as fuel cycle input has been performed. Modified CANDLE burn-up strategy with first and second regions located near the last region (type B) has been applied. This reactor can be operated for 10 years without refuelling and fuel shuffling. Power peaking reduction is conducted by arranging the core radial direction into three regions with respectively uses fuel volume fraction 62.5%, 64% and 67.5%. The average power density in the modified core is about 82 Watt/cc and the power peaking factor decreased from 4.03 to 3.43.

  18. Contingency power for small turboshaft engines using water injection into turbine cooling air

    NASA Technical Reports Server (NTRS)

    Biesiadny, Thomas J.; Klann, Gary A.; Clark, David A.; Berger, Brett

    1987-01-01

    Because of one engine inoperative requirements, together with hot-gas reingestion and hot day, high altitude takeoff situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stresses is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  19. Contingency power for a small turboshaft engine by using water injection into turbine cooling air

    NASA Technical Reports Server (NTRS)

    Biesiadny, Thomas J.; Klann, Gary A.

    1992-01-01

    Because of one-engine-inoperative (OEI) requirements, together with hot-gas reingestion and hot-day, high-altitude take-off situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation by using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stress is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  20. Power flattening on modified CANDLE small long life gas-cooled fast reactor

    NASA Astrophysics Data System (ADS)

    Monado, Fiber; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Ariani, Menik; Sekimoto, Hiroshi

    2014-09-01

    Gas-cooled Fast Reactor (GFR) is one of the candidates of next generation Nuclear Power Plants (NPPs) that expected to be operated commercially after 2030. In this research conceptual design study of long life 350 MWt GFR with natural uranium metallic fuel as fuel cycle input has been performed. Modified CANDLE burn-up strategy with first and second regions located near the last region (type B) has been applied. This reactor can be operated for 10 years without refuelling and fuel shuffling. Power peaking reduction is conducted by arranging the core radial direction into three regions with respectively uses fuel volume fraction 62.5%, 64% and 67.5%. The average power density in the modified core is about 82 Watt/cc and the power peaking factor decreased from 4.03 to 3.43.

  1. Conductively cooled high-power high-brightness bars and fiber-coupled arrays

    NASA Astrophysics Data System (ADS)

    Zhou, Hailong; Mondry, Mark; Fouksman, Michael; Weiss, Eli; Anikitchev, Serguei; Kennedy, Keith; Li, Jun; Zucker, Erik; Rudy, Paul; Kongas, Jukka; Haapamaa, Jouko; Lehkonen, Sami

    2005-03-01

    Solid-state-laser and fiber laser pumping, reprographics, medical and materials processing applications require high power, high-brightness bars and fiber-coupled arrays. Conductively cooled laser diode bars allow customers to simplify system design and reduce operational size, weight, and costs. We present results on next generation high brightness, high reliability bars and fiber-coupled arrays at 790-830 nm, 940 nm and 980 nm wavelengths. By using novel epitaxial structures, we have demonstrated highly reliable 808 nm, 30% fill-factor conductively cooled bars operating at 60W CW mode, corresponding to a linear power density (LPD) of 20 mW/&mum. At 25C, the bars have shown greater than 50% wall-plug-efficiency (WPE) when operating at 60W. Our novel approach has also reduced the fast-axis divergence FWHM from 31 to less than 24. These bars have a 50% brightness improvement compared to our standard products with this geometry. At 980nm, we have demonstrated greater than 100W CW from 20% fill-factor conductively cooled bars, corresponding to a LPD of 50 mW/?m. At 25C, the WPE for 976nm bars consistently peaks above 65% and remains greater than 60% at 100W. We coupled the beam output from those high-brightness bars into fiber-array-packages ("FAPs"), and we also achieved high-brightness and high-efficiency FAPs. We demonstrated 60W from a 600?m core-diameter fiber-bundle with a high WPE of 55%, and a low numerical aperture of 0.115. The brightness of such FAPs is four times higher than our standard high-power 40W FAP products at Coherent. Ongoing life test data suggests an extrapolated lifetime greater than 10,000 hours at 80W CW operating-condition based on 30%FF conductively cooled bar geometry.

  2. Fibre-coupled air-cooled high-power diode laser systems

    NASA Astrophysics Data System (ADS)

    Bartoschewski, Daniel; Meinschien, Jens; Fornahl, Udo

    2008-02-01

    Current laser systems based on high-power laser diode bars need active cooling either water cooling or the use of thermo-electric coolers to ensure an adequate operating temperature for a reasonable lifetime. Here is a solution with a bonded fin heat sink and forced ventilation introduced, a diode laser bar with an improved efficiency and a low thermal resistance as well as an optical system for a highly efficient fibre coupling. With this system it is possible to couple 25 Watt continuous wave power from a single laser diode bar on a passive heat sink into a fibre with 200 μm core diameter. The basis for this performance is a heat sink with an exceptionally low thermal resistance. Several new features are introduced to reach a low overall gradient between the laser diode temperature and the ambient temperature. In addition, it does geometrically fit to the layout of the optical design. Shape and aspect ratio of both heat sink and housing of the laser system are matched to each other. Another feature is the use of hard-soldered or pressed bars to achieve a thermo-mechanically stable performance. The long-term thermal characteristic was tested. The operation temperature comes to saturation after about 30 minutes. Therefore it can be used for continuous wave operation at 25 Watt output power. At a quasi continuous operation at 70 percent duty cycle a peak power of 30 Watt out of the fibre is possible. From this technology results a compact fibre coupled laser system what is simple to drive compared with current high power laser systems, because there is no need to control the operating temperature. This gives way for more compact driver solutions. Fields of application are laser marking systems and material processing, where a simple driver system is requested. Also medical applications need this requirement and a compact cooling too so that mobile integrated solutions become possible. Further developments allow multiple laser diode systems for specific industrial applications demanding more power. Our measurements show the potential for direct air-cooled laser systems with 100 Watt power out of the fibre.

  3. Multi-criteria decision analysis of concentrated solar power with thermal energy storage and dry cooling.

    PubMed

    Klein, Sharon J W

    2013-12-17

    Decisions about energy backup and cooling options for parabolic trough (PT) concentrated solar power have technical, economic, and environmental implications. Although PT development has increased rapidly in recent years, energy policies do not address backup or cooling option requirements, and very few studies directly compare the diverse implications of these options. This is the first study to compare the annual capacity factor, levelized cost of energy (LCOE), water consumption, land use, and life cycle greenhouse gas (GHG) emissions of PT with different backup options (minimal backup (MB), thermal energy storage (TES), and fossil fuel backup (FF)) and different cooling options (wet (WC) and dry (DC). Multicriteria decision analysis was used with five preference scenarios to identify the highest-scoring energy backup-cooling combination for each preference scenario. MB-WC had the highest score in the Economic and Climate Change-Economy scenarios, while FF-DC and FF-WC had the highest scores in the Equal and Availability scenarios, respectively. TES-DC had the highest score for the Environmental scenario. DC was ranked 1-3 in all preference scenarios. Direct comparisons between GHG emissions and LCOE and between GHG emissions and land use suggest a preference for TES if backup is require for PT plants to compete with baseload generators. PMID:24245524

  4. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors J Appendix J to Part 50 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. J Appendix J to Part 50—Primary Reactor Containment Leakage Testing for Water-Cooled...

  5. RESIDUAL OXIDANTS REMOVAL FROM COASTAL POWER PLANT COOLING SYSTEM DISCHARGES: FIELD EVALUATION OF SO2 ADDITION SYSTEM

    EPA Science Inventory

    The report gives results of an evaluation of the performance of a dechlorination system that uses SO2 to remove residual oxidants from chlorinated sea water in a power plant cooling system. Samples of unchlorinated, chlorinated, and dechlorinated cooling water were obtained at Pa...

  6. Achieving more reliable operation of turbine generators at nuclear power plants by improving the water chemistry of the generator stator cooling system

    NASA Astrophysics Data System (ADS)

    Tyapkov, V. F.; Chudakova, I. Yu.; Alekseenko, O. A.

    2011-08-01

    Ways of improving the water chemistry used in the turbine generator stator's cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.

  7. Effect of makeup water properties on the condenser fouling in power planr cooling system

    SciTech Connect

    Safari, I.; Walker, M.; Abbasian, J.; Arastoopour, H.; Hsieh, M-K.; Dzombak, D.; Miller, D.

    2011-01-01

    The thermoelectric power industry in the U.S. uses a large amount of fresh water. As available freshwater for use in thermoelectric power production becomes increasingly limited, use of nontraditional water sources is of growing interest. Utilization of nontraditional water, in cooling systems increases the potential for mineral precipitation on heat exchanger surfaces. In that regard, predicting the accelerated rate of scaling and fouling in condenser is crucial to evaluate the condenser performance. To achieve this goal, water chemistry should be incorporated in cooling system modeling and simulation. This paper addresses the effects of various makeup water properties on the cooling system, namely pH and aqueous speciation, both of which are important factors affecting the fouling rate in the main condenser. Detailed modeling of the volatile species desorption (i.e. CO{sub 2} and NH{sub 3}), the formation of scale in the recirculating system, and the relationship between water quality and the corresponding fouling rates is presented.

  8. Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond

    SciTech Connect

    Farfan, E. B.; Jannik, G. T.; Marra, J. C.; Oskolkov, B. Ya.; Bondarkov, M. D.; Gaschak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.

    2009-11-09

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  9. ENVIRONMENTAL PROBLEMS ASSOCIATED WITH DECOMMISSIONING THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

    SciTech Connect

    Farfan, E.

    2009-09-30

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  10. Laser pumped superconductive energy storage system

    SciTech Connect

    Wolf, A.A.

    1983-11-08

    A superconductive energy storage system comprising a magnetic field surrounding a superconducting coil having large currents circulating therein, cooling said coil to superconducting temperatures, starting said circulating current in said superconducting coil inductively by a small primer coil, transmitting additional energy into said energy storage system utilizing a laser beam, and retaining said energy in said energy storage system until needed.

  11. AP1000{sup R} nuclear power plant safety overview for spent fuel cooling

    SciTech Connect

    Gorgemans, J.; Mulhollem, L.; Glavin, J.; Pfister, A.; Conway, L.; Schulz, T.; Oriani, L.; Cummins, E.; Winters, J.

    2012-07-01

    The AP1000{sup R} plant is an 1100-MWe class pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance, safety and costs. The AP1000 design uses passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems such as AC power, component cooling water, service water or HVAC. Furthermore, these passive features 'fail safe' during a non-LOCA event such that DC power and instrumentation are not required. The AP1000 also has simple, active, defense-in-depth systems to support normal plant operations. These active systems provide the first level of defense against more probable events and they provide investment protection, reduce the demands on the passive features and support the probabilistic risk assessment. The AP1000 passive safety approach allows the plant to achieve and maintain safe shutdown in case of an accident for 72 hours without operator action, meeting the expectations provided in the U.S. Utility Requirement Document and the European Utility Requirements for passive plants. Limited operator actions are required to maintain safe conditions in the spent fuel pool via passive means. In line with the AP1000 approach to safety described above, the AP1000 plant design features multiple, diverse lines of defense to ensure spent fuel cooling can be maintained for design-basis events and beyond design-basis accidents. During normal and abnormal conditions, defense-in-depth and other systems provide highly reliable spent fuel pool cooling. They rely on off-site AC power or the on-site standby diesel generators. For unlikely design basis events with an extended loss of AC power (i.e., station blackout) or loss of heat sink or both, spent fuel cooling can still be provided indefinitely: - Passive systems, requiring minimal or no operator actions, are sufficient for at least 72 hours under all possible pool heat load conditions. - After 3 days, several different means are provided to continue spent fuel cooling using installed plant equipment as well as off-site equipment with built-in connections. Even for beyond design basis accidents with postulated pool damage and multiple failures in the passive safety-related systems and in the defense-in-depth active systems, the AP1000 multiple spent fuel pool spray and fill systems provide additional lines of defense to prevent spent fuel damage. (authors)

  12. European development of He-cooled divertors for fusion power plants

    NASA Astrophysics Data System (ADS)

    Norajitra, P.; Giniyatulin, R.; Ihli, T.; Janeschitz, G.; Karditsas, P.; Krauss, W.; Kruessmann, R.; Kuznetsov, V.; Maisonnier, D.; Mazul, I.; Nardi, C.; Ovchinnikov, I.; Papastergiou, S.; Pizzuto, A.; Sardain, P.

    2005-11-01

    Helium-cooled divertor concepts are considered suitable for use in fusion power plants for safety reasons, as they enable the use of a coolant compatible with any blanket concept, since water would not be acceptable, e.g. in connection with ceramic breeder blankets using large amounts of beryllium. Moreover, they allow for a high coolant exit temperature for increasing the efficiency of the power conversion system. Within the framework of the European power plant conceptual study, different helium-cooled divertor concepts based on different heat transfer mechanisms are being investigated at ENEA Frascati, Italy, and Forschungszentrum Karlsruhe, Germany. They are based on a modular design which helps reduce thermal stresses. The design goal is to withstand a high heat flux of about 10-15 MW m-2, a value which is considered relevant to future fusion power plants to be built after ITER. The development and optimization of the divertor concepts require an iterative design approach with analyses, studies of materials and fabrication technologies and the execution of experiments. These issues and the state of the art of divertor development shall be the subject of this report.

  13. Palm-size miniature superconducting bulk magnet

    NASA Astrophysics Data System (ADS)

    Saho, Norihide; Matsuda, Kazuya; Nishijima, Noriyo

    The development of a small, light, powerful and energy-efficient superconducting magnet has been desired in order to realize better efficiency and manipulability in guiding magnetic nano-particles, magnetic organic cells and other items to the right place. This study focuses on the development of a high-temperature superconducting (HTS) bulk magnet characterized by comparatively low leak magnetism despite a relatively high magnetic field. On this basis, the authors developed a palm-sized superconducting bulk magnet, which is the world's smallest, lightest, and lowest power consuming, as well as a new technology to effectively magnetize such a bulk magnet in a compact Stirling-cycle cryocooler (magnet C) with a pre-magnetized HTS bulk magnet (magnet B) in a compact cryocooler. This technology is demonstrated in two steps. In the first step, magnet B is magnetized using a superconducting solenoid magnet with a high magnetic field (magnet A) via the field cooling method. In the second step, magnet C is magnetized in the high magnetic field of magnet B. The prototype magnet C weighs 1.8 kg, and measures 235 65 115 mm (L W H). Magnet B was magnetized to 4.9 T using a 5 T magnet, and the target, magnet C, was magnetized using magnet B so that its maximum trapped magnetic flux density reached the value of 3.15 T. The net power consumption in a steady cooling state was 23 W, which is very low and comparable to that of a laptop computer.

  14. Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

    NASA Astrophysics Data System (ADS)

    Foley, T. Q.; Oskolkov, B. Y.; Bondarkov, M. D.; Gashchak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.; Jannik, G. T.; Farfan, E. B.; Marra, J. C.

    2009-12-01

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination is a fairly pressing issue. Significant problems may result from decommissioning of cooling ponds. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained bodies of water in the Chernobyl Region and Ukrainian Polesye with a water surface area of 22.9 km2. The major hydrological feature of the ChNPP Cooling Pond is that its water level is 6-7 m higher than the water level in the Pripyat River and water losses due to seepage and evaporation are replenished by pumping water from the Pripyat River. In 1986, the accident at the ChNPP #4 Reactor Unit significantly contaminated the ChNPP Cooling Pond. According to the 2001 data, the total radionuclide inventory in the ChNPP Cooling Pond bottom deposits was as follows: 16.28 ± 2.59 TBq for 137Cs; 2.4 ± 0.48 TBq for 90Sr, and 0.00518 ± 0.00148 TBq for 239+240Pu. Since ChNPP is being decommissioned, the ChNPP Cooling Pond of such a large size will no longer be needed and cost effective to maintain. However, shutdown of the water feed to the Pond would expose the contaminated bottom deposits and change the hydrological features of the area, destabilizing the radiological and environmental situation in the entire region in 2007 - 2008, in order to assess potential consequences of draining the ChNPP Cooling Pond, the authors conducted preliminary radio-ecological studies of its shoreline ecosystems. The radioactive contamination of the ChNPP Cooling Pond shoreline is fairly variable and ranges from 75 to 7,500 kBq/m2. Three areas with different contamination levels were selected to sample soils, vegetation, small mammals, birds, amphibians, and reptilians in order to measure their 137Cs and 90Sr content. Using the ERICA software, their dose exposures were estimated. For the 2008 conditions, the estimated dose rates were found to be as follows: amphibians - 11.4 µGy/hr; birds - 6.3 µGy/hr; mammals - 15.1 µGy/hr; reptilians - 10.3 µGy/hr, with the recommended maximum allowable limit of 40 µGy/hr. The conservative risk coefficient ranged from 0.51 for birds to 1.82 for amphibians. In spite of a high contamination level of the shoreline areas, the current total doses received by the animals do not reach the recommended maximum allowable doses. However, drainage of the ChNPP Cooling Pond is likely to increase the dose rates as follows: amphibians - 94.5, birds - 95.2, mammals - 284.0, reptilians - 847.0 µGy/hr, which will significantly exceed the maximum allowable values. These predictions are conservative and prior to making the final decision on the fate of the ChNPP Cooling Pond, a detailed radio-ecological assessment of its drainage will have to be performed.

  15. Superconducting mirror for laser gyroscope

    SciTech Connect

    Wang, X.

    1991-05-14

    This paper describes an apparatus for reflecting a light beam. It comprises: a mirror assembly comprising a substrate and a superconductive mirror formed on such substrate, wherein: the substrate is optically transparent to the light beam and has a thickness of from about 0.5 to about 1.0 millimeter, and the superconductive mirror has a thickness of from about 0.5 to about 1.0 microns; means for cooling the superconductive mirror; means for measuring the temperature of the superconductive mirror; means for determining the reflectivity of the superconductive mirror; and means for varying the reflectivity of the superconductive mirror.

  16. Transport and deposition of activation products in a helium cooled fusion power plant

    SciTech Connect

    Bickford, W.E.

    1980-09-01

    The transport and deposition of neutron activation products in a helium cooled tokamak fusion power plant are investigated. Stainless steel is used as coolant channel material for a helium/steam system. The important gamma emitting nuclides /sup 56/Mn, /sup 54/Mn, /sup 57/Co, /sup 58/Co, /sup 60/Co, /sup 51/Cr, and /sup 99/Mo are considered. The dominant release mechanism identified is direct daughter recoil emission from (n,x) type reactions. Corrosion and evaporation are discussed. The radionuclide inventory released by these mechanisms is predicted to exceed 1 x 10/sup 4/ Ci for a reference reactor design after only several days of operation, and approach 3.5 x 10/sup 4/ Ci in equilibrium. A mass transport model is then used to predict the deposition pattern of this inventory in the reactor cooling system.

  17. Cooling, heating, generating power, and recovering waste heat with thermoelectric systems.

    PubMed

    Bell, Lon E

    2008-09-12

    Thermoelectric materials are solid-state energy converters whose combination of thermal, electrical, and semiconducting properties allows them to be used to convert waste heat into electricity or electrical power directly into cooling and heating. These materials can be competitive with fluid-based systems, such as two-phase air-conditioning compressors or heat pumps, or used in smaller-scale applications such as in automobile seats, night-vision systems, and electrical-enclosure cooling. More widespread use of thermoelectrics requires not only improving the intrinsic energy-conversion efficiency of the materials but also implementing recent advancements in system architecture. These principles are illustrated with several proven and potential applications of thermoelectrics. PMID:18787160

  18. Efficiency and its bounds for thermal engines at maximum power using Newton's law of cooling

    NASA Astrophysics Data System (ADS)

    Yan, H.; Guo, Hao

    2012-01-01

    We study a thermal engine model for which Newton's cooling law is obeyed during heat transfer processes. The thermal efficiency and its bounds at maximum output power are derived and discussed. This model, though quite simple, can be applied not only to Carnot engines but also to four other types of engines. For the long thermal contact time limit, new bounds, tighter than what were known before, are obtained. In this case, this model can simulate Otto, Joule-Brayton, Diesel, and Atkinson engines. While in the short contact time limit, which corresponds to the Carnot cycle, the same efficiency bounds as that from Esposito [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.105.150603 105, 150603 (2010)] are derived. In both cases, the thermal efficiency decreases as the ratio between the heat capacities of the working medium during heating and cooling stages increases. This might provide instructions for designing real engines.

  19. Cooling, Heating, Generating Power, and Recovering Waste Heat with Thermoelectric Systems

    NASA Astrophysics Data System (ADS)

    Bell, Lon E.

    2008-09-01

    Thermoelectric materials are solid-state energy converters whose combination of thermal, electrical, and semiconducting properties allows them to be used to convert waste heat into electricity or electrical power directly into cooling and heating. These materials can be competitive with fluid-based systems, such as two-phase air-conditioning compressors or heat pumps, or used in smaller-scale applications such as in automobile seats, night-vision systems, and electrical-enclosure cooling. More widespread use of thermoelectrics requires not only improving the intrinsic energy-conversion efficiency of the materials but also implementing recent advancements in system architecture. These principles are illustrated with several proven and potential applications of thermoelectrics.

  20. Efficiency and its bounds for thermal engines at maximum power using Newton's law of cooling.

    PubMed

    Yan, H; Guo, Hao

    2012-01-01

    We study a thermal engine model for which Newton's cooling law is obeyed during heat transfer processes. The thermal efficiency and its bounds at maximum output power are derived and discussed. This model, though quite simple, can be applied not only to Carnot engines but also to four other types of engines. For the long thermal contact time limit, new bounds, tighter than what were known before, are obtained. In this case, this model can simulate Otto, Joule-Brayton, Diesel, and Atkinson engines. While in the short contact time limit, which corresponds to the Carnot cycle, the same efficiency bounds as that from Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)] are derived. In both cases, the thermal efficiency decreases as the ratio between the heat capacities of the working medium during heating and cooling stages increases. This might provide instructions for designing real engines. PMID:22400551

  1. The natural draught, indirect dry cooling system for the 6 times 686 MWe Kendal Power Station, RSA

    SciTech Connect

    Trage, B. ); Ham, A.J. ); Vicary, T.C. )

    1990-01-01

    The use of dry cooling systems in power plants is a relatively new development and limited to only a few applications worldwide. The locations in question are those at which wet cooling system could not be used economically due to a shortage of making-up water. The power plants using dry cooling systems which have been built to date world- wide, and which have a power generation capacity of over 100 MWe are listed. It is evident from this that there is a predominance of indirect cooling systems. Although the actual investment costs for the direct system are lower, the reasons for selecting an indirect system for Kendal power station was essentially for conservative reasons. A long term comparison of the two different systems is made considering all influences including weather, long term durability, and availability. The two systems have seldom before been assessed correctly from an economic stand point.

  2. High-Powered Gas-Cooled Microwave Ablation: Shaft Cooling Creates an Effective Stick Function Without Altering the Ablation Zone

    PubMed Central

    Knavel, Erica M.; Hinshaw, J. Louis; Lubner, Meghan G.; Andreano, Anita; Warner, Thomas F.; Lee, Fred T.; Brace, Christopher L.

    2012-01-01

    OBJECTIVE The purpose of our study was to validate the ability of a new gas-cooled microwave device to secure antennas into tissue before ablation via shaft cooling and to verify that such cooling does not compromise the intended ablation. MATERIALS AND METHODS The force required to extract several types of applicators from ex vivo bovine liver before and after ablation was measured. Six groups were compared: cooled needle and multitined radiofrequency electrodes, secured and unsecured cryoprobes, and gas-cooled microwave antennas (n = 6 each). Ablations were next created in in vivo porcine livers for 2 and 10 minutes (n = 6 each) using the gas-cooled microwave system at 140 W. Extraction force was again measured before and after ablation and compared between groups using analysis of variance with post hoc Student t tests. Histologic analysis of the ablation zone was performed to evaluate cellular necrosis along the antenna shaft. RESULTS Ex vivo, the secured cryoprobe and microwave antenna required significantly more force to remove than unsecured radiofrequency, cryoprobe, and microwave applicators (p < 0.05, all comparisons). The multitined radiofrequency electrode and cooled radiofrequency electrode required significantly more force to remove after ablation than before ablation (p = 0.006 and 0.02, respectively). In vivo, the secured antenna required significantly more force to remove before ablation than after ablation at both 2 (p < 0.0001) and 10 minutes (p < 0.0001). There was no histologic evidence of cell preservation along the antenna shaft. CONCLUSION The gas cooling used in this microwave device can effectively secure antennas into tissue without altering ablation shape or reducing the intended thermal damage. PMID:22358023

  3. Transport critical current measurement apparatus using liquid nitrogen cooled high-T(c) superconducting magnet with variable temperature insert.

    PubMed

    Nishijima, G; Kitaguchi, H; Tshuchiya, Y; Nishimura, T; Kato, T

    2013-01-01

    We have developed an apparatus to investigate transport critical current (I(c)) as a function of magnetic field and temperature using only liquid nitrogen. The apparatus consists of a (Bi,Pb)(2)Sr(2)Ca(2)Cu(3)O(10) (Bi-2223) superconducting magnet, an outer dewar, and a variable temperature insert (VTI). The magnet, which is operated in depressurized liquid nitrogen, generates magnetic field up to 1.26 T. The sample is also immersed in liquid nitrogen. The pressure in the VTI is controlled from 0.02 to 0.3 MPa, which corresponds to temperature ranging from 66 to 88 K. We have confirmed the long-term stable operation of the Bi-2223 magnet at 1 T. The temperature stability of the sample at high transport current was also demonstrated. The apparatus provides easy-operating I(c) measurement environment for a high-T(c) superconductor up to 500 A in magnetic fields up to 1 T and in temperatures ranging from 66 to 88 K. PMID:23387701

  4. High temperature superconductivity: A joint feasibility study for a power application with HTS cable by PECO Energy Company. Final report

    SciTech Connect

    1998-11-01

    High temperature superconductivity (HTS) cables have the potential to revolutionize the power delivery industry by reducing costs and maximizing the use of existing conduits for underground transmission. In 1986 a class of ceramic materials showing superconductivity slightly below the temperature of liquid nitrogen was discovered and, when used in cables, can carry two to five times more current than conventional cables of comparable size. In October of 1996, EPRI, Pirelli Cable Corporation, and PECO Energy Company performed a joint study to assess the technical and economic feasibility of installing a HTS cable system in downtown Philadelphia. The project team concluded that HTS system could be designed to meet the requirements of a standard underground transmission cable at distribution voltages, and be more advantageous than a conventional system because of better utilization of the existing duct system.

  5. State of the art of superconducting fault current limiters and their application to the electric power system

    NASA Astrophysics Data System (ADS)

    Morandi, Antonio

    2013-01-01

    Modern electric power systems are becoming more and more complex in order to meet new needs. Nowadays a high power quality is mandatory and there is the need to integrate increasing amounts of on-site generation. All this translates in more sophisticated electric network with intrinsically high short circuit rate. This network is vulnerable in case of fault and special protection apparatus and procedures needs to be developed in order to avoid costly or even irreversible damage. A superconducting fault current limiter (SFCL) is a device with a negligible impedance in normal operating conditions that reliably switches to a high impedance state in case of extra-current. Such a device is able to increase the short circuit power of an electric network and to contemporarily eliminate the hazard during the fault. It can be regarded as a key component for future electric power systems. In this paper the state of the art of superconducting fault current limiters mature for applications is briefly resumed and the potential impact of this device on the paradigm of design and operation of power systems is analyzed. In particular the use of the FCL as a mean to allow more interconnection of MV bus-bars as well an increased immunity with respect to the voltage disturbances induced by critical customer is discussed. The possibility to integrate more distributed generation in the distribution grid is also considered.

  6. High-power laser phosphor light source with liquid cooling for digital cinema applications

    NASA Astrophysics Data System (ADS)

    Li, Kenneth

    2014-02-01

    Laser excited phosphor has been used to excite phosphor material, producing high intensity light output with smaller etendue than that of LEDs with the same long lifetime. But due to the high intensity of the laser light, phosphor with organic binder burns at low power, which requires the phosphor to be deposited on a rotating wheel in practical applications. Phosphor with inorganic binders, commonly known as ceramic phosphor, on the other hand, does not burn, but efficiency goes down as temperature goes up under high power excitation. This paper describes cooling schemes in sealed chambers such that the phosphor materials using organic or inorganic binders can be liquid cooled for high efficiency operations. Confined air bubbles are introduced into the sealed chamber accommodating the differential thermal expansion of the liquid and the chamber. For even higher power operation suitable for digital cinema, a suspension of phosphor in liquid is described suitable for screen brightness of over 30,000 lumens. The aging issues of phosphor can also be solved by using replaceable phosphor cartridges.

  7. Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen

    NASA Astrophysics Data System (ADS)

    Iwakuma, M.; Adachi, K.; Yun, K.; Yoshida, K.; Sato, S.; Suzuki, Y.; Umeno, T.; Konno, M.; Hayashi, H.; Eguchi, T.; Izumi, T.; Shiohara, Y.

    2015-12-01

    We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3 ϕ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN2. The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN2. In this paper we investigate the behaviour of subcooled LN2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.

  8. Compatibility tests of materials for a lithium-cooled space power reactor concept

    NASA Technical Reports Server (NTRS)

    Sinclair, J. H.

    1973-01-01

    Materials for a lithium-cooled space power reactor concept must be chemically compatible for up to 50,000 hr at high temperature. Capsule tests at 1040 C (1900 F) were made of material combinations of prime interest: T-111 in direct contact with uranium mononitride (UN), Un in vacuum separated from T-111 by tungsten wire, UN with various oxygen impurity levels enclosed in tungsten wire lithium-filled T-111 capsules, and TZM and lithium together in T-111 capsules. All combinations were compatible for over 2800 hr except for T-111 in direct contact with UN.

  9. Water chemistry of a combined-cycle power plant's auxiliary equipment cooling system

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Korotkov, A. N.; Oparin, M. Yu.; Larin, A. B.

    2013-04-01

    Results from an analysis of methods aimed at reducing the corrosion rate of structural metal used in heat-transfer systems with water coolant are presented. Data from examination of the closed-circuit system for cooling the auxiliary mechanisms of a combined-cycle plant-based power unit and the results from adjustment of its water chemistry are given. A conclusion is drawn about the possibility of using a reagent prepared on the basis of sodium sulfite for reducing the corrosion rate when the loss of coolant is replenished with nondeaerated water.

  10. Magnetocaloric effect and refrigeration cooling power in amorphous Gd7Ru3 alloys

    NASA Astrophysics Data System (ADS)

    Kumar, Pramod; Kumar, Rachana

    2015-07-01

    In this paper, we report the magnetic, heat capacity and magneto-caloric effect (MCE) of amorphous Gd7Ru3 compound. Both, temperature dependent magnetization and heat capacity data reveals that two transitions at 58 K and 34 K. MCE has been calculated in terms of isothermal entropy change (?SM) and adiabatic temperature change (?Tad) using the heat capacity data in different fields. The maximum values of ?SM and ?Tad are 21 Jmol-1K-1 and 5 K respectively, for field change of 50 kOe whereas relative cooling power (RCP) is 735 J/kg for the same field change.

  11. Determining Optimal Equipment Capacities in Cooling, Heating and Power (CHP) Systems

    SciTech Connect

    DeVault, Robert C; Hudson II, Carl Randy

    2006-01-01

    Evaluation of potential cooling, heating and power (CHP) applications requires an assessment of the operations and economics of a particular system in meeting the electric and thermal demands of a specific end-use facility. A key determinate in whether a candidate system will be economic is the proper selection of equipment capacities. A methodology to determine the optimal capacities for CHP prime movers and absorption chillers using nonlinear optimization algorithms has been coded into a Microsoft Excel spreadsheet tool that performs the capacity optimization and operations simulation. This paper presents details on the use and results of this publicly available tool.

  12. Outbreak of legionnaires' disease from a cooling water system in a power station.

    PubMed Central

    Morton, S; Bartlett, C L; Bibby, L F; Hutchinson, D N; Dyer, J V; Dennis, P J

    1986-01-01

    In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures. PMID:3756116

  13. The cooling pond of the Chernobyl Nuclear Power Plant: A groundwater remediation case history

    NASA Astrophysics Data System (ADS)

    Bugai, Dmitri A.; Waters, Robert D.; Dzhepo, Sergei P.; Skalsk'ij, Alexander S.

    1997-04-01

    The cooling pond of the Chernobyl nuclear power plant was heavily contaminated as a result of the reactor accident in April 1986. From 1989 to 1993 the cooling pond represented one of the major sources of 90Sr migration from the Chernobyl site to the Dnieper River. Several attempts have been made to contain radioactive contamination within the pond. Overestimation of releases via groundwater pathway and design mistakes led to unsuccessful remedial actions in 1986 and in later periods. In addition, remediation criteria based solely on comparison of contaminant concentrations in groundwater with drinking water standards were not effective from the health risk perspective, because the public was not directly exposed to contaminated groundwater; the exclusion zone surrounding the site acted as an institutional control to prevent public access. In light of recent estimates of low risks due to radionuclide transport outside the exclusion zone, a "no action" approach may represent the most reasonable strategy for the near-term management of the cooling pond.

  14. Analysis of the solar powered/fuel assisted Rankine cycle cooling system. Phase 1: Revision

    NASA Astrophysics Data System (ADS)

    Lior, N.; Koai, K.; Yeh, H.

    1985-04-01

    The subject of this analysis is a solar cooling system which consists of a conventional open-compressor chiller, driven by a novel hybrid steam Rankine cycle. Steam is generated by the use of solar energy collected at about 100C, and it is then superheated to about 600C in a fossil-fuel fired superheater. The steam drives a novel counter-rotating turbine, some of the heat from it is regenerated, and it is then condensed. Thermal storage is implemented as an integral part of the cycle, by means of hot-water which is flashed to steam when needed for driving the turbine. For the solar energy input, both evacuated and double-glazed flat-plate collectors were considered. A comprehensive computer program was developed to analyze the operation and performance of the entire power/cooling system. Each component was described by a separate subroutine to compute its performance from basic principles, and special attention was given to the parasitic losses, including pumps, fans and pressure drops in the piping and heat exchangers, and to describe the off-design performance of the components. The thermophysical properties of the fluids used are also described in separate subroutines. Transient simulation of the entire system was performed on an hourly basis over a cooling season in two representative climatic regions (Washington, DC, and Phoenix, AZ) for a number of system configurations.

  15. The effects of age on nuclear power plant containment cooling systems

    SciTech Connect

    Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A.; Davis, J.

    1994-04-01

    A study was performed to assess the effects of aging on the performance and availability of containment cooling systems in US commercial nuclear power plants. This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. The effects of age were characterized for the containment cooling system by reviewing and analyzing failure data from national databases, as well as plant-specific data. The predominant failure causes and aging mechanisms were identified, along with the components that failed most frequently. Current inspection, surveillance, and monitoring practices were also examined. A containment cooling system unavailability analysis was performed to examine the potential effects of aging by increasing failure rates for selected components. A commonly found containment spray system design and a commonly found fan cooler system design were modeled. Parametric failure rates for those components in each system that could be subject to aging were accounted for in the model to simulate the time-dependent effects of aging degradation, assuming no provisions are made to properly manage it. System unavailability as a function of increasing component failure rates was then calculated.

  16. Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

    SciTech Connect

    Apfelbaum, Steven; Duvall, Kenneth; Nelson, Theresa; Mensing, Douglas; Bengtson, Harlan; Eppich, John; Penhallegon, Clayton; Thompson, Ry

    2013-09-30

    Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive ancillary socio-economic, ecosystem, and water treatment/polishing benefits when used to complement water resources at thermoelectric power plants. Through the Phase II pilot study segment of the contract, the project team partnered with Progress Energy Florida (now Duke Energy Florida) to quantify the wetland water cooling benefits at their Hines Energy Complex in Bartow, Florida. The project was designed to test the wetland’s ability to cool and cleanse power plant cooling pond water while providing wildlife habitat and water harvesting benefits. Data collected during the monitoring period was used to calibrate a STELLA model developed for the site. It was also used to inform management recommendations for the demonstration site, and to provide guidance on the use of cooling wetlands for other power plants around the country. As a part of the pilot study, Duke Energy is scaling up the demonstration project to a larger, commercial scale wetland instrumented with monitoring equipment. Construction is expected to be finalized in early 2014.

  17. Presence of pathogenic amoebae in power plant cooling waters. Final report, October 15, 1977-September 30, 1979. [Naegleria fowleri

    SciTech Connect

    Tyndall, R.L.; Willaert, E.; Stevens, A.R.

    1981-03-01

    Cooling-water-associated algae and sediments from five northern and five southern or western electric power plants were tested for the presence of pathogenic amoebae. In addition, water algae and sediments from five northern and five southern/western sites not associated with power plants were tested. There was a significant correlation at northern power plants between the presence of thermophilic, pathogenic amoebae in cooling waters and thermal additions. Presence of the pathogenic did not correlate with salinity, pH, conductivity, or a variety of various chemical components of the cooling waters. Selected pathogenic isolates were tested serologically and were classified as Naegleria fowleri. Although thermal additions were shown to be contributing factor in predisposing cooling waters to the growth of pathogenic amoebae, the data suggest the involvement of other currently undefined parameters associated with the presence of the pathogenic amoebae. 35 refs., 21 tabs.

  18. Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System.

    PubMed

    Lee, Chengming; Chen, Rongshun

    2015-01-01

    Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption. PMID:26007725

  19. Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System

    PubMed Central

    Lee, Chengming; Chen, Rongshun

    2015-01-01

    Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server’s fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption. PMID:26007725

  20. A passive bearing system using superconducting magnets

    NASA Technical Reports Server (NTRS)

    Huang, X.; Eyssa, Y. M.

    1990-01-01

    A passive radial bearing concept is presented using superconducting magnets which can generate a bearing pressure as high as 360 N/sq cm, comparable to a conventional active bearing system. The system consists of a number of solenoidal superconducting coils of alternating current direction. These coils are stacked axially over the bearing length and connected in series. The currents in stator and rotor coils are in the opposite directions, generating repulsive forces. This system, in comparison with an active system, has the advantage of much smaller power dissipation in the coils since the coil currents are mostly dc currents. The cooling for the superconducting coils is therefore simpler, and the coils are more stable. An optimization study seeking the maximum bearing pressure was conducted. Details of the design, pressure calculations, and results are presented.

  1. Oak Ridge National Laboratory (ORNL) Superconducting Technology Program for electric power systems. Annual report for FY 1994

    SciTech Connect

    Koncinski, W.S.; Hawsey, R.A.

    1994-12-01

    The Oak Ridge National Laboratory (ORNL) Superconducting Technology Program is conducted as part of a national effort by the US Department of Energy`s Office of Energy Efficiency and Renewable Energy to develop the technology base needed by US industry for commercial development of electric power applications of high-temperature superconductivity. The three major elements of this program are conductor development, applications development, and the Superconductivity Partnership Initiative. This document describes the major research and development activities for this program together with related accomplishments. The technical progress reported was summarized from information prepared for the FY 1994 Annual Program Review held July 19--20, 2994. This ORNL program is highly leveraged by the staff and other resources of US industry and universities. In fact, nearly three-fourths of the ORNL effort is devoted to industrial competitiveness projects with private companies. Interlaboratory teams are also in place on a number of industry-driven projects. Patent disclosures, working group meetings, staff exchanges, and joint publications and presentations ensure that there is technology transfer with US industry. Working together, the collaborative teams are making rapid progress in solving the scientific and technical issues necessary for the commercialization of long lengths of practical high-temperature superconductor wire and wire products.

  2. Micro capillary pumped loop system for a cooling high power device

    SciTech Connect

    Wang, Chin-Tsan; Leu, Tzong-Shyng; Lai, Tsai-Ming

    2008-04-15

    This work discusses the operation of a capillary-driven two-phase loop, configured on a micro capillary pumped loop (MCPL) system without an external power supply but capable of automatic heat transmission. The MCPL device, fabricated using MEMS (microelectricomechanical system) technology, was tested and yielded the following results: first, the proposed design of a new MCPL system with a water reservoir operating at low pressures is feasible and requires no additional power supply and instead relies on automatic heat transmission. Second, the issue of depriming in a MCPL was effectively controlled, the endurance of MCPL for the depriming problem can be executed by yielding input heat fluxes of 185.2 W/cm{sup 2} at an evaporator temperature of 165 C, thus revealing that this model provides excellent cooling performance. Third, the effective operation range was determined and its successful operation was confirmed for MCPL. The ease of starting up increased with the temperature of the reservoir. Finally, two-phase tension that originated in the groove structures in the evaporator and condenser was confirmed to control the movement of the fluids throughout the system and verified to be effective in improving cooling efficiency. (author)

  3. Development of an electrochemical antifouling system for seawater cooling pipelines of power plants using titanium.

    PubMed

    Wake, Hitoshi; Takahashi, Hiromichi; Takimoto, Toshihiro; Takayanagi, Hirokazu; Ozawa, Kinichi; Kadoi, Hideo; Okochi, Mina; Matsunaga, Tadashi

    2006-10-20

    Biofouling is the undesirable adhesion and development of microorganisms and macroorganisms in a water environment. An electrochemical antifouling system based on management of primary adhesion of microorganisms was developed employing titanium electrode for antifouling of seawater cooling pipes and marine infrastructures. The system consists of an electrochemical reaction-monitoring unit, a power control unit, and a potential/current remote monitoring and a control unit. Titanium plates and iron plates were used as the working and counter electrode, respectively. Field experiment was conducted in the seawater cooling pipeline system of a thermal power station. Four titanium electrodes with 1.0 m length and 3.0 m width were set in the seawater intake pit and current density was controlled at 50-100 mA/m(2). The electrode surface maintained clean conditions for 2 years. The average wet weight of fouling organisms on the titanium electrode surface was below 100 g/m(2) whereas the corresponding wet weight was above 10 kg/m(2) on the control surface. Using titanium as the electrode material, chlorine and hypochlorite are not generated. The developed electrochemical antifouling system provided an effective, environmentally friendly, and feasible techniques for remote operations. PMID:16752370

  4. Numerical Hydraulic Study on Seawater Cooling System of Combined Cycle Power Plant

    NASA Astrophysics Data System (ADS)

    Kim, J. Y.; Park, S. M.; Kim, J. H.; Kim, S. W.

    2010-06-01

    As the rated flow and pressure increase in pumping facilities, a proper design against surges and severe cavitations in the pipeline system is required. Pressure surge due to start-up, shut-down process and operation failure causes the water hammer in upstream of the closing valve and the cavitational hammer in downstream of the valve. Typical cause of water hammer is the urgent closure of valves by breakdown of power supply and unexpected failure of pumps. The abrupt changes in the flow rate of the liquid results in high pressure surges in upstream of the valves, thus kinetic energy is transformed into potential energy which leads to the sudden increase of the pressure that is called as water hammer. Also, by the inertia, the liquid continues to flow downstream of the valve with initial speed. Accordingly, the pressure decreases and an expanding vapor bubble known as column separation are formed near the valve. In this research, the hydraulic study on the closed cooling water heat exchanger line, which is the one part of the power plant, is introduced. The whole power plant consists of 1,200 MW combined power plant and 220,000 m3/day desalination facility. Cooling water for the plant is supplied by sea water circulating system with a capacity of 29 m3/s. The primary focus is to verify the steady state hydraulic capacity of the system. The secondary is to quantify transient issues and solutions in the system. The circuit was modeled using a commercial software. The stable piping network was designed through the hydraulic studies using the simulation for the various scenarios.

  5. A feasibility study of full-bridge type superconducting fault current controller on electric machine power stability

    NASA Astrophysics Data System (ADS)

    Jang, J. Y.; Hwang, Y. J.; Lee, J.; Ko, T. K.

    2016-02-01

    Recently, because of the advent of Smart Grid and integration of distributed generations, electrical power grids are facing uncountable challenges. Increase of fault current is one of such serious challenges and there are some fault current limiters (FCLs) that can limit the fault current. Existing grid protection FCLs, however, simply limit the fault current passively and can allow the existing protection coordination schemes to fail. This phenomenon leads to catastrophic failure in the complex system and may cause unpredictable power grid operation. Unlike a FCL, a superconducting fault current controller (SFCC) employs a full-bridge thyristor rectifier, a high temperature superconducting (HTS) DC reactor, and an embedded control unit to maintain the fault current level at a proper value by adjusting the phase angle of thyristors. This paper contains experimental and numerical analysis to design and fabricate a SFCC system for protection and stability improvement in power grids. At first, fundamental characteristics of a SFCC system were introduced. System circuit diagram and operational principles were proposed. Secondly, the developed small-scale SFCC system was introduced and verified. A 40 Vrms/30 Arms class prototype SFCC employing HTS DC reactor was fabricated and short circuit tests that simulate various fault conditions were implemented to verify the control performance of the fault current. Finally, the practical feasibility of application of the SFCC system to the power system was studied. The problems caused by three-phase faults from the power grid were surveyed and transient stability analysis of the power system was conducted by simulations. From the experimental and simulation results, we can verify the feasibility of the SFCC in power system.

  6. Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand

    SciTech Connect

    Sarkar, C.K.; Pandit, D.R.; Kwon, S.G.

    1998-12-31

    The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of cooling towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.

  7. DEPOSITION OF NIOBIUM AND OTHER SUPERCONDUCTING MATERIALS WITH HIGH POWER IMPULSE MAGNETRON SPUTTERING: CONCEPT AND FIRST RESULTS

    SciTech Connect

    High Current Electronics Institute, Tomsk, Russia; Anders, Andre; Mendelsberg, Rueben J.; Lim, Sunnie; Mentink, Matthijs; Slack, Jonathan L.; Wallig, Joseph G.; Nollau, Alexander V.; Yushkov, Georgy Yu.

    2011-07-24

    Niobium coatings on copper cavities have been considered as a cost-efficient replacement of bulk niobium RF cavities, however, coatings made by magnetron sputtering have not quite lived up to high expectations due to Q-slope and other issues. High power impulse magnetron sputtering (HIPIMS) is a promising emerging coatings technology which combines magnetron sputtering with a pulsed power approach. The magnetron is turned into a metal plasma source by using very high peak power density of ~ 1 kW/cm{sup 2}. In this contribution, the cavity coatings concept with HIPIMS is explained. A system with two cylindrical, movable magnetrons was set up with custom magnetrons small enough to be inserted into 1.3 GHz cavities. Preliminary data on niobium HIPIMS plasma and the resulting coatings are presented. The HIPIMS approach has the potential to be extended to film systems beyond niobium, including other superconducting materials and/or multilayer systems.

  8. User's guide for the BNW-III optimization code for modular dry/wet-cooled power plants

    SciTech Connect

    Braun, D.J.; Faletti, D.W.

    1984-09-01

    This user's guide describes BNW-III, a computer code developed by the Pacific Northwest Laboratory (PNL) as part of the Dry Cooling Enhancement Program sponsored by the US Department of Energy (DOE). The BNW-III code models a modular dry/wet cooling system for a nuclear or fossil fuel power plant. The purpose of this guide is to give the code user a brief description of what the BNW-III code is and how to use it. It describes the cooling system being modeled and the various models used. A detailed description of code input and code output is also included. The BNW-III code was developed to analyze a specific cooling system layout. However, there is a large degree of freedom in the type of cooling modules that can be selected and in the performance of those modules. The costs of the modules are input to the code, giving the user a great deal of flexibility.

  9. Next generation cooled long range thermal sights with minimum size, weight, and power

    NASA Astrophysics Data System (ADS)

    Breiter, R.; Ihle, T.; Wendler, J.; Rhlich, I.; Ziegler, J.

    2013-06-01

    Situational awareness and precise targeting at day, night and severe weather conditions are key elements for mission success in asymmetric warfare. To support these capabilities for the dismounted soldier, AIM has developed a family of stand-alone thermal weapon sights based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The design driver for these sights is a long ID range <1500m for the NATO standard target to cover the operational range of a platoon with the engagement range of .50 cal rifles, 40mm AGLs or for reconnaissance tasks. The most recent sight WBZG has just entered into serial production for the IdZ enhanced system of the German army with additional capabilities like a wireless data link to the soldier backbone computer. Minimum size, weight and power (SWaP) are most critical requirements for the dismounted soldiers' equipment and sometimes push a decision towards uncooled equipment with marginal performance referring to the outstanding challenges in current asymmetric warfare, e.g. the capability to distinguish between combatants and non-combatants in adequate ranges. To provide the uncompromised e/o performance with SWaP parameters close to uncooled, AIM has developed a new thermal weapon sight based on high operating temperature (HOT) MCT MWIR FPAs together with a new low power single piston stirling cooler. In basic operation the sight is used as a clip-on in front of the rifle scope. An additional eyepiece for stand-alone targeting with e.g. AGLs or a biocular version for relaxed surveillance will be available. The paper will present details of the technologies applied for such long range cooled sights with size, weight and power close to uncooled.

  10. Interim Report: Air-Cooled Condensers for Next Generation Geothermal Power Plants Improved Binary Cycle Performance

    SciTech Connect

    Daniel S. Wendt; Greg L. Mines

    2010-09-01

    As geothermal resources that are more expensive to develop are utilized for power generation, there will be increased incentive to use more efficient power plants. This is expected to be the case with Enhanced Geothermal System (EGS) resources. These resources will likely require wells drilled to depths greater than encountered with hydrothermal resources, and will have the added costs for stimulation to create the subsurface reservoir. It is postulated that plants generating power from these resources will likely utilize the binary cycle technology where heat is rejected sensibly to the ambient. The consumptive use of a portion of the produced geothermal fluid for evaporative heat rejection in the conventional flash-steam conversion cycle is likely to preclude its use with EGS resources. This will be especially true in those areas where there is a high demand for finite supplies of water. Though they have no consumptive use of water, using air-cooling systems for heat rejection has disadvantages. These systems have higher capital costs, reduced power output (heat is rejected at the higher dry-bulb temperature), increased parasitics (fan power), and greater variability in power generation on both a diurnal and annual basis (larger variation in the dry-bulb temperature). This is an interim report for the task Air-Cooled Condensers in Next- Generation Conversion Systems. The work performed was specifically aimed at a plant that uses commercially available binary cycle technologies with an EGS resource. Concepts were evaluated that have the potential to increase performance, lower cost, or mitigate the adverse effects of off-design operation. The impact on both cost and performance were determined for the concepts considered, and the scenarios identified where a particular concept is best suited. Most, but not all, of the concepts evaluated are associated with the rejection of heat. This report specifically addresses three of the concepts evaluated: the use of recuperation, the use of turbine reheat, and the non-consumptive use of EGS make-up water to supplement heat rejection

  11. Experimental investigation of an ammonia-based combined power and cooling cycle

    NASA Astrophysics Data System (ADS)

    Tamm, Gunnar Olavi

    A novel ammonia-water thermodynamic cycle, capable of producing both power and refrigeration, was proposed by D. Yogi Goswami. The binary mixture exhibits variable boiling temperatures during the boiling process, which leads to a good thermal match between the heating fluid and working fluid for efficient heat source utilization. The cycle can be driven by low temperature sources such as solar, geothermal, and waste heat from a conventional power cycle, reducing the reliance on high temperature sources such as fossil fuels. A theoretical simulation of the cycle at heat source temperatures obtainable from low and mid temperature solar collectors showed that the ideal cycle could produce power and refrigeration at a maximum exergy efficiency, defined as the ratio of the net work and refrigeration output to the change in availability of the heat source, of over 60%. The exergy efficiency is a useful measure of the cycle's performance as it compares the effectiveness of different cycles in harnessing the same source. An experimental system was constructed to demonstrate the feasibility of the cycle and to compare the experimental results with the theoretical simulations. In this first phase of experimentation, the turbine expansion was simulated with a throttling valve and a heat exchanger. Results showed that the vapor generation and absorption condensation processes work experimentally. The potential for combined turbine work and refrigeration output was evidenced in operating the system. Analysis of losses led to modifications in the system design, which were implemented to yield improvements in heat exchange, vapor generation, pump performance and overall stability. The research that has been conducted verifies the potential of the power and cooling cycle as an alternative to using conventional fossil fuel technologies. The research that continues is to further demonstrate the concept and direct it towards industry. On the large scale, the cycle can be used for industrial power production or as a central power plant for a community, with refrigeration produced as required by the application. On the small scale, an affordable residential or commercial unit could allow independent electricity generation for the home or business while also cooling it.

  12. Lightweight MgB2 superconducting 10 MW wind generator

    NASA Astrophysics Data System (ADS)

    Marino, I.; Pujana, A.; Sarmiento, G.; Sanz, S.; Merino, J. M.; Tropeano, M.; Sun, J.; Canosa, T.

    2016-02-01

    The offshore wind market demands a higher power rate and more reliable turbines in order to optimize capital and operational costs. The state-of-the-art shows that both geared and direct-drive conventional generators are difficult to scale up to 10 MW and beyond due to their huge size and weight. Superconducting direct-drive wind generators are considered a promising solution to achieve lighter weight machines. This work presents an innovative 10 MW 8.1 rpm direct-drive partial superconducting generator using MgB2 wire for the field coils. It has a warm iron rotor configuration with the superconducting coils working at 20 K while the rotor core and the armature are at ambient temperature. A cooling system based on cryocoolers installed in the rotor extracts the heat from the superconducting coils by conduction. The generator's main parameters are compared against a permanent magnet reference machine, showing a significant weight and size reduction. The 10 MW superconducting generator concept will be experimentally validated with a small-scale magnetic machine, which has innovative components such as superconducting coils, modular cryostats and cooling systems, and will have similar size and characteristics as the 10 MW generator.

  13. Hybrid superconducting magnetic suspensions

    SciTech Connect

    Tixador, P.; Hiebel, P.; Brunet, Y.

    1996-07-01

    Superconductors, especially high T{sub c} ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO.

  14. Superconducting magnet

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Extensive computer based engineering design effort resulted in optimization of a superconducting magnet design with an average bulk current density of approximately 12KA/cm(2). Twisted, stranded 0.0045 inch diameter NbTi superconductor in a copper matrix was selected. Winding the coil from this bundle facilitated uniform winding of the small diameter wire. Test coils were wound using a first lot of the wire. The actual packing density was measured from these. Interwinding voltage break down tests on the test coils indicated the need for adjustment of the wire insulation on the lot of wire subsequently ordered for construction of the delivered superconducting magnet. Using the actual packing densities from the test coils, a final magnet design, with the required enhancement and field profile, was generated. All mechanical and thermal design parameters were then also fixed. The superconducting magnet was then fabricated and tested. The first test was made with the magnet immersed in liquid helium at 4.2K. The second test was conducted at 2K in vacuum. In the latter test, the magnet was conduction cooled from the mounting flange end.

  15. PREFACE: Superconducting materials Superconducting materials

    NASA Astrophysics Data System (ADS)

    Charfi Kaddour, Samia; Singleton, John; Haddad, Sonia

    2011-11-01

    The discovery of superconductivity in 1911 was a great milestone in condensed matter physics. This discovery has resulted in an enormous amount of research activity. Collaboration among chemists and physicists, as well as experimentalists and theoreticians has given rise to very rich physics with significant potential applications ranging from electric power transmission to quantum information. Several superconducting materials have been synthesized. Crucial progress was made in 1987 with the discovery of high temperature superconductivity in copper-based compounds (cuprates) which have revealed new fascinating properties. Innovative theoretical tools have been developed to understand the striking features of cuprates which have remained for three decades the 'blue-eyed boy' for researchers in superconductor physics. The history of superconducting materials has been notably marked by the discovery of other compounds, particularly organic superconductors which despite their low critical temperature continue to attract great interest regarding their exotic properties. Last but not least, the recent observation of superconductivity in iron-based materials (pnictides) has renewed hope in reaching room temperature superconductivity. However, despite intense worldwide studies, several features related to this phenomenon remain unveiled. One of the fundamental key questions is the mechanism by which superconductivity takes place. Superconductors continue to hide their 'secret garden'. The new trends in the physics of superconductivity have been one of the two basic topics of the International Conference on Conducting Materials (ICoCoM2010) held in Sousse,Tunisia on 3-7 November 2010 and organized by the Tunisian Physical Society. The conference was a nice opportunity to bring together participants from multidisciplinary domains in the physics of superconductivity. This special section contains papers submitted by participants who gave an oral contribution at ICoCoM2010 and by invited authors selected by the editor. We are grateful to IUPAP, ICTP and the European Office of Aerospace Research and Development, Air Force Office of Scientific Research, United States Air Force Laboratory. We would like to acknowledge the authors for their careful work, and finally we thank Dr L Smith the publisher of Journal of Physics: Condensed Matter for her patience and help. Superconducting materials contents Raman spectrum in the pseudogap phase of the underdoped cuprates: effect of phase coherence and the signature of the KT-type superconducting transitionTao Li and Haijun Liao Pressure effects on Dirac fermions in ?-(BEDT-TTF)2I3Takahiro Himura, Takao Morinari and Takami Tohyama Effect of Zn doping in hole-type 1111 phase (Pr, Sr)FeAsOXiao Lin, Chenyi Shen, Chen Lv, Jianjian Miao, Hao Tan, Guanghan Cao and Zhu-An Xu Superconductivity and ferromagnetism in EuFe2(As1 - xPx)2*Guanghan Cao, Shenggao Xu, Zhi Ren, Shuai Jiang, Chunmu Feng and Zhu'an Xu OInhomogeneous superconductivity in organic conductors: the role of disorder and magnetic fieldS Haddad, S Charfi-Kaddour and J-P Pouget

  16. FAST TRACK COMMUNICATION: Relative cooling power enhancement in magneto-caloric nanostructured Pr2Fe17

    NASA Astrophysics Data System (ADS)

    Gorria, Pedro; Snchez Llamazares, Jos L.; lvarez, Pablo; Jos Prez, Mara; Snchez Marcos, Jorge; Blanco, Jess A.

    2008-10-01

    The magneto-caloric effect (MCE) of arc-melted bulk and 10 h ball-milled nanostructured Pr2Fe17 powders has been investigated. The maximum value for the magnetic entropy change, |?SM|, in the milled alloy is 4.5 J kg-1 K-1 for ?0H = 5 T, at around room temperature. The full width at half maximum, ?TFWHM, of |?SM|(T) for the nanostructured powders is about 60% greater than that of the starting bulk alloy, thus giving rise to large relative cooling power values of 573 J kg-1 (4.5 J cm-3) for ?0H = 5 T estimated from the product of |?SM|max ?TFWHM. These results have been compared with those of well-known magnetic materials that exhibit a large or giant MCE effect. The potential for using these low-cost iron based nanostructured Pr2Fe17 powders in magnetic refrigeration at room temperature is also discussed.

  17. High power RF test of an 805 MHz RF cavity for a muon cooling channel

    SciTech Connect

    Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

    2002-05-30

    We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

  18. System for thermal energy storage, space heating and cooling and power conversion

    DOEpatents

    Gruen, Dieter M.; Fields, Paul R.

    1981-04-21

    An integrated system for storing thermal energy, for space heating and cong and for power conversion is described which utilizes the reversible thermal decomposition characteristics of two hydrides having different decomposition pressures at the same temperature for energy storage and space conditioning and the expansion of high-pressure hydrogen for power conversion. The system consists of a plurality of reaction vessels, at least one containing each of the different hydrides, three loops of circulating heat transfer fluid which can be selectively coupled to the vessels for supplying the heat of decomposition from any appropriate source of thermal energy from the outside ambient environment or from the spaces to be cooled and for removing the heat of reaction to the outside ambient environment or to the spaces to be heated, and a hydrogen loop for directing the flow of hydrogen gas between the vessels. When used for power conversion, at least two vessels contain the same hydride and the hydrogen loop contains an expansion engine. The system is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators, but may be used with any source of heat, including a source of low-grade heat.

  19. Overturning the Case for Gravitational Powering in the Prototypical Cooling Ly? Nebula

    NASA Astrophysics Data System (ADS)

    Prescott, Moire K. M.; Momcheva, Ivelina; Brammer, Gabriel B.; Fynbo, Johan P. U.; Mller, Palle

    2015-03-01

    The Nilsson et al. Ly? nebula has often been cited as the most plausible example of an Ly? nebula powered by gravitational cooling. In this paper, we bring together new data from the Hubble Space Telescope and the Herschel Space Observatory as well as comparisons to recent theoretical simulations in order to revisit the questions of the local environment and most likely power source for the Ly? nebula. In contrast to previous results, we find that this Ly? nebula is associated with six nearby galaxies and an obscured AGN that is offset by 4? ? 30 kpc from the Ly? peak. The local region is overdense relative to the field, by a factor of 10, and at low surface brightness levels the Ly? emission appears to encircle the position of the obscured AGN, highly suggestive of a physical association. At the same time, we confirm that there is no compact continuum source located within 2-3? ? 15-23 kpc of the Ly? peak. Since the latest cold accretion simulations predict that the brightest Ly? emission will be coincident with a central growing galaxy, we conclude that this is actually a strong argument against, rather than for, the idea that the nebula is gravitationally powered. While we may be seeing gas within cosmic filaments, this gas is primarily being lit up, not by gravitational energy, but due to illumination from a nearby buried AGN.

  20. Use of beryllium oxide to shape power and reduce void reactivity in gas cooled fast reactors

    SciTech Connect

    Handwerk, C. S.; Driscoll, M. J.; Hejzlar, P.

    2006-07-01

    Use of Beryllium Oxide (BeO) as a diluent is explored as a means for both power shaping and void reactivity reduction in fast reactors. A supercritical carbon dioxide (S-CO{sub 2}) cooled fast reactor fueled with Light Water Reactor Transuranics and directly coupled with a Brayton cycle power conversion system is used to investigate the effect of BeO as a diluent. Results show that relatively flat power profiles (peak {<=} 1.22) can be maintained throughout core life using a combination of enrichment and diluent zoning, due to the slight moderating effect of the BeO. Combining BeO diluent with the innovative strategy of using a thick volume of S-CO{sub 2} coolant as the radial reflector yields negative void reactivities throughout core life. The ability to maintain negative coolant void reactivity comes from a combination of the effects of spectral softening due to the BeO diluent and the enhanced leakage upon voiding of the S-CO{sub 2} radial reflector. (authors)

  1. Power Tests of a String of Magnets Comprising a Full Cell of the Superconducting Super Collider

    SciTech Connect

    Burgett, W.; Cromer, L.; Haenni, D.; Hentges, M.; Jaffrey, T.; Kraushaar, P.; Levin, M.; Mulholland, G.; Richter, D.; Robinson, W.; Weisend II, J.; Zapotek, J.

    1995-06-28

    In this paper we describe the operation and testing of a string of magnets comprising a full cell of the Superconducting Super Collider (SSC). The full cell configuration composed of ten dipoles, two quadrupoles, and three spool pieces is the longest SSC magnet string ever tested. Although the tests of the full cell were undertaken after the SSC project was marked for termination, their completion was deemed necessary and useful to future efforts at other accelerator laboratories utilizing Superconducting magnets. The focus of this work is on the electrical and cryogenic performance of the string components and the quench protection system with an emphasis on solving some of the questions concerning electrical performance raised during the previous two experimental runs involving a half cell configuration.

  2. Development of 10 kA high temperature superconducting power cable for railway systems

    NASA Astrophysics Data System (ADS)

    Tomita, M.; Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.

    2012-03-01

    The superconducting Bi2Sr2Ca2Cu3Oy "Bi-2223" tapes made with a powder-in-tube process laminated with a copper alloy have been used to design and develop a 5 m long multilayer concentric cable to be applied in railway systems. The electrical performance of the conductor has been evaluated with DC transport current at an economical 77 K (liquid nitrogen temperature) in the self-field. The inner and outer sheet wires were able to sustain electric currents of 10 130 A and 10 910 A, respectively. These values are sufficient for several types of commercial applications. The current values are significantly higher than the earlier reported ones in Bi-2223 or YBa2Cu3Oy "Y-123" superconducting cables, indicating that the tape quality has considerably improved.

  3. Solid-Core, Gas-Cooled Reactor for Space and Surface Power

    SciTech Connect

    King, Jeffrey C.; El-Genk, Mohamed S.

    2006-01-20

    The solid-core, gas-cooled, Submersion-Subcritical Safe Space (S and 4) reactor is developed for future space power applications and avoidance of single point failures. The Mo-14%Re reactor core is loaded with uranium nitride fuel in enclosed cavities, cooled by He-30%Xe, and sized to provide 550 kWth for seven years of equivalent full power operation. The beryllium oxide reflector disassembles upon impact on water or soil. In addition to decreasing the reactor and shadow shield mass, Spectral Shift Absorber (SSA) materials added to the reactor core ensure that it remains subcritical in the worst-case submersion accident. With a 0.1 mm thick boron carbide coating on the outside surface of the core block and 0.25 mm thick iridium sleeves around the fuel stacks, the reflector outer diameter is 43.5 cm and the combined reactor and shadow shield mass is 935.1 kg. With 12.5 atom% gadolinium-155 added to the fuel, 2.0 mm diameter gadolinium-155 sesquioxide intersititial pins, and a 0.1 mm thick gadolinium-155 sesquioxide coating, the S and 4 reactor has a slightly smaller reflector outer diameter of 43.0 cm, and a total reactor and shield mass of 901.7 kg. With 8.0 atom% europium-151 added to the fuel, 2.0 mm diameter europium-151 sesquioxide interstitial pins, and a 0.1 mm thick europium-151 sesquioxide coating, the reflector's outer diameter and the total reactor and shield mass are further reduced to 41.5 cm and 869.2 kg, respect0011ive.

  4. Solid-Core, Gas-Cooled Reactor for Space and Surface Power

    NASA Astrophysics Data System (ADS)

    King, Jeffrey C.; El-Genk, Mohamed S.

    2006-01-01

    The solid-core, gas-cooled, Submersion-Subcritical Safe Space (S?4) reactor is developed for future space power applications and avoidance of single point failures. The Mo-14%Re reactor core is loaded with uranium nitride fuel in enclosed cavities, cooled by He-30%Xe, and sized to provide 550 kWth for seven years of equivalent full power operation. The beryllium oxide reflector disassembles upon impact on water or soil. In addition to decreasing the reactor and shadow shield mass, Spectral Shift Absorber (SSA) materials added to the reactor core ensure that it remains subcritical in the worst-case submersion accident. With a 0.1 mm thick boron carbide coating on the outside surface of the core block and 0.25 mm thick iridium sleeves around the fuel stacks, the reflector outer diameter is 43.5 cm and the combined reactor and shadow shield mass is 935.1 kg. With 12.5 atom% gadolinium-155 added to the fuel, 2.0 mm diameter gadolinium-155 sesquioxide intersititial pins, and a 0.1 mm thick gadolinium-155 sesquioxide coating, the S?4 reactor has a slightly smaller reflector outer diameter of 43.0 cm, and a total reactor and shield mass of 901.7 kg. With 8.0 atom% europium-151 added to the fuel, 2.0 mm diameter europium-151 sesquioxide interstitial pins, and a 0.1 mm thick europium-151 sesquioxide coating, the reflector's outer diameter and the total reactor and shield mass are further reduced to 41.5 cm and 869.2 kg, respectively.

  5. Summary results of an assessment of research projects in the superconductivity for electric power systems program

    SciTech Connect

    1992-10-01

    The Office of Program Analysis undertook an assessment of 37 research projects sponsored by the High Temperature Superconductivity Program. This report summarizes the results of the review. Rating factors included scientific and technical merit, mission relevance, appropriateness and level of innovation, quality of project team, productivity, and probable impact on the program`s mission. Some research needs and opportunities are described that were identified by the reviewers in the areas of wire development, deposited film technology, and systems development.

  6. HOM damping properties of fundamental power couplers in the superconducting electron gun of the energy recovery LINAC at Brookhaven National Laboratory

    SciTech Connect

    Hammons, L.; Hahn, H.

    2011-03-28

    Among the accelerator projects under construction at the Relativistic Heavy Ion Collider (RHIC) is an R and D energy recovery LINAC (ERL) test facility. The ERL includes both a five-cell superconducting cavity as well as a superconducting, photoinjector electron gun. Because of the high-charge and high-current demands, effective higher-order mode (HOM) damping is essential, and several strategies are being pursued. Among these is the use of the fundamental power couplers as a means for damping some HOMs. Simulation studies have shown that the power couplers can play a substantial role in damping certain HOMs, and this presentation discusses these studies along with measurements.

  7. Development of quench detection/protection system based on active power method for superconducting magnet by using capacitor circuit

    NASA Astrophysics Data System (ADS)

    Nanato, N.; Otsuka, T.; Hesaka, S.; Murase, S.

    2013-01-01

    When a quench occurs in a superconducting magnet, excessive joule heating in normal region may damage the magnet. It is necessary to detect the quench as soon as possible and discharge magnetic energy stored in the magnet. The authors have presented a quench detection/protection system based on an active power method which detects the quench regardless of a self-inductive and mutual-inductive voltages and electromagnetic noise. In the conventional active power method, the inductive voltages are removed by cancel coils. In this paper, the authors propose a method to cancel an inductive voltage using a capacitor circuit. The quench detection/protection system becomes more precise and smaller than the conventional system through the capacitor circuit.

  8. The development of high cooling power and low ultimate temperature superfluid Stirling refrigerators

    NASA Astrophysics Data System (ADS)

    Patel, Ashok B.

    The superfluid Stirling refrigerator (SSR) is a recuperative Stirling cycle refrigerator which provides cooling to below 2 K by using a liquid 3He-4He mixture as the working fluid. In 1990, Kotsubo and Swift demonstrated the first SSR, and by 1995, Brisson and Swift had developed an experimental prototype capable of reaching a low temperature of 296 mK. The goal of this thesis was to improve these capabilities by developing a better understanding of the SSR and building SSR's with higher cooling powers and lower ultimate temperatures. This thesis contains four main parts. In the first part, a numerical analysis demonstrates that the optimal design and ultimate performance of a recuperative Stirling refrigerator is fundamentally different from that of a standard regenerative Stirling refrigerator due to a mass flow imbalance within the recuperator. The analysis also shows that high efficiency recuperators remain a key to SSR performance. Due to a quantum effect called Kapitza resistance, the only realistic and economical method of creating higher efficiency recuperators for use with an SSR is to construct the heat exchangers from very thin (12 ?m - 25 ?m thick) plastic films. The second part of this thesis involves the design and construction of these recuperators. This research resulted in Kapton heat exchangers which are leaktight to superfluid helium and capable of surviving repeated thermal cycling. In the third part of this thesis, two different single stage SSR's are operated to test whether the plastic recuperators would actually improve SSR performance. Operating from a high temperature of 1.0 K and with 1.5% and 3.0% 3He-4He mixtures, these SSR's achieved a low temperature of 291 mK and delivered net cooling powers of 3705 ?W at 750 mK, 977 ?W at 500 mK, and 409 ?W at 400 mK. Finally, this thesis describes the operation of three versions of a two stage SSR. Unfortunately, due to experimental difficulties, the merits of a two stage SSR were not demonstrated and further work is still required. However, despite these difficulties, one of the two stage SSR's was able to reach an ultimate low temperature of 248 mK from a high temperature of 1.03 K. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

  9. Optimization of power-cycle arrangements for Supercritical Water cooled Reactors (SCWRs)

    NASA Astrophysics Data System (ADS)

    Lizon-A-Lugrin, Laure

    The world energy demand is continuously rising due to the increase of both the world population and the standard of life quality. Further, to assure both a healthy world economy as well as adequate social standards, in a relatively short term, new energy-conversion technologies are mandatory. Within this framework, a Generation IV International Forum (GIF) was established by the participation of 10 countries to collaborate for developing nuclear power reactors that will replace the present technology by 2030. The main goals of these nuclear-power reactors are: economic competitiveness, sustainability, safety, reliability and resistance to proliferation. As a member of the GIF, Canada has decided to orient its efforts towards the design of a CANDU-type Super Critical Water-cooled Reactor (SCWR). Such a system must run at a coolant outlet temperature of about 625C and at a pressure of 25 MPa. It is obvious that at such conditions the overall efficiency of this kind of Nuclear Power Plant (NPP) will compete with actual supercritical water-power boilers. In addition, from a heat-transfer viewpoint, the use of a supercritical fluid allows the limitation imposed by Critical Heat Flux (CHF) conditions, which characterize actual technologies, to be removed. Furthermore, it will be also possible to use direct thermodynamic cycles where the supercritical fluid expands right away in a turbine without the necessity of using intermediate steam generators and/or separators. This work presents several thermodynamic cycles that could be appropriate to run SCWR power plants. Improving both thermal efficiency and mechanical power constitutes a multi-objective optimization problem and requires specific tools. To this aim, an efficient and robust evolutionary algorithm, based on genetic algorithm, is used and coupled to an appropriate power plant thermodynamic simulation model. The results provide numerous combinations to achieve a thermal efficiency higher than 50% with a mechanical power of 1200 MW. It is observed that in most cases the landscape of Pareto's front is mostly controlled only by few key parameters. These results may be very useful for future plant design engineers. Furthermore, some calculations for pipe sizing and temperature variation between coolant and fuel have been carried out to provide an idea on their order of magnitude.

  10. High-Temperature Superconductivity

    NASA Astrophysics Data System (ADS)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  11. Passive radiative cooling of a HTS coil for attitude orbit control in micro-spacecraft

    NASA Astrophysics Data System (ADS)

    Inamori, Takaya; Ozaki, Naoya; Saisutjarit, Phongsatorn; Ohsaki, Hiroyuki

    2015-02-01

    This paper proposes a novel radiative cooling system for a high temperature superconducting (HTS) coil for an attitude orbit control system in nano- and micro-spacecraft missions. These days, nano-spacecraft (1-10 kg) and micro-spacecraft (10-100 kg) provide space access to a broader range of spacecraft developers and attract interest as space development applications. In planetary and high earth orbits, most previous standard-size spacecraft used thrusters for their attitude and orbit control, which are not available for nano- and micro-spacecraft missions because of the strict power consumption, space, and weight constraints. This paper considers orbit and attitude control methods that use a superconducting coil, which interacts with on-orbit space plasmas and creates a propulsion force. Because these spacecraft cannot use an active cooling system for the superconducting coil because of their mass and power consumption constraints, this paper proposes the utilization of a passive radiative cooling system, in which the superconducting coil is thermally connected to the 3 K cosmic background radiation of deep space, insulated from the heat generation using magnetic holders, and shielded from the sun. With this proposed cooling system, the HTS coil is cooled to 60 K in interplanetary orbits. Because the system does not use refrigerators for its cooling system, the spacecraft can achieve an HTS coil with low power consumption, small mass, and low cost.

  12. THE CHANDRA DEEP PROTOCLUSTER SURVEY: Ly{alpha} BLOBS ARE POWERED BY HEATING, NOT COOLING

    SciTech Connect

    Geach, J. E.; Alexander, D. M.; Lehmer, B. D.; Matsuda, Y.; Smail, Ian; Bower, R. G.; Chapman, S. C.; Scharf, C. A.; Bauer, F. E.; Basu-Zych, A.; Ivison, R. J.; Volonteri, M.; Yamada, T.; Blain, A. W.

    2009-07-20

    We present the results of a 400 ks Chandra survey of 29 extended Ly{alpha} emitting nebulae (Ly{alpha} Blobs, LABs) in the z = 3.09 protocluster in the SS A22 field. We detect luminous X-ray counterparts in five LABs, implying a large fraction of active galactic nuclei (AGN) in LABs, f{sub AGN} = 17{sup +12}{sub -7}% down to L{sub 2-32keV} {approx} 10{sup 44} erg s{sup -1}. All of the AGN appear to be heavily obscured, with spectral indices implying obscuring column densities of N{sub H} > 10{sup 23} cm{sup -2}. The AGN fraction should be considered a lower limit, since several more LABs not detected with Chandra show AGN signatures in their mid-infrared (mid-IR) emission. We show that the UV luminosities of the AGN are easily capable of powering the extended Ly{alpha} emission via photoionization alone. When combined with the UV flux from a starburst component, and energy deposited by mechanical feedback, we demonstrate that 'heating' by a central source, rather than gravitational cooling is the most likely power source of LABs. We argue that all LABs could be powered in this manner, but that the luminous host galaxies are often just below the sensitivity limits of current instrumentation, or are heavily obscured. No individual LABs show evidence for extended X-ray emission, and a stack equivalent to a {approx}>9 Ms exposure of an average LAB also yields no statistical detection of a diffuse X-ray component. The resulting diffuse X-ray/Ly{alpha} luminosity limit implies there is no hot (T {approx}> 10{sup 7} K) gas component in these halos, and also rules out inverse Compton scattering of cosmic microwave background photons, or local far-IR photons, as a viable power source for LABs.

  13. Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent

    PubMed Central

    Chien, Shih-Hsiang; Dzombak, David A.; Vidic, Radisav D.

    2013-01-01

    Abstract Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2–3, and 0.5–1 mg/L as Cl2 for NaOCl, preformed NH2Cl, and ClO2, respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup. PMID:23781129

  14. DEVELOP A CONCENTRATED SOLAR POWER-BASED THERMAL COOLING SYSTEM VIA SIMULATION AND EXPERIMENTAL STUDIES

    EPA Science Inventory

    A small scale CSP-based cooling system prototype (300W cooling capacity) and the system performance simulation tool will be developed as a proof of concept. Practical issues will be identified to improve our design.

  15. High-power frequency-stabilized laser for laser cooling of metastable helium at 389 nm

    SciTech Connect

    Koelemeij, J.C.J.; Hogervorst, W.; Vassen, W.

    2005-03-01

    A high-power, frequency-stabilized laser for cooling of metastable helium atoms using the 2 {sup 3}S{sub 1}{yields}3 {sup 3}P{sub 2} transition at 389 nm has been developed. The 389 nm light is generated by frequency doubling of a titanium:sapphire laser in an external enhancement cavity containing a lithium-triborate nonlinear crystal. With a maximum conversion efficiency of 75%, 1 W of useful 389 nm power is produced out of 2 W at 778 nm. While being stabilized to the 2 {sup 3}S{sub 1}{yields}3 {sup 3}P{sub 2} transition, the 389 nm frequency is tunable over {+-}150 MHz with respect to the field-free atomic resonance frequency. This is accomplished by Zeeman tuning of the absorption lines used in the frequency-stabilization scheme. The setup for saturated absorption spectroscopy in an rf discharge cell, used to stabilize the 389 nm laser to the atomic transition, is described in detail.

  16. ELECTRON COOLING OF RHIC.

    SciTech Connect

    BEN-ZVI, I.; LITVINENKO, V.; BARTON, D.; ET AL.

    2005-05-16

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV.

  17. Helium Transfer System for the Superconducting Devices at NSRRC

    NASA Astrophysics Data System (ADS)

    Li, H. C.; Hsiao, F. Z.; Chang, S. H.; Chiou, W. S.

    2006-04-01

    A helium cryogenic plant with a maximum cooling power of 450 W at 4.5K was installed at the end of the year 2003. This plant has provide the cooling power for the test of one superconducting cavity and the commission of one superconducting magnet for nine months. In November 2004, we installed one helium transfer system in NSRRC's storage ring to fulfill the cooling requirement for the operation of one superconducting cavity and two superconducting magnets. This helium transfer system consists of a switch valve box and the nitrogen-shielding multi-channel transfer lines. The averaged heat leak to the helium process line (including the straight section, the joint, the elbow, the coupling) at liquid helium temperature is specified to be less than 0.1 W/m at 4.2K; the total heat leak of the switching valve box to helium process lines is less than 16 W at 4.2K. In this paper we present the function, design parameters and test result of the helium transfer system. Commissioning results of both the cavity and the magnets using this helium transfer system will be shown as well.

  18. REMOVING COOL CORES AND CENTRAL METALLICITY PEAKS IN GALAXY CLUSTERS WITH POWERFUL ACTIVE GALACTIC NUCLEUS OUTBURSTS

    SciTech Connect

    Guo Fulai; Mathews, William G.

    2010-07-10

    Recent X-ray observations of galaxy clusters suggest that cluster populations are bimodally distributed according to central gas entropy and are separated into two distinct classes: cool core (CC) and non-cool core (NCC) clusters. While it is widely accepted that active galactic nucleus (AGN) feedback plays a key role in offsetting radiative losses and maintaining many clusters in the CC state, the origin of NCC clusters is much less clear. At the same time, a handful of extremely powerful AGN outbursts have recently been detected in clusters, with a total energy {approx}10{sup 61}-10{sup 62} erg. Using two-dimensional hydrodynamic simulations, we show that if a large fraction of this energy is deposited near the centers of CC clusters, which is likely common due to dense cores, these AGN outbursts can completely remove CCs, transforming them to NCC clusters. Our model also has interesting implications for cluster abundance profiles, which usually show a central peak in CC systems. Our calculations indicate that during the CC to NCC transformation, AGN outbursts efficiently mix metals in cluster central regions and may even remove central abundance peaks if they are not broad enough. For CC clusters with broad central abundance peaks, AGN outbursts decrease peak abundances, but cannot effectively destroy the peaks. Our model may simultaneously explain the contradictory (possibly bimodal) results of abundance profiles in NCC clusters, some of which are nearly flat, while others have strong central peaks similar to those in CC clusters. A statistical analysis of the sizes of central abundance peaks and their redshift evolution may shed interesting insights on the origin of both types of NCC clusters and the evolution history of thermodynamics and AGN activity in clusters.

  19. Removing Cool Cores and Central Metallicity Peaks in Galaxy Clusters with Powerful Active Galactic Nucleus Outbursts

    NASA Astrophysics Data System (ADS)

    Guo, Fulai; Mathews, William G.

    2010-07-01

    Recent X-ray observations of galaxy clusters suggest that cluster populations are bimodally distributed according to central gas entropy and are separated into two distinct classes: cool core (CC) and non-cool core (NCC) clusters. While it is widely accepted that active galactic nucleus (AGN) feedback plays a key role in offsetting radiative losses and maintaining many clusters in the CC state, the origin of NCC clusters is much less clear. At the same time, a handful of extremely powerful AGN outbursts have recently been detected in clusters, with a total energy ~1061-1062 erg. Using two-dimensional hydrodynamic simulations, we show that if a large fraction of this energy is deposited near the centers of CC clusters, which is likely common due to dense cores, these AGN outbursts can completely remove CCs, transforming them to NCC clusters. Our model also has interesting implications for cluster abundance profiles, which usually show a central peak in CC systems. Our calculations indicate that during the CC to NCC transformation, AGN outbursts efficiently mix metals in cluster central regions and may even remove central abundance peaks if they are not broad enough. For CC clusters with broad central abundance peaks, AGN outbursts decrease peak abundances, but cannot effectively destroy the peaks. Our model may simultaneously explain the contradictory (possibly bimodal) results of abundance profiles in NCC clusters, some of which are nearly flat, while others have strong central peaks similar to those in CC clusters. A statistical analysis of the sizes of central abundance peaks and their redshift evolution may shed interesting insights on the origin of both types of NCC clusters and the evolution history of thermodynamics and AGN activity in clusters.

  20. Study of using microfiltration and reverse osmosis membrane technologies for reclaiming cooling water in the power industry.

    PubMed

    Li, J; Xu, Z Y; An, H G; Liu, L Q

    2007-07-01

    A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times. PMID:17710919

  1. Thermal effluent from the power sector: an analysis of once-through cooling system impacts on surface water temperature

    NASA Astrophysics Data System (ADS)

    Madden, N.; Lewis, A.; Davis, M.

    2013-09-01

    In this study, we review federal datasets to assess the impacts of once-through power plant cooling systems on summer freshwater temperatures in the United States from 1996 to 2005. We find that maximum reported temperature discharges averaged 37? C (1996-2005) and were 9.5? C (1996-2000) to 10? C (2001-2005) higher than maximum reported intake temperatures during the summer. More than half of all power plant cooling systems report maximum temperature discharges that exceed 32? C and increase water temperatures enough to potentially impact aquatic life. However, current federal data on thermal discharges from power plants are insufficient to adequately assess their impact on in stream temperatures, or their subsequent effects on aquatic ecosystems and biodiversity. A preliminary analysis indicates that certain watersheds, primarily in the Southeastern and Midwestern United States, are good candidates for more focused study of power plant temperature impacts.

  2. WET/DRY COOLING AND COOLING TOWER BLOWDOWN DISPOSAL IN SYNTHETIC FUEL AND STEAM-ELECTRIC POWER PLANTS

    EPA Science Inventory

    This report extends the results of a previous study dealing with the detailed determination of consumptive water use and wet-solids residuals for coal and oil shale conversion plants and coal-fired steam-electric power generation plants located in the western United States. The p...

  3. Superconducting wire with improved strain characteristics

    DOEpatents

    Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (E. Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

    1982-01-01

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.

  4. Superconducting wire with improved strain characteristics

    DOEpatents

    Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (East Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

    1982-01-01

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

  5. Evaluation of Gas-Cooled Pressurized Phosphoric Acid Fuel Cells for Electric Utility Power Generation

    NASA Technical Reports Server (NTRS)

    Faroque, M.

    1983-01-01

    Gas cooling is a more reliable, less expensive and a more simple alternative to conventional liquid cooling for heat removal from the phosphoric acid fuel cell (PAFC). The feasibility of gas-cooling was already demonstrated in atmospheric pressure stacks. Theoretical and experimental investigations of gas-cooling for pressurized PAFC are presented. Two approaches to gas cooling, Distributed Gas-Cooling (DIGAS) and Separated Gas-Cooling (SGC) were considered, and a theoretical comparison on the basis of cell performance indicated SGC to be superior to DIGAS. The feasibility of SGC was experimentally demonstrated by operating a 45-cell stack for 700 hours at pressure, and determining thermal response and the effect of other related parameters.

  6. Development of superconductive magnets

    NASA Technical Reports Server (NTRS)

    Laurence, J. C.

    1970-01-01

    Survey of superconductive magnets considers - stabilization problems, advances in materials and their uses, and design evolution. Uses of superconducting magnets in particle accelerators and bubble chambers, as well as possible applications in magnetohydrodynamic and thermonuclear power generation and levitation are discussed.

  7. Superconducting integrated terahertz receivers

    NASA Astrophysics Data System (ADS)

    Koshelets, V. P.; Ermakov, A. B.; Filippenko, L. V.; Fomisky, M. Yu; Kinev, N. V.; Kiselev, O. S.; de Lange, A.; de Lange, G.; Rudakov, K. E.; Torgashin, M. Yu; Vaks, V. L.; Yuan, J.; Wang, H. B.

    2014-03-01

    A Superconducting Integrated Receiver (SIR) comprises on one chip all elements needed for heterodyne detection. Light weight and low power consumption combined with nearly quantum limited sensitivity and a wide tuning range of the superconducting local oscillator make SIR a perfect candidate for many practical applications.

  8. Organic Fluids and Passive Cooling in a Supercritical Rankine Cycle for Power Generation from Low Grade Heat Sources

    NASA Astrophysics Data System (ADS)

    Vidhi, Rachana

    Low grade heat sources have a large amount of thermal energy content. Due to low temperature, the conventional power generation technologies result in lower efficiency and hence cannot be used. In order to efficiently generate power, alternate methods need to be used. In this study, a supercritical organic Rankine cycle was used for heat source temperatures varying from 125C to 200C. Organic refrigerants with zero ozone depletion potential and their mixtures were selected as working fluid for this study while the cooling water temperature was changed from 10-25C. Operating pressure of the cycle has been optimized for each fluid at every heat source temperature to obtain the highest thermal efficiency. Energy and exergy efficiencies of the thermodynamic cycle have been obtained as a function of heat source temperature. Efficiency of a thermodynamic cycle depends significantly on the sink temperature. At areas where water cooling is not available and ambient air temperature is high, efficient power generation from low grade heat sources may be a challenge. Use of passive cooling systems coupled with the condenser was studied, so that lower sink temperatures could be obtained. Underground tunnels, buried at a depth of few meters, were used as earth-air-heat-exchanger (EAHE) through which hot ambient air was passed. It was observed that the air temperature could be lowered by 5-10C in the EAHE. Vertical pipes were used to lower the temperature of water by 5C by passing it underground. Nocturnal cooling of stored water has been studied that can be used to cool the working fluid in the thermodynamic cycle. It was observed that the water temperature can be lowered by 10-20C during the night when it is allowed to cool. The amount of water lost was calculated and was found to be approximately 0.1% over 10 days. The different passive cooling systems were studied separately and their effects on the efficiency of the thermodynamic cycle were investigated. They were then combined into a novel condenser design that uses passive cooling technology to cool the working fluid that was selected in the first part of the study. It was observed that the efficiency of the cycle improved by 2-2.5% when passive cooling system was used.

  9. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CFR 50.12, are still applicable to Option B of this appendix if necessary, unless specifically revoked...-Cooled Power Reactors J Appendix J to Part 50 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. J Appendix J to Part 50—Primary Reactor...

  10. 10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors. 50.46 Section 50.46 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... or construction permit issued under this part, applicant for a standard design certification...

  11. CLOSED-CYCLE COOLING SYSTEMS FOR STEAM-ELECTRIC POWER PLANTS: A STATE-OF-THE-ART MANUAL

    EPA Science Inventory

    The report, in a practical manual format, gives results of a technical review of the state-of-the-art of thermal pollution control and treatment of cooling water in the steam-electric power generation industry. It assesses current, near horizon, and future technologies utilized o...

  12. Preliminary analysis of problem of determining experimental performance of air-cooled turbine III : methods for determining power and efficiency

    NASA Technical Reports Server (NTRS)

    Ellerbrock, Herman H , Jr; Ziemer, Robert R

    1950-01-01

    Suggested formula are given for determining air-cooled turbine-performance characteristics, such as power and efficiency, as functions of certain parameters. These functions, generally being unknown, are determined from experimental data obtained from specific investigations. Special plotting methods for isolating the effect of each parameter are outlined.

  13. Minnesota Project: district heating and cooling through power plant retrofit and distribution network. Final report. Phase 1. [Minnesota Project

    SciTech Connect

    1980-01-01

    Appendices are presented for the Minnesota Project: District Heating and Cooling Through Power Plant Retrofit and Distribution Network. These are: SYNTHA results (SYNTHA II is a proprietary program of the SYNTHA Corporation); Market Survey Questionnaire: Environmental Review Procedures; Public Service Commission Regulation of District Heating; Energy Use Normalization Procedures; Power Plant Description; Letters of Commitment; Bond Opinion and Issuance; and Marvin Koeplin Letter, Chairman of Public Service Commission, Moorehead, Minnesota.

  14. Numerical analyses of the electromagnetic force acting on high-temperature superconducting power cables due to fault current

    NASA Astrophysics Data System (ADS)

    Wang, X.; Ishiyama, A.; Ohya, M.; Maruyama, O.; Ohkuma, T.

    2012-05-01

    In Japan, the development of the 66 kV class REB2C3O7-x (RE123; RE stands for rare earth) high-temperature superconducting (HTS) power cable was begun in 2008 as a national project. 66 kV class RE123 HTS power cables may be subjected to a fault current of 31.5 kArms for 2 s. Therefore, the electromagnetic and thermal characteristics of HTS power cables have to be determined under fault conditions to ensure stability and feasibility. In this study, numerical analyses were performed using a computer program on the basis of the finite element method and an equivalent circuit model to evaluate the electromagnetic and thermal behaviors of a 66 kV class HTS model cable resulting from the fault current. The electromagnetic forces acting on coated conductors that are assembled in the HTS model cable were also numerically simulated under the fault condition. The result found was that the maximum electromagnetic force acting on the coated conductor in the peeling and compression direction was less than 20 kPa. However, the irreversible Ic degradations caused by the peeling and compression stress were above several MPa in previous studies. Thus, the results of this study indicate a low probability of Ic degradation of the 66 kV class HTS power cable being caused by the electromagnetic force due to the fault current.

  15. Superconducting levitating bearing

    NASA Technical Reports Server (NTRS)

    Moon, Francis C. (Inventor)

    1996-01-01

    A superconducting bearing assembly includes a coil field source that may be superconducting and a superconducting structure. The coil field source assembly and superconducting structure are positioned so as to enable relative rotary movement therebetween. The structure and coil field source are brought to a supercooled temperature before a power supply induces a current in the coil field source. A Meissner-like effect is thereby obtained and little or no penetration of the field lines is seen in the superconducting structure. Also, the field that can be obtained from the superconducting coil is 2-8 times higher than that of permanent magnets. Since the magnetic pressure is proportioned to the square of the field, magnetic pressures from 4 to 64 times higher are achieved.

  16. Improvement of a high current dc power supply system for testing the large scaled superconducting cables and magnets

    SciTech Connect

    Yamada, Shuichi; Chikaraishi, Hirotaka; Tanahashi, Shugo

    1994-07-01

    A dc 75 kA power supply system was constructed to test the SC (superconducting) R and D (research and development) cables and magnets for the Large Helical Device (LHD). It consists of three 25 kA unit banks. A unit bank has two double-star-rectifier connections with the inter-phase reactors. A digital feedback control method is applied to the automatic current regulation (ACR) in each unit bank. For shortening the dead time of the feedback process, a new algorithm of a digital phase controller for the ACR is investigated. A Bode diagram of the feedback process is directly measured. It is confirmed that the dead time of the feedback process is reduced to one sixth, and that the feedback gain of PID (proportional, integral and differential) compensation is improved by a factor of two from the original method.

  17. Improvement of a high current DC power supply system for testing the large scaled superconducting cables and magnets

    NASA Astrophysics Data System (ADS)

    Yamada, Shuichi; Chikaraishi, Hirotaka; Tanahashi, Shugo; Mito, Toshiyuki; Takahata, Kazuya; Yanagi, Nagato; Sakamoto, Mizuki; Nishimura, Arata; Motojima, Osamu; Yamamoto, Junya

    1994-07-01

    A dc 75 kA power supply system was constructed to test the SC (superconducting) R&D (research and development) cables and magnets for the Large Helical Device (LHD). It consists of three 25 kA unit banks. A unit bank has two double-star-rectifier connections with the inter-phase reactors. A digital feedback control method is applied to the automatic current regulation (ACR) in each unit bank. For shortening the dead time of the feedback process, a new algorithm of a digital phase controller for the ACR is investigated. A Bode diagram of the feedback process is directly measured. It is confirmed that the dead time of the feedback process is reduced to one sixth, and that the feedback gain of PID (proportional, integral and differential) compensation is improved by a factor of two from the original method.

  18. Improvement of a high current DC power supply system for testing the large scaled superconducting cables and magnets

    NASA Astrophysics Data System (ADS)

    Yamada, Shuichi; Chikaraishi, Hirotaka; Tanahashi, Shugo

    1993-11-01

    A dc 75 kA power supply system was constructed to test the superconducting (SC) R and D cables and magnets for the Large Helical Device. It consists of three 25 kA unit banks. A unit bank has two double-star-rectifier connections with the inter-phase reactors. A digital feedback control method is applied to the automatic current regulation (ACR) in each unit bank. For shortening the dead time of the feedback process, a new algorithm of a digital phase controller for the ACR is investigated. A Bode diagram of the feedback process is directly measured. It is confirmed that the dead time of the feedback process is reduced to one sixth, and that the feedback gain of PID compensation is improved by a factor of two from the original method.

  19. European roadmap on superconductive electronics - status and perspectives

    NASA Astrophysics Data System (ADS)

    Anders, S.; Blamire, M. G.; Buchholz, F.-Im.; Crété, D.-G.; Cristiano, R.; Febvre, P.; Fritzsch, L.; Herr, A.; Il'ichev, E.; Kohlmann, J.; Kunert, J.; Meyer, H.-G.; Niemeyer, J.; Ortlepp, T.; Rogalla, H.; Schurig, T.; Siegel, M.; Stolz, R.; Tarte, E.; ter Brake, H. J. M.; Toepfer, H.; Villegier, J.-C.; Zagoskin, A. M.; Zorin, A. B.

    2010-12-01

    Executive SummaryFor four decades semiconductor electronics has followed Moore’s law: with each generation of integration the circuit features became smaller, more complex and faster. This development is now reaching a wall so that smaller is no longer any faster. The clock rate has saturated at about 3-5 GHz and the parallel processor approach will soon reach its limit. The prime reason for the limitation the semiconductor electronics experiences is not the switching speed of the individual transistor, but its power dissipation and thus heat. Digital superconductive electronics is a circuit- and device-technology that is inherently faster at much less power dissipation than semiconductor electronics. It makes use of superconductors and Josephson junctions as circuit elements, which can provide extremely fast digital devices in a frequency range - dependent on the material - of hundreds of GHz: for example a flip-flop has been demonstrated that operated at 750 GHz. This digital technique is scalable and follows similar design rules as semiconductor devices. Its very low power dissipation of only 0.1 μW per gate at 100 GHz opens the possibility of three-dimensional integration. Circuits like microprocessors and analogue-to-digital converters for commercial and military applications have been demonstrated. In contrast to semiconductor circuits, the operation of superconducting circuits is based on naturally standardized digital pulses the area of which is exactly the flux quantum Φ0. The flux quantum is also the natural quantization unit for digital-to-analogue and analogue-to-digital converters. The latter application is so precise, that it is being used as voltage standard and that the physical unit ‘Volt’ is defined by means of this standard. Apart from its outstanding features for digital electronics, superconductive electronics provides also the most sensitive sensor for magnetic fields: the Superconducting Quantum Interference Device (SQUID). Amongst many other applications SQUIDs are used as sensors for magnetic heart and brain signals in medical applications, as sensor for geological surveying and food-processing and for non-destructive testing. As amplifiers of electrical signals, SQUIDs can nearly reach the theoretical limit given by Quantum Mechanics. A further important field of application is the detection of very weak signals by ‘transition-edge’ bolometers, superconducting nanowire single-photon detectors, and superconductive tunnel junctions. Their application as radiation detectors in a wide frequency range, from microwaves to X-rays is now standard. The very low losses of superconductors have led to commercial microwave filter designs that are now widely used in the USA in base stations for cellular phones and in military communication applications. The number of demonstrated applications is continuously increasing and there is no area in professional electronics, in which superconductive electronics cannot be applied and surpasses the performance of classical devices. Superconductive electronics has to be cooled to very low temperatures. Whereas this was a bottleneck in the past, cooling techniques have made a huge step forward in recent years: very compact systems with high reliability and a wide range of cooling power are available commercially, from microcoolers of match-box size with milli-Watt cooling power to high-reliability coolers of many Watts of cooling power for satellite applications. Superconductive electronics will not replace semiconductor electronics and similar room-temperature techniques in standard applications, but for those applications which require very high speed, low-power consumption, extreme sensitivity or extremely high precision, superconductive electronics is superior to all other available techniques. To strengthen the European competitiveness in superconductor electronics research projects have to be set-up in the following field: Ultra-sensitive sensing and imaging. Quantum measurement instrumentation. Advanced analogue-to-digital converters. Superconductive electronics technology.

  20. Technical analysis of a river basin-based model of advanced power plant cooling technologies for mitigating water management challenges

    NASA Astrophysics Data System (ADS)

    Stillwell, Ashlynn S.; Clayton, Mary E.; Webber, Michael E.

    2011-07-01

    Thermoelectric power plants require large volumes of water for cooling, which can introduce drought vulnerability and compete with other water needs. Alternative cooling technologies, such as cooling towers and hybrid wet-dry or dry cooling, present opportunities to reduce water diversions. This case study uses a custom, geographically resolved river basin-based model for eleven river basins in the state of Texas (the Brazos and San Jacinto-Brazos, Colorado and Colorado-Brazos, Cypress, Neches, Nueces, Red, Sabine, San Jacinto, and Trinity River basins), focusing on the Brazos River basin, to analyze water availability during drought. We utilized two existing water availability models for our analysis: (1) the full execution of water rightsa scenario where each water rights holder diverts the full permitted volume with zero return flow, and (2) current conditionsa scenario reflecting actual diversions with associated return flows. Our model results show that switching the cooling technologies at power plants in the eleven analyzed river basins to less water-intensive alternative designs can potentially reduce annual water diversions by 247-703 million m3enough water for 1.3-3.6 million people annually. We consider these results in a geographic context using geographic information system tools and then analyze volume reliability, which is a policymaker's metric that indicates the percentage of total demand actually supplied over a given period. This geographic and volume reliability analysis serves as a measure of drought susceptibility in response to changes in thermoelectric cooling technologies. While these water diversion savings do not alleviate all reliability concerns, the additional streamflow from the use of dry cooling alleviates drought concerns for some municipal water rights holders and might also be sufficient to uphold instream flow requirements for important bays and estuaries on the Texas Gulf coast.

  1. A Study of Power Systems Stability Enhancement Effects by Excitation Control of Superconducting Generator with High Response Excitation based on Detailed Excitation Circuit Model

    NASA Astrophysics Data System (ADS)

    Wu, Guohong; Shirato, Hideyuki

    SCG (Superconducting Generator) has a superconducting field winding, which leads to many advantages such as small size, high generation efficiency, low impedance, and so on, and be considered as one of the candidates to meet the needs of high stability and high efficiency in the future power system networks. SCG with high response excitation is especially expected to be able to enhance the transient stability of power system by its SMES (Superconducting Magnetic Energy System) effect. The SMES effect of SCG is recognized that its behaviors are dominated by the structures and controls of its excitation system. For this reason, in order to verify exactly how the SMES effect of SCG influences on the power system stability, the electrical circuits of SCG high response excitation are modeled in detail for conducting digital simulation, and its influence on excitation voltage and active power output of SCG are discussed as well. The simulation results with a typical one machine - infinite bus power system model shows that the SMES effect can be certainly obtained when its exciting power is supplied from SCG terminal bus and may considerably lead to an improvement of power system transient stability.

  2. New 30 kA power system at Fermilab and its use for measuring the effects of ripple current on the performance of superconducting high field magnets

    SciTech Connect

    Carcagno, R.; Feher, S.; Garvey, J.; Jaskierny, W.; Lamm, M.; Makulski, A.; Orris, D.F.; Pfeffer, H.; Tartaglia, M.; Tompkins, J.; Wolff, D.; /Fermilab

    2004-12-01

    A new 30 kA, 30 V dc Power System was designed, built, and commissioned at Fermilab for testing Superconducting High Field Magnets. This system has been successfully supporting operations at the Fermilab Magnet Test Facility since April 2002. It is based on six commercial 150 kW Power Energy Industries power supply modules and the following in-house modules: six 720 Hz filters, two 15 kA/1kV dc solid-state dump switch, and a 3 MJ/30 kA/1 kV dc dump resistor. Additional inhouse electronic components were designed and built to provide precise current regulation and distribution of current and current rate of change. An industrial-type Programmable Logic Controller system was used to provide equipment interlocks and monitoring. This paper summarizes studies on the influence of characteristics of this new power system--such as ripple current--on the performance of High Field Superconducting magnets.

  3. Micro Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center, Mississippi State University

    SciTech Connect

    Louay Chamra

    2008-09-26

    Initially, most micro-CHP systems will likely be designed as constant-power output or base-load systems. This implies that at some point the power requirement will not be met, or that the requirement will be exceeded. Realistically, both cases will occur within a 24-hour period. For example, in the United States, the base electrical load for the average home is approximately 2 kW while the peak electrical demand is slightly over 4 kW. If a 3 kWe micro- CHP system were installed in this situation, part of the time more energy will be provided than could be used and for a portion of the time more energy will be required than could be provided. Jalalzadeh-Azar [6] investigated this situation and presented a comparison of electrical- and thermal-load-following CHP systems. In his investigation he included in a parametric analysis addressing the influence of the subsystem efficiencies on the total primary energy consumption as well as an economic analysis of these systems. He found that an increase in the efficiencies of the on-site power generation and electrical equipment reduced the total monthly import of electricity. A methodology for calculating performance characteristics of different micro-CHP system components will be introduced in this article. Thermodynamic cycles are used to model each individual prime mover. The prime movers modeled in this article are a spark-ignition internal combustion engine (Otto cycle) and a diesel engine (Diesel cycle). Calculations for heat exchanger, absorption chiller, and boiler modeling are also presented. The individual component models are then linked together to calculate total system performance values. Performance characteristics that will be observed for each system include maximum fuel flow rate, total monthly fuel consumption, and system energy (electrical, thermal, and total) efficiencies. Also, whether or not both the required electrical and thermal loads can sufficiently be accounted for within the system specifications is observed. Case study data for various micro-CHP system configurations have been discussed and compared. Comparisons are made of the different prime mover/fuel combinations. Also, micro- CHP monthly energy cost results are compared for each system configuration to conventional monthly utility costs for equivalent monthly building power, heating, and cooling requirements.

  4. Thermal ecology of Naegleria fowleri from a power plant cooling reservoir.

    PubMed Central

    Huizinga, H W; McLaughlin, G L

    1990-01-01

    The pathogenic, free-living amoeba Naegleria fowleri is the causative agent of human primary amebic meningoencephalitis. N. fowleri has been isolated from thermally elevated aquatic environments worldwide, but temperature factors associated with occurrence of the amoeba remain undefined. In this study, a newly created cooling reservoir (Clinton Lake, Illinois) was surveyed for Naegleria spp. before and after thermal additions from a nuclear power plant. Water and sediment samples were collected from heated and unheated arms of the reservoir and analyzed for the presence of thermophilic Naegleria spp. and pathogenic N. fowleri. Amoebae were identified by morphology, in vitro cultivation, temperature tolerance, mouse pathogenicity assay, and DNA restriction fragment length analysis. N. fowleri was isolated from the thermally elevated arm but not from the ambient-temperature arm of the reservoir. The probability of isolating thermophilic Naegleria and pathogenic N. fowleri increased significantly with temperature. Repetitive DNA restriction fragment profiles of the N. fowleri Clinton Lake isolates and a known N. fowleri strain of human origin were homogeneous. Images PMID:1975164

  5. Thermal ecology of Naegleria fowleri from a power plant cooling reservoir

    SciTech Connect

    Huizinga, H.W. ); McLaughlin, G.L. )

    1990-07-01

    The pathogenic, free-living amoeba Naegleria fowleri is the causative agent of human primary amebic meningoencephalitis. N. fowleri has been isolated from thermally elevated aquatic environments worldwide, but temperature factors associated with occurrence of the amoeba remain undefined. In this study, a newly created cooling reservoir (Clinton Lake, Illinois) was surveyed for Naegleria spp. before and after thermal additions from a nuclear power plant. Water and sediment samples were collected from heated and unheated arms of the reservoir and analyzed for the presence of thermophilic Naegleria spp. and pathogenic N. fowleri. Amoebae were identified by morphology, in vitro cultivation, temperature tolerance, mouse pathogenicity assay, and DNA restriction fragment length analysis. N. fowleri was isolated from the thermally elevated arm but not from the ambient-temperature arm of the reservoir. The probability of isolating thermophilic Naegleria and pathogenic N. fowleri increased significantly with temperature. Repetitive DNA restriction fragment profiles of the N. fowleri Clinton Lake isolates and a known N. fowleri strain of human origin were homogeneous.

  6. Magnetocaloric properties and critical behavior of high relative cooling power FeNiB nanoparticles

    SciTech Connect

    Chaudhary, V.; Maheswar Repaka, D. V.; Chaturvedi, A.; Ramanujan, R. V.; Sridhar, I.

    2014-10-28

    Low cost magnetocaloric nanomaterials have attracted considerable attention for energy efficient applications. We report a very high relative cooling power (RCP) in a study of the magnetocaloric effect in quenched FeNiB nanoparticles. RCP increases from 89.8 to 640 J kg{sup −1} for a field change of 1 and 5 T, respectively, these values are the largest for rare earth free iron based magnetocaloric nanomaterials. To investigate the magnetocaloric behavior around the Curie temperature (T{sub C}), the critical behavior of these quenched nanoparticles was studied. Detailed analysis of the magnetic phase transition using the modified Arrott plot, Kouvel-Fisher method, and critical isotherm plots yields critical exponents of β = 0.364, γ = 1.319, δ = 4.623, and α = −0.055, which are close to the theoretical exponents obtained from the 3D-Heisenberg model. Our results indicate that these FeNiB nanoparticles are potential candidates for magnetocaloric fluid based heat pumps and low grade waste heat recovery.

  7. Nonequilibrium Thermoelectrics: Low-Cost, High-Performance Materials for Cooling and Power Generation

    SciTech Connect

    Li, Q.

    2011-05-18

    Thermoelectric materials can be made into coolers (TECs) that use electricity to develop a temperature difference, cooling something, or generators (TEGs) that convert heat directly to electricity. One application of TEGs is to place them in a waste heat stream to recuperate some of the power being lost and putting it to use more profitably. To be effective thermoelectrics, however, materials must have both high electrical conductivity and low thermal conductivity, a combination rarely found in nature. Materials selection and processing has led to the development of several systems with a figure of merit, ZT, of nearly unity. By using non-equilibrium techniques, we have fabricated higher efficiency thermoelectric materials. The process involves creating an amorphous material through melt spinning and then sintering it with either spark plasma or a hot press for as little as two minutes. This results in a 100% dense material with an extremely fine grain structure. The grain boundaries appear to retard phonons resulting in a reduced thermal conductivity while the electrons move through the material relatively unchecked. The techniques used are low-cost and scaleable to support industrial manufacturing.

  8. Power combiners/dividers for loop pickup and kicker arrays for FNAL stochastic cooling rings

    SciTech Connect

    Johnson, J.K.; Nemetz, R.

    1985-05-01

    The anti-proton accumulator and debuncher at FNAL will use stochastic methods to ''cool'' the beam. Pairs of quarter-wavelength directional-coupler loops are used to detect and kick the beam. The loops are copper plates which are flush with the upper and lower wall of a rectangular beam pipe. The plates, when surrounded by a properly sized pocket, form a 100-ohm transmission-line directional coupler. As the beam passes, a signal which gives position and time information, is induced in the plates. But, because the signal levels are low (<.5 picowatts per pair), a power combiner (usually several primary combiners feeding a secondary combiner) is used to combine the outputs of many loops. Subsequently, the combined signal is amplified, filtered and then fed into a divider, (that is, a combiner operating in reverse). The divider distributes the signal into a different set of loops which modify (kick) the beam's position. Since the loop couplers are arranged linearly, in arrays of various lengths, combiners also provide a convenient method of reducing the number of vacuum feedthroughs and preamplifiers and their related costs in performance and dollars. In this note we describe various stripline combiner systems that add the outputs of 4, 8, 16 or 32 loops.

  9. Assessment of the suitability of agricultural waste water for geothermal power plant cooling in the Imperial Valley. 1: Water quality

    NASA Astrophysics Data System (ADS)

    Morris, W. F.

    1981-09-01

    Evaluation of the quality of agricultural waste water is the first step in assessing the suitability of agricultural waste water for geothermal power plant cooling. Samples of agricultural waste water from the New and Alamo rivers located in the Imperial Valley of California were analyzed. Determinations of standard water quality parameters, solids content, and inorganic compositions of the solids were made. The results are compared with data on samples of irrigation water and steam condensate also obtained from sites in the Imperial Valley. The data were evaluated in relation to cooling tower operation, waste generation, and waste disposal.

  10. Electric Current Dependence of a Self-Cooling Device Consisting of Silicon Wafers Connected to a Power MOSFET

    NASA Astrophysics Data System (ADS)

    Nakatsugawa, H.; Okamoto, Y.; Kawahara, T.; Yamaguchi, S.

    2014-06-01

    A self-cooling device has been developed by combining a commercial n-channel power metal-oxide-semiconductor field-effect transistor (MOSFET) and single-crystalline Sb-doped n-type or B-doped p-type silicon wafers in order to improve the heat removal or cooling quantitatively. The electric current dependence of the temperature distribution in the self-cooling device and the voltage between the source and drain electrodes have been measured to estimate the Peltier heat flux. We found that the average temperature is decreased for a power MOSFET in which an electric current of 50 A flows. In particular, the average temperature of the power MOSFET was decreased by 2.7C with the n-type Si wafer and by 3.5C with the p-type Si wafer, although an electric current of 40 A makes little difference. This certainly warrants further work with improved measurement conditions. Nonetheless, the results strongly indicate that such n-type or p-type silicon wafers are candidate materials for use in self-cooling devices.

  11. Cooling through heat pumps powered by a combustion engine for natural gas

    NASA Astrophysics Data System (ADS)

    Janovcov, Martina; Janda?ka, Jozef; Ki, Roman

    2014-08-01

    The heat pump can be used both for heating and hot water in winter, but in the case of reversible heat pumps also air-conditioning in summer. Currently, air conditioners are becoming standard equipment for residential and industrial buildings. Heating and cooling occurs separately in many cases, ie that for the purpose of heating is used a separate heat source and for the cooling production other source of cold with own equipment and distribution systems. The heat pump is one device that can heat and cool often at a much lower price. This article deals with the research parameters of the gas heat pump in cooling mode.

  12. High temperature superconducting transmission cables: The future of power transmission in North America

    SciTech Connect

    Rahman, M.M.; Wen, Y.; Marciano, F.; Doench, C.

    1996-10-01

    Today, in the area of underground transmission cables the need for new installation or replacement of the existing ones with larger capacity cables is greater and greater for various reasons. Development of high temperature superconducting (HTS) transmission cable systems provides an opportunity to bring he transmission systems towards an advanced generation with largely increased capacity. This paper describes the design concept of a room temperature dielectric HTS cable and summarizes its development program. The advantages and applications of HTS cables are also discussed. Taking into account that HTS cable systems will be competitive with conventional ones it is foreseen that a large portion of North American utilities will adopt the new generation of cables in the near future.

  13. Modeling of a 22.9 kV 50 MVA superconducting power cable based on PSCAD/EMTDC for application to the Icheon substation in Korea

    NASA Astrophysics Data System (ADS)

    Lee, S.; Yoon, J.; Lee, B.; Yang, B.

    2011-11-01

    Two projects for high temperature superconducting (HTS) power cable have been carried out in Korea since 2001. One of them is a HTS cable project in DAPAS (Development of Advanced Power system by Applied Superconductivity technologies) program funded by the Ministry of Education, Science and Technology. In this project, LS Cable Ltd. (LSC) and Korea Electrotechnology Research Institute (KERI) jointly developed a 22.9 kV, 50 MVA, 3 phase, 100 m HTS cable using first generation (1G) HTS wire in 2006. The HTS cable system has been tested in a power test center of Korea Electric Power Corporation (KEPCO). LSC and KEPCO have been developing a 22.9 kV, 50 MVA, 3 phase, 500 m HTS cable system using second generation (2G) HTS wire since 2008, based on the technology of the DAPAS project. This project is called as GENI (Green Superconducting Electric Power Network at the Icheon Substation) project. The target of GENI project is to install and operate the HTS cable system in the Icheon substation located in near Seoul. In order to analyze the Icheon substation power system employing the HTS cable, an analysis model of the HTS cable is necessary. This paper describes the development of an analysis model for the 22.9 kV, 50 MVA HTS cable that will be applied to the Icheon substation in Korea.

  14. Design study of the cooling scheme for SMES system in ASPCS by using liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Makida, Yasuhiro; Shintomi, Takakazu; Asami, Takuya; Suzuki, Goro; Takao, Tomoaki; Hamajima, Takataro; Tsuda, Makoto; Miyagi, Daisuke; Munakata, Kouhei; Kajiwara, Masataka

    2013-11-01

    From the point of view of environment and energy problems, the renewable energies have been attracting attention. However, fluctuating power generation by the renewable energies affects the stability of the power network. Thus, we propose a new electric power storage and stabilization system, Advanced Superconducting Power Conditioning System (ASPCS), in which a Superconducting Magnetic Energy Storage (SMES) and a hydrogen-energy-storage converge on a liquid hydrogen station for fuel cell vehicles. The ASPCS proposes that the SMES coils wound with MgB2 conductor are indirectly cooled by thermo-siphon circulation of liquid hydrogen to use its cooling capability. The conceptual design of cooling scheme of the ASPCS is presented.

  15. Evaluation of distributed gas cooling of pressurized PAFC for utility power generation

    NASA Technical Reports Server (NTRS)

    Farooque, M.; Hooper, M.; Maru, H.

    1981-01-01

    A proof-of-concept test for a gas-cooled pressurized phosphoric acid fuel cell is described. After initial feasibility studies in short stacks, two 10 kW stacks are tested. Progress includes: (1) completion of design of the test stations with a recirculating gas cooling loop; (2) atmospheric testing of the baseline stack.

  16. Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

    2009-06-30

    This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well as feasibility of managing cooling water quality with traditional chemical management schemes. Options for chemical treatment to prevent corrosion, scaling, and biofouling were identified through review of current practices, and were tested at bench and pilot-scale. Secondary treated wastewater is the most widely available impaired water that can serve as a reliable source of cooling water makeup. There are no federal regulations specifically related to impaired water reuse but a number of states have introduced regulations with primary focus on water aerosol 'drift' emitted from cooling towers, which has the potential to contain elevated concentrations of chemicals and microorganisms and may pose health risk to the public. It was determined that corrosion, scaling, and biofouling can be controlled adequately in cooling systems using secondary treated municipal wastewater at 4-6 cycles of concentration. The high concentration of dissolved solids in treated AMD rendered difficulties in scaling inhibition and requires more comprehensive pretreatment and scaling controls. Addition of appropriate chemicals can adequately control corrosion, scaling and biological growth in ash transport water, which typically has the best water quality among the three waters evaluated in this study. The high TDS in the blowdown from pilot-scale testing units with both passively treated mine drainage and secondary treated municipal wastewater and the high sulfate concentration in the mine drainage blowdown water were identified as the main challenges for blowdown disposal. Membrane treatment (nanofiltration or reverse osmosis) can be employed to reduce TDS and sulfate concentrations to acceptable levels for reuse of the blowdown in the cooling systems as makeup water.

  17. Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues.

    SciTech Connect

    Kimmell, T. A.; Veil, J. A.; Environmental Science Division

    2009-04-03

    This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on water uses, particularly during drought conditions, this report focuses solely on impacts to the U.S. steam electric power plant fleet. Included are both fossil-fuel and nuclear power plants. One plant examined also uses biomass as a fuel. The purpose of this project is to estimate the impact on generation capacity of a drop in water level at U.S. steam electric power plants due to climatic or other conditions. While, as indicated above, the temperature of the water can impact decisions to halt or curtail power plant operations, this report specifically examines impacts as a result of a drop in water levels below power plant submerged cooling water intakes. Impacts due to the combined effects of excessive temperatures of the returned cooling water and elevated temperatures of receiving waters (due to high ambient temperatures associated with drought) may be examined in a subsequent study. For this study, the sources of cooling water used by the U.S. steam electric power plant fleet were examined. This effort entailed development of a database of power plants and cooling water intake locations and depths for those plants that use surface water as a source of cooling water. Development of the database and its general characteristics are described in Chapter 2 of this report. Examination of the database gives an indication of how low water levels can drop before cooling water intakes cease to function. Water level drops are evaluated against a number of different power plant characteristics, such as the nature of the water source (river vs. lake or reservoir) and type of plant (nuclear vs. fossil fuel). This is accomplished in Chapter 3. In Chapter 4, the nature of any compacts or agreements that give priority to users (i.e., which users must stop withdrawing water first) is examined. This is examined on a regional or watershed basis, specifically for western water rights, and also as a function of federal and state water management programs. Chapter 5 presents the findings and conclusions of this study. In addition to the above, a related intent of this study is to conduct preliminary modeling of how lowered surface water levels could affect generating capacity and other factors at different regional power plants. If utility managers are forced to take some units out of service or reduce plant outputs, the fuel mix at the remaining plants and the resulting carbon dioxide emissions may change. Electricity costs and other factors may also be impacted. Argonne has conducted some modeling based on the information presented in the database described in Chapter 2 of this report. A separate report of the modeling effort has been prepared (Poch et al. 2009). In addition to the U.S. steam electric power plant fleet, this modeling also includes an evaluation of power production of hydroelectric facilities. The focus of this modeling is on those power plants located in the western United States.

  18. Improved Performance of an Air Cooled Condenser (ACC) Using SPX Wind Guide Technology at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2010-12-31

    This project added a new airflow enhancement technology to an existing ACC cooling process at a selected coal power plant. Airflow parameters and efficiency improvement for the main plant cooling process using the applied technology were determined and compared with the capabilities of existing systems. The project required significant planning and pre-test execution in order to reach the required Air Cooled Condenser system configuration for evaluation. A host Power Plant ACC system had to be identified, agreement finalized, and addition of the SPX ACC Wind Guide Technology completed on that site. Design of the modification, along with procurement, fabrication, instrumentation, and installation of the new airflow enhancement technology were executed. Baseline and post-modification cooling system data was collected and evaluated. The improvement of ACC thermal performance after SPX wind guide installation was clear. Testing of the improvement indicates there is a 5% improvement in heat transfer coefficient in high wind conditions and 1% improvement at low wind speed. The benefit increased with increasing wind speed. This project was completed on schedule and within budget.

  19. MULTI-TUBE POWER LEADS TOWER FOR BEPCII IR MAGNETS.

    SciTech Connect

    JIA,L.X.; ZHANG,X.B.; WANG,L.; WANG,T.H.; YAO,Z.L.

    2004-05-11

    A power lead tower containing the multi-tube power leads is designed and under fabrication for the superconducting IR quadrupole magnets in the Beijing Electron Position Collider Upgrade (BEPCII). The lead tower consists of six pairs of gas-cooled leads for seven superconducting coils at various operating currents. The power lead is designed in a modular fashion, which can be easily applied to suit different operating current. The end copper block of the tube lead has a large cold mass that provide a large time constant in case of cooling flow interruption. A novel cryogenic electrical isolator is used for the leads.

  20. A near-field scanning microwave microscope based on a superconducting resonator for low power measurements.

    PubMed

    de Graaf, S E; Danilov, A V; Adamyan, A; Kubatkin, S E

    2013-02-01

    We report on the design and performance of a cryogenic (300 mK) near-field scanning microwave microscope. It uses a microwave resonator as the near-field sensor, operating at a frequency of 6 GHz and microwave probing amplitudes down to 100 ?V, approaching low enough photon population (N ? 1000) of the resonator such that coherent quantum manipulation becomes feasible. The resonator is made out of a miniaturized distributed fractal superconducting circuit that is integrated with the probing tip, micromachined to be compact enough such that it can be mounted directly on a quartz tuning-fork, and used for parallel operation as an atomic force microscope (AFM). The resonator is magnetically coupled to a transmission line for readout, and to achieve enhanced sensitivity we employ a Pound-Drever-Hall measurement scheme to lock to the resonance frequency. We achieve a well localized near-field around the tip such that the microwave resolution is comparable to the AFM resolution, and a capacitive sensitivity down to 6.4 10(-20) F/Hz, limited by mechanical noise. We believe that the results presented here are a significant step towards probing quantum systems at the nanoscale using near-field scanning microwave microscopy. PMID:23464217

  1. Demonstration of desiccant dehumidification components compatible with solar-powered residential cooling systems. Final report

    SciTech Connect

    Howell, J.R.

    1982-08-01

    The research reported here is an experimental study to determine the performance and economics of an alternative to presently available heat-driven cooling cycles. This alternative, called desiccant cooling, uses a drying agent (desiccant) to remove almost all of the moisture from outside air. In this work, the absorber, which is the particular part of the desiccant system that brings the air in contact with the desiccant while simultaneously providing cooling, has been tested. The results are compared with previously done computer models of the absorber behavior. The projected economics of the system are also examined, and the system is found to show promise against projected deregulated conventional energy costs.

  2. PH adjustment of power plant cooling water with flue gas/fly ash

    SciTech Connect

    Brady, Patrick V.; Krumhansl, James L.

    2015-09-22

    A system including a vessel including a heat source and a flue; a turbine; a condenser; a fluid conduit circuit disposed between the vessel, the turbine and the condenser; and a diverter coupled to the flue to direct a portion of an exhaust from the flue to contact with a cooling medium for the condenser water. A method including diverting a portion of exhaust from a flue of a vessel; modifying the pH of a cooling medium for a condenser with the portion of exhaust; and condensing heated fluid from the vessel with the pH modified cooling medium.

  3. Evaluation of the Impact of Off-Design Operation on an Air-Cooled Binary Power Plant

    SciTech Connect

    Mines, Gregory Lee

    2002-09-01

    Geothermal power plants are designed and constructed to provide a rated power output at specific resource and ambient conditions. Due to both diurnal and seasonal changes in the ambient air temperature, as well as a decline in resource productivity over time, plants seldom operate at these "design" conditions. This paper examines the impact of "off- design" operation of an air-cooled binary geothermal power plant. An available energy analysis is used to evaluate operation at these conditions. This evaluation identifies those portions of the power cycle that are most sensitive to changing resource and ambient conditions, as well as where improvements in cycle component or system performance would have the largest impact in increasing power output.

  4. Evaluation of the Impact of Off-Design Operation on an Air-Cooled Binary Power Plant

    SciTech Connect

    Mines, G.L.

    2002-06-17

    Geothermal power plants are designed and constructed to provide a rated power output at specific resource and ambient conditions. Due to both diurnal and seasonal changes in the ambient air temperature, as well as a decline in resource productivity over time, plants seldom operate at these ''design'' conditions. This paper examines the impact of ''off- design'' operation of an air-cooled binary geothermal power plant. An available energy analysis is used to evaluate operation at these conditions. This evaluation identifies those portions of the power cycle that are most sensitive to changing resource and ambient conditions, as well as where improvements in cycle component or system performance would have the largest impact in increasing power output.

  5. USE OF PRODUCED WATER IN RECIRCULATING COOLING SYSTEMS AT POWER GENERATING FACILITIES

    SciTech Connect

    Kent Zammit; Michael N. DiFilippo

    2005-01-01

    The purpose of this study is to evaluate produced water as a supplemental source of water for the San Juan Generating Station (SJGS). This study incorporates elements that identify produced water volume and quality, infrastructure to deliver it to SJGS, treatment requirements to use it at the plant, delivery and treatment economics, etc. SJGS, which is operated by Public Service of New Mexico (PNM) is located about 15 miles northwest of Farmington, New Mexico. It has four units with a total generating capacity of about 1,800 MW. The plant uses 22,400 acre-feet of water per year from the San Juan River with most of its demand resulting from cooling tower make-up. The plant is a zero liquid discharge facility and, as such, is well practiced in efficient water use and reuse. For the past few years, New Mexico has been suffering from a severe drought. Climate researchers are predicting the return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters. Produced water is generated nationally as a byproduct of oil and gas production. Seven states generate 90 percent of the produced water in the continental US. About 37 percent of the sources documented in the US Geological Survey's (USGS) Produced Waters Database have a TDS of less than 30,000 mg/l. This is significant because produced water treatment for reuse in power plants was found to be very costly above 30,000 mg/l TDS. For the purposes of this report, produced water treatment was assessed using the technologies evaluated for the San Juan Generating Station (SJGS) in Deliverable 3, Treatment and Disposal Analysis. Also, a methodology was developed to readily estimate capital and operating costs for produced water treatment. Two examples are presented to show how the cost estimating methodology can be used to evaluate the cost of treatment of produced water at power plants close to oil and gas production.

  6. Aerospace applications of high temperature superconductivity

    NASA Technical Reports Server (NTRS)

    Heinen, V. O.; Connolly, D. J.

    1991-01-01

    Space application of high temperature superconducting (HTS) materials may occur before most terrestrial applications because of the passive cooling possibilities in space and because of the economic feasibility of introducing an expensive new technology which has a significant system benefit in space. NASA Lewis Research Center has an ongoing program to develop space technology capitalizing on the potential benefit of HTS materials. The applications being pursued include space communications, power and propulsion systems, and magnetic bearings. In addition, NASA Lewis is pursuing materials research to improve the performance of HTS materials for space applications.

  7. Flux free growth of large FeSe1/2Te1/2 superconducting single crystals by an easy high temperature melt and slow cooling method

    NASA Astrophysics Data System (ADS)

    Maheshwari, P. K.; Jha, Rajveer; Gahtori, Bhasker; Awana, V. P. S.

    2015-09-01

    We report successful growth of flux free large single crystals of superconducting FeSe1/2Te1/2 with typical dimensions of up to few cm. The AC and DC magnetic measurements revealed the superconducting transition temperature (Tc) value of around 11.5K and the isothermal MH showed typical type-II superconducting behavior. The lower critical field (Hc1) being estimated by measuring the low field isothermal magnetization in superconducting regime is found to be above 200Oe at 0K. The temperature dependent electrical resistivity ?(T ) showed the Tc (onset) to be 14K and the Tc(? = 0) at 11.5K. The electrical resistivity under various magnetic fields i.e., ?(T)H for H//ab and H//c demonstrated the difference in the width of Tc with applied field of 14Tesla to be nearly 2K, confirming the anisotropic nature of superconductivity. The upper critical and irreversibility fields at absolute zero temperature i.e., Hc2(0) and Hirr(0) being determined by the conventional one-band Werthamer-Helfand-Hohenberg (WHH) equation for the criteria of normal state resistivity (?n) falling to 90% (onset), and 10% (offset) is 76.9Tesla, and 37.45Tesla respectively, for H//c and 135.4Tesla, and 71.41Tesla respectively, for H//ab. The coherence length at the zero temperature is estimated to be above 20 by using the Ginsburg-Landau theory. The activation energy for the FeSe1/2Te1/2 in both directions H//c and H//ab is determined by using Thermally Activation Flux Flow (TAFF) model.

  8. FEASIBILITY OF RECOVERING USEFUL SALTS FROM IRRIGATION WASTEWATER CONCENTRATES PRODUCED BY POWER PLANT COOLING

    EPA Science Inventory

    The report evaluates the feasibility of a novel energy-conserving way to recover useful salts (sodium sulfate and calcium sulfate) from concentrated brines by evaporation/crystallization. The concentrated brines examined were cooling tower blowdown from agricultural wastewater an...

  9. Superconducting magnet

    DOEpatents

    Satti, John A.

    1980-01-01

    A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

  10. Superconducting light generator for large offshore wind turbines

    NASA Astrophysics Data System (ADS)

    Sanz, S.; Arlaban, T.; Manzanas, R.; Tropeano, M.; Funke, R.; Kov?, P.; Yang, Y.; Neumann, H.; Mondesert, B.

    2014-05-01

    Offshore wind market demands higher power rate and reliable turbines in order to optimize capital and operational cost. These requests are difficult to overcome with conventional generator technologies due to a significant weight and cost increase with the scaling up. Thus superconducting materials appears as a prominent solution for wind generators, based on their capacity to held high current densities with very small losses, which permits to efficiently replace copper conductors mainly in the rotor field coils. However the state-of-the-art superconducting generator concepts still seem to be expensive and technically challenging for the marine environment. This paper describes a 10 MW class novel direct drive superconducting generator, based on MgB2 wires and a modular cryogen free cooling system, which has been specifically designed for the offshore wind industry needs.

  11. Feasibility study of a superconducting motor for electrical helicopter propulsion

    NASA Astrophysics Data System (ADS)

    Simons, C. A. B. A. E.; Sanabria-Walter, C.; Polinder, H.

    2014-05-01

    During the past decades, superconducting electrical machines have become more suitable to replace conventional iron based designs, because of their lower weight and higher torque density. These properties make them good candidates for use in More Electric Aircraft (MEA). Especially helicopter propulsion systems could benefit from the increased performance. This paper describes the feasibility study of a superconducting motor to be used for helicopter propulsion as part of a More Electric Aircraft (MEA). For this, the armature, field windings and cryostat are designed, aiming at meeting the difficult specifications. Since superconductors have virtually no electrical resistance when cooled down below a certain critical temperature, they can be used to build high field and low weight coils for electrical machines. Especially the possibility to not use iron can make the superconducting motor lighter with a higher power density compared with conventional Permanent Magnet (PM) motors.

  12. Development of a high-power water cooled beryllium target for use in accelerator-based boron neutron capture therapy.

    PubMed

    Blackburn, B W; Yanch, J C; Klinkowstein, R E

    1998-10-01

    In order for ABNCT (accelerator-based boron neutron capture therapy) to be successful, 10-16 kW or more must be dissipated from a target. Beryllium is well suited as a high-power target material. Beryllium has a thermal conductivity of 200 W/mK at 300 K which is comparable to aluminum, and it has one of the highest strength to weight ratios of any metal even at high temperatures (100 MPa at 600 degrees C). Submerged jet impingement cooling has been investigated as an effective means to remove averaged power densities on the order of 2 x 10(7) W/m2 with local power densities as high as 6 x 10(7) W/m2. Water velocities required to remove these power levels are in excess of 24 m/s with volumetric flow rates of nearly 100 GPM. Tests on a prototype target revealed that the heat transfer coefficient scaled as Re0.6. With jet-Reynolds numbers as high as 5.5 x 10(5) heat transfer coefficients of 2.6 x 10(5) W/m2K were achieved. With this type of cooling configuration 30 kW of power could be effectively removed from a beryllium target placed on the end of an accelerator. A beryllium target utilizing a proton beam of 3.7 MeV and cooled by submerged jet impingement could be used to deliver a dose of 13 RBE cGy/min mA to a tumor at a depth of 4 cm. With a beam power of 30 kW, 1500 cGy could be delivered in 14.2 min. PMID:9800705

  13. Site dependent factors affecting the economic feasibility of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1978-01-01

    A procedure was developed to evaluate the cost effectiveness of combining an absorption cycle chiller with a solar energy system. A basic assumption of the procedure is that a solar energy system exists for meeting the heating load of the building, and that the building must be cooled. The decision to be made is to either cool the building with a conventional vapor compression cycle chiller or to use the existing solar energy system to provide a heat input to the absorption chiller. Two methods of meeting the cooling load not supplied by solar energy were considered. In the first method, heat is supplied to the absorption chiller by a boiler using fossil fuel. In the second method, the load not met by solar energy is net by a conventional vapor compression chiller. In addition, the procedure can consider waste heat as another form of auxiliary energy. Commercial applications of solar cooling with an absorption chiller were found to be more cost effective than the residential applications. In general, it was found that the larger the chiller, the more economically feasible it would be. Also, it was found that a conventional vapor compression chiller is a viable alternative for the auxiliary cooling source, especially for the larger chillers. The results of the analysis gives a relative rating of the sites considered as to their economic feasibility of solar cooling.

  14. Performance of a directly water-cooled silicon crystal for use in high-power synchrotron radiation applications

    SciTech Connect

    Oversluizen, T.; Stefan, P.M.; Sharma, S.; Matsushita, T.; Ishikawa, T.; Mikuni, A.; National Lab. for High Energy Physics, Tsukuba, Ibaraki )

    1989-01-01

    Results of measurements made using the Multipole Wiggler at Beamline 16 of Photon Factory are reported. Double crystal rocking curves, Si(111) and Si(333) topographs, and thermal maps of the cooled crystal surface were measured at total incident power levels up to 1600 W and power densities up to 0.7 W/mm{sup 2}, for two different crystal designs. Significant crystal deformation occurred in the form of surface curvature for both designs. Finite element calculations provided a preview of the experimental results and proved very valuable in interpretation of the measurements. 16 refs., 10 figs., 5 tabs.

  15. On the flow and water quality in the Tokyo Bay including effect of cooling water for the Power Generating Plant

    NASA Astrophysics Data System (ADS)

    Kitahara, Kouichi; Wada, Akira; Uehara, Yoshikazu; Fukuoka, Ippei; Kawanaga, Mitsuhito; Takano, Tairyu

    Driving forces of seawater current in the Tokyo Bay have several factors including the tide, the density structure, the river inflow and others. On the other hand, many power plants of total output of 185.4 MW (as of 1995) are located along the coast of the bay, together with a large number of factors which load the sea area with cooling water and heat. Although these facilities might be considered to affect water current in the bay, few studies have been made on the effects which these artificial inputs may exert on water current. The present study reports computation results, using a 3-dimentional current model on effects of water intake and effluent by a possibly increasing number of power plants on the current in the bay. It was concluded that an additional power plant output of 103.1 MW (corresponding to increase of cooling water by 30% and of heat load by 20% from the present levels) might bring about only slight changes except for altered water current and temperature in the vicinities of power plants of which power output were increased. Average temperature rise of 0.1 C was also predicted in the surface water throughout the bay.

  16. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    NASA Astrophysics Data System (ADS)

    Sant, T.; Buhagiar, D.; Farrugia, R. N.

    2014-06-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

  17. Numerical simulation of heat transfer performance of an air-cooled steam condenser in a thermal power plant

    NASA Astrophysics Data System (ADS)

    Gao, Xiufeng; Zhang, Chengwei; Wei, Jinjia; Yu, Bo

    2009-09-01

    Numerical simulation of the thermal-flow characteristics and heat transfer performance is made of an air-cooled steam condenser (ACSC) in a thermal power plant by considering the effects of ambient wind speed and direction, air-cooled platform height, location of the main factory building and terrain condition. A simplified physical model of the ACSC combined with the measured data as input parameters is used in the simulation. The wind speed effects on the heat transfer performance and the corresponding steam turbine back pressure for different heights of the air-cooled platform are obtained. It is found that the turbine back pressure (absolute pressure) increases with the increase of wind speed and the decrease of platform height. This is because wind can not only reduce the flowrate in the axial fans, especially at the periphery of the air-cooled platform, due to cross-flow effects, but also cause an air temperature increase at the fan inlet due to hot air recirculation, resulting in the deterioration of the heat transfer performance. The hot air recirculation is found to be the dominant factor because the main factory building is situated on the windward side of the ACSC.

  18. Helical Muon Beam Cooling Channel Engineering Design

    SciTech Connect

    Kashikhin, V.S.; Lopes, M.L.; Romanov, G.V.; Tartaglia, M.A.; Yonehara, K.; Yu, M.; Zlobin, A.V.; Flanagan, G.; Johnson, R.P.; Kazakevich, G.M.; Marhauser, F.; /MUONS Inc., Batavia

    2012-05-01

    The Helical Cooling Channel (HCC), a novel technique for six-dimensional (6D) ionization cooling of muon beams, has shown considerable promise based on analytic and simulation studies. However, the implementation of this revolutionary method of muon cooling requires new techniques for the integration of hydrogen-pressurized, high-power RF cavities into the low-temperature superconducting magnets of the HCC. We present the progress toward a conceptual design for the integration of 805 MHz RF cavities into a 10 T Nb{sub 3}Sn based HCC test section. We include discussions on the pressure and thermal barriers needed within the cryostat to maintain operation of the magnet at 4.2 K while operating the RF and energy absorber at a higher temperature. Additionally, we include progress on the Nb{sub 3}Sn helical solenoid design.

  19. Development of a Novel Method for the Exploration of the Thermal Response of Superfluid Helium Cooled Superconducting Cables to Pulse Heat Loads

    NASA Astrophysics Data System (ADS)

    Winkler, T.; Koettig, T.; van Weelderen, R.; Bremer, J.; ter Brake, H. J. M.

    Management of transient heat deposition in superconducting magnets and its extraction from the aforementioned is becoming increasingly important to bring high energy particle accelerator performance to higher beam energies and intensities. Precise knowledge of transient heat deposition phenomena in the magnet cables will permit to push the operation of these magnets as close as possible to their current sharing limit, without unduly provoking magnet quenches. With the prospect of operating the Large Hadron Collider at CERN at higher beam energies and intensities an investigation into the response to transient heat loads of LHC magnets, operating in pressurized superfluid helium, is being performed. The more frequently used approach mimics the cable geometry by resistive wires and uses Joule-heating to deposit energy. Instead, to approximate as closely as possible the real magnet conditions, a novel method for depositing heat in cable stacks made out of superconducting magnet-cables has been developed. The goal is to measure the temperature difference as a function of time between the cable stack and the superfluid helium bath depending on heat load and heat pulse length. The heat generation in the superconducting cable and precise measurement of small temperature differences are major challenges. The functional principle and experimental set-up are presented together with proof of principle measurements.

  20. High-Temperature Superconductive Cabling Investigated for Space Solar Power Satellites

    NASA Technical Reports Server (NTRS)

    Tew, Roy C.; Juhasz, Albert J.

    2000-01-01

    NASA has been directed by Congress to take a fresh look at the Space Solar Power (SSP) concept that was studied by the Department of Energy and NASA about 20 years ago. To summarize, the concept involves (1) collecting solar energy and converting it to electrical energy via photovoltaic arrays on satellites in Earth orbit, (2) conducting the electricity to the microwave transmitting portion of the satellite, and (3) transmitting the power via microwave transmitters (or possibly via lasers) to ground power station antennas located on the surface of the Earth. One Sun Tower SSP satellite concept is illustrated here. This figure shows many photovoltaic arrays attached to a "backbone" that conducts electricity down to a wireless transmitter, which is pointed toward the Earth. Other variations on this concept use multiple backbones to reduce the overall length of the satellite structure. In addition, non-Sun-Tower concepts are being considered. The objective of the work reported here was to determine the benefits to the SSP concept of using high-temperature superconductors (HTS) to conduct the electricity from the photovoltaic arrays to the wireless power transmitters. Possible benefits are, for example, reduced mass, improved efficiency, and improved reliability. Dr. James Powell of Plus Ultra Technologies, Inc., of Stony Brook, New York, is conducting the study, and it is being managed by the NASA Glenn Research Center at Lewis Field via a task-order contract through Scientific Applications International Corp. (SAIC).

  1. Evaluation of distributed gas cooling of pressurized PAFC for utility power generation

    NASA Technical Reports Server (NTRS)

    Farooque, M.; Maru, H.; Skok, A.

    1981-01-01

    Two short stacks were pressure tested at 446 kPa (4.4 atm.) and the pressure gains were more than the theoretically predicted gains. Temperature profiles were observed to be independent of operating pressure. The pressure drop was found to be inversely proportional to operating pressure as expected. Continuous pressurized operation of a stack for 1000 hours verified the compatability of the fuel cell component design. A simple pressurization procedure was also developed. Six separate designs, covering two gas cooling schemes (DIGAS and separated) and two cooling channel geometries (straight through and treed), were analysed on the net voltage output basis. Separated cooling with 5 cells per cooler was recognized to be the best among the designs considered.

  2. POWERFUL H{sub 2} LINE COOLING IN STEPHAN's QUINTET. I. MAPPING THE SIGNIFICANT COOLING PATHWAYS IN GROUP-WIDE SHOCKS

    SciTech Connect

    Cluver, M. E.; Ogle, P.; Reach, W. T.; Appleton, P. N.; Lu, N.; Xu, C. K.; Boulanger, F.; Guillard, P.; Duc, P.-A.; Smith, J. D.; Tuffs, R.; Yun, M. S.

    2010-02-10

    We present results from the mid-infrared spectral mapping of Stephan's Quintet using the Spitzer Space Telescope. A 1000 km s{sup -1} collision (t{sub col} = 5 x 10{sup 6} yr) has produced a group-wide shock, and for the first time the large-scale distribution of warm molecular hydrogen emission is revealed, as well as its close association with known shock structures. In the main shock region alone we find 5.0 x 10{sup 8} M{sub sun} of warm H{sub 2} spread over {approx}480 kpc{sup 2} and additionally report the discovery of a second major shock-excited H{sub 2} feature, likely a remnant of previous tidal interactions. This brings the total H{sub 2} line luminosity of the group in excess of 10{sup 42} erg s{sup -1}. In the main shock, the H{sub 2} line luminosity exceeds, by a factor of 3, the X-ray luminosity from the hot shocked gas, confirming that the H{sub 2}-cooling pathway dominates over the X-ray. [Si II]34.82 {mu}m emission, detected at a luminosity of 1/10th of that of the H{sub 2}, appears to trace the group-wide shock closely, and in addition, we detect weak [Fe II]25.99 {mu}m emission from the most X-ray luminous part of the shock. Comparison with shock models reveals that this emission is consistent with regions of fast shocks (100 km s{sup -1} < V{sub s} < 300 km s{sup -1}) experiencing depletion of iron and silicon onto dust grains. Star formation in the shock (as traced via ionic lines, polycyclic aromatic hydrocarbon and dust emission) appears in the intruder galaxy, but most strikingly at either end of the radio shock. The shock ridge itself shows little star formation, consistent with a model in which the tremendous H{sub 2} power is driven by turbulent energy transfer from motions in a post-shocked layer which suppresses star formation. The significance of the molecular hydrogen lines over other measured sources of cooling in fast galaxy-scale shocks may have crucial implications for the cooling of gas in the assembly of the first galaxies.

  3. Technical and economic assessment of the use of ammonia expanders for energy recovery in air-cooled power plants

    SciTech Connect

    Hauser, S.G.; Hane, G.J.; Johnson, B.M.

    1982-07-01

    Binary cycle power plants have been the subject of much discussion among engineers and scientists for nearly 100 years. Current economic and environmental concerns have stimulated new interest and research. Ammonia has been recommended by other studies as the leading contender for use as simply the heat rejection medium in an air-cooled power plant. This study investigates the technical feasibility and economic potential of including an expander in the heat rejection system of an air-cooled power plant. The expander would be used during certain parts of the year to increase the total output of the power plant. Five different plant locations (Miami, San Francisco, Bakersfield, Chicago, Anchorage) were investigated to show the effect which climate has on the economic potential of this ammonia bottoming cycle. The study shows that the expected energy costs for the bottoming cycle only will be less than 50 mills/kWh for any of the five plant locations. This cost assumes that an ammonia phase-change heat rejection system is already a part of the existing plant. The colder climates of Chicago and Anchorage demonstrate an even smaller energy cost of less than 15 mills/kWh. Further investigation of the concept is merited to substantiate these costs and determine the needed technology.

  4. High Power Intermodulation Measurements up to 30 W of High Temperature Superconducting Filters

    NASA Technical Reports Server (NTRS)

    Wilker, Charles; Carter, Charles F., III; Shen, Zhi-Yuan

    1999-01-01

    We have demonstrated a high power intermodulation measurement set-up capable of delivering 30 W in each of two fundamental tones. For closely spaced frequencies (less than 35 MHz), the dynamic range of the measurement is limited by the nonlinear performance of the mixer in the front end of the HP71210C spectrum analyzer. A tunable TE(sub 011) mode copper cavity was fabricated in which one of the endwalls could be adjusted shifting its resonant frequency between 5.7 and 6.6 GHz. Since the Q-value of this cavity is high, greater than 10(exp 4), and its bandwidth is small, less than 1 MHz, it can be used to attenuate the two fundamental tones relative to one of the harmonic tones, which greatly enhances the dynamic range of the measurement. This set-up can be used to measure the two-tone intermodulation distortion of any passive microwave device, e.g. a HTS filter, a connector, a cable, etc., over a frequency range of 5.9 to 6.4 GHz and a power range of 0.1 to 30 W. The third order intercept (TOI) of a prototype HTS filter measured at powers up to 30 W was +81.3 dBm.

  5. Economic analysis of wind-powered refrigeration cooling/water-heating systems in food processing. Final report

    SciTech Connect

    Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.; Welch, M.

    1980-03-01

    Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in refrigeration cooling and water heating systems in food processing plants. Types of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture.

  6. Self-cooling mono-container fuel cell generators and power plants using an array of such generators

    DOEpatents

    Gillett, J.E.; Dederer, J.T.; Zafred, P.R.

    1998-05-12

    A mono-container fuel cell generator contains a layer of interior insulation, a layer of exterior insulation and a single housing between the insulation layers, where fuel cells, containing electrodes and electrolyte, are surrounded by the interior insulation in the interior of the generator, and the generator is capable of operating at temperatures over about 650 C, where the combination of interior and exterior insulation layers have the ability to control the temperature in the housing below the degradation temperature of the housing material. The housing can also contain integral cooling ducts, and a plurality of these generators can be positioned next to each other to provide a power block array with interior cooling. 7 figs.

  7. Self-cooling mono-container fuel cell generators and power plants using an array of such generators

    DOEpatents

    Gillett, James E.; Dederer, Jeffrey T.; Zafred, Paolo R.

    1998-01-01

    A mono-container fuel cell generator (10) contains a layer of interior insulation (14), a layer of exterior insulation (16) and a single housing (20) between the insulation layers, where fuel cells, containing electrodes and electrolyte, are surrounded by the interior insulation (14) in the interior (12) of the generator, and the generator is capable of operating at temperatures over about 650.degree. C., where the combination of interior and exterior insulation layers have the ability to control the temperature in the housing (20) below the degradation temperature of the housing material. The housing can also contain integral cooling ducts, and a plurality of these generators can be positioned next to each other to provide a power block array with interior cooling.

  8. Review of new energy. Superconductivity

    NASA Astrophysics Data System (ADS)

    1989-03-01

    An summary is given of the research and development on high temperature superconductivity. It begins with a description of superconducting state and enumerates chemical elements, in particular oxides, associated with high temperature superconductivity. A brief account is next given on the progress of research and development on the present subject. Some of well known topics associated with superconductivity are described shortly, namely Meissner effect, quenching (transition to normal conducting state from superconducting one), Perovskite structure, positive hole earrier, Josephson effect, SQUID (superconducting quantum interference device) and so on. Various devices or technology are enumerated, to which superconductivity, in particular high temperature one, is proposed to apply, namely electromagnet, MRI (magnetic resonance imaging), particle accelerator, linear motor car, electric power storage and so on. The summary is finished with a future outlook.

  9. Use of remote sensing data to enhance the performance of a hydrodynamic simulation of a partially frozen power plant cooling lake

    NASA Astrophysics Data System (ADS)

    Arsenovic, May V.; Salvaggio, Carl; Garrett, Alfred J.; Bartlett, Brent D.; Faulring, Jason W.; Kremens, Robert L.; Salvaggio, Philip S.

    2009-05-01

    The effectiveness of a power generation site's cooling pond has a significant impact on the overall efficiency of a power plant. The ability to monitor a cooling pond using thermal remote sensing, coupled with hydrodynamic models, is a valuable tool for determining the driving characteristics of a cooling system. However, the thermodynamic analysis of a cooling lake can become significantly more complex when a power generation site is located in a northern climate. The heated effluent from a power plant entering a cooling lake is often not enough to keep a lake from freezing during winter months. Once the lake is partially or fully frozen, the predictive capabilities of the hydrodynamic model are weakened due to an insulating surface layer of ice and snow. Thermal imagery of a cooling pond was collected over a period of approximately 16 weeks in tandem with high-density thermal measurements both in open water and embedded in ice, meteorological data, and snow layer characterization data. The proposed research presents a method to employ thermal imagery to improve the performance of a 3-D hydrodynamic model of a power plant cooling pond in the presence of ice and snow.

  10. Superconducting elementary antennas

    NASA Astrophysics Data System (ADS)

    Pavliuk, V. A.; Krivosheev, E. F.

    1981-05-01

    A theoretical and experimental study evaluates the possibility of increasing gain, Q-factor, sensitivity, and radiating power of simple small-size antennas as a consequence of reduced Joule losses, higher electric current densities, Josephson effects, and magnetic field quantization resulting from a superconducting state. Improved characteristics of loop and whip antennas are demonstrated as a consequence of superconductivity. Technological difficulties and the advisability of somewhat higher temperatures are briefly discussed.

  11. REPRODUCTION AND DISTRIBUTION OF FISHES IN A COOLING LAKE: WISCONSIN POWER PLANT IMPACT STUDY

    EPA Science Inventory

    Spatial and temporal patterns during reproduction and early life history of fishes were studied in a manmade cooling lake. Lake Columbia, impounded in 1974, near Portage, Wisconsin, has an area of 190 ha, a mean depth of 2.1 m, and a 15C temperature gradient derived from the ther...

  12. Use of Air2Air Technology to Recover Fresh-Water from the Normal Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2009-06-30

    This program was undertaken to build and operate the first Air2Air{trademark} Water Conservation Cooling Tower at a power plant, giving a validated basis and capability for water conservation by this method. Air2Air{trademark} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10%-25% annually, depending on the cooling tower location (climate).

  13. Investigation of Absorption Cooling Application Powered by Solar Energy in the South Coast Region of Turkey

    NASA Astrophysics Data System (ADS)

    Babayigit, O.; Aksoy, M. H.; Ozgoren, M.; Solmaz, O.

    2013-04-01

    In this study, an absorption system using ammonia-water (NH3-H2O) solution has been theoretically examined in order to meet the cooling need of a detached building having 150 m2 floor area for Antalya, Mersin and Mugla provinces in Turkey. Hourly dynamic cooling load capacities of the building were determined by using Radiant Time Series (RTS) method in the chosen cities. For the analysis, hourly average meteorological data such as atmospheric air temperature and solar radiation belonging to the years 1998-2008 are used for performance prediction of the proposed system. Thermodynamic relations for each component of absorption cooling system is explained and coefficients of performance of the system are calculated. The maximum daily total radiation data were calculated as 7173 W/m2day on July 15, 7277 W/m2 day on July 19 and 7231 W/m2day on July 19 for Mersin, Antalya and Mugla, respectively on the 23 toward to south oriented panels from horizontal surface. The generator operating temperatures are considered between 90-130C and the best result for 110C is found the optimum degree for maximum coefficient of performance (COP) values at the highest solar radiation occurred time during the considered days for each province. The COP values varies between 0.521 and 0.530 for the provinces. In addition, absorber and condenser capacities and thermal efficiency for the absorption cooling system were calculated. The necessary evacuated tube collector area for the different provinces were found in the range of 45 m2 to 47 m2. It is shown that although the initial investment cost is higher for the proposed absorption cooling system, it is economically feasible because of its lower annual operation costs and can successfully be operated for the considered provinces.

  14. Thermal and dynamic analysis of the RING (Radiatively-cooled, Inertially-driven Nuclear Generator) power system radiator

    SciTech Connect

    Apley, W.J.; Babb, A.L.

    1989-01-01

    The nuclear option for a space-based power system appears most suitable for missions that require long-term, sustained operation at power levels above 100 kWe. Systems currently available operate at relatively low thermal efficiencies (6--10%). Thus, a 100 kWe system must discharge nearly 2 MWth of waste heat through the comparatively inefficient process of radiative cooling. The impact of the resultant radiator assembly size on overall power system weight is significant, and has led to proposals for radiators with potentially higher efficiencies. Examples include the: liquid droplet radiator; fabric radiator; bubble membrane radiator; rotating film radiator; and dust radiator. 14 refs., 2 figs., 2 tabs.

  15. Single-phase AC losses in prototype HTS conductors for superconducting power transmission lines

    NASA Astrophysics Data System (ADS)

    Daney, D. E.; Maley, M. P.; Boenig, H. J.; Willis, J. O.; Coulter, J. Y.; Gherardi, L.; Coletta, G.

    1998-12-01

    We report single-phase AC loss measurements on 8-, 4-, and 3-layer, multi-strand, HTS prototype conductors for power transmission lines. We use both calorimetric and electrical techniques. The agreement between the two techniques suggests that the interlayer current distribution in 1-m long conductors are representative of those in long conductors. The losses for the 8- and 4-layer conductors are in rough agreement, with the 8-layer losses being somewhat lower. The 3-layer conductor losses are substantially higher - probably due to unbalanced azimuthal currents for this configuration.

  16. Superconductive wire

    DOEpatents

    Korzekwa, D.A.; Bingert, J.F.; Peterson, D.E.; Sheinberg, H.

    1995-07-18

    A superconductive article is made by inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing or ironing the composite intermediate article to a predetermined cross-sectional diameter, and sintering the reduced or ironed composite intermediate article at temperatures and for time sufficient for the superconductive material or superconductive precursor to exhibit superconductivity. 2 figs.

  17. Superconductive wire

    DOEpatents

    Korzekwa, David A.; Bingert, John F.; Peterson, Dean E.; Sheinberg, Haskell

    1995-01-01

    A superconductive article is made by inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing or ironing the composite intermediate article to a predetermined cross-sectional diameter, and sintering the reduced or ironed composite intermediate article at temperatures and for time sufficient for the superconductive material or superconductive precursor to exhibit superconductivity.

  18. Expanding the potential for saline formations : modeling carbon dioxide storage, water extraction and treatment for power plant cooling.

    SciTech Connect

    Not Available

    2011-04-01

    The National Water, Energy and Carbon Sequestration simulation model (WECSsim) is being developed to address the question, 'Where in the current and future U.S. fossil fuel based electricity generation fleet are there opportunities to couple CO{sub 2} storage and extracted water use, and what are the economic and water demand-related impacts of these systems compared to traditional power systems?' The WECSsim collaborative team initially applied this framework to a test case region in the San Juan Basin, New Mexico. Recently, the model has been expanded to incorporate the lower 48 states of the U.S. Significant effort has been spent characterizing locations throughout the U.S. where CO{sub 2} might be stored in saline formations including substantial data collection and analysis efforts to supplement the incomplete brine data offered in the NatCarb database. WECSsim calculates costs associated with CO{sub 2} capture and storage (CCS) for the power plant to saline formation combinations including parasitic energy costs of CO{sub 2} capture, CO{sub 2} pipelines, water treatment options, and the net benefit of water treatment for power plant cooling. Currently, the model can identify the least-cost deep saline formation CO{sub 2} storage option for any current or proposed coal or natural gas-fired power plant in the lower 48 states. Initial results suggest that additional, cumulative water withdrawals resulting from national scale CCS may range from 676 million gallons per day (MGD) to 30,155 MGD depending on the makeup power and cooling technologies being utilized. These demands represent 0.20% to 8.7% of the U.S. total fresh water withdrawals in the year 2000, respectively. These regional and ultimately nation-wide, bottom-up scenarios coupling power plants and saline formations throughout the U.S. can be used to support state or national energy development plans and strategies.

  19. Superconducting Cable Termination

    DOEpatents

    Sinha, Uday K. (Carrollton, GA); Tolbert, Jerry (Newnan, GA)

    2005-08-30

    Disclosed is a termination that connects high temperature superconducting (HTS) cable immersed in pressurized liquid nitrogen to high voltage and neutral (shield) external bushings at ambient temperature and pressure. The termination consists of a splice between the HTS power (inner) and shield (outer) conductors and concentric copper pipes which are the conductors in the termination. There is also a transition from the dielectric tape insulator used in the HTS cable to the insulators used between and around the copper pipe conductors in the termination. At the warm end of the termination the copper pipes are connected via copper braided straps to the conventional warm external bushings which have low thermal stresses. This termination allows for a natural temperature gradient in the copper pipe conductors inside the termination which enables the controlled flashing of the pressurized liquid coolant (nitrogen) to the gaseous state. Thus the entire termination is near the coolant supply pressure and the high voltage and shield cold bushings, a highly stressed component used in most HTS cables, are eliminated. A sliding seal allows for cable contraction as it is cooled from room temperature to 72-82 K. Seals, static vacuum, and multi-layer superinsulation minimize radial heat leak to the environment.

  20. Superconducting Cable Termination

    DOEpatents

    Sinha, Uday K.; Tolbert, Jerry

    2005-08-30

    Disclosed is a termination that connects high temperature superconducting (HTS) cable immersed in pressurized liquid nitrogen to high voltage and neutral (shield) external bushings at ambient temperature and pressure. The termination consists of a splice between the HTS power (inner) and shield (outer) conductors and concentric copper pipes which are the conductors in the termination. There is also a transition from the dielectric tape insulator used in the HTS cable to the insulators used between and around the copper pipe conductors in the termination. At the warm end of the termination the copper pipes are connected via copper braided straps to the conventional warm external bushings which have low thermal stresses. This termination allows for a natural temperature gradient in the copper pipe conductors inside the termination which enables the controlled flashing of the pressurized liquid coolant (nitrogen) to the gaseous state. Thus the entire termination is near the coolant supply pressure and the high voltage and shield cold bushings, a highly stressed component used in most HTS cables, are eliminated. A sliding seal allows for cable contraction as it is cooled from room temperature to ˜72-82 K. Seals, static vacuum, and multi-layer superinsulation minimize radial heat leak to the environment.