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1

Electric power losses of current input into superconducting devices cooled by supercritical helium  

Microsoft Academic Search

This paper deals with the methods and results of calculations to minimize power losses in cryogenic installations related to current input into superconducting systems with forced supercritical helium cooling. Different schemes and modes of cooling the current leads with a superconducting region at the cold end are examined. Optimum helium flow rate and minimum power losses in an idealized and

V. Maximov; A. I. Malykhin

1979-01-01

2

Cooling of the 200 m superconducting DC power transmission system at Chubu University  

NASA Astrophysics Data System (ADS)

The fourth cooling test of the superconducting DC power transmission system of Chubu University was conducted in August of 2011. The heat leak from the cryogenic pipe and the eect of reducing the outer pipe temperature were tested. The heat leak from the cryogenic pipe was improved relative to that recorded during the second cooling test performedintheprevious summer,a season similartothatin whichthe fourth cooling testwas conducted.Asigni?cant reduction of the outer pipe temperature was achieved by an infrared re?ective coating, and a reduction of the heat leak was observed.

Watanabe, Hirofumi; Sun, Jian; Ivanov, Yury; Hamabe, Makoto; Kawahara, Toshio; Yamaguchi, Satarou

3

Thermal optimum analyses and mechanical design of 10-kA, vapor-cooled power leads for SSC superconducting magnet tests at MTL. Revision A.  

National Technical Information Service (NTIS)

The spiral-fin, 10-kA, helium vapor-cooled power leads have been designed for Superconducting Super Collider superconducting magnet tests at the Magnet Test Laboratory. In order to thermally optimize the parameters of the power leads, the lead diameters-w...

Q. S. Shu J. Demko R. Dorman D. Finan D. Hatfield

1992-01-01

4

Thermal optimum analyses and mechanical design of 10-kA, vapor-cooled power leads for SSC superconducting magnet tests at MTL.  

National Technical Information Service (NTIS)

The spiral-fin, 10-kA, helium vapor-cooled power leads have been designed for Superconducting Super Collider superconducting magnet tests at the Magnet Test Laboratory. In order to thermally optimize the parameters of the power leads, the lead diameters-w...

Q. S. Shu J. Demko R. Doman D. Finan D. Hatfield

1992-01-01

5

The experiments of 200-meter superconducting DC power cable in Chubu university and the estimation for longer cable cooling  

NASA Astrophysics Data System (ADS)

After the 200-meter superconducting DC power cable experimental facility had been completed in spring of 2010, three experiments have been done until March, 2011. We adapt the straight pipe for the inner cryogenic pipe to reduce the heat leak and the pressure drop of liquid nitrogen circulation because the surface area is minimized for the straight pipe, and the terminal cryostats of the cable ends are movable to absorb the shrinkage of the cable in the cooling-down phase and the expansion in warming-up phase to reduce the tensile strain of the high temperature superconductor tape. We also continue the Peltier current lead experiment to reduce the heat leak at the terminal. We performed several kinds of the experiments to obtain the basic data for a long cable system. We changed and improved the experimental devices during the experiments. The pressure drop of the liquid nitrogen circulation was around 1 kPa for the flow rate of 10 L/min in the experiment. We summarized the experimental results briefly, and estimate the pressure drop of the circulation for a longer cable system (~2 km) depending on the experimental conditions.

Yamaguchi, Satarou; Ivanov, Yury; Sun, Jian; Watanabe, Hirofumi; Hamabe, Makoto; Kawahara, Toshio; Iiyoshi, Atsuo

2012-06-01

6

Electric power applications of superconductivity  

Microsoft Academic Search

The development of superconducting systems for electric power is driven by the promise of improved efficiency, smaller size, and reduced weight as compared to existing technologies and by the possibility of new applications. Superconducting power components can also contribute to improved power quality and increased system reliability. This paper addresses historical developments and technology status of four superconducting power applications:

WILLIAM V. HASSENZAHL; DREW W. HAZELTON; BRIAN K. JOHNSON; PETER KOMAREK; MATHIAS NOE; CHANDRA T. REIS

2004-01-01

7

Superconducting Materials, Magnets and Electric Power Applications  

NASA Astrophysics Data System (ADS)

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 Nb3Sn 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 Nb3Sn. 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.

Crabtree, George

2011-03-01

8

Two phase cooling for superconducting magnets  

SciTech Connect

Comments on the use of two phase helium in a closed circuit tubular cooling system and some results obtained with the TPC superconducting magnet are given. Theoretical arguments and experimental evidence are given against a previously suggested method to determine helium two phase flow regimes. Two methods to reduce pressure in the magnet cooling tubes during quenches are discussed; (1) lowering the density of helium in the magnet cooling tubes and (2) proper location of pressure relief valves. Some techniques used to protect the refrigerator from too much cold return gas are also mentioned. 10 refs., 1 fig., 5 tabs.

Eberhard, P.H.; Gibson, G.A.; Green, M.A.; Ross, R.R.; Smits, R.G.; Taylor, J.D.; Watt, R.D.

1986-01-01

9

Power electronics cooling apparatus  

DOEpatents

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.

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

2000-01-01

10

Power electronics cooling apparatus  

SciTech Connect

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.

Sanger, P.A.; Lindberg, F.A.; Garcen, W.

2000-01-18

11

Cooling system for superconducting magnet  

DOEpatents

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.

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

1998-01-01

12

Two phase cooling for superconducting magnets  

SciTech Connect

A closed circuit tubular cooling system for superconducting magnets offers advantages of limiting boiloff and containing high pressures during quenches. Proper location of automatic valves to lower pressures and protect the refrigerator in the event of quenches is described. Theoretical arguments and exprimental evidence are given against a previously suggested method to determine He two phase flow regimes. If loss of flow occurs due to some types of refrigeration failure and transfer lines have enough heat leak to warm up, quenches are induced when the flow is restored. Examples are taken from experience with the TPC magnet.

Eberhard, P.H.; Gibson, G.A.; Green, M.A.; Ross, R.R.; Smits, R.G.; Taylor, J.D.; Watt, R.D.

1985-08-01

13

Superconducting shield for solenoid of electron cooling system  

NASA Astrophysics Data System (ADS)

Ensuring the high homogeneity of a magnetic field in the straight solenoid of an electron cooling system is a very important task. In the electron cooling system of the collider in the NICA project, it is planned to use superconducting solenoids for the generation of a longitudinal magnetic field. Using of the superconducting shield is proposed to achieve the required homogeneity of the magnetic field in the cooling section. This article discusses the design of the superconducting shield and presents experimental and numerical studies into the homogeneity of the magnetic field in solenoids with the superconducting shield.

Agapov, N. N.; Donets, D. E.; Drobin, V. M.; Kulikov, E. A.; Malinovski, H.; Pivin, R. V.; Smirnov, A. V.; Prokofichev, Yu. V.; Trubnikov, G. V.; Dorofeev, G. L.

2012-07-01

14

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

Microsoft Academic Search

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.

Jae Hong Park; Yong Ha Kwon; Young Soo Kim

2005-01-01

15

Cooling of superconducting devices by liquid storage and refrigeration unit  

SciTech Connect

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.

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

2013-08-20

16

Power transformer with superconducting windings  

SciTech Connect

The authors have designed, constructed and tested a 330 kVA power transformer with superconducting windings. A niobium-titanium based superconducting wire optimized for AC applications was used in die windings. The transformer worked according to its design at rated power. The total heat input to the liquid helium bath at this power was 9.4 Watts, of which the AC losses dissipated in the windings were about one Watt per winding. The low voltage feedthroughs which had to carry 830 A[sub rms] at rated power worked adequately. The transformer revealed an apparent current limiting effect. This property can be utilized to limit currents in a network for time periods 10-50 ms. A quench protection device was designed and incorporated in the test circuit.

Hoernfeldt, S.; Albertsson, O. (ABB Corp. Research, Vaesteraas (Sweden)); Bonmann, D. (ABB Transformatoren GmbH, Mannheim (Germany)); Koenig, F. (ABB Corp. Research, Zuerich (Switzerland). Oerlikon Works)

1993-11-01

17

Operating experience of the IFSMTF (International Fusion Superconducting Magnet Test Facility) vapor-cooled lead system  

Microsoft Academic Search

The International Fusion Superconducting Magnet Test Facility (IFSMTF) uses six pairs of vapor-cooled leads (VCLs) to introduce electric power to six test coils. Each VCL is housed in a dewar outside the 11-m vacuum vessel and is connected to the coal via a superconducting bus duct;the various VCLs are rated at 12 to 20 kA. Heat loss through the leads

J. W. Lue; D. T. Fehling; W. A. Fietz; M. S. Lubell; J. N. Luton; S. W. Schwenterly; S. S. Shen; R. E. Stamps; D. H. Thompson; C. T. Wilson

1987-01-01

18

Compact he II Cooling System for Superconducting Cavities  

Microsoft Academic Search

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

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

2008-01-01

19

Efficient cooling of superconducting fiber core via holey cladding  

NASA Astrophysics Data System (ADS)

Superconductivity has the potential to alter the entire landscape of technological advancement and innovation. Unfortunately, its true potential has been limited, in part, by the lack of conventional geometries, adequate stability, cooling efficiencies and in turn, cost. In this study, we demonstrate an optical fiber design with a superconducting core that is cooled via the flow of liquid helium in holes disposed in the fused silica cladding. The efficiently micro cooled superconducting fiber lends itself to low current electronic applications such as ultrasensitive sensing and imaging, quantum measurement instrumentation and supercomputing. Although not presently applicable for large scale applications such as high current transmission lines or motors, the basic approach may be combined with other traditional technologies to improve cooling efficiency and reliability.

Homa, Daniel; Kaur, Gurbinder; Pickrell, Gary; Liang, Yongxuan

2014-05-01

20

Compact he II Cooling System for Superconducting Cavities  

NASA Astrophysics Data System (ADS)

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.

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

2008-03-01

21

Direct cooled power electronics substrate  

DOEpatents

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.

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

22

Cooling arrangement for a superconducting coil  

DOEpatents

A superconducting device, 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.

Herd, Kenneth Gordon (Niskayuna, NY); Laskaris, Evangelos Trifon (Schenectady, NY)

1998-06-30

23

Hydraulic characteristics in superconducting power transmission cables  

NASA Astrophysics Data System (ADS)

The hydraulic characteristics of sub-cooled nitrogen in superconducting power transmission line have been investigated to design the transmission line. To estimate the friction factor in corrugated pipes, the pressure drop was measured across a 10-m length corrugated pipe for various mass flow rates and compared with that in smooth pipes (Proc. 17th Cryo. Eng. Conf. (1998) 475). Another concern is the cooling method of the transmission line. A usual counter-flow cooling method has been found to be very difficult at liquid nitrogen temperature, because the thermal conductivity of the dielectric materials between the counter-flows at liquid nitrogen temperature are 10 times larger than that at liquid helium temperature. Instead, an externally cooling method was proposed (Proc. 17th Cryo. Eng. Conf. (1998) 475). As the results, the friction factor of outer corrugated jacket within three cables has become an important parameter to design the transmission lines. This friction factor is measured and compared with various formulas in this paper.

Fuchino, S.; Tamada, N.; Ishii, I.; Higuchi, N.

2001-05-01

24

Evaluating Cooling Performance of High-Thermal-Conduction Composite in Conduction-Cooled Superconducting Coils  

Microsoft Academic Search

Aluminum nitride (AlN) has been widely used as a heat sink material in conduction-cooled superconducting coils but is hard to process. We have therefore developed an easily processed Dyneema-fiber-reinforced plastic (DFRP) with high thermal conductivity. Making small superconducting coils with DFRP or AlN bobbins, cooling them to a cryogenic temperature by using a refrigerator, and comparing their voltage profiles when

Tomoaki Takao; Takuroh Yuhara; Ryo Sakuma; Takayuki Goto; Atsuhiko Yamanaka

2010-01-01

25

System and method for cooling a super-conducting device  

SciTech Connect

A system and method for cooling a superconductive rotor coil. The system comprises a rotatable shaft coupled to the superconductive rotor coil. The rotatable shaft may comprise an axial passageway extending through the rotatable shaft and a first passageway extending through a wall of the rotatable shaft to the axial passageway. The axial passageway and the first passageway are operable to convey a cryogenic fluid to the superconductive rotor coil through the wall of the rotatable shaft. A cryogenic transfer coupling may be provided to supply cryogenic fluid to the first passageway.

Bray, James William (Niskayuna, NY); Steinbach, Albert Eugene (Schenectady, NY); Dawson, Richard Nils (Voorheesville, NY); Laskaris, Evangelos Trifon (Schenectady, NY); Huang, Xianrul (Clifton Park, NY)

2008-01-08

26

Solar powered cooling device  

SciTech Connect

The system contains an unique solar collector for transferring heat energy from the sun to a solution comprising a two-phase refrigerant and a fluid absorbent. Solar radiation causes a vaporization of the refrigerant which exits from the solar panel through a separate path from the remainder of the fluid. The vaporized refrigerant is returned to a liquid state and passed through an evaporator in a lower pressure environment for producing a cooling effect. The refrigerant is recombined with the absorbent and returned to the solar collector in a high pressure environment. Three modes of operation are included in the system. Continuous cooling is the first mode. The second mode consists of storing the liquid refrigerant after separation from the refrigerant absorbent fluid. The refrigerant and absorbent are stored for future use. The third mode of operation provides cooling in the absence of solar radiation by the use of the stored refrigerant and subsequent combination of the refrigerant with absorbent which fluid is then stored in a separate reservoir. The system also is provided with a solar tracking arrangement by which one or more solar collectors will be automatically oriented directly toward the sun for assuring maximum utilization of the sun's energy.

Ferriera, C.R.

1981-08-04

27

Status of superconducting power transformer development  

SciTech Connect

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.

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

1996-03-01

28

Sisyphus cooling and amplification by a superconducting qubit  

NASA Astrophysics Data System (ADS)

Laser cooling of atoms paved the way for remarkable achievements in quantum optics, including Bose-Einstein condensation and trapping in optical lattices. Recently, superconducting qubits-micrometre-size superconducting circuits-were shown to act as artificial atoms, exhibiting quantum effects such as Rabi oscillations and Ramsey fringes. Coupling superconducting circuits to resonators brought them into the realm of quantum electrodynamics and opened up perspectives for using them as micro-coolers or to create a population inversion inducing lasing behaviour. Here, we demonstrate so-called Sisyphus cooling and amplification of an LC resonator, which consists of an inductor L and a capacitor C, by a superconducting qubit, furthering the analogies between optical and circuit quantum electrodynamics. In quantum optics, the motion of the atom is cooled or amplified by a laser driving its electronic degrees of freedom. In our system, the roles of the two degrees of freedom are played by the levels of the resonator and the qubit. Red-detuned high-frequency driving of the qubit produces cooling, because the low-frequency LC circuit carries out work in the forward and backward oscillation cycle, always increasing the energy of the qubit. For blue-detuning, the same mechanism leads to Sisyphus amplification and a precursor of lasing. Parallel to the experimental demonstration, we analyse these processes theoretically, quantitatively confirming our interpretation.

Grajcar, M.; van der Ploeg, S. H. W.; Izmalkov, A.; Il'Ichev, E.; Meyer, H.-G.; Fedorov, A.; Shnirman, A.; Schön, Gerd

2008-08-01

29

Progress on the superconducting magnets for the MICE cooling channel  

NASA Astrophysics Data System (ADS)

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.

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

30

Development of Superconducting Power Transmission Technology.  

National Technical Information Service (NTIS)

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...

E. B. Forsyth

1985-01-01

31

Microwave-induced cooling of a superconducting qubit.  

PubMed

We demonstrated microwave-induced cooling in a superconducting flux qubit. The thermal population in the first-excited state of the qubit is driven to a higher-excited state by way of a sideband transition. Subsequent relaxation into the ground state results in cooling. Effective temperatures as low as approximately 3 millikelvin are achieved for bath temperatures of 30 to 400 millikelvin, a cooling factor between 10 and 100. This demonstration provides an analog to optical cooling of trapped ions and atoms and is generalizable to other solid-state quantum systems. Active cooling of qubits, applied to quantum information science, provides a means for qubit-state preparation with improved fidelity and for suppressing decoherence in multi-qubit systems. PMID:17158325

Valenzuela, Sergio O; Oliver, William D; Berns, David M; Berggren, Karl K; Levitov, Leonid S; Orlando, Terry P

2006-12-01

32

Electrical Breakdown Characteristics of Superconducting Magnet System in Sub-Cooled Liquid Nitrogen  

Microsoft Academic Search

Dielectric characteristics of gaseous helium (GHe) injected into the cooling system to make sub-cooled nitrogen condition with constant pressure is found to be extraordinarily weak in dielectric strength by H. Mitsuii (1998). In high voltage superconducting machines using the sub-cooled nitrogen cooling system, the current lead part in GHe environment could be electrical weak points rather than the superconducting magnet

Hyoungku Kang; Chanjoo Lee; Tae Kuk Ko; Bok-Yeol Seok

2007-01-01

33

Solar-powered cooling system  

DOEpatents

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.

Farmer, Joseph C

2013-12-24

34

Power application of superconductivity technology in China  

NASA Astrophysics Data System (ADS)

As a result of the fast rise in power consumption, electrical power generation in China during the past 20 years has increased at an average rate of higher than 8% per year. It is estimated that the power generation capacity in 2020 will be more than 1100 GW. Nevertheless, China is currently experiencing a shortage in the electricity supply, and there are concerns about insufficient availability of mineral resources in the future. The fast expanding power industry has room therefore for applying new technologies, and high temperature superconductivity is one such promising energy saving and environment friendly new technology. Our analysis suggests that the price of high temperature superconductivity equipment will not be an obstacle for large scale applications. Recently, there has been increased support for R&D for high temperature superconductivity applications in China. Several projects, including production of long lengths of Bi-2223 tapes and high temperature superconducting power cables, have been successfully implemented.

Han, Z.; Hu, X. H.

2006-03-01

35

Pool-cooled superconducting magnet design of large helical device  

NASA Astrophysics Data System (ADS)

The Large Helical Device is the next generation in helical equipment for nuclear fusion. The large scale superconducting magnets are going to be applied to these coils. The major and minor radius of the helical coil system are 4 and 0.96 m respectively and the magnetic field is 4 T at the plasma center and 8 T at the coil surface. The coil system stores about 2 GJ of total energy. The superconductor of the helical coil is pure aluminum stabilized Nb-Ti compacted strand cable with copper housing. The coils have a stainless-steel helium can that is filled with liquid helium. This pool-cooled superconducting helical coil system satisfies the fully stabilized condition. The superconducting poloidal coils are composed of six (three pairs) circular coils and use forced-cooled superconductors to reduce the eddy current losses by the field changing operation. The helical and poloidal coil system are built in the large bell-jar (vacuum vessel for thermal insulation) with outer diameter of 13 m. Conductor design and stability of superconducting magnets for helical and poloidal coil systems are described.

Suzuki, S.; Miyazawa, H.; Saito, R.; Iida, F.; Ogata, H.; Yamazaki, Y.; Motojima, Osamu; Yamamoto, Junya; Fujiwara, Masami; Takeo, M.

1990-03-01

36

Thermoelectric cooling and power generation  

PubMed

In a typical thermoelectric device, a junction is formed from two different conducting materials, one containing positive charge carriers (holes) and the other negative charge carriers (electrons). When an electric current is passed in the appropriate direction through the junction, both types of charge carriers move away from the junction and convey heat away, thus cooling the junction. Similarly, a heat source at the junction causes carriers to flow away from the junction, making an electrical generator. Such devices have the advantage of containing no moving parts, but low efficiencies have limited their use to specialty applications, such as cooling laser diodes. The principles of thermoelectric devices are reviewed and strategies for increasing the efficiency of novel materials are explored. Improved materials would not only help to cool advanced electronics but could also provide energy benefits in refrigeration and when using waste heat to generate electrical power. PMID:10426986

DiSalvo

1999-07-30

37

Surface Power Radiative Cooling Tests  

NASA Astrophysics Data System (ADS)

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.

Vaughn, Jason; Schneider, Todd

2006-01-01

38

Flow Cooling of Superconducting Magnets for Spacecraft Applications  

NASA Astrophysics Data System (ADS)

The development and testing of a flow cooling system for high-temperature superconducting (HTS) magnets is described. The system includes a turbo-Brayton cryocooler, a magnet thermal interface, and a magnet thermal isolation and support system. The target application is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). Turbo-Brayton coolers are well suited to such spacecraft applications, as they are compact, modular, lightweight, and efficient, with long maintenance-free lifetimes. Furthermore, the technology scales well to high-cooling capacities. The feasibility of using turbo-Brayton coolers in this application was proven in a design exercise in which existing cooler designs were scaled to provide cooling for the magnet sets required by 200 kW and 1 MW VASIMR engines. The performance of the concepts for the thermal interface and the thermal isolation and support system were measured in separate laboratory tests with a demonstration system built about a representative HTS magnet. Cooling for these tests was provided by a flow cooling loop comprising a compressor, recuperator and GM cryocooler, with the flow pressure, temperature, and mass flow rate selected to effectively simulate the turbo-Brayton operating condition. During system testing, the magnet was cooled below its design operating temperature of 35 K, and good thermal uniformity (<0.4 K) and low thermal loads (<0.5 W) were demonstrated.

Dietz, A. J.; Audette, W. E.; Barton, M. D.; Hilderbrand, J. K.; Marshall, W. S.; Rey, C. M.; Winter, D. S.; Petro, A. J.

2008-03-01

39

Power plant cooling systems: policy alternatives  

Microsoft Academic Search

Policies and pressures emanating from the 1972 Amendments to the Federal Water Pollution Control Act favor the installation of cooling towers, or closed-cycle cooling systems, in power plants. An assessment of the relative risks of alternative cooling system designs indicates that, in general, adverse environmental effects associated with cooling towers are more certain, are of larger scale, and are more

J. Z. Reynolds

1980-01-01

40

Power Plant Cooling Systems: Policy Alternatives  

Microsoft Academic Search

Policies and pressures emanating from the 1972 Amendments to the Federal Water Pollution Control Act favor the installation of cooling towers, or closed-cycle cooling systems, in power plants. An assessment of the relative risks of alternative cooling system designs indicates that, in general, adverse environmental effects associated with cooling towers are more certain, are of larger scale, and are more

John Z. Reynolds

1980-01-01

41

Power plant cooling systems: policy alternatives.  

PubMed

Policies and pressures emanating from the 1972 Amendments to the Federal Water Pollution Control Act favor the installation of cooling towers, or closedcycle cooling systems, in power plants. An assessment of the relative risks of alternative cooling system designs indicates that, in general, adverse environmental effects associated with cooling towers are more certain, are of larger scale, and are more likely to be irreversible than impacts associated with once-through cooling systems and cooling reservoirs. Adverse environmental effects associated with once-through cooling and cooling reservoirs are largely amenable to mitigation in the context of resource management principles. These factors, together with the greater costs associated with cooling towers, indicate that wherever the feasibility is demonstrated and there is minimal risk to aquatic ecosystems, once-through cooling systems or cooling reservoirs should be preferred. PMID:17833533

Reynolds, J Z

1980-01-25

42

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

NASA Astrophysics Data System (ADS)

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.

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

43

Evaluation of existing cooling systems for reducing cooling power consumption  

Microsoft Academic Search

This work was designed to estimate the cooling load power consumption during the summer in the hot and humid areas of Iran. The actual electrical energy consumption for cooling systems of some typical buildings with various applications (3 residential home buildings, 2 industrial plant buildings, a trade center with 38 shops, 3 public sectors and a city hospital) in a

M. S. Hatamipour; H. Mahiyar; M. Taheri

2007-01-01

44

Water for Power Plant Cooling.  

National Technical Information Service (NTIS)

Future demands for cooling water needed for the production of electrical energy; possible sources of cooling water, including agricultural and municipal waste water, brackish and saline interior water, geothermal water, ground water, and fresh surface wat...

1977-01-01

45

Optimizing cooling policy for power plant system  

Microsoft Academic Search

A dynamic programing model was developed to minimize the cooling costs of a series of power plants along a tributary discharging into an estuary. Heat production and dissipation equations are utilized. The cooling method studied is a once-through, no recycle system utilizing cooling ponds. Minimal cost policy is subject to several constraints, including stream and estuary standards, land availability, budget

L. Lum; L. W. Mays

1979-01-01

46

Compact, lightweight, superconducting power generators  

Microsoft Academic Search

Many future military systems will depend heavily on high electrical power input ranging from 100's kilowatts up to the multimegawatt level. These weapon systems include electromagnetic launch applications as well as electrically driven directed energy weapons (DEW), such as high power microwaves and solid state lasers. These power generation subsystems must often be packaged using limited space and strict weight

Paul N. Barnes; Gregory L. Rhoads; Justin C. Tolliver; Michael D. Sumption; Kevin W. Schmaeman

2004-01-01

47

Compact, lightweight, superconducting power generators  

Microsoft Academic Search

Many future military systems will depend heavily on high electrical power input ranging from hundreds of kilowatts up to the multimegawatt level. These weapon systems include electromagnetic launch applications as well as electrically driven directed energy weapons (DEW), such as high-power microwaves and solid-state lasers. These power generation subsystems must often be packaged using limited space and strict weight limits

Paul N. Barnes; Gregory L. Rhoads; Justin C. Tolliver; Michael D. Sumption; Kevin W. Schmaeman

2005-01-01

48

The Results of Cooling Test on Hts Power Cable of Kepco  

NASA Astrophysics Data System (ADS)

Due to the inherent characteristics of the superconductivity that allows large power transmission capability, much research on high-temperature superconducting (HTS) power cables has been carried out world-wide. KEPCO (Korea Electric Power Corporation) had installed a three-phase, 100-m class, HTS cable system at Gochang power test center of KEPCO that handles 22.9 kV, 1250 A, 50 MVA. The HTS cable system of KEPCO consists of two terminations, the HTS power cable, and cooling system. Sub-cooled liquid nitrogen is used for the HTS power cable coolant, providing an inlet temperature to the cable during operations from 66 K to 77 K. Circulation cooling tests at different temperatures were performed to investigate operating conditions, and heat losses under alternating-current (AC) load conditions were measured. The results of performance correlated with cooling test will be presented in this paper.

Lim, J. H.; Sohn, S. H.; Yang, H. S.; Kim, D. L.; Ryoo, H. S.; Hwang, S. D.

2008-03-01

49

Design Issues for Cryogenic Cooling of Short Period Superconducting Undulators  

SciTech Connect

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.

Green, M.A.; Dietderich, D.R.; Marks, S.; Prestemon, S.O.; Schlueter, R.D. [Lawrence Berkeley National Laboratory, Berkeley CA 94720 (United States)

2004-06-23

50

Bent Superconducting Solenoids for the Muon Cooling Experiment  

SciTech Connect

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.

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

1999-03-18

51

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

NASA Astrophysics Data System (ADS)

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.

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

2005-01-01

52

Development of superconducting power devices in Europe  

NASA Astrophysics Data System (ADS)

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, …).

Tixador, Pascal

2010-11-01

53

Development of binary superconducting current leads with a gas cooled normal part  

NASA Astrophysics Data System (ADS)

The design of a binary superconducting 1 kA current lead, operating between 300 K and 4.2 K, will be presented. The normal conducting part of the lead,: will be cooled by high pressure helium gas of 60 K inlet temperature. The resulting warm end temperature of the conduction cooled high-temperature superconductor (HTSC) part is about 67 K and as a consequence a magnetic stray field of 0.2 T can be tolerated. A total heat load of 0.2 W at 4.2 K has been foreseen. The required room temperature power input of the refrigerator is reduced to about 25 % as compared to an optimised conventional current lead.

Fuchs, A. M.; Anghel, A.; Jakob, B.; Pasztor, G.; Vécsey, G.; Wesche, R.

1994-08-01

54

Cryogenic System for DC Superconducting Power Transmission Line  

Microsoft Academic Search

Due to the recent developments of the electric power devices and the HTS power cables, DC superconducting power transmission system is considered to be practical. As one of the R & D issues of the DC superconducting power transmission system, we measured the radiation heat of the thermally-isolated stainless steel pipes with different surfaces. As the result, one sheet of

Makoto Hamabe; Atsushi Sasaki; Tosin S. Famakinwa; Akira Ninomiya; Yasuhide Ishiguro; Satarou Yamaguchi

2007-01-01

55

Development of a forced-cooling D-shaped superconducting coil by supercritical helium  

Microsoft Academic Search

A D-shaped 12 Tesla superconducting coil with forced cooling NbâSn superconductor is developed. Cryogenic stability and conduit stress analyses, result of winding test of copper dummy coil, and cooing system for the test coil are presented.

Y. Wachi; A. Miura; T. Hamajima; T. Uchida; M. Yamaguchi; H. Ohguma; S. Murase; H. Shiraki; T. Fujioka

1983-01-01

56

Development of superconducting power transmission technology  

SciTech Connect

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.

Forsyth, E.B.

1985-01-01

57

Operating experience of the IFSMTF (International Fusion Superconducting Magnet Test Facility) vapor-cooled lead system  

SciTech Connect

The International Fusion Superconducting Magnet Test Facility (IFSMTF) uses six pairs of vapor-cooled leads (VCLs) to introduce electric power to six test coils. Each VCL is housed in a dewar outside the 11-m vacuum vessel and is connected to the coal via a superconducting bus duct;the various VCLs are rated at 12 to 20 kA. Heat loss through the leads constitutes the single largest source of heat load to the cryogenic system. Concerns about voltage breakdown if a coil quenches have led to precautionary measures such as installation of a N/sub 2/-purged box near the top of the lead and shingles to collect water that condenses on the power buses. A few joints between power buses and VCLs were found to be inadequate during preliminary single-coil tests. This series of tests also pointed to the need for automatic control of helium flow through the leads. This was achieved by using the resistance measurements of the leads to control flow valves automatically. By the time full-array tests were started, a working scheme had developed that required little attention to the leads and that had little impact on the refrigerator between zero and full current to the coils. The operating loss of the VCLs at full current is averaging at about 7.4 gs of warm flow and 360 W of cold-gas return load. These results are compared with predictions that were based on earlier tests. 4 refs., 6 figs

Lue, J.W.; Fehling, D.T.; Fietz, W.A.; Lubell, M.S.; Luton, J.N.; Schwenterly, S.W.; Shen, S.S.; Stamps, R.E.; Thompson, D.H.; Wilson, C.T.

1987-01-01

58

Investigation of the cooling conditions for the Fast Ramped Superconducting Magnets of the SIS100 Synchrotron  

NASA Astrophysics Data System (ADS)

The dynamic losses in fast ramped super ferric magnets will create the main part of the expected heat losses in the superconducting synchrotron SIS100 – the primary accelerator in the Facility for Antiproton and Ion Research (FAIR). The data measured on dipole models at the cryogenic magnet test facility at GSI allow to predict the static and dynamic losses in the superconducting magnets for different operation modes of the SIS100 synchrotron. The calculations of the expected mass flow rates in the cooling channels of the superconducting magnets together with the analysis of the cooling system for different operation modes of the synchrotron will be presented.

Bleile, A.; Fischer, E.; Khodzhibagiyan, H.; Mireau, A.; Schnizer, P.

2014-05-01

59

The integration of liquid cryogen cooling and cryocoolers with superconducting electronic systems  

NASA Astrophysics Data System (ADS)

The need for cryogenic cooling has been a critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of many of the superconducting circuits is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a serious disadvantage. This paper discusses the process of refrigerating superconducting devices with cryogenic liquids and small cryocoolers. Three types of cryocoolers are compared for vibration, efficiency and reliability. The connection of a cryocooler to the load is discussed. A comparison of using flexible copper straps to carry the heat load and using heat pipe is shown. The type of instrumentation needed for monitoring and controlling the cooling is discussed.

Green, Michael A.

2003-12-01

60

Ice pond cooling system for power plants  

Microsoft Academic Search

The use of melting ice to cool the power plant condenser effluent is considered as an alternative approach for high latitude locations where ice is readily available. The main interest in this technique is the expected reduction in water consumption. The results of a feasibility study of the engineering and economical possibilities of a power plant employing this technique are

Arthur C. Miller; Jorge A. Pena; John Urbsanski; Sonja N. Kerr

1983-01-01

61

Electrical insulation specification and design method for superconducting power equipment  

Microsoft Academic Search

To ensure the feasibility of the introduction of superconductivity into electric power systems, the reliability of the electrical insulation must be incorporated in the design from the early beginning of the development of any superconducting power equipment. The compilation and analysis of valuable background data are considered to be very important to this end. This paper deals with specification of

M. Hara; J. Gerhold

1998-01-01

62

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

SciTech Connect

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.

Noda, Tsuneo; Hashimoto, Masa-aki [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 (Japan); Yasutake, Nobutoshi [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Maruyama, Toshiki [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Tatsumi, Toshitaka [Department of Physics, Kyoto University, Kitashirakawa-Oiwake-cho, Kyoto 606-8502 (Japan); Fujimoto, Masayuki [Department of Physics, Hokkaido University, Kita-10 Nishi-8, Kita-ku, Sapporo, Hokkaido 060-0810 (Japan)

2010-08-12

63

Potential Refrigerants for Power Electronics Cooling  

SciTech Connect

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.

Starke, M.R.

2005-10-24

64

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

65

High power cable with internal water cooling  

Microsoft Academic Search

The transmission capacity of conventional cables will not be sufficient for the increasing requirements of electrical energy. For this reason in the 110kV-range an high power cable with internal water cooling was developed. The development included the construction of the cable components as well as that of the sealing ends and of the joints, furthermore all necessary auxiliary equipment. By

D. Hotz; R. D. Steckel; E. Zimmermann

1977-01-01

66

Auxiliary Power System for Activity Cooled Aircraft.  

National Technical Information Service (NTIS)

A method is described for extracting heat energy from an active cooling system in an aircraft as a source of auxiliary power. A secondary coolant such as a water-glycol mixture removes heat from near the outer surfaces of the vehicle and circulates throug...

R. A. Jones

1976-01-01

67

Auxiliary power system for activity cooled aircraft  

Microsoft Academic Search

A method is described for extracting heat energy from an active cooling system in an aircraft as a source of auxiliary power. A secondary coolant such as a water-glycol mixture removes heat from near the outer surfaces of the vehicle and circulates through a heat exchanger. Cryogenic fuel such as liquid hydrogen is first pressurized and passed through the heat

1976-01-01

68

Cooling by heating: refrigeration powered by photons.  

PubMed

We propose a new mechanism for refrigeration powered by photons. We identify the strong coupling regime for which maximum efficiency is achieved. In this case, the cooling flux is proportional to T in the low temperature limit T?0. PMID:22540566

Cleuren, B; Rutten, B; Van den Broeck, C

2012-03-23

69

Application of Superconducting Power Cables to DC Electric Railway Systems  

NASA Astrophysics Data System (ADS)

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.

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

70

Hydrogen cooling options for MgB2-based superconducting systems  

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

71

Problems of Superconducting Magnet Cooling under Beam Induced Heating Conditions.  

National Technical Information Service (NTIS)

In IHEP accelerating storage complex (ASC) it is planned to attain the 5x10 exp 14 proton/impulse intensity. In the superconducting coils of the ACS magnets considerable radiation heat release is possible due to particle losses. By evaluations the value o...

A. I. Ageev Y. G. Vinokur I. P. Vishner

1980-01-01

72

Pool-cooled superconducting magnet design of large helical device  

Microsoft Academic Search

The Large Helical Device is the next generation in helical equipment for nuclear fusion. The large scale superconducting magnets are going to be applied to these coils. The major and minor radius of the helical coil system are 4 and 0.96 m respectively and the magnetic field is 4 T at the plasma center and 8 T at the coil

S. Suzuki; H. Miyazawa; R. Saito; F. Iida; H. Ogata; Y. Yamazaki; Osamu Motojima; Junya Yamamoto; Masami Fujiwara; M. Takeo

1990-01-01

73

Superconductivity  

NASA Astrophysics Data System (ADS)

Many potential high-temperature superconductivity (HTS) military applications have been demonstrated by low-temperature superconductivity systems; they encompass high efficiency electric drives for naval vessels, airborne electric generators, energy storage systems for directed-energy weapons, electromechanical launchers, magnetic and electromagnetic shields, and cavity resonators for microwave and mm-wave generation. Further HST applications in militarily relevant fields include EM sensors, IR focal plane arrays, SQUIDs, magnetic gradiometers, high-power sonar sources, and superconducting antennas and inertial navigation systems. The development of SQUID sensors will furnish novel magnetic anomaly detection methods for ASW.

Yeo, Yung K.

74

Superconducting magnetic energy storage for power system transient stability improvement.  

National Technical Information Service (NTIS)

This paper shows, through a feasibility study carried out with the Hydro-Quebec ST-600 transient stability program, how a SMES (Superconducting Magnetic Energy Storage) can improve the transient stability and the damping of power systems either by active ...

P. Nonnon M. Gavrilovic G. Begin

1994-01-01

75

Prospects for cooling nanomechanical motion by coupling to a superconducting microwave resonator  

Microsoft Academic Search

Recent theoretical work has shown that radiation pressure effects can in principle cool a mechanical degree of freedom to its ground state. In this paper, we apply this theory to our realization of an optomechanical system in which the motion of mechanical oscillator modulates the resonance frequency of a superconducting microwave circuit. We present experimental data demonstrating the large mechanical

J. D. Teufel; C. A. Regal; K. W. Lehnert

2008-01-01

76

Presence of Pathogenic Microorganisms in Power Plant Cooling Waters.  

National Technical Information Service (NTIS)

The content of Legionnaires' Disease Bacteria (LDB) in air discharged from industrial and power plant cooling towers was compared with the concentrations found in the cooling-tower basin water. Concentrates of the power plant air samples were also tested ...

R. L. Tyndall

1983-01-01

77

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

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

78

Heat pipe cooling of power processing magnetics  

NASA Technical Reports Server (NTRS)

A heat pipe cooled transformer and input filter were developed for the 2.4 kW beam supply of a 30 cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. The design details are presented along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor.

Hansen, I. G.; Chester, M. S.

1979-01-01

79

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

80

Partial discharge performance of lapped plastic insulation for superconducting power transmission cables and the dielectric strength of supercritical helium gas  

Microsoft Academic Search

A superconducting power transmission cable was designed using a flexible ac cable with Nb3Sn superconductor force cooled by supercritical helium. A lapped, multilayer plastic tape construction was selected for the electrical insulation with supercritical helium gas filling the butt spaces between tapes. Evaluation of many different tapes showed biaxially oriented laminated polypropylene tape to be a promising dielectric. A series

A. J. Pearmain; M. Kosaki; R. A. Thomas

1978-01-01

81

Development of a High Field Superconducting Magnet Cooled by a 2 K Cryocooler (1) - Magnet and Cooling System  

NASA Astrophysics Data System (ADS)

A high field magnet cooled by a small 2 K cryocooler has been developed. The superconducting magnet consists of one NbTi coil and two Nb3Sn coils. The innermost bore is 30 mm. The designed value of magnetic field is 18 T. A GM/JT cryocooler, which has a capacity of 1 W at 1.8 K has been developed for cooling this magnet. A single stage GM cryocooler is also used for cooling current leads and thermal shield. The coils were mounted on a copper plate with a cave, which was connected to the JT circuit. Each coil was attached to the copper plate with pure aluminum foil to improve thermal conduction. The magnet was cooled from room temperature to 4 K within about 80 hours and cooled from 4 K to 2 K within 10 minutes. The lowest temperature of coils was 1.67 K, and the maximum temperature difference between the coils and the copper plate was 0.02 K except during the excitation period. During excitation process the magnet temperature increased gradually as the operation current increased. However, we could hold the magnet temperature less than 2.1 K and succeeded to generate 17.3 T, which is the world highest field in a conduction-cooled magnet using a cryocooler.

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

2004-06-01

82

Decoupled Control Techniques for Dual Flying Capacitor Bridge Power Supplies of Large Superconductive Magnets.  

National Technical Information Service (NTIS)

The dual flying capacitor (DFC) was developed in 1976 as a method of supplying efficient bilateral power to large superconductive magnets. This power supply concept uses a second superconductive coil for energy storage. Large reversible power demands of t...

M. Ehsani A. Hozhabri R. L. Kustom

1986-01-01

83

Surface superconductivity, positive field cooled magnetization, and peak-effect phenomenon observed in a spherical single crystal of niobium  

NASA Astrophysics Data System (ADS)

We report the observation of surface superconductivity as well as positive field cooled magnetization, along with peak-effect phenomenon in ac and dc magnetization measurements in a high-purity spherical single crystal of niobium. We study how the surface superconductivity and the positive field cooled magnetization evolve over the field (H) and the temperature (T) phase space. We suggest that the observed evolution in the strength of the positive field cooled magnetization signal may be understood on the basis of the temperature dependence of the superconducting coherence length.

Das, Pradip; Tomy, C. V.; Banerjee, S. S.; Takeya, H.; Ramakrishnan, S.; Grover, A. K.

2008-12-01

84

Experimental validation of field cooling simulations for linear superconducting magnetic bearings  

NASA Astrophysics Data System (ADS)

For practical stability of a superconducting magnetic bearing the refrigeration process must occur with the superconductor in the presence of the magnetic field (a field cooling (FC) process). This paper presents an experimental validation of a method for simulating this system in the FC case. Measured and simulated results for a vertical force between a high temperature superconductor and a permanent magnet rail are compared. The main purpose of this work is to consolidate a simulation tool that can help in future projects on superconducting magnetic bearings for MagLev vehicles.

Dias, D. H. N.; Motta, E. S.; Sotelo, G. G.; de Andrade, R., Jr.

2010-07-01

85

Solid-Cryogen Cooling Technique for Superconducting Magnets of NMR and MRI  

NASA Astrophysics Data System (ADS)

This paper describes a solid-cryogen cooling technique currently being developed at the M.I.T. Francis Bitter Magnet Laboratory for application to superconducting magnets of NMR and MRI. The technique is particularly appropriate for “dry” magnets that do not rely on liquid cryogen, e.g., liquid helium (LHe), as their primary cooling sources. In addition, the advantages of a cryocirculator (a combination of a cryocooler and a working fluid circulator) over a cryocooler as the primary cooling source for dry magnets are described. The four magnets described here, all incorporating this cooling technique described and currently being developed at the FBML, are: 1) a solid-nitrogen (SN2)-cooled Nb3Sn 500-MHz/200-mm MRI magnet with an operating temperature range between 4.2 K (nominal) and 6.0 K (maximum with its primary cooling source off); 2) an SN2-cooled MgB2 0.5-T/800-mm MRI magnet, 1015 K; 3) an SN2-cooled compact YBCO “annulus” 100-MHz/9-mm NMR magnet, 10-15 K; 4) an SN2-cooled 1.5T/75-mm NbTi magnet for slow magic-angle-spinning NMR/MRI, 4.5-5.5 K.

Iwasa, Yukikazu; Bascuñán, Juan; Hahn, Seungyong; Park, Dong Keun

86

Emerging Two-Phase Cooling Technologies for Power Electronic Inverters  

Microsoft Academic Search

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

2005-01-01

87

Continuous Cooling Transformation Atlas for Commercial Power Plant Materials,  

National Technical Information Service (NTIS)

A weld thermal simulation technique has been used to investigate the continuous cooling transformation characteristics of a range of commercial power plant materials. Continuous cooling transformation data are presented for various regions of a weld heat ...

P. J. Alberry B. Chew T. C. Gilmore P. Woodlands

1987-01-01

88

Venus Surface Power and Cooling System Design  

NASA Technical Reports Server (NTRS)

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.

Landis, Geoffrey A.; Mellott, Kenneth D.

2004-01-01

89

DEVELOPMENT OF A SOLAR POWERED DIFFUSION ABSORPTION COOLING MACHINE  

Microsoft Academic Search

This paper is about the development, investigation and simulation of a single-effect solar powered ammonia\\/water (NH3\\/H2O) Diffusion-Absorption Cooling Machine (DACM). The designed cooling capacity of the cooling machine is 2.5 kW at evaporator temperatures ranging between -10°C and +5°C. The indirectly heated, solar powered generator with its bubble pump is the main new feature of this cooling machine. The challenges

Uli Jakob; Ursula Eicker; Ahmad H. Taki; Malcolm J. Cook

90

Stability of a NbTi forced-cooled superconducting coil by subcooled supercritical helium  

Microsoft Academic Search

The stability and quench characteristics of a NbTi forced-cooled superconducting coil at the subcooled condition were investigated. The test coil was wound in a one-layer solenoid from a cable-in-conduit-type conductor of 1.5 kA at 7 T, whose total length was 34 m. It was installed in a background coil and tested between the subcooled condition below 4.5 K and the

Y. Wachi; M. Shimada; T. Hamajima; M. Yamaguchi

1992-01-01

91

Liquid Metal Cooled Reactor for Space Power  

NASA Astrophysics Data System (ADS)

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.

Weitzberg, Abraham

2003-01-01

92

Performance Analysis of XCPC Powered Solar Cooling Demonstration Project  

NASA Astrophysics Data System (ADS)

A solar thermal cooling system using novel non-tracking External Compound Parabolic Concentrators (XCPC) has been built at the University of California, Merced and operated for two cooling seasons. Its performance in providing power for space cooling has been analyzed. This solar cooling system is comprised of 53.3 m2 of XCPC trough collectors which are used to power a 23 kW double effect (LiBr) absorption chiller. This is the first system that combines both XCPC and absorption chilling technologies. Performance of the system was measured in both sunny and cloudy conditions, with both clean and dirty collectors. It was found that these collectors are well suited at providing thermal power to drive absorption cooling systems and that both the coinciding of available thermal power with cooling demand and the simplicity of the XCPC collectors compared to other solar thermal collectors makes them a highly attractive candidate for cooling projects.

Widyolar, Bennett K.

93

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

NASA Astrophysics Data System (ADS)

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.

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

94

Impact of superconductive magnetic energy storage on electric power transmission  

Microsoft Academic Search

The authors demonstrate that a superconductive magnetic energy storage (SMES) system can provide a significant positive impact on electric power transmission. By using SMES, transmission-line loadings during heavy load hours can be reduced if the SMES system is located near the major load. Transmission losses as well as the fuel cost for the losses over a 24 hr period can

K.-S. Tam; P. Kumar

1990-01-01

95

Personal cooling in nuclear power stations. Final report  

Microsoft Academic Search

Two approaches to personal, non-restrictive cooling of workers exposed to high-temperature work environments in nuclear power plants were evaluated. Both approaches involved a cooling garment designed to be worn under the protective clothing donned in penetration into radiation areas. One garmet was developed to cool by direct body contact with small packets of frozen water enclosed in the pockets of

Kamon

1983-01-01

96

POWER PLANT COOLING SYSTEM WATER CONSUMPTION AND NONWATER IMPACT REPORTS  

EPA Science Inventory

This study dealt with water evaporation and consumption of power plant cooling systems and evaluated six simple generic evaporation prediction models, one for cooling towers and five for cooling ponds/lakes using field data provided by twelve utilities. Also evaluated in the stud...

97

Hydraulic behavior of forced-flow cooled superconducting coils for the large helical device  

NASA Astrophysics Data System (ADS)

The large helical device (LHD) has been operated since 1998 and the 13th experimental campaign was conducted in 2009. Before final assembling, cool-down and excitation tests for the Inner Vertical (IV) field coil, which is one of the LHD poloidal field coils, were carried out in 1995. This coil, which consists of a cable-in-conduit conductor, (CICC) is cooled by the forced-flow of supercritical helium. During the tests of the IV coil, hydraulic characteristics, such as flow distribution among cooling channels and friction factors, were measured. In this paper, the consistency of the behavior of the IV coil will be presented and comparison with other fusion devices using superconducting coils will also be made at not only cryogenic temperatures but also at room temperature.

Park, Soo-Hwan; Takahata, Kazuya

2011-06-01

98

High power electronic devices cooling at minimum ventilation power  

NASA Astrophysics Data System (ADS)

In the present work, the cooling of a high power electronic device is studied. The device is in contact with a heat dissipator crossed by air. The air motion through the dissipator is forced by a fan whose supplied power is to be minimized. A finite element dynamic model of the dissipator is firstly created, taking geometrical and physical properties into account as well as steady state experimental data. A simplified model is then obtained, which reproduces the time pattern of the maximum dissipator temperature as a response of the thermal flux removed from the electronic device and the mass flow rate of the air. Afterwards, the simplified model is utilized to build a control system which allows the electronic device to be correctly cooled at minimum air ventilation power during transition to steady states. Genetic algorithms are used to find the parameters of the finite element model and of the control system. Some functioning conditions of the electronic device are lastly considered and discussed.

Fabbri, Giampietro

2008-01-01

99

Counterflow cool down of cryogenic power transmission lines  

NASA Astrophysics Data System (ADS)

Cool down of cryogenic power transmission lines which use a counterflow cooling arrangement is investigated analytically, numerically, and experimentally. The results demonstrate that the cool down time, tcd, is given by fx463-1 where U is the overall heat transfer coefficient between the go and return streams, l the length, and ? the mass flow rate. The accuracy and utility of a previously reported numerical cool down model are also confirmed by comparison with experiment.

Daney, D. E.; Jones, M. C.

100

Experimental simulation of helium pressure rise during a quench of a superconducting coil cooled by a superfluid helium bath  

NASA Astrophysics Data System (ADS)

Experimental and numerical studies have been conducted with the aim of modeling pressure rises which occur in the helium, during quenches of the 11.7-T superconducting magnet named Iseult. Iseult is based on a double-pancake winding internally cooled by superfluid helium channels opening into a pressurized He II bath at 1.8 K. A scale mock-up has been built of 10 copper equivalent pancake slices and 7 helium channels per pancake. The heat produced by a quench of the Iseult magnet is simulated by electrical heaters put inside each copper plate. Cryogenic pressure and temperature sensors have been fitted in the helium channels and in the bath. Bath pressure measurements are given for various heating powers, various numbers of heated plates and various bath volumes. Comparisons with a simple numerical model permit to identify the main physical mechanisms which drive the pressure rise during a quench.

Meuris, C.

2013-01-01

101

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

Microsoft Academic Search

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

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

2004-01-01

102

Inverter power module with distributed support for direct substrate cooling  

DOEpatents

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.

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

103

High temperature superconducting current leads for fusion magnet systems.  

National Technical Information Service (NTIS)

Superconducting magnets for fusion applications typically have very high operating currents. These currents are transmitted from the room temperature power supplies to the low temperature superconducting coils by way of helium-vapor-cooled current leads. ...

J. L. Wu J. T. Dederer S. K. Singh J. R. Hull

1991-01-01

104

Steam powered heating\\/cooling systems  

Microsoft Academic Search

A cooling system is described having a boiler, a heat source for the boiler including a burner, an absorption machine having a generator section and an absorber section, a steam trap for the generator section of the absorption machine, a condensate tank with a vent line to atmosphere and work to be heated. The cooling system consists of a steam

1987-01-01

105

Floating power optimization studies for the cooling system of a geothermal power plant  

Microsoft Academic Search

The floating power concept was studied for a geothermal power plant as a method of increasing the plant efficiency and decreasing the cost of geothermal power. The stored cooling concept was studied as a method of reducing the power fluctuations of the floating power concept. Parametric and optimization studies were conducted for a variety of different types of cooling systems

C. J. Shaffer

1977-01-01

106

Potential impact of superconductivity on power quality enhancment  

NASA Astrophysics Data System (ADS)

Electric power quality problems are estimated to cost U.S. industry $26 billion dollars per year in lost production. This paper provides a summary of the problem's magnitude, an overview of the underlying causes, discusses the present methods used by industry to reduce the problem's impact and the associated cost, and examines the potential for superconducting technology to effect alternative solutions. The present market for uninterruptible power supplies (UPS) and power conditioners is also discussed and the benefits of applying high temperature superconductors (HTS) are summarized.

McConnell, B. W.

1992-02-01

107

High voltage insulation performance of cryogenic liquids for superconducting power apparatus  

SciTech Connect

This paper describes high voltage insulation technology of cryogenic liquids for superconducting power apparatus. The insulation of a superconducting transformer is classified into several insulation components. The authors investigate fundamental insulation characteristics peculiar to the superconducting and cryogenic circumstances: area and volume effects on breakdown strength, V-t characteristics, quench-induced dynamic breakdown characteristics and so on. Finally, they systematize the electrical insulation of cryogenic liquids, and propose the flow chart for the practical insulation design of superconducting power apparatus.

Okubo, H.; Hikita, M.; Goshima, H.; Sakakibara, H.; Hayakawa, N. [Nagoya Univ. (Japan)] [Nagoya Univ. (Japan)

1996-07-01

108

Cryogenic Fluid Dynamics for DC Superconducting Power Transmission Line  

Microsoft Academic Search

Distributions of the velocity, the temperature and the pressure of a liquid nitrogen (LN2) flow are analyzed at hydraulic cross-sections on two types of superconducting power transmission lines (SC PT). One is on a DC-SC PT, the other is on a three phase AC-SC PT. Inflow heat from the pipe wall and the cables to LN2 are evaluated, however the

Atsushi Sasaki; Makoto Hamabe; Tosin Famakinwa; Satarou Yamaguchi; Alexey Radovinsky; Haruhiko Okumura; Masahiko Emoto; Toshihiro Toyota

2007-01-01

109

High-Tc superconducting materials for electric power applications.  

PubMed

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

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

2001-11-15

110

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

DOEpatents

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.

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

2001-01-01

111

Liquid cooling methods for power electronics in an automotive environment  

Microsoft Academic Search

This work compares the performance of “Liquid Pin” coolers and other advanced cooling techniques like “ShowerPower”, pin fin and microchannel. Water glycol mixture (40 % v\\/v glycol) is used as a cooling agent at temperatures of 5 °C, 20 °C, 40 °C and 60 °C. Various characteristics of the coolers like pressure drop, thermal resistance and impedance are examined.

M. Baumann; J. Lutz; W. Wondrak

2011-01-01

112

Development of a solar-powered passive ejector cooling system  

Microsoft Academic Search

This paper describes the development of an ejector refrigeration system that is powered by solar thermal energy. The cooling system contains no active parts and is therefore deemed passive. Water is used as the refrigerant though other natural refrigerants could be used for lower temperature operation. A prototype system was built with a nominal cooling capacity of 7 kW. This

V. M Nguyen; S. B Riffat; P. S Doherty

2001-01-01

113

Impact of superconductive magnetic energy storage on electric power transmission  

SciTech Connect

This paper demonstrates that a superconductive magnetic energy storage (SMES) system can provide a significant positive impact on electric power transmission. Through the use of SMES, transmission line loadings during heavy load hours can be reduced. Transmission losses as well as the fuel cost for these losses over a 24-hour period can also be decreased. A new SMES scheme, the SMES/dc link, is introduced in this paper for energy storage and control of power flow. The operation of this scheme and the benefits it provides are presented in this paper.

Tam, K.S.; Kumar, P. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA). Dept. of Electrical Engineering)

1990-09-01

114

Emerging Two-Phase Cooling Technologies for Power Electronic Inverters  

SciTech Connect

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.

Hsu, J.S.

2005-08-17

115

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

Federal Register 2010, 2011, 2012, 2013

...NRC-2012-0293] Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY...DG-1259, ``Initial Test Programs for Water-Cooled Nuclear Power Plants...entitled, ``Initial Test Programs for Water-Cooled Nuclear Power...

2012-12-07

116

Results of the APT RF power coupler development for superconducting linacs.  

SciTech Connect

For the new baseline APT (Accelerator Production of Tritium) linac design, the power couplers are required to transmit 420 kW of CW RF power to the superconducting cavities at 700 MHz. These couplers consist of an airside waveguide-to-coax transition, an air/vacuum break made by two planar, coaxial windows, and a vacuum-side coaxial antenna section. The coaxial antenna allows adjustability of the RF matching to the superconducting cavities. Design, fabrication, and testing of the power coupler/window occurred over the last four years, and room temperature testing of the prototype design is complete. Coupler/window assemblies have transmitted power to 1 MW, CW and have handled full reflected 850 kW, CW over a limited standing-wave phase range. Couplers were tested with a portion of the outer conductor cooled by liquid nitrogen to study the effects of condensed gases. No hard multipacting barriers were encountered during any of this room temperature testing. Final results, conclusions, and lessons learned about the coupler design, fabrication, and testing will be discussed.

Schmierer, E. N. (Eric N.); Haynes, W. B. (William B.); Krawczyk, F. L. (Frank L.); Gautier, D. C. (Donald Cort); Gioia, J. G. (Jack G.); Madrid, M. A. (Michael A.); Lujan, R. E. (Richard E.); Chan, K. D. (Kwok-Chi D.); Schrage, D. L. (Dale L.); Smith, B. G. (Brian G.); Waynert, J. A. (Joseph A.); Rusnak, B. (Brian)

2001-01-01

117

Presence of Pathogenic Microorganisms in Power Plant Cooling Waters.  

National Technical Information Service (NTIS)

Cooling waters from eleven geographically disparate power plants were tested for the presence of Naegleria fowleri and Legionella pneumophila (LDB). Control source waters for each plant were also tested for these pathogens. Water from two of the eleven pl...

R. L. Tyndall

1982-01-01

118

THE COOLING POWER OF THE PIGEON HEAD  

Microsoft Academic Search

Summary Resting pigeons preheated to a stable core temperature of 43.2 ?C, which is within the range of body temperatures recorded during flight, were able to cool their body at high rates if their head and upper neck were exposed to an air stream at 23.5 ?C. The heat dissipation capacity of the head and neck, estimated from measurements made

ROBERT ST-LAURENT; JACQUES LAROCHELLE

1994-01-01

119

Operational characteristics of a 1000 MVA superconducting power transmission system  

SciTech Connect

Over the last three years, the power transmission project at Brookhaven National Laboratory has been testing two flexible superconducting cables for the transmission of ac electric power. These cables are each 115 m long and are rated at 80 kV, 4100 A single-phase for a power rating of 333 MVA - (1000 MVA, 138 kV, 3 phase). They have been operated over the range of 7 to 12/sup 0/K in supercritical helium at 14 to 15 atm. The cables have been tested at currents and voltages above their ratings and have also been operated with no coolant flow to study the effects of loss of refrigeration on cable performance. The insights gained from the operating of the system over this extended period are presented. Finally, those areas are delineated which will require further research before this technology can be integrated into the US electrical power delivery system.

Thomas, R.A.

1984-09-10

120

Operational characteristics of a 1000 MVA superconducting power transmission system  

SciTech Connect

Over the last three years, the power transmission project at Brookhaven National Laboratory has been testing two flexible superconducting cables for the transmission of ac electric power. These cables are each 115 m long and are rated at 80 kV, 4100 A singlephase for a power rating of 333 MVA - (1000 MVA, 138 kV, 3 phase). They have been operated over the range of 7-12 K in supercritical helium at 14-15 atm. The cables have been tested at currents and voltages above their ratings and have also been operated with no coolant flow to study the effects of loss of refrigeration on cable performance. The insights gained from the operating of the system over this extended period will be presented. Finally, we will delineate those areas which will require further research before this technology can be integrated into the U.S. electrical power delivery system.

Thomas, R.A.

1985-03-01

121

Integrated cooling, heating, and power systems  

US Patent & Trademark Office Database

One exemplary embodiment of this invention provides a single-effect absorption chiller including an absorber operatively connected to a solution heat exchanger and a generator, and a condenser in fluid communication with the absorber, wherein the absorber is sized and configured to receive a feed of water from a source of water and to transfer heat to the feed of water and then to convey the feed of water to the condenser without further heat conditioning of the feed of water prior to its entry into the condenser, and wherein the condenser is sized and configured to receive the feed of water from the absorber and to transfer heat to the feed of water, thereby cooling the condenser without resorting to an external heat exchanger such as a conventional cooling tower.

2014-06-03

122

Characterisation of cooling curves for power device die attach using a transient cooling curve measurement  

Microsoft Academic Search

In this paper the analysis of cooling curves for power levels of up to 65 W is presented. The paper details a constant temperature fixture to keep a test vehicle at a constant temperature for these power levels. The test vehicle consists of a special designed copper block, a die attachment layer and a bare die for heating and sensing.

Matthias Ludwig; Alexander Gaedke; O. Slattery; J. Flannery; S. C. O'Mathuna

2000-01-01

123

Refrigeration system of superconducting generators for large power plants  

NASA Astrophysics Data System (ADS)

An electric generator with superconductor field windings with a capacity of 1000 to 2000 MVA was considered. No reliable equipment for refrigeration exists in order to adopt this technique in a power plant. The basic equipment, including the specifications of machines and apparatus, and a reliability study of such equipment able to function without maintenance more than 30,000 hours, were worked out. The selected cooling system consists of a compressor, a battery of heat exchangers, and a dewar liquid helium storage tank at a pressure of 1.2 bars and with a capacity of 5 m3. The liquid helium flows to the generator rotor and gaseous helium with ambient conditions leaves the generator and is fed to the refrigerator for reliquification. A quantity of 5 g/sec of liquid helium is required for a generator with a capacity of 1000 MVA. The equipment and the exploitation method are described, e.g., starting of cooling the installation, starting of cooling dewar container, starting of cooling generator, stopping of installation, behavior under variable charge conditions, and short breakdown of cooling equipment. The construction and the testing of a helium cooling system is mentioned.

Glatthaar, R.

1982-06-01

124

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

SciTech Connect

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.

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

1988-10-25

125

Eddy Current Testing Utilizing Cooled Normal Pickup Coil and Superconducting Quantum Interference Device Picovoltmeter  

NASA Astrophysics Data System (ADS)

An eddy current probe utilizing a cooled normal pickup coil and a high-Tc superconducting quantum interference device (SQUID) picovoltmeter was developed. The pickup coil could be moved in an unshielded environment, during which the signal voltage across the pickup coil was transferred to the SQUID picovoltmeter, which was fixed in a cylindrical magnetic shield. By moving the pickup coil, we successfully detected a small crack on the back surface of a Cu plate in the unshielded environment. The dependences of the detected signal on the excitation frequency and thickness of the Cu plate were clarified. The frequency dependence could be used to estimate the depth of the crack from the surface of the Cu plate.

Yang, Tong Qing; Yao, Kenichiro; Yamasaki, Daisuke; Enpuku, Keiji

2005-08-01

126

Superconductivity  

SciTech Connect

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.

Langone, J.

1989-01-01

127

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

Microsoft Academic Search

This paper presents a two-phase cooling method using the R134a refrigerant to dissipate the heat energy (loss) generated by power electronics (PEs), such as those associated with rectifiers, converters, and inverters for a specific application in hybrid-electric vehicles. The cooling method involves submerging PE devices in an R134a bath, which limits the junction temperature of PE devices while conserving weight

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

2007-01-01

128

Two-phase cooling method using R134a refrigerant to cool power electronic devices  

Microsoft Academic Search

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

Jeremy B. Campbell; Leon M. Tolbert; Curt W. Ayers; Burak Ozpineci

2005-01-01

129

Dependence of the residual surface resistance of superconducting radio frequency cavities on the cooling dynamics around Tc  

NASA Astrophysics Data System (ADS)

We report a strong effect of the cooling dynamics through Tc 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.

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

2014-05-01

130

Resistance and Cooling Power of Various Radiators  

NASA Technical Reports Server (NTRS)

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.

Smith, R H

1928-01-01

131

Evacuation time of cryogenic pipes for superconducting power transmission  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

132

Concurrent Wind Cooling in Power Transmission Lines  

SciTech Connect

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.

Jake P Gentle

2012-08-01

133

Gas-cooled reactor power systems for space  

SciTech Connect

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.

Walter, C.E.

1987-01-01

134

Design of a cryogenic system for a 20m direct current superconducting MgB2 and YBCO power cable  

NASA Astrophysics Data System (ADS)

The Massachusetts Institute of Technology, the University of Cambridge in the United Kingdom, and Tsinghua University in Beijing, China, are collaborating to design, construct, and test a 20 m, direct current, superconducting MgB2 and YBCO power cable. The cable will be installed in the State Key Laboratory of Power Systems at Tsinghua University in Beijing beginning in 2013. In a previous paper [1], the cryogenic system was briefly discussed, focusing on the cryogenic issues for the superconducting cable. The current paper provides a detailed discussion of the design, construction, and assembly of the cryogenic system and its components. The two-stage system operates at nominally 80 K and 20 K with the primary cryogen being helium gas. The secondary cryogen, liquid nitrogen, is used to cool the warm stage of binary current leads. The helium gas provides cooling to both warm and cold stages of the rigid cryostat housing the MgB2 and YBCO conductors, as well as the terminations of the superconductors at the end of the current leads. A single cryofan drives the helium gas in both stages, which are thermally isolated with a high effectiveness recuperator. Refrigeration for the helium circuit is provided by a Sumitomo RDK415 cryocooler. This paper focuses on the design, construction, and assembly of the cryostat, the recuperator, and the current leads with associated superconducting cable terminations.

Cheadle, Michael J.; Bromberg, Leslie; Jiang, Xiaohua; Glowacki, Bartek; Zeng, Rong; Minervini, Joseph; Brisson, John

2014-01-01

135

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)

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.

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

2005-02-01

136

Design and optimization of geothermal power generation, heating, and cooling  

NASA Astrophysics Data System (ADS)

Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the net power output by up to 31 percent, 35 percent, and 54 percent, respectively, at optimum operating conditions. An economic comparison of these designs appears to favor the combined flash/binary design, followed by the double-flash design.

Kanoglu, Mehmet

137

Application of Superconducting Magnet Energy Storage to Power System Stabilizing Control.  

National Technical Information Service (NTIS)

The application of Superconducting Magnet Energy Storage (SMES) to the stabilizing control of power systems with a long distance bulk power transmission line and with longitudinal interconnected structure is presented. Control schemes for stabilization us...

Y. Mitani K. Tsuji Y. Murakami

1986-01-01

138

LN 2 circulation in cryopipes of superconducting power transmission line  

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

139

Keeping Cool With Solar-Powered Refrigeration  

NASA Technical Reports Server (NTRS)

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.

2003-01-01

140

Gas-cooled reactor power systems for space  

SciTech Connect

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.

Walter, C.E.

1987-01-01

141

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

National Technical Information Service (NTIS)

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 h...

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

1999-01-01

142

Exergy Analysis of Solar Rankine Power Cycles Used for Cooling.  

National Technical Information Service (NTIS)

Second-law (exergy) analysis was performed on two types of solar-cooling systems which are based on a vapor-compression cycle driven by a Rankine cycle: those energized by the sun at one temperature and using organic fluids in the power cycle, and a hybri...

N. S. S. Lior W. J. Brady

1983-01-01

143

Pathogenic Amoebae in Power-Plant Cooling Lakes. Final Report.  

National Technical Information Service (NTIS)

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/weste...

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

1981-01-01

144

Presence of Pathogenic Amoebae in Power Plant Cooling Waters.  

National Technical Information Service (NTIS)

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 site...

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

1981-01-01

145

Gas-cooled cermet reactor system for planetary base power.  

National Technical Information Service (NTIS)

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 temperatu...

S. N. Jahshan J. A. Borkowski

1992-01-01

146

Legionnaires' disease bacteria in power plant cooling systems: Phase 2  

Microsoft Academic Search

Legionnaires' Disease Bacteria (Legionella) are a normal component of the aquatic community. The study investigated various environmental factors that affect Legionella profiles in power plant cooling waters. The results indicate that each of the four factors investigated (incubation temperature, water quality, the presence and type of associated biota, and the nature of the indigenous Legionella population) is important in determining

R. L. Tyndall; S. W. Christensen; J. A. Solomon

1985-01-01

147

Evaporative spray cooling of power electronics using high temperature coolant  

Microsoft Academic Search

A pressure atomized evaporative spray cooling nozzle array was used to thermally manage the power electronics of a 3 phase inverter module. The module tested was a COTS module manufactured by Semikron, Inc., and has a maximum DC power input of 180 kW (450 VDC and 400 A) with 25degC coolant. However, the standard heat sink that the module uses

Louis J. Turek; Daniel P. Rini; Benjamin A. Saarloos; Louis C. Chow

2008-01-01

148

Design of RF power coupler for superconducting cavities  

NASA Astrophysics Data System (ADS)

A new power coupler has been designed and is being prototyped by Argonne National Laboratory (ANL) for use with any of the ANL proposed superconducting (SC) half- or quarter-wave cavities for SARAF [1] and Project-X [2]. The 50 Ohm coaxial capacitive coupler is required to operate in the CW regime with up to 15 kW of forward power and under any condition for the reflected power. A key feature is a moveable copper plated stainless steel bellows which will permit up to 3 cm of axial stroke and adjustment of the external quality factor by roughly one order of magnitude in the range of 105 to 106. The mechanical and vacuum design includes two ceramic windows, one operating at room temperature and another at 70 Kelvin. The two window design allows the portion of the coupler assembled onto the SC cavity in the clean room to be compact and readily cleanable. Other design features include thermal intercepts to provide a large margin for RF heating and a mechanical guide assembly to operate cold and under vacuum with high reliability.

Kutsaev, S. V.; Kelly, M. P.; Ostroumov, P. N.

2012-11-01

149

Summary of development of 70 MW class model superconducting generator--research and development of superconducting for electric power application  

NASA Astrophysics Data System (ADS)

A 70 MW class superconducting model generator was designed, manufactured, and tested from 1988 to 1999 as Phase I, which was Japan's national project on applications of superconducting technologies to electric power apparatuses that was commissioned by NEDO as part of New Sunshine Program of AIST and MITI. Phase II then is now being carried out by almost same organization as Phase I. With the development of the 70 MW class superconducting model generator, technologies for a 200 MW class pilot generator were established. The world's largest output (79 MW), world's longest continuous operation (1500 h), and other sufficient characteristics were achieved on the 70 MW class superconducting model generator, and key technologies of design and manufacture required for the 200 MW class pilot generator were established. This project contributed to progress of R&D of power apparatuses. Super-GM has started the next project (Phase II), which shall develop the key technologies for larger-capacity and more-compact machine and is scheduled from 2000 to 2003. Phase II shall be the first step for commercialization of superconducting generator.

Oishi, Ikuo; Nishijima, Kenichi

2002-03-01

150

Feasibility of alternative cooling systems for power plants in the northern Great Plains  

Microsoft Academic Search

Partial Contents: Power plant water requirements; Operational\\/engineering considerations of wet and dry cooling tower systems; Environmental impacts of closed-cycle cooling systems; Economics of wet and dry cooling towers.

B. A. Tichenor; J. W. Shaw

1974-01-01

151

Specific power of liquid-metal-cooled reactors  

SciTech Connect

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.

Dobranich, D.

1987-10-01

152

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

153

SUPERCONDUCTING PHOTOINJECTOR  

SciTech Connect

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..

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

154

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

Microsoft Academic Search

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

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

1994-01-01

155

Potential minimum cost of electricity of superconducting coil tokamak power reactors  

Microsoft Academic Search

The potential minimum cost of electricity (COE) for superconducting tokamak power reactors is estimated by increasing the physics (confinement, beta-limit, bootstrap current fraction) and technology (neutral beam energy, toroidal field, or TF, coil allowable stresses, divertor heat flux, superconducting coil critical field, critical temperature, and quench temperature rise) constraints far beyond those assumed for the ITER (International Thermonuclear Experimental Reactor)

R. L. Reid; Y.-K. M. Peng

1989-01-01

156

Superconductivity  

SciTech Connect

The author presents treatment of the field of superconductivity, from its inception in 1911 to the present day. Its discussions range from scientific aspects to applications in business, medicine, etc. This book provides definitions and a selective bibliography.

Mayo, J.L.

1988-01-01

157

Passively cooled diode laser for high-power applications  

NASA Astrophysics Data System (ADS)

For the usage of diode lasers in industrial applications, customers ask today for expected lifetimes of more then 30.000 hours. To match the request for low costs per Watt as well, the output power has to be as high as possible. To achieve a maximum power out of a diode laser bar, heat removal must be extremely efficient. Today, micro channel heatsinks (MCHS) are the only way to achieve the high power level of 50W. But due to erosion/corrosion effects the lifetime of MCHS is limited at 15000...20.000 hours today. Finally we have to determine that for selected semiconductor materials not the semiconductor but the heatsink is limiting the expected lifetime of high power diode lasers today. Passive heat sinks based on solid copper are not limiting lifetime expectations in any way. But as cooling efficiency is lower, the power has to be reduced to a level of 30...40W. The first time ever, the JENOPTIK Laserdiode can present today a cooling technique that combines the passive cooling of a diode laser bar with the optical output a power of a bar, mounted on a MCHS. Using a special heat exchanger called DCB (patent pending) we were able to increase the power to 50W per bar while looking forward to extend the expected lifetime to more than 30.000 hours for selected materials. Restrictions on the quality of the water by means of deionization grade or PH- level are no longer necessary. The device is operating with regular water. The flow rate is as low as on MCHS, the pressure drop over the DCB is comparable. Additionally, the measurements will show an even lower thermal resistance compared to MCHS. The second generationof engineering samples is built up for pumping rows. A vertical stack design will be available for evaluating purposes soon. All these efforts are part of the JENOPTIK Laserdiode's LongLifeTechnology.

Bonati, Guido F.; Hennig, Petra; Schmidt, Karsten

2004-06-01

158

Application of superconducting magnet energy storage to improve power system dynamic performance  

Microsoft Academic Search

The application of superconducting magnet energy storage (SMES) to the stabilization of a power system with long-distance bulk power transmission lines which has the problem of poorly damped power oscillations is presented. Control schemes for stabilization using SMES capable of controlling active and reactive power simultaneously in four quadrant ranges are proposed. The effective locations and the necessary capacities of

Y. Mitani; K. Tsuji; Y. Murakami

1988-01-01

159

Developmental condition and technical problems on electric insulation for super-conducting electric power machine  

NASA Astrophysics Data System (ADS)

The present situations of superconducting electric power machines in the world and studied problems were investigated from viewpoint of the electric insulation. 50MVA generator (CRIE/Hitachi) or 120MVA generator (KWU/Siemens) where the dc superconducting technique was applied on field windings, are developed. As to Superconducting transformer, 220KVA transformer is trially manufactured and the conceptual design of 1,000MVA transformer is made by W.H. or Alstom. Future problems are the study of protecting method for the overvoltage to superconducting electric power machines and the study to prevent the quench for superconducting windings. The respective insulating characteristics of solid and liquid insulators become clear gradually under the cryogenic condition but a large part of insulating characteristics of composite insulator prepared by combination of both insulators are not clear, so that these problems must be clarified.

Motoyama, H.

1989-05-01

160

High voltage insulation for power cables utilizing high temperature superconductivity  

Microsoft Academic Search

It is worth noting that, with a few exceptions, the efforts to develop dielectric systems, especially for the LTD superconducting cables, are lagging behind the intense efforts to develop more efficient HT superconducting materials, tapes, and conductors. The results presented here and reported in the literature confirm that lifetime is usually greater for cryogenic insulation, and thus the impulse and

Alexander Bulinski; John Densley

1999-01-01

161

Portable, low-power, mechanically cooled Ge spectrometer  

NASA Astrophysics Data System (ADS)

A light-weight portable mechanically cooled ?-ray spectrometer has been constructed and tested. The spectrometer is based on a high-purity n-type Ge coaxial crystal, ˜5 cm long×5 cm diameter, a small, low-power Stirling cycle microcooler, and a low-power custom electronics package. The energy resolution of the spectrometer is ˜3.5 keV at E?=662 keV, the power requirements are ˜15 W DC, and the combined weight of the Ge, housing, and controller is approximately 10 pounds. The spectrometer qualifies therefore as "hand held". It is suitable for field operations, because of its light-weight, low-power draw, and operational lifetime. The microcooler itself has a MTBF >30,000 h, and the spectrometer runs for several months (at least 6) before a 2 day recycle is required.

Becker, J. A.; Cork, C. P.; Fabris, L.; Madden, N. W.

2003-06-01

162

Use of reclaimed water for power plant cooling.  

SciTech Connect

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.

Veil, J. A.; Environmental Science Division

2007-10-16

163

A gas-cooled reactor surface power system  

SciTech Connect

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.

Lipinski, Ronald J.; Wright, Steven A.; Lenard, Roger X.; Harms, Gary A. [Sandia National Laboratories, MS-1146, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States)

1999-01-22

164

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

NASA Astrophysics Data System (ADS)

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.

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

165

Development of passive dry cooling system for power plants in arid land  

Microsoft Academic Search

Availability of large amounts of cooling water is essential for steam power plants. In inland arid areas, gas turbines are usually used for electric power generation at low efficiency and high operation costs. Dry cooling towers are another option but they are not effective with high ambient temperature. This work explores the use of radiative cooling for power plants and

J. A. Sabbagh; A. M. A. Khalifa; I. A. Olwi

1993-01-01

166

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

167

Study on heat pipe sink for cooling high power LED  

NASA Astrophysics Data System (ADS)

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 (0.025m×0.025m×0.005m), 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 0.8964°C /W and the junction temperature was 47.39°C . Meanwhile, the finite element method was used to simulate this cooling system, and got that the junction temperature was 47.54°C , and the error of the two means is only 0.15°C , 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.

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

2012-10-01

168

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

SciTech Connect

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.

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

2011-07-25

169

Helium gas evacuation in superconducting RFQ structure  

Microsoft Academic Search

The PIAVE injector for the Legnaro Accelerator complex is an accelerating machine made of superconducting resonators. One of them, the superconducting RFQ, needs to be cooled by the helium bath on the whole outer surfaces. In particular the region of the electrode tips and the lower vertical electrode are involved in RF power dissipation and can have a trapped volume

A. Lombardi; G. Bisoffi; F. Chiurlotto; E. Tovo; A. M. Porcellato; L. Badan; L. Taffarello; G. Navarro; M. Antonello; M. Masi

1999-01-01

170

Superconductivity:  

NASA Astrophysics Data System (ADS)

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.

Sacchetti, N.

171

Solar-powered Rankine heat pump for heating and cooling  

NASA Technical Reports Server (NTRS)

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.

Rousseau, J.

1978-01-01

172

SAFE AND FAST QUENCH RECOVERY OF LARGE SUPERCONDUCTING SOLENOIDS COOLED BY FORCED TWO-PHASE HELIUM FLOW.  

SciTech Connect

The cryogenic characteristics in energy extraction of the four fifteen-meter-diameter superconducting solenoids of the g-2 magnet are reported in this paper. The energy extraction tests at full-current and half-current of its operating value were deliberately carried out for the quench analyses and evaluation of the cryogenic system. The temperature profiles of each coil mandrel and pressure profiles in its helium cooling tube during the energy extraction are discussed. The low peak temperature and pressure as well as the short recovery time indicated the desirable characteristics of the cryogenic system.

JIA,L.X.

1999-07-12

173

Superconductivity  

NASA Astrophysics Data System (ADS)

Part I. Phenomenological Theories of Suoerconductivity: 1. Introduction; 2. The London-London equation; 3. Pippard's equation; 4. Thermodynamics of type I superconductor; 5. The intermediate state; 6. Surface energy between a normal and a superconducting metal; 7. Quantized vorticity; 8. Type II superconductivity; 9. The Ginzburg-Landau theory; 10. The upper critical field of a type II superconductor; 11. The anisotropic superconductor; 12. Superconductivity in thin slabs; 13. Surface superconductivity; 14. The type II superconductor for H just below Hc2; 15. The Josephson effect; 16. The Josephson lattice in 1D; 17. Vortex structures in layered superconductors; 18. Granular superconductors; the Josephson lattice in 2D and 3D; 19. Wave propagation in Josephson junctions, superlattices and arrays; 20. Flux pinning and flux motion; 21. Time dependent Ginzburg-Landau theory; 22. Fluctuation effects; 23. Ginzburg-Landau theory of an unconventional superfluid; 24. Landau Fermi liquid theory; Part II. The Microscopic Theory of a Uniform Superconductor: 25. The Cooper problem: pairing of two electrons above a filled Fermi sea; 26. The Bardeen-Cooper-Schrieffer theory of the superconducting ground state; 27. Elementary excitations; the Bogoliubov-Valatin transformation; 28. Calculation of the thermodynamic properties using the Bogoliubov-Valatin method; 29. Quasiparticle tunneling; 30. Pair tunneling: the microscopic theory of the Josephson effects; 31. Simplified discussion of pairing mechanisms; 32. The effect of Coulomb repulsion on Tc; 33. The two band superconductor; 34. Time dependent perturbations; 35. Non equilibrium superconductivity; Part III. Non Uniform Superconductors: 36. Bogoliubov's self-consistent potential equations; 37. Self consistency conditions and the free energy; 38. Linearized self consistency and the correlation function; 39. Behaviour of the correlation function in the clean and dirty limits; 40. Self consistency condition; 41. Effects involving electron spin; 42. Boundary conditions; 43. The proximity effect at zero field; 44. Proximity effect in a magnetic field; 45. Derivation of the Ginzburg-Landau theory; 46. Gauge invariance; Diamagnetism in the low field limit; 47. The quasi-classical case; 48. The isolated vortex line; 49. Time dependent Bogoliubov equations; 50. The response of a superconductor to an electromagnetic field; 51. The Bogoliubov equations for an unconventional superfluid; 53. Superfluid 3He; 54. Collective modes in normal and superfluid Fermi systems; 55. Green's functions; Appendix A. The occupation number representation; Appendix B. Some calculations involving the BCS wavefunction; Appendix C. The gap as a perturbation through third order; References; Additional reading; List of mathematical and physical symbols; Index.

Ketterson, J. B.; Song, S. N.

1999-02-01

174

Possibility of a gas-cooled Peltier current lead in the 200 m-class superconducting direct current transmission and distribution system of CASER-2  

NASA Astrophysics Data System (ADS)

Global energy problems should be solved quickly, and superconducting applications are highly demanded as energy saving technologies. Among them, long-distance superconducting transmission seems to be one of the most promising for energy saving by energy sharing. On the other hand, such large systems can be constructed from smaller network systems that can be enhanced by scaling up to the superconducting grid. Reducing heat leak to the low temperature end is the most important aspect of technology for practical superconducting applications, and heat leak reduction at the terminal is a key goal especially for small-length applications. At Chubu University, we have developed a 200 m-class superconducting direct current transmission and distribution system (CASER-2), in which we also used a Peltier current lead (PCL) as heat insulation at the terminal. PCL is composed of a thermoelectric material and a copper lead. In actual transmission and distribution applications, the cables are also cooled by the coolant. After the circulation, the coolant could also be used to cool the current lead. We will discuss the performance of such gas-cooled systems as the total performance of applied superconducting systems using the experimental parameters obtained in CASER-2.

Kawahara, Toshio; Emoto, Masahiko; Watanabe, Hirofumi; Hamabe, Makoto; Yamaguchi, Sataro; Hikichi, Yasuo; Minowa, Masahiro

175

Microgravity Spray Cooling Research for High Powered Laser Applications  

NASA Technical Reports Server (NTRS)

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.

Zivich, Chad P.

2004-01-01

176

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

NASA Astrophysics Data System (ADS)

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.

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

2004-06-01

177

Power Conversion Study for High Temperature Gas-Cooled Reactors  

SciTech Connect

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.

Chang Oh; Richard Moore; Robert Barner

2005-05-01

178

Thermal optimization of the helium-cooled power leads for the SSC.  

National Technical Information Service (NTIS)

The optimum thermal design of the power leads for the Superconducting Super Collider (SSC) will minimize the amount of Carnot work (which is a combination of refrigeration and liquefaction work) required. This optimization can be accomplished by the judic...

J. A. Demko W. E. Schiesser R. Carcagno M. McAshan R. McConeghy

1992-01-01

179

First high power pulsed tests of a dressed 325 MHz superconducting single spoke resonator at Fermilab  

SciTech Connect

In the recently commissioned superconducting RF cavity test facility at Fermilab (SCTF), a 325 MHz, {beta} = 0.22 superconducting single-spoke resonator (SSR1) has been tested for the first time with its input power coupler. Previously, this cavity had been tested CW with a low power, high Q{sub ext} test coupler; first as a bare cavity in the Fermilab Vertical Test Stand and then fully dressed in the SCTF. For the tests described here, the design input coupler with Q{sub ext} {approx} 10{sup 6} was used. Pulsed power was provided by a Toshiba E3740A 2.5 MW klystron.

Madrak, R.; Branlard, J.; Chase, B.; Darve, C.; Joireman, P.; Khabiboulline, T.; Mukherjee, A.; Nicol, T.; Peoples-Evans, E.; Peterson, D.; Pischalnikov, Y.; /Fermilab

2011-03-01

180

Smoothing control of wind power generator output by superconducting magnetic energy storage system  

Microsoft Academic Search

This paper proposes a system composed of a wind turbine generator system (WTGS) and superconducting magnetic energy storage (SMES) unit, in which SMES is controlled for smoothing the wind generator output power. A determination of power capacity of SMES unit which is sufficient for the smoothing control but as small as possible is very important problem. In this paper, an

Tomoki Asao; Rion Takahashi; Toshiaki Murata; Junji Tamura; Masahiro Kubo; Akira Kuwayama; Takatoshi Matsumoto

2007-01-01

181

Dynamic simulation of hybrid wind-diesel power generation system with superconducting magnetic energy storage  

Microsoft Academic Search

In this paper, a systematic method of choosing the gain parameter of the wind turbine generator pitch control is presented, using the Lyapunov technique, that guarantees stability. A comprehensive digital computer model of a hybrid wind-Diesel power generation system, including the Diesel and wind power dynamics with a superconducting magnetic energy storage (SMES) unit, for stability evaluation is developed. The

S. C. Tripathy

1997-01-01

182

Power Supply Optimization for the Superconducting Coil System of HELIAS Fusion Reactor  

Microsoft Academic Search

A. power supply system for feeding the superconducting coils of the Helias reactor, an upgraded system of the WENDELSTEIN-7X device, has been investigated. This multi- converter supply system has been optimized, in view of low losses in the components and only small negative impact to the power grid. The design of the optimized multi-converter supply system was studied by means

O. Gaupp; E. Harmeyer; A. Wieczorek; H. Wobig

2006-01-01

183

Application studies of superconducting fault current limiters in electric power systems  

Microsoft Academic Search

In power systems, superconducting fault current limiters (SFCLs) can limit the prospective short-circuit currents to lower levels, so that the underrated switchgear can be operated safely. This paper presents a detailed theoretical analysis of improving power system stability by using SFCLs. Electromagnetic Transient Program (EMTP) simulation results based on a model system also show that SFCLs are effective for enhancing

Lin Ye; LiangZhen Lin; Klaus-Peter Juengst

2002-01-01

184

THERMAL STRESS CALCULATIONS FOR HEATPIPE-COOLED REACTOR POWER SYSTEMS.  

SciTech Connect

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.

Kapernick, R. J. (Richard J.); Guffee, R. M. (Ray M.)

2001-01-01

185

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)

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.

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

2014-04-01

186

Manufacture of a 6-m superconducting solenoid indirectly cooled by supercritical helium  

Microsoft Academic Search

A design study is presented as performed with the superconducting solenoid for a pulsed muon channel. The main part of the development was the construction and testing of epoxy-impregnated model soils and supercritical helium experiments. The solenoide operates satisfactorily and has been used on a high-flux pulsed muon beam. Continuous operation for 2500 hours has been achieved. This is the

T. Satow; T. Kawaguchi; T. Kawamura; O. Ogino

1982-01-01

187

Kapitza resistance cooling of single crystal (111) niobium for superconducting rf cavities  

Microsoft Academic Search

The use of large grains or single crystal niobium to improve the Q factor of superconducting rf cavities for particle accelerators, is presently under study. Heat extraction which plays a decisive role in the thermomagnetic stability of these devices depends on the thermal conductivity of niobium K and the thermal boundary (Kapitza) resistance RK at the niobium\\/superfluid helium interface. Here

Jay Amrit; Claire Z. Antoine

2010-01-01

188

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

Microsoft Academic Search

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,

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

2010-01-01

189

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

SciTech Connect

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 Houston’s innovation is based on engineering nanoscale defects in the superconducting film. This could quadruple the current relative to today’s 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.

None

2012-01-01

190

Both sides cooled packages for high-power diode laser bars  

Microsoft Academic Search

The packaging of high power diode laser bars requires a high cooling efficiency and long-term stability. Due to the increasing output power of the diode laser bars the cooling performance of the packaging becomes more important. Nowadays micro-channel heat sinks seem to be the most efficient cooling concept with regard to high power applications. The active area of the p-side

M. Leers; T. Westphalen; E. Liermann

2010-01-01

191

Superconducting Transducer.  

National Technical Information Service (NTIS)

The patent application describes a high power density, low frequency superconducting transducer which includes an electro-dynamic drive wherein a superconducting magnet provides the primary driving force for two AC-driven copper coils. Each of the copper ...

M. G. Karamargin

1975-01-01

192

Development of REBCO superconducting power transformers in Japan  

NASA Astrophysics Data System (ADS)

In Japan we started a national project to develop a 66/6.9 kV-20 MVA transformer with REBCO superconducting tapes in 2006. This paper gives an overview of progress of the development of superconducting transformers in Japan and also describes the fundamental technologies studied before now to realize a 66/6.9 kV-20 MVA transformer as follows. To reduce the ac loss in REBCO superconducting thin tapes, authors proposed a new method different from the conventional technique of reducing the ac loss in superconducting multifilamentary wires. It consists of scribing process into a multifilamentary structure by laser or chemical etching, and a special winding process. Making a multilayered solenoidal coil with laser-scribed REBCO tapes, we verified the ac loss reduction in proportion to a filament width even in coil configuration. In addition, to realize a current capacity more than the rated secondary current of 2.4 kA, we first investigated the workability of REBCO tapes in the actual winding process with forming a transposed parallel conductor, where REBCO tapes were bent edgewise at transposing points. Making a test coil of a 24-strand parallel conductor, we verified no degradation of the critical current and nearly uniform current distribution among the tapes. The result suggests the applicability of the method of enhancing the current capacity by forming a parallel conductor with REBCO tapes. Further, to realize the dielectric strength regulated for the Japanese standards, i.e. lightning impulse withstand level of 350 kV and excess ac voltage of 140 kV, we made test coils and carried out dielectric breakdown tests. As a result, we got hold of the required insulation distance at the important points from the viewpoint of insulation design.

Iwakuma, M.; Hayashi, H.; Okamoto, H.; Tomioka, A.; Konno, M.; Saito, T.; Iijima, Y.; Suzuki, Y.; Yoshida, S.; Yamada, Y.; Izumi, T.; Shiohara, Y.

2009-10-01

193

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

NASA Astrophysics Data System (ADS)

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.

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

194

Design of a superconducting alternator for space-based power generation  

SciTech Connect

The superconducting alternator has received considerable international attention over the last decade, with active programs to develop commercial units underway worldwide. Projected gains in efficiency and potential reductions in mass and construction costs have fueled superconducting alternator research. Although current research is focused on developing electric machines to supplant existing conventional alternators, the high power-density of the superconducting alternator makes it an attractive choice for generating electricity in space. This paper presents the results of a study to assess the feasibility of using a superconducting alternator for space power generation, and to develop a preliminary machine design. The preliminary design study examined a low power (20 MW) machine and a higher power (200 MW) machine. The superconducting alternator consists of a rotor with superconducting field windings and a counter rotating armature with normally conducting helical windings. A unique feature of this design is the counter rotation of the alternator armature. This will allow balancing the rotational inertia in the machine so that no torque is applied to the space platform. In addition this will provide a higher relative rotational velocity between the stator and rotor without requiring increased mechanical structure. The principal disadvantage of this design is the requirement for high-power slip rings and additional relative rotation fluid couplings. Three shielding options are considered; unshielded, image shielded, and iron shielded. The unshielded design provides the lightest system but produces a large external magnetic field. The iron shielded design is heaviest but provides the highest conversion efficiency. The image shield has the lowest efficiency and must be placed some distance from the machine but is relatively lightweight. 7 refs., 5 figs., 1 tab.

Dodge, R.E. Jr.; Coomes, E.P.; Kirtley, J.L. Jr.; McCabe, S.J.

1986-04-01

195

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

SciTech Connect

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.

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

1987-06-11

196

High Temperature Superconducting Degaussing-Cooling Two Hts Coils with One Cryocooler for the Littoral Combat Ship  

NASA Astrophysics Data System (ADS)

The concept of creating a high temperature superconducting degaussing system has previously been studied by the Navy and shown to provide significant weight savings over conventional copper based degaussing systems. Modeling efforts have shown that in a HTS Degaussing System (HTSDG) for the Littoral Combat Ship, the dominant costs are cryocoolers. In an effort to minimize the number of cryocoolers, a two coil demonstrator cooled by one cryocooler has been constructed at NSWCCD Philadelphia. The demonstration consists of two 22 m long sections of flexible cryostat that are electrically isolated but connected in series through two junction boxes for serial gas flow. Within each cryostat section, 12 turns of HTS represent a vertical and horizontal degaussing coil. Use of Helium as the working fluid reduces safety impacts and allows higher current density in the HTS conductor due to lower temperature operation. Design, testing results, and lessons learned from the installation and operation of this cable are presented in this paper.

Fitzpatrick, B. K.; Golda, E. M.; Kephart, J. T.

2008-03-01

197

Hydraulic behavior of forced-flow cooled superconducting coils for the large helical device  

Microsoft Academic Search

The large helical device (LHD) has been operated since 1998 and the 13th experimental campaign was conducted in 2009. Before final assembling, cool-down and excitation tests for the Inner Vertical (IV) field coil, which is one of the LHD poloidal field coils, were carried out in 1995. This coil, which consists of a cable-in-conduit conductor, (CICC) is cooled by the

Soo-Hwan Park; Kazuya Takahata

2011-01-01

198

EXPERIMENTAL BASED METHOD FOR SIZING PHOTOVOLTAIC POWER SYSTEM SUITABLE FOR COOLING GREENHOUSES  

Microsoft Academic Search

This paper presents new method for designing photovoltaic power system (PVPS) suitable for cooling the greenhouses. The designed PVPS is installed at Serw station at Domietta for cooling cucumber crop. The greenhouse, under test has the geometrical configuration of, 6m length, 4m width and 2m height. The indoor temperature of the greenhouse is 50°c before cooling. This level of temperature

H. M. NOOR

199

Air-cycle cooling of electric power cables: Phase I. Final report  

Microsoft Academic Search

A study was conducted to determine the feasibility of using an air cycle system for cooling underground electrical power transmission cables. The air cycle system features an expansion turbine where ambient air is expanded to subatmospheric pressure; this air is circulated in a plate fin heat exchanger and cools the cable dielectric oil. The cooling capacity of the low pressure

Limberg

1981-01-01

200

USE of mine pool water for power plant cooling.  

SciTech Connect

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.

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

2006-11-27

201

Gas-cooled reactor for space power systems  

SciTech Connect

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.

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

1987-05-01

202

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

SciTech Connect

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.

Wolsky, A.M.

1998-05-01

203

Pathogenic amoebae in power-plant cooling lakes. Final report  

SciTech Connect

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.

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

1981-06-01

204

Thermomechanical properties of a 66 kV superconducting power cable system  

Microsoft Academic Search

To verify the practicability for intended application, TEPCO and SEI have jointly developed a 100 m, 66 kV class High Temperature superconducting power cable system and tested for a long duration one year at the CRIEPI test site. The cable has three cores in a cryostat and a cold dielectric configuration. The three cores are stranded loosely to manage thermal

Michihiko Watanabe; Takato Masuda; Yuichi Ashibe; Masayuki Hirose; Shigeki Isojima; Shoichi Honjo; Toshiyuki Uchiyama; Masato Shimodate; Yoshihisa Takahashi; Hiroshi Suzuki

2003-01-01

205

First High Temperature Superconducting ECRIS  

Microsoft Academic Search

The first High Temperature Superconducting Electron Cyclotron Resonance Ion Source (HTS-ECRIS) called PKDELIS has been developed as a collaborative project. The source has been designed for suitable use on a high voltage platform with minimum requirements of electrical power and water cooling. The design is based on the required A\\/q of ~ 7 for the High Current Injector (HCI) of

D. Kanjilal; G. O. Rodrigues; P. Kumar; C. P. Safvan; U. K. Rao; A. Mandal; A. Roy; C. Bieth; S. Kantas; P. Sortais

2005-01-01

206

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

NASA Technical Reports Server (NTRS)

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.

Bartlett, J. C.

1977-01-01

207

Analyzing the alternative shutdown cooling behaviors for Chinshan Nuclear Power Plant using CFD simulation  

Microsoft Academic Search

The Chinshan Nuclear Power Plant (CSNPP) is a GE-designed BWR4 plant, having two identical units with rated core thermal power of 1804MWt each unit. Several alternative shutdown cooling methods driven by natural or mixed convection has been proposed by the plant for studying the core cooling capability when the Residual Heat Removal (RHR) systems are not available or the refueling

Yung-Shin Tseng; Chih-Hung Lin; Yng-Ruey Yuann; Jong-Rong Wang; F. Peter Tsai

2011-01-01

208

A new combined cooling, heating and power system driven by solar energy  

Microsoft Academic Search

A new combined cooling, heating and power (CCHP) system is proposed. This system is driven by solar energy, which is different from the current CCHP systems with gas turbine or engine as prime movers. This system combines a Rankine cycle and an ejector refrigeration cycle, which could produce cooling output, heating output and power output simultaneously. The effects of hour

Jiangfeng Wang; Yiping Dai; Lin Gao; Shaolin Ma

2009-01-01

209

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

Microsoft Academic Search

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

John W

1977-01-01

210

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

Microsoft Academic Search

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 are 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

1977-01-01

211

Fabrication of a diffusion cooled superconducting hot electron bolometer for THz mixing applications  

Microsoft Academic Search

Recent interest in bolometers for heterodyne mixing applications has prompted development of microbridges which are small enough to allow electron diffusion to dominate over electron-phonon interaction as a cooling mechanism. Prior results at 533 GHz have demonstrated several GHz intermediate frequency (IF) bandwidth. Here we describe our processing method in which the bolometer element is a 10 nm thin film

Bruce Bumble; Henry G. LeDuc

1997-01-01

212

Safety and Stability of Superconducting Magnets for Fusion Using Internally Cooled Conductors.  

National Technical Information Service (NTIS)

Vincent Arp's computer code for the stability analysis of internally cooled conductors (ICC) has been combined with ANL's TASS code to create the code SSICC for the analysis of the safety and stability of ICC. The code has been tested against the ICC expe...

L. R. Turner R. D. Ryne

1982-01-01

213

At the Frontiers of Science Superconductivity and Its Electric Power Applications  

SciTech Connect

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.

None

1998-07-01

214

Remote Measurement of Heat Flux from Power Plant Cooling Lakes  

SciTech Connect

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 ? 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 ?. 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 ? 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 ? and q? of 0.45 and 0.76, respectively. Values of q? computed from a function of ? 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.

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

2013-01-01

215

Mechanical Analysis of High Power Internally Cooled Annular Fuel  

SciTech Connect

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.

Zhao Jiyun; No, Hee Cheon; Kazimi, Mujid S. [Center for Advanced Nuclear Energy Systems (United States)

2004-05-15

216

Exergy analysis of solar Rankine power cycles used for cooling  

SciTech Connect

Second-law (exergy) analysis was performed on two types of solar-cooling systems which are based on a vapor-compression cycle driven by a Rankine cycle: those energized by the sun at one temperature and using organic fluids in the power cycle, and a hybrid cycle which is energized by a solar source at a low temperature and by a fossil source at a higher temperature and using steam as the fluid. Some of the major conclusions are: (1) A better thermodynamic match is obtained between the energy sources and sinks in the hybrid cycle, which results in a doubling of the cycle's efficiency as compared to the single-temperature organic-fluid cycle. Nevertheless, there still exists a large difference between the temperatures of combustion (approx. 1500/sup 0/C) and superheated steam (approx. 600/sup 0/C), and thus the superheater's effectiveness is relatively low. This points to several methods of improvement, including improved heat-transfer design, and utilization of the stack gases. (2) Applying superheat by solar concentrators instead of combustion improves cycle effectiveness by about 40%, and (3) the heat exchangers to recover heat from the steam after it has been exhausted from the turbine have an important influence on energy and exergy recovery but need to be carefully optimized.

Lior, N.: Subbiah, S.; Brady, W.J. III

1983-01-01

217

Simulation of cooling-water discharges from power plants.  

PubMed

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

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

2001-01-01

218

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

ScienceCinema

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.

219

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

SciTech Connect

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.

Li, Qiang (BNL Condensed Matter Physics and Materials Science Department) [BNL Condensed Matter Physics and Materials Science Department

2011-01-19

220

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

SciTech Connect

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.

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

221

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

222

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

SciTech Connect

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.

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

2012-07-01

223

Simplified models for solar-powered absorption cooling systems  

Microsoft Academic Search

Ideal three-heat-reservoir cycles with constant internal irreversibilities and external heat transfer irrevesibilities are used to obtain the performance limits of solar operated absorption cooling systems. Analytical expressions are obtained for the coefficient of performance (COP) and the cooling capacity of the plant. The results for ideal cycles are compared with those obtained by detailed simulation of the absorption machine. The

N. E. Wijeysundera

1999-01-01

224

A study on insulation characteristics according to cooling methods of the HTS SMES  

NASA Astrophysics Data System (ADS)

The high temperature superconducting magnetic energy storage (HTS SMES) stores electric power in the form of magnetic energy, and then converts it to electric energy. For the operation, the HTS SMES must have a cryogenic temperature. The cooling methods for a cryogenic temperature are divided into an immersed method and a conduction cooled method. The immersed method is a direct cooling method that immerses the superconducting magnet into a cryogen. On the other hand, the conduction cooled method is an indirect cooling method that cools a superconductor through thermal conduction with a cryocooler. This paper classified the structures of insulation according to cooling methods, and studied the insulation characteristics of each insulation factor.

Choi, J. H.; Cheon, H. G.; Choi, J. W.; Kim, H. J.; Seong, K. C.; Kim, S. H.

2010-11-01

225

The impact of high temperature superconductivity on the electric power sector  

SciTech Connect

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.

Wolsky, A.M.

1996-01-01

226

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

SciTech Connect

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.

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

1982-10-01

227

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

228

Design and cost estimate of an 800 MVA superconducting power transmission  

SciTech Connect

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.

Alex, P.; Ernst, A. (Underground Systems, Inc., Armonk, NY (USA)); Forsyth, E.; Gibbs, R.; Thomas, R.; Muller, T. (Brookhaven National Lab., Upton, NY (USA))

1990-10-18

229

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

230

Engineering development of superconducting RF linac for high-power applications  

SciTech Connect

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.

Dominic Chan, K.C.; Rusnak, B.; Gentzlinger, R.C.; Campbell, B.M.; Kelley, J.P. [Los Alamos National Lab., NM (United States); Safa, H. [CEA Saclay (France)

1998-12-31

231

Kapitza resistance cooling of single crystal (111) niobium for superconducting rf cavities  

NASA Astrophysics Data System (ADS)

The use of large grains or single crystal niobium to improve the Q factor of superconducting rf cavities for particle accelerators, is presently under study. Heat extraction which plays a decisive role in the thermomagnetic stability of these devices depends on the thermal conductivity of niobium K and the thermal boundary (Kapitza) resistance RK at the niobium/superfluid helium interface. Here we present the first measurements of RK performed between 1.5-2.1 K with single crystal (111) niobium, having two different surface morphologies, namely, a surface with a damage layer and a chemically polished surface. The thermal conductivity of the single crystal Nb samples is also simultaneously determined. For monocrystalline niobium we demonstrate that RK is an increasing primary limiting factor with temperature, contrary to the behavior found for polycrystalline cavities. The present investigation reveals for the first time that the presence of impurities (metallic particles and oxygen) within the damage layer leads to a stronger RK, although the effective heat exchange area to the superfluid is increased. We further show the importance of dislocations in the thermal conductivity of monocrystalline niobium.

Amrit, Jay; Antoine, Claire Z.

2010-02-01

232

Supercritical-pressure, light-water-cooled reactors for economical nuclear power plants  

Microsoft Academic Search

Design studies of supercritical-pressure light-water-cooled reactors (SCLWRs) have been carried out to pursue drastic improvement of the economy of nuclear power generation. The core is cooled by supercritical water which is superheated without the phase change. The cooling system is a once-through type; the whole core flow is driven by the feedwater pumps and is directly led to the turbine.

S. Koshizuka; Y. Oka

1998-01-01

233

Dry and wet-peaking tower cooling systems for power plant application  

Microsoft Academic Search

A new concept of power plant heat-sink system is presented which employs the combination of a conventional wet-tower and a conventional dry-tower. The purpose of this cooling system is to reduce wet cooling-tower makeup-water requirements in water-short areas. The dry tower operates all year around while the wet-peaking tower is used only above certain ambient dry-bulb temperatures. The two cooling

M. W. Larinoff; L. L. Forster

1976-01-01

234

Dry and wet-peaking tower cooling systems for power plant application  

Microsoft Academic Search

A new concept of power plant heat-sink system is presented which employs the combination of a conventional wet-tower and a conventional dry-tower. The purpose of this cooling system is to reduce wet cooling-tower makeup-water requirements in water-short areas. The dry tower operates all year around while the wet-peaking tower is used only above certain ambient dry-bulb temperatures. The two cooling

M. W. Larinoff; L. L. Forster

1977-01-01

235

Environmental and economic comparison of cooling-system designs for steam-electric power plants  

Microsoft Academic Search

The selection of waste heat rejection systems for steam-electric power plants involves a trade-off among environmental, energy and water conservation, and economic factors. This study compares four general types of cooling systems on the basis of these factors. The cooling systems chosen for study are: once-through systems including surface canals and submerged multiport diffusers; shallow closed cycle cooling ponds; mechanical

K. F. Najjar; J. J. Shaw; E. E. Adams; G. H. Jirka; D. R. F. Harleman

1979-01-01

236

Self-cooling on power MOSFET using n-type Si wafer  

NASA Astrophysics Data System (ADS)

The self-cooling device was developed by combining the commercial n-channel power MOSFET and the copper plating single-crystalline Sb doped n-type silicon wafer in order to improve heat removal or cooling for power devices. The time dependence of the temperature distribution of the self-cooling device was measured to estimate the heat flux both by the thermal conduction and by the Peltier effect. We found that the average temperature of the upper side of the power MOSFET was cooled down about 0.7°C by the addition of the copper plating n-type Si wafer after 40 minutes despite enlargement of the temperature distribution range. This fact strongly indicates that the copper plating ntype Si wafer is one of the candidate materials for use in self-cooling devices.

Nakatsugawa, H.; Sato, T.; Okamoto, Y.; Kawahara, T.; Yamaguchi, S.

2012-06-01

237

Development of a Niobium-copper-invar composite conductor for an AC superconducting power transmission cable  

Microsoft Academic Search

A superconducting ac power cable has been developed using Nb\\/Cu\\/Invar composite conductors and shields in a coaxial configuration with pressurized. He at 4.7 K as the primary dielectric. Two major concerns for this cable system were the accommodation of fault currents and the differential thermal expansion between the conductor assembly and the cryogenic envelope. We have shown that a Nb\\/Cu\\/Invar

1975-01-01

238

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

DOEpatents

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.

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

1984-01-01

239

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

DOEpatents

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.

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

1982-07-29

240

Robust damping controller design in power systems with superconducting magnetic energy storage devices  

Microsoft Academic Search

The decentralized design of low-order robust damping controllers is presented based on a weighted and normalized eigenvalue-distance minimization method (WNEDM) employing several superconducting magnetic energy storage (SMES) devices. These controllers are aimed at enhancing the damping of multiple inter-area modes in a large power system. This paper describes a comprehensive and systematic way of designing these controllers. Nonlinear simulations further

Bikash C. Pal; Alun H. Coonick; D. C. Macdonald

2000-01-01

241

10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors  

Code of Federal Regulations, 2012 CFR

...Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors J Appendix...Reactor Containment Leakage Testing for Water-Cooled Power Reactors This appendix...licenses under part 52 of this chapter for water-cooled power reactors as...

2014-01-01

242

Calorimeters for precision power dissipation measurements on controlled-temperature superconducting radiofrequency samples.  

PubMed

Two calorimeters, with stainless steel and Cu as the thermal path material for high precision and high power versions, respectively, have been designed and commissioned for the 7.5 GHz surface impedance characterization system at Jefferson Lab to provide low temperature control and measurement for CW power up to 22 W on a 5 cm diameter disk sample which is thermally isolated from the radiofrequency (RF) portion of the system. A power compensation method has been developed to measure the RF induced power on the sample. Simulation and experimental results show that with these two calorimeters, the whole thermal range of interest for superconducting radiofrequency materials has been covered. The power measurement error in the interested power range is within 1.2% and 2.7% for the high precision and high power versions, respectively. Temperature distributions on the sample surface for both versions have been simulated and the accuracy of sample temperature measurements have been analyzed. Both versions have the ability to accept bulk superconductors and thin film superconducting samples with a variety of substrate materials such as Al, Al(2)O(3), Cu, MgO, Nb, and Si. PMID:23278016

Xiao, B P; Reece, C E; Phillips, H L; Kelley, M J

2012-12-01

243

Calorimeters for Precision Power Dissipation Measurements on Controlled-Temperature Superconducting Radiofrequency Samples  

SciTech Connect

Two calorimeters, with stainless steel and Cu as the thermal path material for high precision and high power versions, respectively, have been designed and commissioned for the surface impedance characterization (SIC) system at Jefferson Lab to provide low temperature control and measurement for CW power up to 22 W on a 5 cm dia. disk sample which is thermally isolated from the RF portion of the system. A power compensation method has been developed to measure the RF induced power on the sample. Simulation and experimental results show that with these two calorimeters, the whole thermal range of interest for superconducting radiofrequency (SRF) materials has been covered. The power measurement error in the interested power range is within 1.2% and 2.7% for the high precision and high power versions, respectively. Temperature distributions on the sample surface for both versions have been simulated and the accuracy of sample temperature measurements have been analysed. Both versions have the ability to accept bulk superconductors and thin film superconducting samples with a variety of substrate materials such as Al, Al{sub 2}O{sub 3}, Cu, MgO, Nb and Si.

Xiao, Binping P.; Kelley, Michael J.; Reece, Charles E.; Phillips, H. L.

2012-12-01

244

Development of 275kV gas cooled type gas-insulated power transformer  

Microsoft Academic Search

A world's first 275kV gas cooled type gas insulated power transformer with a low sound level ideal for urban area, which depends on SF6 gas alone for both insulation and cooling, was developed and has been put into commercial service since 1990 in Hong Kong. This paper presents the design philosophy, the principal technical items, the rating and the feature

A. Kudo; T. Nishitani; T. Yoshikawa; C. T. Wan

1993-01-01

245

Wind Tunnel Experimental Study on Effect of Nuclear Power Plant Cooling Tower on Radioactive Plume Dispersion  

Microsoft Academic Search

A wind tunnel experiment for the effect of the cooling tower in an inland nuclear power plant on flow and dispersion of radioactive plume was introduced in paper. The model scale is 1:1500. Measurements of mean flow, turbulence characteristics and wake structure with different orientations of cooling tower and other buildings were made by using an X-array hot wire probe.

Qingdang Qiao; Zhanjie Guo; Runying Wang; Rentai Yao; Dongpeng Guo; Dan Fan; Xiaofen Hou

2011-01-01

246

Radionuclides in the Natural–Anthropogenic System Comprising a Nuclear Power Plant and a Cooling Reservoir  

Microsoft Academic Search

The sources of technological radionuclides coming into the ecosystem of a nuclear power plant (NPP) cooling reservoir are considered and estimated. The information about the volumetric and mass activity in the biotic and abiotic components of the reservoir ecosystem is analyzed. The activity distribution between the components was determined. The activity reserve in the ecosystems of the cooling reservoirs in

Yu. A. Egorov

2002-01-01

247

Reduced order modeling of power electronics cabinet with double-sided cooling  

Microsoft Academic Search

Thermal control of power electronics cabinets requires thermal characterization under multiple length scales and transport modes. Detailed numerical calculations or measurements are often time consuming or simply unfeasible. An efficient multiscale thermal modeling methodology is proposed for electronic cabinets with hybrid liquid, forced air convection, and thermoelectric cooling. Compact models are developed for complex components such as air-cooled heat sinks,

Qihong Nie; Yogendra Joshi

2008-01-01

248

INFLUENCE OF THE COOLING SYSTEM ON THE POWER LIMITS OF PRESSURIZED-LIQUID REACTORS  

Microsoft Academic Search

The technical limits for the optimum design of a reactor are defined in ; diagrams by the maximum heat velocity of the fuel elements and by the indices of ; the cooling system (degree of cooling efficiency, reboil margin, and reactor ; index). The so-called marginal capacity'' of a reactor is determined by the ; power limits of a reactor

Mareske

1963-01-01

249

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...

250

Solar-powered/fuel-assisted Rankine cycle power and cooling system - Sensitivity analysis  

NASA Astrophysics Data System (ADS)

The subject of this analysis is a solar power/cooling system based on a novel hybrid steam Rankine cycle. Steam is generated by the use of solar energy collected at about 100 C, and it is then superheated to about 600 C in a fossil-fuel-fired superheater. The addition of about 20-26 percent of energy as fuel doubles the power cycle's efficiency as compared to organic fluid Rankine cycles operating at similar collector temperatures. A sensitivity analysis of the system's performance to the size and type of its components was performed by a transient (hourly) computer simulation over the month of August in two representative climatic regions (Washington, D.C. and Phoenix, Ariz.), and led to the description of a system configuration which provides optimal energy performance. The newly designed turbine's predicted efficiency is seen to be essentially invariant with system configuration, and has a monthly average value of about 73 percent.

Lior, N.; Koai, K.

1984-11-01

251

High power cable with internal water cooling 400 kV  

Microsoft Academic Search

Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal

W. Rasquin; B. Harjes

1982-01-01

252

Municipal Waste Water as a Source of Cooling Water for California Electric Power Plants.  

National Technical Information Service (NTIS)

This report discusses sources of municipal waste water for potential use as cooling water in California power plants. It notes the major factors which affect this practice. Municipal treatment facilities in California with discharge volumes deemed adequat...

T. MacDonald

1980-01-01

253

Space power reactor ground test in the Experimental Gas Cooled Reactor (EGCR) at Oak Ridge.  

National Technical Information Service (NTIS)

The Experimental Gas Cooled Reactor (EGCR) facility and the supporting technical infrastructure at the Oak Ridge National Laboratory have the capabilities of performing ground tests of space nuclear power reactor systems. A candidate test would be a 10 MW...

M. H. Fontana R. S. Holcomb R. H. Cooper

1992-01-01

254

Solar Thermal Power Generation, 1978; Solar Thermal Heating and Cooling, 1978; Solar Thermal Components, 1978.  

National Technical Information Service (NTIS)

This bibliographic series cites and abstracts the literature and technical papers on electrical power generation primarily through solar thermal processes, the heating and cooling of buildings with solar thermal energy, and components applied to solar the...

1978-01-01

255

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

SciTech Connect

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.

Energetics, Inc.

2000-01-01

256

Studies on advanced water-cooled reactors beyond generation III for power generation  

Microsoft Academic Search

China’s ambitious nuclear power program motivates the country’s nuclear community to develop advanced reactor concepts beyond\\u000a generation III to ensure a long-term, stable, and sustainable development of nuclear power. The paper discusses some main\\u000a criteria for the selection of future water-cooled reactors by considering the specific Chinese situation. Based on the suggested\\u000a selection criteria, two new types of water-cooled reactors

Xu Cheng

2007-01-01

257

Analysis of power and cooling cogeneration using ammonia-water mixture  

Microsoft Academic Search

Development of innovative thermodynamic cycles is important for the efficient utilization of low-temperature heat sources such as solar, geothermal and waste heat sources. This paper presents a parametric analysis of a combined power\\/cooling cycle, which combines the Rankine and absorption refrigeration cycles, uses ammonia-water mixture as the working fluid and produces power and cooling simultaneously. This cycle, also known as

Ricardo Vasquez Padilla; Gökmen Demirkaya; D. Yogi Goswami; Elias Stefanakos; Muhammad M. Rahman

2010-01-01

258

Formation of secondary inorganic aerosols by power plant emissions exhausted through cooling towers in Saxony  

Microsoft Academic Search

Background, aim, and scope  The fraction of ambient PM10 that is due to the formation of secondary inorganic particulate sulfate and nitrate from the emissions of two large, brown-coal-fired\\u000a power stations in Saxony (East Germany) is examined. The power stations are equipped with natural-draft cooling towers. The\\u000a flue gases are directly piped into the cooling towers, thereby receiving an additionally intensified

Detlef Hinneburg; Eberhard Renner; Ralf Wolke

2009-01-01

259

Analysis of distributed cooled high power millimeter wave windows  

SciTech Connect

The sectional high-frequency (100--170 GHz) distributed cooled window has been investigated both electromagnetically and thermally previously using computational electromagnetics (EM) and thermal codes. Recent data describes the relationship to some experimental data for the window. Results are presented for time domain CW EM analyses and CW thermal and stress calculations.

Nelson, S.D.; Caplan, M.; Reitter, T.A.

1995-09-09

260

Investigation of power losses in the 300kw superconductive generator. Final report, January-June 1991  

SciTech Connect

Previous measurements of the current collector power losses in the 3OOkW superconductive generator have shown the losses to be much higher than predicted by theory. The purposes of these experiments was to isolate the source and magnitude of the power losses with more accurate experimental methods and data collection techniques. The losses could then be theoretically extrapolated to predict losses in a full scale machine for ship propulsion. The results showed that the excessive losses were fluid losses due to overfilling of the current collectors with liquid metal, and eddy current losses in the rotor bearings due to the rotation of the electrically conducting balls in the magnetic field.

Maribo, D.W.; Gavrilash, M.M.; Whitestone, R.C.; Sondergaard, N.A.

1992-01-01

261

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

NASA Astrophysics Data System (ADS)

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 (B1) 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 107 spins or 3×104spins/?Hz with averaging.

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

2014-06-01

262

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

NASA Astrophysics Data System (ADS)

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.

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

263

A Unique Approach to Power Electronics and Motor Cooling in a Hybrid Electric Vehicle Environment  

SciTech Connect

An innovative system for cooling the power electronics of hybrid electric vehicles is presented. This system uses a typical automotive refrigerant R-134a (1,1,1,2 tetrafluoroethane) as the cooling fluid in a system that can be used as either part of the existing vehicle passenger air conditioning system or separately and independently of the existing air conditioner. Because of the design characteristics, the cooling coefficient of performance is on the order of 40. Because liquid refrigerant is used to cool the electronics directly, high heat fluxes can result while maintaining an electronics junction temperature at an acceptable value. In addition, an inverter housing that occupies only half the volume of a conventional inverter has been designed to take advantage of this cooling system. Planned improvements should result in further volume reductions while maintaining a high power level.

Ayers, Curtis William [ORNL; Hsu, John S [ORNL; Lowe, Kirk T [ORNL; Conklin, Jim [ORNL

2007-01-01

264

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

PubMed

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

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

2011-05-15

265

Cost analysis of power plant cooling using aquifer thermal energy storage  

SciTech Connect

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.

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

1989-05-01

266

Flux-transfer losses in helically wound superconducting power cables  

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

267

Flux-transfer losses in helically wound superconducting power cables  

SciTech Connect

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.

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

2013-06-25

268

Modeling, Control, and Monitoring of $\\\\hbox{S}^{3} \\\\hbox{RS}$Based Hydrogen Cooling System in Thermal Power Plant  

Microsoft Academic Search

The faster heat dissipation of generators in power plants calls for hydrogen cooling, and water is used as coolant to cool down the hot hydrogen which comes out from the hy- drogen cooling system (HCS) at the generating end. There- fore, in large generating plants, the process of cooling and the coolant become integral parts of the heat exchangers. Hence,

Gyan Ranjan Biswal; R. P. Maheshwari; M. L. Dewal

2012-01-01

269

First High power test results for 2.1 GHz superconducting photonic band gap accelerator cavities.  

PubMed

We report the results of the recent high power testing of superconducting radio frequency photonic band gap (PBG) accelerator cells. Tests of the two single-cell 2.1 GHz cavities were performed at both 4 and 2 K. An accelerating gradient of 15 MV/m and an unloaded quality factor Q(0) of 4×10(9) were achieved. It has been long realized that PBG structures have great potential in reducing long-range wakefields in accelerators. A PBG structure confines the fundamental TM(01)-like accelerating mode, but does not support higher order modes. Employing PBG cavities to filter out higher order modes in superconducting particle accelerators will allow suppression of dangerous beam instabilities caused by wakefields and thus operation at higher frequencies and significantly higher beam luminosities. This may lead towards a completely new generation of colliders for high energy physics and energy recovery linacs for the free-electron lasers. PMID:23215084

Simakov, Evgenya I; Haynes, W Brian; Madrid, Michael A; Romero, Frank P; Tajima, Tsuyoshi; Tuzel, Walter M; Boulware, Chase H; Grimm, Terry L

2012-10-19

270

Comparison of Hybrid Electric Vehicle Power Electronics Cooling Options  

SciTech Connect

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.

O'Keefe, M.; Bennion, K.

2008-01-01

271

Energy and peak power saved by passively cooled residences  

NASA Astrophysics Data System (ADS)

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.

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

1983-11-01

272

Utilization of municipal wastewater for cooling in thermoelectric power plants  

SciTech Connect

A process simulation model has been developed using Aspen Plus(R) 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, NH{sub 3} and CO{sub 2} 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 NH{sub 3} mass transfer coefficient on cooling loop pH appear to be more significant at lower values (e.g., k{sub NH3}< 4×10{sup -3} m/s) when the makeup water alkalinity is low (e.g., <90 mg/L as CaCO{sub 3}). The effect of the CO{sub 2} mass transfer coefficient was found to be significant only at lower alkalinity values (e.g., k{sub CO2}<4×10{{sup -6} m/s).

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

2013-09-01

273

Monolayer graphene dispersion and radiative cooling for high power LED.  

PubMed

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. PMID:24008305

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

2013-10-01

274

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

NASA Astrophysics Data System (ADS)

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.

Farahani, Mohsen; Ganjefar, Soheil

2013-04-01

275

Long-Term Reliability of Railway Power Inverters Cooled by Heat-Pipe-Based Systems  

Microsoft Academic Search

This paper analyzes the impact of a nonuniform temperature distribution inside insulated-gate bipolar transis- tor (IGBT) power modules on the reliability of railway power inverters. The interaction between the chosen cooling system (a heat-pipe-based one) and the power module is considered in detail. After showing the experimental setup and thermal condi- tions, thermal mapping inside the power module is carried

Xavier Perpina; Xavier Jorda; Miquel Vellvehi; Jose Rebollo; Michel Mermet-Guyennet

2011-01-01

276

The natural draught, indirect dry cooling system for the 6 times 686 MWe Kendal Power Station, RSA  

Microsoft Academic Search

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,

B. Trage; A. J. Ham; T. C. Vicary

1990-01-01

277

Calculation and visual displaying of the water chemistry conditions in return cooling systems at thermal power stations  

NASA Astrophysics Data System (ADS)

Matters concerned with treatment of cooling water at thermal power stations are addressed. Problems arising during operation of return cooling systems equipped with cooling towers are analyzed. The software used for monitoring, control, and indication of the hydraulic and water chemistry operating conditions of the circulation system at the Yaivinsk district power station is considered.

Ochkov, V. F.; Orlov, K. A.; Ivanov, E. N.; Makushin, A. A.

2013-07-01

278

Site and design temperature related economics of nuclear power plants with evaporative and non-evaporative cooling tower systems  

Microsoft Academic Search

A comprehensive cost and evaluation study is presented which has been ; conducted for nuclear power plants using cooling systems which employ either ; evaporative or non-evaporative cooling tower types. The primary purpose of the ; study is to develop the economics for two 1000 MW(e) light water reactor power ; plants, one built on a site requiring non-evaporative cooling,

Sebald

1976-01-01

279

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

SciTech Connect

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 l

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

280

The Application of Active Superconducting DC Fault Current Limiter in Hybrid AC\\/DC Power Supply Systems  

Microsoft Academic Search

This paper presents a new topology of the active superconducting DC fault current limiter (DC-SFCL) applied in the hybrid AC\\/DC power supply systems. The proposed DC-SFCL is composed of superconducting transformer, DC chopper and voltage source converter (VSC). The primary winding of the transformer is connected in series with DC transmission line, and the second winding is connected with AC

Jing Shi; Yuejin Tang; Lei Chen; Jin Wang; Li Ren; Jingdong Li; Liang Li; Tao Peng; Shijie Cheng

2008-01-01

281

Superconducting fault-current limiter and inductor design  

SciTech Connect

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.

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

1982-01-01

282

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

SciTech Connect

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.

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

1999-04-01

283

Simulation aided design of a two-phase thermosyphon for power electronics cooling  

Microsoft Academic Search

In this paper we present a novel system for power electronics cooling consisting of a thermosyphon loop composed of an evaporator, to which the power modules are attached, and of a condenser, formed by a set of vertically mounted aluminum panels. To facilitate the optimization of the design of the condenser, which is critical for the whole system performance, we

Francesco Agostini; Thomas Gradinger; Carlo de Falco

2011-01-01

284

Integrated three-dimensional module heat exchanger for power electronics cooling  

DOEpatents

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.

Bennion, Kevin; Lustbader, Jason

2013-09-24

285

Thermoelectric power generator design and selection from TE cooling module specifications  

Microsoft Academic Search

There are many applications where thermoelectric (TE) coolers can be used effectively as power generators. In fact, where temperatures are less than 500 K, TE cooling modules are the best choice for power generation, whether it be from a cost or performance standpoint. The literature available on this subject is scarce and very limited in scope. This paper describes the

Richard J. Buist; Paul G. Lau

1997-01-01

286

Design and performance of secondary cooling systems for the XMA-1 power plant for subsonic applications  

Microsoft Academic Search

In this report, the best designs of secondary cooling systems are evolved, one for each of three modes of power plant operation, for the subsonic application of the XMA-1 power plant. The performance of these systems was evaluated and the operation of the variable geometry features and control system requirements are described.

J. A. Peterson; D. M. Page

1958-01-01

287

Legionnaires' Disease Bacterium in power-plant cooling systems: Phase 1. Final report  

Microsoft Academic Search

A survey was undertaken of the distribution, density, viability, and infectivity of Legionnaires' Disease Bacteria (Legionella) in power plant cooling systems. Water samples were collected during each of the four seasons at various locations within each of nine power plants and from ambient waters at each site. Measurements of a number of physical and chemical characteristics were made, and Legionella

S. W. Christensen; J. A. Solomon; S. B. Gough; R. L. Tyndall; C. B. Fliermans

1983-01-01

288

Performance optimization of dry-cooling systems for power plants through SQP methods  

Microsoft Academic Search

In this study the application of modern optimization techniques to obtain cost optimal design and performance of dry-cooling systems for power plant applications, is illustrated. The Sequential Quadratic Programming (SQP) method, as well as a SQP decomposition technique are implemented. It is shown that through the proper application of these powerful optimization strategies and careful tailoring of the well-constructed optimization

A. E. Conradie; J. D. Buys; D. G. Kröger

1998-01-01

289

Second law analysis of solar powered absorption cooling cycles and systems  

Microsoft Academic Search

The Second Law of Thermodynamics is used to analyze solar powered absorption cooling cycles and systems. Irreversibility is used as a figure of merit for components and cycles. The irreversibility of individual components is determined for several solar-powered absorption cycles and systems. The understanding of the causes of these irreversibilities identifies the areas of possible cycle and system improvements.

D. K. Anand; W. J. Kennish; K. W. Lindler; S. Schweitzer

1984-01-01

290

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

Federal Register 2010, 2011, 2012, 2013

...Regulatory Research, U.S. Nuclear Regulatory Commission...for light water cooled nuclear power plants. This...revised to address design qualification tests for new design...and Approvals for Nuclear Power Plants.'' This...for preoperational, fuel loading, initial...

2013-06-12

291

Joint operation of the superconducting fault current limiter and magnetic energy storage system in an electric power network  

NASA Astrophysics Data System (ADS)

An opportunity of using superconductors as active elements of electric power systems designed to control the electric power distribution, to enhance the systems operating modes and to limit fault currents, was very attractive for investigators for a long time. In this paper, is considered an opportunity to enhance the electric power systems with the aid of superconducting magnetic energy storage systems (SMES) and superconducting fault current limiters (SFCL) operating together. It has been shown that the joint operation of both these superconducting devices allows additional varying of their parameters, what in turn gives a further opportunity to reduce their mass and dimensions and consequently the costs. There had been also shown an additional advantage of the SMES and SFCL joint operation consisting in that they ensure a more effective protection for a power system, preventing its uncontrolled load-off and subsequent acceleration up to the inaccessible rotation speed.

Kopylov, S. I.; Balashov, N. N.; Ivanov, S. S.; Veselovsky, A. S.; Zhemerikin, V. D.

2010-06-01

292

Over-current characteristics of model coil using Y-based multi-filament wire for superconducting power transformers  

NASA Astrophysics Data System (ADS)

In the Japanese national project to develop superconducting power applications using Y-based coated conductors, the present focus is on various aspects of technological development of superconducting power transformers. Since Y-based multi-filament wire contributes to reduction in AC loss of superconducting transformer coils, a 5 mm-wide long-length multi-filament, between the filaments of 3 and 5, has been developing by a laser scribing method. In the case of the project target, a 66 kV/20 MVA power transformer coils require a Y-based multi-filament wire between the lengths of 200 m and 300 m. It also must withstand over-current of about seven times the rated current, which is generated when a power system fault occurs. In this paper, over-current characteristics of model coil using Y-based 3-filament wire were evaluated.

Okamoto, H.; Hayashi, H.; Iwakuma, M.; Tomioka, A.; Saito, T.; Gosho, Y.; Tanabe, K.; Shiohara, Y.

2011-11-01

293

TLS-like temperature and power dependence for loss in superconducting coplanar resonators  

NASA Astrophysics Data System (ADS)

Loss in 2D superconducting coplanar resonators and qubits is often limited by two-level systems thought to be on the metal and substrate surfaces. While these TLSs are thought to be similar to those found in amorphous dielectrics, their nature is generally different. In most experiments, loss in coplanar resonators shows power and temperature dependence which disagrees with TLS theory. Here we will show new data from high-quality Al on sapphire coplanar resonators which is in qualitative agreement with TLS theory, and discuss the quantitative differences to TLS theory. The data on surface TLS behavior will be compared to resonator measurements of ALD-grown thin films.

Gladchenko, S.; Stoutimore, M. J. A.; Khalil, M.; Osborn, K. D.

2013-03-01

294

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

SciTech Connect

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.

Martin, Christopher; Pavlish, John

2013-09-30

295

Study on current source type superconducting magnetic energy storage based on PSCAD\\/EMTDC for the stability of power system  

Microsoft Academic Search

Use current source type superconducting magnetic energy storage (CSMES), a time-domain simulation model founded under the environment of PSCAD\\/EMTDC, to connect to several power systems to verify its good performance on voltage damp, transient stability, sub transient stability. Experimental results show that the model for enhancing the stability of the power system has apparent accomplishment.

Zhang Wei; Xiang Tie-yuan; Hu Wei

2009-01-01

296

Performance evaluation of dry-cooling systems for power plant applications  

Microsoft Academic Search

The performance evaluation of dry-cooling systems rely heavily on the ability to model the physical phenomena of the system. A sophisticated equation-based model, consisting of the conservation equations (energy, mass, momentum) and engineering design relations, is presented to model the dry-cooling systems performance for power plant applications. The implementation of this model gives rise to practical and reliable design methods

A. E. Conradie; D. G. Kröger

1996-01-01

297

Monitoring and simulation of an existing solar powered absorption cooling system in Zaragoza (Spain)  

Microsoft Academic Search

In 2007 and 2008 the performance of a solar powered absorption cooling installation was analyzed. The solar cooling system consists of 37.5 m2 of flat plate collectors, a 4.5 kW, single effect, LiBr–H2O rotary absorption chiller and a dry cooler tower. The performance analysis of the solar driven chiller shows average values of COP close to 0.6 in 2007 and between 0.46

C. Monné; S. Alonso; F. Palacín; L. Serra

2011-01-01

298

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

PubMed

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

Stillwell, Ashlynn S; Webber, Michael E

2014-04-15

299

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

NASA Technical Reports Server (NTRS)

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.

1974-01-01

300

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

NASA Astrophysics Data System (ADS)

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.

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

301

Overview of the development of the advanced power system by the applied superconductivity technologies programme in Korea  

NASA Astrophysics Data System (ADS)

At the end of July 2004, DAPAS (development of the advanced power system by applied superconductivity technologies), which is a 10 year long programme, finished the first of three phases. As a result of the first phase, a process for a metre long coated conductor and the core technologies of the distribution line voltage class high temperature superconductor (HTS) power systems including cables, transformers, fault current limiters (FCLs), and motors have been developed. The ultimate goal of the HTS cable project is to develop 1 GVA class HTS transmission cables. During the first phase, a three-phase 50 MVA/22.9 kV class HTS cable of 30 m length has been developed and tested successfully; it has been installed by LS Cable Ltd. In the second phase, grid-connected HTS cables will be developed and established in the real utility line. In case of FCLs, there were two types of FCL developed during the first phase: a reactive type and a resistive type. Both types had the same project targets with the specification of 6.6 kV/200 A for three-phase, and entered the second phase with the target of a 22.9 kV class. In the case of the HTS transformer project, a 1 MVA/22.9 kV class was developed, and after the second phase this project will be considered for practical application. Technically, the optimal design and the manufacturing technologies of HTS transformers as well as the analysis tools of electromagnetic field in the transformer were developed. Furthermore, a 100 hp class motor has been developed so that the key technologies for the utilization of superconducting motors could be obtained. The developed motor consists of Bi-2223 field coils of 100 A operating current at 30 K and a closed-loop cooling system, the results of which will lead us to develop 1 and 5 MVA motors in the second and third phase, respectively. In the case of the coated conductors (CCs) programme, a batch-type co-evaporation process and a reel-to-reel pulsed laser deposition process gave us 10 m long CC tapes in February 2005. We expect that 100 m long or longer CC will be developed during the second phase.

Ryu, Kang-Sik; Jo, Young-Sik; Park, Minwon

2006-03-01

302

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

SciTech Connect

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.

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

1997-11-01

303

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

NASA Astrophysics Data System (ADS)

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.

Tari, Ilker

2013-03-01

304

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...

305

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

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

306

Method for estimating the refrigeration costs of supercritical helium cooled cable superconductors  

Microsoft Academic Search

Refrigeration costs constitute an important aspect of the economics of force-cooled cable superconductors. The refrigerator power required to operate a forced cooled superconducting magnet is analyzed. The paper develops a simple method for estimating the total refrigerator power associated with a given length of cabled conductor of specified geometry. The estimate relies on the thermodynamics of supercritical helium in the

Adrian Bejan; M. Hoenig

1977-01-01

307

Cooling, Heating, and Power (CHP) for Commercial Buildings Benefits Analysis  

Microsoft Academic Search

We performed a detailed analysis of the energy consumption and end-user economics combined heat and power (CHP) systems in largecommercial buildings that included: •Five generation technologies (standard and advanced microturbines, standard and advanced internal combustion (IC) engines, and high-temperature PEM fuel cells);•Three building types (hospital, large office, and large hotel);•Five US cities (New York, Los Angeles, Chicago, Miami, and Phoenix);

Robert A. Zogg

2004-01-01

308

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

NASA Astrophysics Data System (ADS)

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.

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

1983-11-01

309

Modeling of a 22.9 kV 50 MVA superconducting power cable based on PSCAD\\/EMTDC for application to the Icheon substation in Korea  

Microsoft Academic Search

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

S. Lee; J. Yoon; B. Lee; B. Yang

2011-01-01

310

Economic implications of open versus closed cycle cooling for new steam-electric power plants: a national and regional survey  

Microsoft Academic Search

Current and anticipated thermal pollution regulations will prevent many new steam electric power plants from operating with once-through cooling. Alternative cooling systems acceptable from an environmental view fail to operate with the same efficiencies, in terms of resources consumed per Kwh of electricity produced, offered by once-through cooling systems. As a consequence there are clear conflicts between meeting environmental objectives

J. J. Shaw; E. E. Adams; R. J. Barbera; B. C. Arntzen; D. R. F. Harleman

1979-01-01

311

Steam-generator tube performance: world experience with water-cooled nuclear power reactors during 1977  

Microsoft Academic Search

The performance of steam-generator tubes in water-cooled nuclear power reactors in various countries is reviewed for 1977. Tube failures were reported at 34 of the 79 reactors surveyed. The causes of these failures and the inspection and repair procedures designed to deal with them are presented. Although denting caused by corrosion remained the leading cause of tube failures, specific mechanisms

R. S. Pathania; O. S. Tatone

1979-01-01

312

Hydro energy potential of cooling water at the thermal power plant  

Microsoft Academic Search

The hydro energy of the gravity water flow from the coal-fired thermal power plant units to the river in an open cooling system of turbine condensers is determined. On the basis of statistical data for a long time period, the water net head duration curve due to the river annual level change, as well as the reduction of the hydro

Vladimir D. Stevanovic; Aleksandar Gajic; Ljubodrag Savic; Vladan Kuzmanovic; Dusan Arnautovic; Tina Dasic; Blazenka Maslovaric; Sanja Prica; Bojan Milovanovic

2011-01-01

313

Recovery of a power plant cooling reservoir ecosystem from selenium bioaccumulation  

Microsoft Academic Search

Hyco Reservoir, a North Carolina power plant cooling impoundment, was impacted by selenium toxicity during the late 1970s. Selenium inputs via coal ash discharge resulted in bioaccumulation through the aquatic food chain which caused reproductive failure and population declines of bluegill, other Lepomis spp., largemouth bass, crappie, yellow perch, and sucker species. Following these declines, green sunfish, satinfin shiner, gizzard

John U Crutchfield

2000-01-01

314

The effects of age on nuclear power plant containment cooling systems  

Microsoft Academic Search

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

R. Lofaro; M. Subudhi; R. Travis; A. DiBiasio; A. Azarm; J. Davis

1994-01-01

315

Tritium in a Natural–Technological System of Nuclear Power Plant--Cooling Pool  

Microsoft Academic Search

Information on 3H release at nuclear power plants (NPP), its escape beyond NPP and migration in the atmosphere and cooling pool is generalized and analyzed. It is shown that 3H that has formed in the process of NPP operation and entered the environment is not a radiation hazard to the population and natural objects.

Yu. A. Egorov

2002-01-01

316

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

Microsoft Academic Search

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

Burda

1990-01-01

317

ENVIRONMENTAL PROBLEMS ASSOCIATED WITH DECOMMISSIONING THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND  

Microsoft Academic Search

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

Farfan

2009-01-01

318

PROBLEMS CONCERNING THE SAFETY OF GRAPHITE-MODERATED GAS-COOLED NATURAL URANIUM POWER REACTORS  

Microsoft Academic Search

The safety of natural uranium power reactors, graphitemoderated and gas-; cooled, depends on a number of factors. The most important of these are ; reviewed, and their relative significance in certain hypothetical accident ; conditions is estimated. After a brief outline of the irtrinsic safety ; characteristics of the reactors considered, the precautions to be taken in the ; choice

J. Bourgeois; D. Costes; C. Henri; G. Lamiral; Ch. Segot

1962-01-01

319

Electrodialytic desalinization of water for cooling turbo-generator windings in hydroelectric power plants  

Microsoft Academic Search

The method of salt elimination using electrodialytic devices is discussed. The utilization of these devices makes it possible to considerably simplify the water preparation circuit for cooling turbogenerators in hydroelectric power plants. It is concluded that the salt elimination process should include a sodium-cation filter, an electrodialytic device and a mixing filter. Furthermore, the brine from the concentrate chambers of

Vysotski

1980-01-01

320

Steam Generator Tube Performance: Experience with Water-Cooled Nuclear Power Reactors During 1978.  

National Technical Information Service (NTIS)

The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1978. Tube failures occurred at 31 of the 86 reactors surveyed. Causes of these failures and procedures designed to deal with them are described. A drama...

O. S. Tatone R. S. Pathania

1980-01-01

321

Steam Generator Tube Performance: Experience with Water-Cooled Nuclear Power Reactors During 1977.  

National Technical Information Service (NTIS)

The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1977. Failures were reported in 34 of the 79 reactors surveyed. Causes of these failures and inspection and repair procedures designed to deal with them ...

R. S. Pathania O. S. Tatone

1979-01-01

322

Steam Generator Tube Performance: Experience with Water-Cooled Nuclear Power Reactors During 1983 and 1984.  

National Technical Information Service (NTIS)

A review of the performance of steam generator tubes in water-cooled nuclear power reactors showed that tubes were plugged at 47 (35.6%) of the reactors in 1983 and at 63 (42.6%) of the reactors during 1984. In 1983 and 1984 3291 and 3335 tubes, respectiv...

O. S. Tatone P. Meindl G. F. Taylor

1986-01-01

323

Steam Generator Tube Performance. Experience with Water-Cooled Nuclear Power Reactors During 1982.  

National Technical Information Service (NTIS)

A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4,692 (0.30 percent) in 1981 to 3,22...

O. S. Tatone R. S. Pathania

1984-01-01

324

Steam Generator Tube Performance: Experience with Water-Cooled Nuclear Power Reactors During 1979.  

National Technical Information Service (NTIS)

The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1979. Tube failures occurred at 38 of the 93 reactors surveyed. Causes of these failures and procedures designed to deal with them are described. The def...

O. S. Tatone R. S. Pathania

1981-01-01

325

Steam Generator Tube Performance. Experience with Water-Cooled Nuclear Power Reactors During 1981.  

National Technical Information Service (NTIS)

A review of the performance of steam generator tubes in 110 water-cooled nuclear power reactors showed that tubes were plugged at 46 (42 percent) of the reactors. The number of tubes removed from service increased from 1900 (0.14 percent) in 1980 to 4692 ...

O. S. Tatone R. S. Pathania

1983-01-01

326

Steam Generator Tube Performance. Experience with Water-Cooled Nuclear Power Reactors During 1980.  

National Technical Information Service (NTIS)

The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. Th...

O. S. Tatone R. S. Pathania

1982-01-01

327

Analysis of combustion turbine inlet air cooling systems applied to an operating cogeneration power plant  

Microsoft Academic Search

In this work, combustion turbine inlet air cooling (CTIAC) systems are analyzed from an economic outlook, their effects on the global performance parameters and the economic results of the power plant. The study has been carried out on a combined cogeneration system, composed of a General Electric PG 6541 gas turbine and a heat recovery steam generator. The work has

R. Chacartegui; F. Jiménez-Espadafor; D. Sánchez; T. Sánchez

2008-01-01

328

Steam Generator Tube Failures: Experience with Water-Cooled Nuclear Power Reactors During 1976.  

National Technical Information Service (NTIS)

A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope wit...

O. S. Tatone R. S. Pathania

1978-01-01

329

Nuclear power plant with closed gas-cooling circuit for production of process heat  

Microsoft Academic Search

A power plant is described which has a closed gas-cooling circuit for the production of process heat to be transferred to a secondary circuit. It consists of: (a) a vessel comprising a generally solid block of material; (b) a high-temperature reactor positioned within the vessel; (c) a plurality of heat exchanger units positioned about the reactor in the reactor in

Baumgaertner

1977-01-01

330

Response of unirradiated and irradiated PWR fuel rods tested under power-cooling-mismatch conditions  

Microsoft Academic Search

The report summarizes the results from the single-rod power-cooling-mismatch (PCM) and irradiation effects (IE) tests conducted to date in the Power Burst Facility (PBF) at the U.S. Department of Energy's Idaho National Engineering Laboratory. This work was performed for the U.S. Nuclear Regulatory Commission under contract to the Department of Energy. These tests are part of the Nuclear Regulatory Commission's

P. E. MacDonald; W. J. Quapp; A. S. Mehner; Z. R. Martinson; R. K. McCardell

1978-01-01

331

The thermal effects of cooling system of a thermal power plant on photosynthesis of marine phytoplankton  

Microsoft Academic Search

The activity of photosynthesis and the contents of chlorophylla and pheo-pigments were compared in the samples of the intake and effluent seawater of Owase-Mita Thermal Power Plant and in the seawater samples in the Yoshimi Bay before and after heat treatment. At Owase-Mita Thermal Power Plant, after passage of sea water through the cooling system chlorophylla content reduced to about

Kaoru Takesue; Arao Tsuruta

1978-01-01

332

3Dimensional thermal analysis and active cooling of short-length high-power fiber lasers  

Microsoft Academic Search

A fully 3-dimensional finite element model has been developed that simulates the internal temperature distribution of short-length high-power fiber lasers. We have validated the numerical model by building a short, cladding-pumped, Er-Yb-codoped fiber laser and measuring the core temperature during laser operation. A dual-end-pumped, actively cooled, fiber laser has generated >11 W CW output power at 1535 nm from only

L. Li; H. Li; T. Qiu; V. L. Temyanko; M. M. Morrell; A. Schülzgen; A. Mafi; J. V. Moloney; N. Peyghambarian

2005-01-01

333

Economic assessment of backfitting power plants with closed-cycle cooling systems. Final report, Apr 1974--Oct 1975  

Microsoft Academic Search

The report gives in detail a method for assessing the economic consequences of backfitting electric power plants (currently operating on open-cycle or once-through cooling systems) with conventional closed-cycle cooling systems. Four types of closed-cycle systems were investigated: mechanical- and natural-draft crossflow wet cooling towers, cooling ponds, and spray canals. To estimate operational penalties associated with backfitting, thermodynamic models were used

A. R. Giaquinta; T. E. II Croley; V. C. Patel; J. G. Melville; M. S. Cheng

1976-01-01

334

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

SciTech Connect

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.

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

1998-03-01

335

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

SciTech Connect

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.

Hawsey, R.A. [comp.; Turner, J.W. [ed.

1996-05-01

336

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

SciTech Connect

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.

Hawsey, R.A. [comp.

1994-04-01

337

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

SciTech Connect

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.

Koncinski, W.S. [ed.; Hawsey, R.A. [comp.

1997-05-01

338

Cryogenic System for the Superconducting Tokamak HT-7U  

SciTech Connect

HT-7U is a fully superconducting tokamak. All of the toroidal field and poloidal field superconducting magnets are made of NbTi superconductor and are designed to operate at 3.8 K in the steady-state operation mode. The magnet system will be cooled with forced-flow supercritical helium to this temperature level with an equivalent refrigeration capacity of {approx}2 kW/4.4 K. To satisfy this requirement, a helium refrigerator is designed to be able to provide the cooling power at 3.5, 4.5, and 80 K for the coils, supports, and thermal shields. The refrigerator can also produce liquid helium for the cooling of the current leads. This paper describes the cryogenic system of HT-7U, the refrigeration process and helium plant, and the forced-flow cooling requirement of the superconducting magnets.

Bai Hongyu; Bi Yanfang; Wang Jingrong; Zhuang Ming; Zhu Ping; Sheng Linhai; Zhang Qiyong [Chinese Academy of Sciences (China)

2002-07-15

339

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

SciTech Connect

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 the 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 includes 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.

Schwarze, G.E.

1994-09-01

340

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

NASA Technical Reports Server (NTRS)

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.

Schwarze, G. E.

1985-01-01

341

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

NASA Technical Reports Server (NTRS)

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 the 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.

Schwarze, G. E.

1985-01-01

342

Superconductors for superconducting magnets  

NASA Astrophysics Data System (ADS)

Even in 1913 Kamerlingh Onnes envisioned the use of superconductors to create powerful magnetic fields well beyond the capability provided by cooling normal metals with liquid helium. Only some "bad places" in his Hg and Pb wires seemed to impede his first attempts at this dream, one that he imagined would be resolved in a few weeks of effort. In fact, of course, resolution required another 50 years and development of both a true understanding of the difference between type I and type II superconductors and the discovery of compounds such as Nb3Sn that could remain superconducting to fields as high as 30 T. And then indeed, starting in the 1960s, Onnes's dreams were comfortably surpassed. In the last 45 years virtually all superconducting magnets have been made from just two Nb-base materials, Nb-Ti and Nb3Sn. Now it seems that a new generation of magnets based on cuprate high temperature superconductors with fields well above 30 T are possible using Bi-Sr-Ca-Cu-O and the RE-Ba-Cu-O compounds. We hope that a first demonstration of this possibility will be an all-superconducting 32 T magnet with RE-Ba-Cu-O insert that we are building for NHMFL users. The magnet application potential of this new generation of superconducting conductors will be discussed.

Larbalestier, David

2011-03-01

343

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

National Technical Information Service (NTIS)

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 subsy...

W. Burgett M. Christianson R. Coombes

1992-01-01

344

Laser technologies applied to the fabrication and characterization of bulk Bi2212 superconducting materials for power applications  

Microsoft Academic Search

Lasers are adequate tools in the processing and characterization of materials. The Applied Superconductivity group at the Aragón Materials Science Institute has been applying different laser techniques in the processing, machining and characterization of bulk high temperature superconductors for high power applications. Textured bulk Bi-2212 superconductors have been obtained using laser melting zone techniques. We have produced thin bars, monoliths

L. A. Angurel; J. C. Díez; G. F. de La Fuente; F. Gimeno; F. Lera; C. López-Gascón; E. Martínez; M. Mora; R. Navarro; A. Sotelo; N. Andrés; S. Recuero; M. P. Arroyo

2006-01-01

345

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

Microsoft Academic Search

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

Charles Reece; Hui Tian; Michael Kelley; Chen Xu

2012-01-01

346

Evaluation of the Impact of Superconducting Fault Current Limiters on Power System Network Protections Using a RTS-PHIL Methodology  

Microsoft Academic Search

Planning the integration of a Superconducting Fault Current Limiter (SFCL) in an electric power network mainly consists in predicting the current limiting characteristics in any fault condition, in order to set the protection relays accordingly. Due to the very non linear behavior of the SFCL, modifications to the settings of existing protection relays are expected. To explore the potential changes,

Mouhamadou Dione; Frédéric Sirois; Charles-Henri Bonnard

2011-01-01

347

Liquid Cooled Cold Plates for Industrial High-Power Electronic Devices---Thermal Design and Manufacturing Considerations  

Microsoft Academic Search

Electronics cooling research has been largely focused on high heat flux removal from computer chips in the recent years. However, the equally important field of high-power electronic devices has been experiencing a major paradigm shift from air cooling to liquid cooling over the last decade. For example, multiple 250-W insulated-gate bipolar transistors used in a power drive for a 7000-HP

Satish G. Kandlikar; Clifford N. Hayner II

2009-01-01

348

An assessment of the use of direct contact condensers with wet cooling systems for utility steam power plants  

Microsoft Academic Search

Potential use of a direct contact condenser for steam recovery at the turbine exhaust of a utility power plant using a wet cooling system is investigated. To maintain condensate separate from the cooling water, a bank of plate heat exchangers is used. In a case study for a nominal 130-MW steam power plant, two heat rejection systems, one using a

D. Bharathan; E. Hoo; P. DErrico

1992-01-01

349

Development of a 500 kVA-class oxide-superconducting power transformer operated at liquid-nitrogen temperature  

NASA Astrophysics Data System (ADS)

We have designed and constructed a 500 kVA-class oxide-superconducting power transformer. The windings are cooled by liquid nitrogen or subcooled nitrogen in a G-FRP cryostat of 785 mm in diameter and 1210 mm in height, that has a room-temperature space for an iron core with the diameter of 314 mm. The primary and secondary windings are three-strand and six-strand parallel conductors of a Bi-2223 multifilamentary tape with silver sheath, respectively. The strand 0.22 mm thick and 3.5 mm wide has 61 filaments with no twisting. The ratio of superconductor is 0.284. In the parallel conductors, the strands are transposed five times in each layer for a uniform current distribution among them. It was proved that the transformer has the rated capacity of 500 kVA by means of two-h short-circuit test and half-h no-load test in liquid nitrogen of 77 K. The efficiency is estimated as 99.1% from a core loss of 2.3 kW and a thermal load of 2.2 kW in coolant. The latter is composed of AC losses in windings and heat leakage from the cryostat and current leads, and is multiplied by a refrigeration penalty of liquid nitrogen, 20. Load test was also performed up to 500 kVA. The transformer was furthermore operated in subcooled nitrogen at 66 K with no quenching up to a critical level, that is equivalent to 800 kVA. The efficiency estimated was improved to 99.3% in subcooled nitrogen. Measured a.c. loss in both windings are well explained by a theoretical prediction with the "critical state model". We also discuss prospective applications of the parallel conductors composed of advanced HTS multifilamentary tapes to a.c. windings with large current capacity.

Funaki, K.; Iwakuma, M.; Kajikawa, K.; Takeo, M.; Suehiro, J.; Hara, M.; Yamafuji, K.; Konno, M.; Kasagawa, Y.; Okubo, K.; Yasukawa, Y.; Nose, S.; Ueyama, M.; Hayashi, K.; Sato, K.

350

Suitability of LN2 impregnated Open-Cell Foam as Electric Insulant for Superconducting Power Equipment  

NASA Astrophysics Data System (ADS)

The suitability of an open-cell foam is investigated for the application as electric insulant in superconducting power equipment. The tested foam is made from melamine resin, a thermoset plastic from the aminoplastics group; it is a mechanical very flexible material with excellence compatibility to high and low temperature. The aim of these investigations was to test the aptitude of the liquid nitrogen impregnated open-cell foam with respect to the dielectric properties and the electric strength under different conditions. In this paper the results of permittivity measurements and ramp voltage tests are discussed and an outlook for future applications is given. The tests showed excellence mechanical and thermal characteristics for the application in LN2 vessels. The ACBV of the LN2 impregnated foam was 50 % less than the ACBV of pure LN2.

Sumereder, C.; Mifka, M.; Muhr, M.

2006-06-01

351

Operation of the 30 MJ superconducting magnetic energy storage system in the Bonneville Power Administration Electrical Grid  

SciTech Connect

The 30 MJ superconducting magnetic energy storage (SMES) system was installed in the Bonneville Power Administration (BPA) Tacoma Substation in 1982 to 1983. Operation of the unit since that time has been for over 1200 hours. Specific tests to explore the SMES system's thermal and electrical characteristics and the control functions were conducted. The coil heat load with current modulation was determined. A converter with two 6-pulse bridges interfaces the superconducting coil to the power bus. Equal bridge voltage amplitude and constant reactive power modes of operation of the system were run with computer control of the SCR bridge firing angles. Coil energy dump tests were performed. Electrical grid system response to SMES modulation was observed, and full power SMES modulation was undertaken.

Rogers, J.D.; Boenig, H.J.; Schermer, R.I.; Hauer, J.F.

1984-01-01

352

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

NASA Astrophysics Data System (ADS)

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.

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

353

A gas-cooled cermet reactor system for planetary base power  

SciTech Connect

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.

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

1992-08-01

354

A gas-cooled cermet reactor system for planetary base power  

SciTech Connect

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.

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

1992-01-01

355

Shutdown Cooling Helium Circulator Design Considerations for MHTGR (Modular High Temperature Gas-Cooled Reactor) Power Plant.  

National Technical Information Service (NTIS)

The Modular High Temperature Gas-Cooled Reactor (MHTGR) plant embodies a shutdown cooling system to expedite plant cooldown for refueling, maintenance, and repair in the event that the main cooling loop is unavailable. This is a non safety related system....

C. F. McDonald

1989-01-01

356

The effect of variable microwave power on the low-field absorption in high-T c superconducting cuprates  

NASA Astrophysics Data System (ADS)

The well established low-field microwave absorption below Tc has been investigated using the ESR technique at 9 GHz, as a function of incident microwave power, in a range of superconducting cuprates, namely Er 2Ba 4Cu 7O 15- x, Tl 2Ba 2CeCu 2O x and YBa 2Cu 3O 7- x. In all cases, the signal was “saturated” above a critical microwave power level; we observed that this effect was sample-dependent.

Jane, R.; Liu, R. S.; Edwards, P. P.; Tallon, J. L.

1990-05-01

357

Flux-Based Modeling of Inductive Shield-Type High-Temperature Superconducting Fault Current Limiter for Power Networks  

Microsoft Academic Search

Distributed power generation and the ever-growing load demand have caused fault current levels to exceed the nominal rating of the power system devices, and fault current limiters are more needed. Superconducting fault current limiter (SFCL) forms an important category of current limiters. In this paper, a novel flux-based model for the inductive shield-type high- temperature SFCL is developed based on

Arsalan Hekmati; Mehdi Vakilian; Mehdi Fardmanesh

2011-01-01

358

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

PubMed

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: ¹³?Cs: 16.28 ± 2.59 TBq; ??Sr: 2.4 ± 0.48 TBq; and ²³?+²??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?¹ for amphibians, 6.3 ?Gy h?¹ for birds, 15.1 ?Gy h?¹ for mammals, and 10.3 ?Gy h?¹ for reptiles, with the recommended maximum dose rate being equal to 40 ?Gy h?¹. However, drying the ChNPP Cooling Pond may increase the exposure doses to 94.5 ?Gy h?¹ for amphibians, 95.2 ?Gy h?¹ for birds, 284.0 ?Gy h?¹ for mammals, and 847.0 ?Gy h?¹ for reptiles. All of these anticipated dose rates exceed the recommended values. PMID:20938234

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

2010-11-01

359

Cold shock to aquatic organisms: guidance for power-plant siting, design, and operation. [Effects of power plant cooling systems  

Microsoft Academic Search

Problems of cold-shock damages to aquatic organisms have arisen at some condenser cooling-water discharges of thermal power stations when the warm-water releases have suddenly terminated. The basis for such damage lies in the exposure of resident organisms to a rapid decrease in temperature and a sustained exposure to low temperature that induces abnormal behavioral or physiological performance and often leads

1977-01-01

360

Use of remote sensing data to enhance the performance of a hydrodynamic simulation of a partially frozen power plant cooling lake  

Microsoft Academic Search

The eectiveness of a power generation site's cooling pond has a signicant impact on the overall eciency 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 thermo- dynamic analysis of a cooling lake can become

Alfred J. Garrett; Brent D. Bartlett; Jason W. Faulring; Robert L. Kremens; Philip S. Salvaggio

361

On the development of an ion-beam stochastic cooling system for the nuclotron superconducting accelerator complex  

NASA Astrophysics Data System (ADS)

The Joint Institute for Nuclear Research (JINR) initiated the creation of a unique heavy-ion collider, the Nuclotron-based ion collider facility (NICA), which is planned to be put into commission in 2016. According to the calculation data, the collider luminosity, which should be kept at a record high level of 1027 cm-2 s-1, will gradually decrease, mainly due to intrabeam scattering. To maintain luminosity at a high level, it is necessary to include a cooling system in the base project of the accelerator. Among the two cooling methods (electron and stochastic) most frequently used for heavy ion beams, stochastic cooling seems more attractive. However, there has been a lack of experience in the development and commissioning of such systems in Russia. For this reason, an experiment on stochastic cooling on the Nuclotron accelerator is being prepared to explore the technology and possibilities of this method. In this work, the method of stochastic cooling, the technique for calculating the cooling dynamics, and the experimental setup under development are briefly described.

Kobets, A. G.; Sidorin, A. O.; Trubnikov, G. V.; Shurkhno, N. A.

2012-07-01

362

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

NASA Astrophysics Data System (ADS)

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.

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

2011-02-01

363

All-solid-state high-power conduction-cooled Nd:YLF rod laser.  

PubMed

A high-average-power conduction-cooled diode-pumped Nd:YLF rod laser has been developed. A new conduction-cooled side-pumping scheme with a solid prismatic pump-light confinement cavity was employed. A transparent, high-thermal-conductivity MgF>(2) prism was used as a highly efficient pump cavity as well as a low-thermal-resistance heat spreader. The pumping efficiency and thermal resistance of the cavity were 85% and 0.20 degrees C degrees W, respectively. When this scheme was combined with heat pipes for heat removal, a maximum average output power of 72 W was demonstrated, with an optical slope efficiency as high as 49%. PMID:18066156

Hirano, Y; Yanagisawa, T; Ueno, S; Tajime, T; Uchino, O; Nagai, T; Nagasawa, C

2000-08-15

364

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

SciTech Connect

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.

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

1984-07-01

365

Survey of Remote Area Monitoring Systems at U.S. Light-Water-Cooled Power Reactors  

SciTech Connect

A study was made of the capabilities and operating practices, including calibration, of remote area monitoring (RAM) systems at light-water-cooled power reactors in the United States. The information was obtained by mail questionaire. Specific design capabilities, including range, readout and alarm features are documented along with the numbers and location of detectors, calibration and operational procedures. Comments of respondents regarding RAM systems are also included.

Kathren, R. L.; Mileham, A. P.

1982-04-01

366

Technological Advance in Cooling Systems at U.S. Power Plants  

Microsoft Academic Search

Prior to adoption of the 1972 Clean Water Act (CWA) most U.S. power plants used once-through cooling water systems that discharged large quantities of warm water and resulted in significant amounts of thermal pollution in neighboring bodies of water. The CWA essentially mandated recirculating systems for most new facilities. This paper investigates whether there was either cost-saving or performance enhancing

Allen S Bellas; Duane Finney; Ian Lange

2011-01-01

367

Superconducting magnets for MRI  

SciTech Connect

Three types of magnets are currently used to provide the background field required for magnet resonance imaging (MRI). (i) Permanent magnets produce fields of up to 0.3 T in volumes sufficient for imaging the head or up to 0.15 T for whole body imaging. Cost and simplicity of operation are advantages, but relatively low field, weight (up to 100 tonnes) and, to a small extent, instability are limitations. (ii) Water-cooled magnets provide fields of up to 0.25 T in volumes suitable for whole body imaging, but at the expense of power (up to 150 kW for 0.25 T) and water-cooling. Thermal stability of the field requires the maintenance of constant temperature through periods both of use and of quiescence. (iii) Because of the limitations imposed by permanent and resistive magnets, particularly on field strength, the superconducting magnet is now most widely used to provide background fields of up to 2 T for whole body MRI. It requires very low operating power and that only for refrigeration. Because of the constant low temperature, 4.2 K, at which its stressed structure operates, its field is stable. The following review deals principally with superconducting magnets for MRI. However, the sections on field analysis apply to all types of magnet and the description of the source terms of circular coils and of the principals of design of solenoids apply equally to resistive solenoidal magnets.

Williams, J.E.

1984-08-01

368

Development of practical high temperature superconducting wire for electric power applications  

SciTech Connect

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.

Hawsey, R.A. [Oak Ridge National Lab., TN (United States); Sokolowski, R.S.; Haldar, P. [Intermagnetics General Corp., Latham, NY (United States); Motowidlo, L.R. [IGC/Advanced Superconductors, Inc., Waterbury, CT (United States)

1994-09-01

369

Development of practical high temperature superconducting wire for electric power application  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

370

Passively cooled diode lasers in the cw power range of 120 to 200W  

NASA Astrophysics Data System (ADS)

Improvements of laser diode bar efficiency and mounting technology have boosted output powers of passively cooled diode lasers beyond the 100W cw limit. After an introduction about reliablity statements and reliability assessment, the performance increase by technology improvements is documented in current-step failure discrimination tests. Electro-optical parameters of improved diode lasers are subsequently presented in detail as well as the results of lifetime tests at different powers and in different operation modes - steady-state and repetitive/intermittent ("hard pulse") cw operation.

Lorenzen, Dirk; Meusel, Jens; Schröder, Dominic; Hennig, Petra

2008-03-01

371

A HIGH POWER RF COUPLER DESIGN FOR MUON COOLING RF CAVITIES.  

SciTech Connect

We present a high power RF coupler design for an interleaved {pi}/2 805 MHz standing wave accelerating structure proposed for an muon cooling experiment at FNAL. The coupler, in its simplest form, is a rectangular waveguide directly connected to an accelerating Cell through an open slot on the cavity side-wall or end-plates. Two of such couplers are needed to feed the interleaved cavities. Current high power RF test requires the coupler to be at critical coupling. Numerical simulations on the coupler designs using MAFIA will be presented.

CORLETT,J.; LI,DERUN; RIMMER,R.; HOLTKAMP,N.; MORETTI,A.; KIRK,H.G.

1999-03-29

372

Heat pipe cooled reactors for multi-kilowatt space power supplies  

SciTech Connect

Three nuclear reactor space power system designs are described that demonstrate how the use of high temperature heat pipes for reactor heat transport, combined with direct conversion of heat to electricity, can result in eliminating pumped heat transport loops for both primary reactor cooling and heat rejection. The result is a significant reduction in system complexity that leads to very low mass systems with high reliability, especially in the power range of 1 to 20 kWe. In addition to removing heat exchangers, electromagnetic pumps, and coolant expansion chambers, the heat pipe/direct conversion combination provides such capabilities as startup from the frozen state, automatic rejection of reactor decay heat in the event of emergency or accidental reactor shutdown, and the elimination of single point failures in the reactor cooling system. The power system designs described include a thermoelectric system that can produce 1 to 2 kWe, a bimodal modification of this system to increase its power level to 5 kWe and incorporate high temperature hydrogen propulsion capability, and a moderated thermionic reactor concept with 5 to 20 kWe power output that is based on beryllium modules that thermally couple cylindrical thermionic fuel elements (TFEs) to radiator heat pipes.

Ranken, W.A.; Houts, M.G.

1995-01-01

373

Heat pipe cooled reactors for multi-kilowatt space power supplies  

NASA Astrophysics Data System (ADS)

Three nuclear reactor space power system designs are described that demonstrate how the use of high temperature heat pipes for reactor heat transport, combined with direct conversion of heat to electricity, can result in eliminating pumped heat transport loops for both primary reactor cooling and heat rejection. The result is a significant reduction in system complexity that leads to very low mass systems with high reliability, especially in the power range of 1 to 20 kWe. In addition to removing heat exchangers, electromagnetic pumps, and coolant expansion chambers, the heat pipe/direct conversion combination provides such capabilities as startup from the frozen state, automatic rejection of reactor decay heat in the event of emergency or accidental reactor shutdown, and the elimination of single point failures in the reactor cooling system. The power system designs described include a thermoelectric system that can produce 1 to 2 kWe, a bimodal modification of this system to increase its power level to 5 kWe and incorporate high temperature hydrogen propulsion capability, and a moderated thermionic reactor concept with 5 to 20 kWe power output that is based on beryllium modules that thermally couple cylindrical thermionic fuel elements (TFE's) to radiator heat pipes.

Ranken, W. A.; Houts, M. G.

374

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)

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.

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

375

Allocation and Circuit Parameter Design of Superconducting Fault Current Limiters in Loop Power System by a Genetic Algorithm  

NASA Astrophysics Data System (ADS)

In near future, many Independent Power Producers (IPPs) will participate in power generations according to their own strategic contracts by the deregulation. Loop or mesh systems can be designed to balance the power flow and to regulate the voltage resulting to the flexibility of power system operation, improvement of reliability and economical efficiency. Nevertheless, they bring to the problem of increased fault levels which may raise beyond the withstand capability of existing circuit breakers in the power systems. Short-circuit current is strongly related to the cost of apparatus and the effective use of power transmissions. Therefore, the introduction of Superconducting Fault Current Limiters (SFCLs) becomes an effective way for suppressing such a large short-circuit current. In this paper, first the authors evaluate the behavior of the S/N transition-type SFCL by considering the sub-transient and transient effects of generators in order to obtain smaller SFCL circuit parameters, i.e.\\ the resistance of the superconducting coil and the reactance of the current-limiting inductor. Then the authors propose a method by using a hierarchical genetic algorithm (HGA) combined with a micro-genetic algorithm (micro-GA) to search for the optimal locations and the smallest SFCL circuit parameters simultaneously. The flexibility in defining the required objective function by using the proposed method makes it possible to evaluate the requirement of SFCLs in large power systems. Analysis by computer simulation has been carried out in an example loop power system.

Hongesombut, Komsan; Furusawa, Ken; Mitani, Yasunori; Tsuji, Kiichiro

376

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

NASA Technical Reports Server (NTRS)

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.

Biesiadny, Thomas J.; Klann, Gary A.

1992-01-01

377

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

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

378

Fibre-coupled air-cooled high-power diode laser systems  

NASA Astrophysics Data System (ADS)

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 ?m 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.

Bartoschewski, Daniel; Meinschien, Jens; Fornahl, Udo

2008-03-01

379

Electromagnetic and thermal analysis of distributed cooled high power millimeter wave windows  

SciTech Connect

The sectional high-frequency internally-cooled window, as proposed by General Atomics, has unique potential for allowing microwave sources to reach multi-megawatt CW levels with application to ECRH. Designs are being investigated using computational electromagnetic (EM), thermal, and mechanical codes at 110 GHz and 170 GHz to examine the design tradeoffs between RF performance and thermal mechanical safety margins. The EM analyses are for the window, under vacuum at one MW and includes variations in the shapes of the cooling fins, the surface treatment of the window elements themselves, the cooling fin tip treatment, the window pitch angle, and the waveguide effects. One advantage of the distributed cooled window is it`s extensibility to higher power levels. Results in the modeling efforts are presented showing the EM field concentrations (which then will feed into the thermal analysis), the energy scattering/reflection, the transmitted launch angle variation as a function of physical geometry, and the spatial energy distribution and loss as a function of time and position.

Nelson, S.D.; Reitter, T.; Caplan, M. [and others

1995-05-12

380

Assessment of the use of direct contact condensers with wet cooling systems for utility steam power plants.  

National Technical Information Service (NTIS)

Potential use of a direct contact condenser for steam recovery at the turbine exhaust of a utility power plant using a wet cooling system is investigated. To maintain condensate separate from the cooling water, a bank of plate heat exchangers is used. In ...

D. Bharathan E. Hoo P. D'Errico

1992-01-01

381

Development of Emergency Core Cooling Systems in the PWR, BWR, and HWR Candu Type of Nuclear Power Plants.  

National Technical Information Service (NTIS)

Emergency core cooling systems in the PWR, BWR, and HWR-Candu type of nuclear power plant are reviewed. In PWR and BWR the emergency cooling can be catagorized as active high pressure, active low pressure, and a passive one. The PWR uses components of the...

D. Mursid

1976-01-01

382

Training and degradation of a model superconducting winding depending on cooling conditions and conductor cross-section  

NASA Astrophysics Data System (ADS)

The process of training single-layer windings in an external magnetic field under various cooling conditions is described in the first part of this Paper. The character and duration of training under various cooling conditions showed the influence of cooling on the superconductor stability. Limiting currents corresponding to saturation of training were found to be the same in the pressurized and saturated He II and even in He I at a temperature near the ? point. A reduction of training in He II against He I was found. The lack of limiting current dependence on the electric insulation layer introduces an additional thermal resistance. The training process for various conductor cross-sections is described in the second part of the Paper under similar conditions to the case of He I cooling. The winding was made of four insulated parallel wires. By means of varying the electrical connections of separate wires one can simulate changing sizes of conductor cross-sections in the ratio 1:2:4, under otherwise equal conditions. An increase in the limiting attainable current density was found with increase of conductor cross-section, giving a simultaneous reduction of training. A simple method of calculating the theoretical limit of attainable current was formulated. Calculated values of current agree well with those obtained experimentally.

Keilin, V. E.; Kovalev, I. A.; Kruglov, S. L.

383

Electronic Coolers Based on Superconducting Tunnel Junctions: Fundamentals and Applications  

NASA Astrophysics Data System (ADS)

Thermo-electric transport at the nano-scale is a rapidly developing topic, in particular in superconductor-based hybrid devices. In this review paper, we first discuss the fundamental principles of electronic cooling in mesoscopic superconducting hybrid structures, the related limitations and applications. We review recent work performed in Grenoble on the effects of Andreev reflection, photonic heat transport, phonon cooling, as well as on an innovative fabrication technique for powerful coolers.

Courtois, H.; Hekking, F. W. J.; Nguyen, H. Q.; Winkelmann, C. B.

2014-06-01

384

Effect of makeup water properties on the condenser fouling in power planr cooling system  

SciTech Connect

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.

Safari, I.; Walker, M.; Abbasian, J.; Arastoopour, H.; Hsieh, M-K.; Dzombak, D.; Miller, D.

2011-01-01

385

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

NASA Astrophysics Data System (ADS)

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.

Mahdad, Belkacem; Srairi, K.

2013-12-01

386

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

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

387

Numerical analysis on the beam quality improvements of high power chemical laser system with water cooled mirrors  

Microsoft Academic Search

Chemical laser is one of the most widely used high power infrared sources. Thermal deformation of mirrors in a resonator is a key factor which hinders the improvement of the beam quality in high power chemical lasers, and it has been a matter of the utmost concern in the design of high power chemical laser systems. Water-cooled technique is one

Kai Han; Bin Li; Xiao-Jun Xu

2011-01-01

388

Analysis of a new thermodynamic cycle for combined power and cooling using low and mid temperature solar collectors  

Microsoft Academic Search

A combined thermal power and cooling cycle is proposed which combines the Rankine and absorption refrigeration cycles. It can provide power output as well as refrigeration with power generation as a primary goal. Ammonia-water mixture is used as a working fluid. The boiling temperature of the ammonia-water mixture increases as the boiling process proceeds until all liquid is vaporized, so

D. Yogi Goswami; Feng Xu

1999-01-01

389

Application Study of a High Temperature Superconducting Fault Current Limiter for Electric Power System  

NASA Astrophysics Data System (ADS)

Using high temperature superconductor, a Superconducting Fault Current Limiter (SFCL) was made and tested. Superconductor and vacuum interrupter as commutation switch are connected in parallel with bypass coil. When a fault occurs and the excessive current flows, superconductor is first quenched and the current is transferred to bypass coil because on voltage drop of superconductor. At the same time, since magnetic field is generated by current which flows in bypass coil, commutation switch is immediately driven by electromagnetic repulsion plate connected to driving rod of vacuum interrupter, and superconductor is separated from this circuit. Using the testing model, we could separate the superconductor from a circuit due to movement of vacuum interrupter within half-cycle current and transfer all current to bypass coil. Since operation of a commutation switch is included in current limiting operation of this testing model, it is one of helpful circuit of development of SFCL in the future. Moreover, since it can make the consumed energy of superconductor small during fault state due to realization of high-speed switch with simple composition, the burden of superconductor is reduced compared with conventional resistive type SFCL and it is considered that the flexibility of a SFCL design increases. Cooperation with a circuit breaker was also considered, the trial calculation of a parameter and energy of operation is conducted and discussion in the case of installing the SFCL to electric power system is made.

Naito, Yuji; Shimizu, Iwao; Yamaguchi, Iwao; Kaiho, Katsuyuki; Yanabu, Satoru

390

Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond  

NASA Astrophysics Data System (ADS)

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.

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

391

The Effect of Circulating Water Masses of Nuclear Power Plants on the Distribution of Bacterial Plankton in Cooling Ponds  

Microsoft Academic Search

The distribution of bacterial plankton in two types of cooling ponds of nuclear power plants is considered. The main factors affecting the abundance of planktonic bacteria in various water masses are identified.

A. L. Suzdaleva

2001-01-01

392

Efficiency and its bounds for thermal engines at maximum power using Newton's law of cooling  

NASA Astrophysics Data System (ADS)

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.

Yan, H.; Guo, Hao

2012-01-01

393

Cooling, Heating, Generating Power, and Recovering Waste Heat with Thermoelectric Systems  

NASA Astrophysics Data System (ADS)

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.

Bell, Lon E.

2008-09-01

394

Pulse Generator Utilizing Superconducting Apparatus.  

National Technical Information Service (NTIS)

High power, phase coherent pulses are generated by superconducting apparatus which includes a superconducting cavity resonator that is pumped by a low power microwave source while being isolated from a load. Switching of the cavity to an emitting mode is ...

D. B. Birx

1978-01-01

395

High-Powered Gas-Cooled Microwave Ablation: Shaft Cooling Creates an Effective Stick Function Without Altering the Ablation Zone  

PubMed Central

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.

Knavel, Erica M.; Hinshaw, J. Louis; Lubner, Meghan G.; Andreano, Anita; Warner, Thomas F.; Lee, Fred T.; Brace, Christopher L.

2012-01-01

396

High-power laser phosphor light source with liquid cooling for digital cinema applications  

NASA Astrophysics Data System (ADS)

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.

Li, Kenneth

2014-02-01

397

Medium factors of electrical insulation systems in high temperature superconducting power apparatus with coil structure for equivalent ac withstand voltage test at room temperature  

Microsoft Academic Search

Equivalent insulation test voltage at room temperature of high temperature superconducting (HTS) power apparatus with coil structure for power frequency withstand voltage tests is discussed based on medium factors of insulation weak parts in electrical insulation elements of the HTS power apparatus. Uniform and non-uniform field gaps, triple junction and solid insulator surface are selected as the insulation weak parts,

M. Hara; T. Kurihara; R. Nakano; J. Suehiro

2005-01-01

398

Macrofouling communities in the cooling system of the Vladivostok heat and power plant  

NASA Astrophysics Data System (ADS)

The composition, structure, and distribution of flora and fauna on hydraulic facilities in the cooling system of the Vladivostok combined heat and power plant-2 were studied in summer and autumn of 2001. Cluster analysis was applied to differentiate Balanus rostratus, Mytilus trossulus, Jassa marmorata, Crassostrea gigas + Balanus rostratus, Modiolus modiolus + Pachycheles stevensii, Hydroides ezoensis, and Amphibalanus improvisus communities. The groups of fouling organisms found on the studied objects were shown to be assigned both to “physically controlled” and “biologically balanced” benthic communities. This study stresses the high similarity between the fouling communities of anthropogenic substrata and natural intertidal and subtidal benthic communities from adjacent areas of Peter the Great Bay.

Moshchenko, Alexander V.; Zvyagintsev, Alexander Yu.

2010-03-01

399

Water chemistry of a combined-cycle power plant's auxiliary equipment cooling system  

NASA Astrophysics Data System (ADS)

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.

Larin, B. M.; Korotkov, A. N.; Oparin, M. Yu.; Larin, A. B.

2013-04-01

400

Compatibility tests of materials for a lithium-cooled space power reactor concept  

NASA Technical Reports Server (NTRS)

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.

Sinclair, J. H.

1973-01-01

401

Determining Optimal Equipment Capacities in Cooling, Heating and Power (CHP) Systems  

SciTech Connect

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.

DeVault, Robert C [ORNL; Hudson II, Carl Randy [ORNL

2006-01-01

402

Realization of High-Temperature Superconductivity in Nano-Carbon Materials and Its Power Application.  

National Technical Information Service (NTIS)

Nano-carbon materials (carbon nanotubes (CNTs) and graphenes) are attracting significant attention. In particular, they have possibility for realization of high- transition temperature (Tc) superconductivity (SC) (e.g., Tc > 40K). In the present work, the...

J. Haruyama

2012-01-01

403

The effects of age on nuclear power plant containment cooling systems  

SciTech Connect

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.

Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A. [Brookhaven National Lab., Upton, NY (United States); Davis, J. [Science Applications International Corp., New York, NY (United States)

1994-04-01

404

Analysis of the solar powered/fuel assisted Rankine cycle cooling system. Phase I. Revision  

SciTech Connect

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 100/sup 0/C, and it is then superheated to about 600/sup 0/C 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.

Lior, N.; Koai, K.; Yeh, H.

1985-04-01

405

Outbreak of legionnaires' disease from a cooling water system in a power station.  

PubMed Central

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.

Morton, S; Bartlett, C L; Bibby, L F; Hutchinson, D N; Dyer, J V; Dennis, P J

1986-01-01

406

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

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.

Apfelbaum, Steven; Duvall, Kenneth; Nelson, Theresa; Mensing, Douglas; Bengtson, Harlan; Eppich, John; Penhallegon, Clayton; Thompson, Ry

2013-09-30

407

State of the art of superconducting fault current limiters and their application to the electric power system  

NASA Astrophysics Data System (ADS)

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.

Morandi, Antonio

2013-01-01

408

Transport critical current measurement apparatus using liquid nitrogen cooled high-Tc superconducting magnet with variable temperature insert  

NASA Astrophysics Data System (ADS)

We have developed an apparatus to investigate transport critical current (Ic) as a function of magnetic field and temperature using only liquid nitrogen. The apparatus consists of a (Bi,Pb)2Sr2Ca2Cu3O10 (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 Ic measurement environment for a high-Tc superconductor up to 500 A in magnetic fields up to 1 T and in temperatures ranging from 66 to 88 K.

Nishijima, G.; Kitaguchi, H.; Tshuchiya, Y.; Nishimura, T.; Kato, T.

2013-01-01

409

Numerical Hydraulic Study on Seawater Cooling System of Combined Cycle Power Plant  

NASA Astrophysics Data System (ADS)

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.

Kim, J. Y.; Park, S. M.; Kim, J. H.; Kim, S. W.

2010-06-01

410

The prototype fundamental power coupler for the spallation neutron source superconducting cavities : design and initial test results /  

SciTech Connect

Each of the 805 MHz superconducting cavities of the Spallation Neutron Source (SNS) is powered via a coaxial Fundamental Power Coupler (FPC) with a 50 {Omega} impedance and a warm planar alumina window. The design is derived from the experience of other laboratories; in particular, a number of details are based on the coupler developed for the KEK B-Factory superconducting cavities. However, other design features have been modified to account for the fact that the SNS FPC will transfer a considerably lower average power than the KEK-B coupler. Four prototypes have been manufactured so far, and preliminary tests performed on two of them at Los Alamos National Laboratory (LANL). During these tests, peak powers of over 700 kW were transferred through the couplers in the test stand designed and built for this purpose. This paper gives details of the coupler design and of the results obtained from the RF tests on the test stand during the last few months. A more comprehensive set of tests is planned for the near future.

Campisi, I. E.; Daly, E. F.; Davis, G. K.; Drury, M.; Henry, J. E.; Kneisel, P.; Powers, T.; Myneni, G.; Schneider, W; Stirbet, M.; Kang, Y. (Yunghee); Cummings, K. A. (Karen Ann); Wilson, K. M.

2001-01-01

411

Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants  

Microsoft Academic Search

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

Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

2009-01-01

412

A passive bearing system using superconducting magnets  

NASA Technical Reports Server (NTRS)

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.

Huang, X.; Eyssa, Y. M.

1990-01-01

413

Oak Ridge National Laboratory (ORNL) Superconducting Technology Program for electric power systems. Annual report for FY 1994  

SciTech Connect

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.

Koncinski, W.S. [ed.; Hawsey, R.A. [comp.

1994-12-01

414

Next generation cooled long range thermal sights with minimum size, weight, and power  

NASA Astrophysics Data System (ADS)

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.

Breiter, R.; Ihle, T.; Wendler, J.; Rühlich, I.; Ziegler, J.

2013-06-01

415

High speed 5000 hp superconducting propulsion motor for marine electric drives utilizing YBCO field coils  

Microsoft Academic Search

An electrical summary of a 2-pole, 900 kAT, 5000 HP compact superconducting propulsion motor with YBCO rotor windings and liquid nitrogen cooling with a power density of 3750 kVA\\/m3 is presented. This is a retrofit to the field of the 5.0 Tesla superconducting turbine generator built with a Nb-Ti conductor. The paper presents the electrical machine design and preliminary certification

Stephen Kuznetsov

1999-01-01

416

Experimental investigation of an ammonia-based combined power and cooling cycle  

NASA Astrophysics Data System (ADS)

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.

Tamm, Gunnar Olavi

417

ANALYSIS OF A HIGH TEMPERATURE GAS-COOLED REACTOR POWERED HIGH TEMPERATURE ELECTROLYSIS HYDROGEN PLANT  

SciTech Connect

An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The reactor heat is used to produce heat and electric power to the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.

M. G. McKellar; E. A. Harvego; A. M. Gandrik

2010-11-01

418

Interim Report: Air-Cooled Condensers for Next Generation Geothermal Power Plants Improved Binary Cycle Performance  

SciTech Connect

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

Daniel S. Wendt; Greg L. Mines

2010-09-01

419

Peltier cooling stage utilizing a superconductor-semiconductor junction  

SciTech Connect

This paper describes a Peltier cooling stack. It comprises: a first electrode; a superconducting layer electrically coupled to the first electrode; a semiconducting layer electrically coupled to the superconducting layer; and a second superconducting layer electrically coupled to the semiconductor layer; and a second electrode electrically coupled to the second superconducting layer, electrons flowing under an applied voltage from the first electrode through the first superconducting layer, semiconductor layer, second superconducting layer and second electrode, the electrical junction between the first superconducting layer and semiconductor providing Peltier cooling while the electrical junction between the semiconductor layer and the second superconducting layer providing Peltier heating, whereby a cryogenic Peltier cooling stack is provided.

Skertic, M.M.

1991-04-09

420

The potential for solar powered single-stage desiccant cooling in southern Europe  

Microsoft Academic Search

Desiccant cooling is an environmentally friendly technology which can be used to condition the internal environment of buildings. Unlike conventional air conditioning systems, which rely on electrical energy to drive the cooling cycle, desiccant cooling is a heat driven cycle. Desiccant cooling systems have been used successfully in northern Europe and a number of studies have demonstrated that solar energy

P. Mavroudaki; C. B. Beggs; P. A. Sleigh; S. P. Halliday

2002-01-01

421

Kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems  

Microsoft Academic Search

The results of applying a kinetic model to the chlorination data supplied by Commonwealth Edison on the once-through cooling system at the Quad Cities Nuclear Station provide a validation of the model. The two examples given demonstrate that the model may be applied to either once-through cooling systems or to cooling systems involving cooling towers.

Lietzke

1977-01-01

422

X-ray optics power considerations for high intensity x-ray free-electron lasers based on superconducting technology  

NASA Astrophysics Data System (ADS)

X-ray free-electron lasers generate ultrashort and very intense x-ray radiation in the wavelength domain reaching from the VUV (100 nm and shorter) all the way to the hard x-ray domain (typically 0.1 nm). FEL radiation features extreme brilliance, ultrashort pulse duration, and high peak power. Superconducting accelerators provide furthermore the possibility to accelerate a large number of electron bunches during a single radio-frequency pulse. Likewise the total number of x-ray pulses available for the experiments is increased leading to a significantly higher average brilliance. FEL light sources, and those based on super-conducting accelerator technology, are therefore considered to provide a new quality of short wavelength radiation if compared to existing x-ray sources. The high intensity and the high repetition rate lead to new requirements for x-ray optics in terms of peak and average power. Values for peak and average power are presented in relation to the proposed realization of the photon beamlines at the European XFEL facility.

Tschentscher, Th.; Sinn, H.; Tiedtke, K.; Wabnitz, H.

2007-05-01

423

DEPOSITION OF NIOBIUM AND OTHER SUPERCONDUCTING MATERIALS WITH HIGH POWER IMPULSE MAGNETRON SPUTTERING: CONCEPT AND FIRST RESULTS  

SciTech Connect

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.

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

424

Influence of a voltage compensation type active superconducting fault current limiter on the transient stability of power system  

NASA Astrophysics Data System (ADS)

We have proposed a voltage compensation type active superconducting fault current limiter (SFCL). In this paper, the influence of the SFCL on the transient stability of power system is investigated. For the typical one-machine infinite-bus system, the power-angle characteristics of generator with SFCL are studied in different working conditions, and the transient physical process is analyzed. Using MATLAB SIMULINK, the power-angle swing curves are simulated under different current-limiting modes, fault types and fault clearance times. The results show that the proposed SFCL can effectively reduce the transient swing amplitude of rotor and extend the critical clearance time under mode 1, compared with mode 2 and mode 3 having few effects on enhancing the transient stability.

Chen, L.; Tang, Y. J.; Shi, J.; Chen, N.; Song, M.; Cheng, S. J.; Hu, Y.; Chen, X. S.

2009-10-01

425

Evaluation method of power rating and energy capacity of Superconducting Magnetic Energy Storage system for output smoothing control of wind farm  

Microsoft Academic Search

This paper proposes a system composed of a wind turbine generator system and superconducting magnetic energy storage (SMES) unit, in which SMES is controlled for smoothing the wind generator output power. A determination of power rating and storage energy capacity of SMES unit which are sufficient for the smoothing control but as small as possible is very important problem. In

Tomoki Asao; Rion Takahashi; Toshiaki Murata; Junji Tamura; Masahiro Kubo; Yoshiharu Matsumura; Akira Kuwayama; Takatoshi Matsumoto

2008-01-01

426

Thermal bubble dynamics in cryogenic liquids under non-uniform electric fields on superconducting power apparatus  

Microsoft Academic Search

Thermal bubbles in the liquid coolant of superconducting and cryogenic apparatus are considered to be one of the factors that reduce the electrical breakdown voltage of the apparatus. This paper describes an experimental study of the influence of a non-uniform electric field on bubble behaviour and motion in liquid nitrogen. The electric field effect is quantitatively investigated by performing experiments

P. Wang; D. J. Swaffield; P. L. Lewin; G. Chen

2005-01-01

427

Four quadrant multilevel current source power conditioning for superconductive magnetic energy Storage  

Microsoft Academic Search

The main purpose of this paper is to describe advances in high current source converter (CSC) and control for use in superconductive magnetic energy storage (SMES) schemes instead of the conventional PWM-chopper based VSC configurations. The multi-level current reinjection (MLCR) CSC provides the simplest structure, as well as switching at zero current, a property that permits retaining the use of

N. J. Murray; J. Arrillaga; N. R. Watson; Y. H. Liu

2009-01-01

428

Investigation of the power losses in a laminated dipole magnet with superconducting coils  

Microsoft Academic Search

Dynamic processes in a window-frame dipole with superconducting windings and a cold, laminated iron yoke have been investigated experimentally at JINR (Dubna, Russia), and theoretically at GSI (Darmstadt, Germany). The main aim of these investigations was a reduction of energy losses in the yoke during ramping. These losses are produced mainly by energy dissipation due to eddy currents and hysteresis

Alexander Kalimov; Egbert Fischer; Guenter Hess; Gebhard Moritz; Carsten Mühle

2004-01-01

429

Experiments on solar photovoltaic power generation using concentrator and liquid cooling  

NASA Technical Reports Server (NTRS)

Calculations and experimental data are presented leading to the development of a practical, economical solar photovoltaic power supply. The concept involves concentration of sunlight up to about 100 times normal solar intensity in a solar tracking collector and directing this to an array of solar cells. The cells are immersed in water circulated from a thermal reservoir which limits cell temperature rise to about 20 C above ambient during the day and which cools to ambient temperature during the night. Experiments were conducted on solar cells using a Fresnel lens for magnification, a telescope equatorial mount with clock drive, and tap water circulated through the solar cell holder cavity. Test results show that cells operate satisfactorily under these conditions. Power outputs achieved experimentally with cell optimized for 25 suns were linear with concentration to about 15 suns. Cells optimized for 100 suns were not available, but a corresponding linear relation of power output with concentration is anticipated. Test results have been used in a design analysis of the cost of systems utilizing this technique.

Beam, B. H.; Hansen, C. F.

1975-01-01

430

System for thermal energy storage, space heating and cooling and power conversion  

DOEpatents

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.

Gruen, Dieter M. (Downers Grove, IL); Fields, Paul R. (Chicago, IL)

1981-04-21

431

High power RF test of an 805 MHz RF cavity for a muon cooling channel  

NASA Astrophysics Data System (ADS)

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 Q0 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.

Li, D.; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.

2002-05-01

432

Solid-Core, Gas-Cooled Reactor for Space and Surface Power  

SciTech Connect

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.

King, Jeffrey C.; El-Genk, Mohamed S. [Institute for Space and Nuclear Power Studies, University of New Mexico, Albuquerque, NM 87131 (United States); Chemical and Nuclear Engineering Dept., University of New Mexico, Albuquerque, NM 87131 (United States)

2006-01-20

433

Design and optimization of the heat rejection system for a liquid cooled thermionic space nuclear reactor power system  

NASA Astrophysics Data System (ADS)

The heat transport subsystem for a liquid metal cooled thermionic space nuclear power system was modelled using algorithms developed in support of previous nuclear power system study programs, which date back to the SNAP-10A flight system. The model was used to define the optimum dimensions of the various components in the heat transport subsystem subjected to the constraints of minimizing mass and achieving a launchable package that did not require radiator deployment. The resulting design provides for the safe and reliable cooling of the nuclear reactor in a proven lightweight design.

Moriarty, Michael P.

1993-01-01

434

The development of high cooling power and low ultimate temperature superfluid Stirling refrigerators  

NASA Astrophysics Data System (ADS)

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.)

Patel, Ashok B.

435

On new possibilities in microwave superconductivity  

NASA Astrophysics Data System (ADS)

Superconductivity is a phenomenon that has been fascinating scientists, engineers, and the general public since its discovery in 1911. Many people associate the properties of superconductors with the astonishing demonstration of a levitating magnet over a superconductor when it is cooled down below its transition temperature. We now know that superconductivity is a very common phenomenon present in many metals in the periodic table. It was not until 1986 that superconductivity above about 30 K was discovered, giving birth to the era of high temperature superconductors. Today many applications take advantage of this property, ranging from medical instrumentation, transportation, high energy particle accelerators, to digital and analog electronics. Most of the applications fall within two well differentiated uses of superconductors, for which different properties are being exploited. One example is the use of superconductors to generate very large static magnetic fields, which usually employ newly discovered high temperature superconductors, taking advantage of their very large upper critical magnetic field. Alternatively, applications involving high-power microwaves usually rely on superconductors with high lower critical magnetic field, for which niobium is commonly the material of choice. Almost a century after the discovery of superconductivity, this dissertation explores potential new possibilities for high power microwave superconducting applications. First, we study and model a new method of determining the magnetic critical field of superconducting materials at microwave frequencies. Subsequently, we numerically study the theoretical performance of multilayer structures composed of alternating superconducting and dielectric materials. These structures theoretically allow us to sustain higher magnetic fields than niobium at microwave frequencies.

Canabal, Alberto

436

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent  

PubMed Central

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.

Chien, Shih-Hsiang; Dzombak, David A.; Vidic, Radisav D.

2013-01-01

437

Development of superconducting AC generator  

SciTech Connect

A 50 MVA superconducting (AC) generator with a superconducting field winding was manufactured and tested. Conceptual design of a 1000 MW superconducting generator was carried out. Key components of the superconducting field winding, cryogenic multi-cylindrical rotor, helium cooling system and airgap armature winding were required to operate without problems for a long time. This paper describes test results for the 50 MVA generator and design results of the 1000 MW generator. Furthermore, a technical overview of superconducting generator development is made on the basis of these results.

Maki, N.; Yamaguchi, K.; Takahashi, M.; Shiobara, R.

1988-03-01

438

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. ...

439

Development of 10 kA high temperature superconducting power cable for railway systems  

NASA Astrophysics Data System (ADS)

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.

Tomita, M.; Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.

2012-03-01

440

Optimum combinations of cooling alternatives for stream - electric power plants. Volume II. Final report  

Microsoft Academic Search

An overview of cooling alternatives and detailed system thermodynamics are presented. Two sets of computer models are developed for the analysis of wet tower\\/cooling pond and wet tower\\/once-through combination cooling systems. The models are used to study the thermal characteristics, economics, and water consumption of these combination cooling systems. The effects of both meteorological conditions and economic parameters such as

T. E. Croley; A. R. Giaquinta; R. M. H. Lee; T. Hsu

1978-01-01

441

Recent advances in actively cooled high-power laser diode bars  

NASA Astrophysics Data System (ADS)

In order to meet the ever increasing demands of many high power laser diode customers, Nuvonyx has worked to improve a number of key metrics of the diode laser package. The most often challenged specifications are power per bar, efficiency, and reliability in both hard pulse and constant current mode. In response to these requests, Nuvonyx has worked to offer commercial component devices in excess of 100 and 150 watts per bar package in multiple wavelengths. The packages are routinely combined to form single stacks that generate greater than 3.5 kilowatts each and two-dimensional arrays which produce light in excess of 10 kilowatts. These parts all demonstrate predicted lifetimes in excess of 10,000 hours. The micro-channel cooled heat sink has also been improved by closer matching the coefficient of thermal expansion of the cooler to the laser diode bar, which allows for harder solders such as gold-tin to be employed. All of this work has helped to meet the specifications of the most demanding laser diode customers.

Ostrom, Nels P.; Roh, S. D.; Grasso, Daniel M.; Kane, Thomas J.

2007-03-01

442

Insulation studies and experimental results for high Tc superconducting power cable  

Microsoft Academic Search

In this paper, we studied electric insulation characteristics of synthetic Laminated Polypropylene Paper (LPP) in liquid nitrogen (LN2) for the application to high temperature superconducting (HTS) cable. And, we selected the insulation paper\\/LN2 composite insulation type for the electric insulation design of a HTS cable. Furthermore, we compared the breakdown characteristics of the butt gap and bent mini-model cable that

H. J. Kim; D. S. Kwag; J. W. Cho; K. C. Seong; K. D. Sim; S. H. Kim

2005-01-01

443

Optimum combinations of cooling alternatives for stream-electric power plants, volume 2  

Microsoft Academic Search

Cooling alternatives and system thermodynamics are presented. Two sets of computer models are developed for the analysis through combination cooling systems. The models are used to study the thermal characteristics, economics, and water consumption of these combination cooling systems. The effects of both meteorological conditions and economic parameters such as various unit costs, were examined in the identification of optimum

T. E. Croley; A. R. Giaquinta; R. M. H. Lee; T. D. Hsu

1978-01-01

444

A Model to Predict Total Chlorine Residue in the Cooling Seawater of a Power Plant Using Iodine Colorimetric Method  

PubMed Central

A model experiment monitoring the fate of total residue oxidant (TRO) in water at a constant temperature and salinity indicated that it decayed exponentially with time, and with TRO decaying faster in seawater than in distilled water. The reduction of TRO by temperature (°K) was found to fit a curvilinear relationship in distilled water (r2 = 0.997) and a linear relationship in seawater (r2 = 0.996). Based on the decay rate, flow rate, and the length of cooling water flowing through at a given temperature, the TRO level in the cooling water of a power plant could be estimated using the equation developed in this study. This predictive model would provide a benchmark for power plant operators to adjust the addition of chlorine to levels necessary to control bio-fouling of cooling water intake pipelines, but without irritating ambient marine organisms.

Wang, Jih-Terng; Chen, Ming-Hui; Lee, Hung-Jen; Chang, Wen-Been; Chen, Chung-Chi; Pai, Su-Cheng; Meng, Pei-Jie

2008-01-01

445

Thermal effluent from the power sector: an analysis of once-through cooling system impacts on surface water temperature  

NASA Astrophysics Data System (ADS)

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.

Madden, N.; Lewis, A.; Davis, M.

2013-09-01

446

PREFACE: Superconducting materials Superconducting materials  

NASA Astrophysics Data System (ADS)

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

Charfi Kaddour, Samia; Singleton, John; Haddad, Sonia

2011-11-01

447

Removing Cool Cores and Central Metallicity Peaks in Galaxy Clusters with Powerful Active Galactic Nucleus Outbursts  

NASA Astrophysics Data System (ADS)

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.

Guo, Fulai; Mathews, William G.

2010-07-01

448

Load Excitation at the Superconducting Cable Test Facility.  

National Technical Information Service (NTIS)

The superconducting cable test facility was constructed to evaluate and demonstrate flexible superconducting power transmission cables under realistic conditions. Power supplies were installed to excite two superconducting cables either separately or simu...

E. B. Forsyth A. J. McNerney M. Meth

1979-01-01

449

MoXy fiber with active cooling cap for bovine prostate vaporization with high power 200W 532 nm laser  

NASA Astrophysics Data System (ADS)

A novel MoXyTM fiber delivery device with Active Cooling Cap (ACCTM) is designed to transmit up to 180W of 532 nm laser light to treat benign prostatic hyperplasia (BPH). Under such high power tissue ablation, effective cooling is key to maintaining fiber power transmission and ensuring the reliability of the fiber delivery device To handle high power and reduce fiber degradation, the MoXy fiber features a larger core size (750 micrometer) and an internal fluid channel to ensure better cooling of the fiber tip to prevent the cap from burning, detaching, or shattering during the BPH treatment. The internal cooling channel was created with a metal cap and tubing that surrounds the optical fiber. In this study MoXy fibers were used to investigate the effect of power levels of 120 and 200 W on in-vitro bovine prostate ablation using a 532 nm XPSTM laser system. For procedures requiring more than 100 kJ, the MoXy fiber at 200W removed tissue at twice the rate of the current HPS fiber at 120W. The fiber maintained a constant tissue vaporization rate during the entire tissue ablation process. The coagulation at 200W was about 20% thicker than at 120W. In conclusion, the new fibers at 200W doubled the tissue removal rate, maintained vaporization efficiency throughout delivery of 400kJ energy, and induced similar coagulation to the existing HPS fiber at 120W.

Peng, Steven Y.; Kang, Hyun Wook; Pirzadeh, Homa; Stinson, Douglas

2011-02-01

450

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...

451

CFD simulation on a thermal power plant with air-cooled heat exchanger system in north China  

Microsoft Academic Search

Purpose – The purpose of this paper is to investigate the overall flow and temperature field of the air in the whole power plant, especially around the air-cooled heat exchanger (ACHE) to evaluate the feasibility of the thermal plant project. Design\\/methodology\\/approach – The commercial computational fluid dynamics code FLUENT with standard k-? turbulent model was used. The buoyancy of the

Q. W. Wang; D. J. Zhang; M. Zeng; M. Lin; L. H. Tang

2008-01-01

452

Coupled RELAP/PARCS Full Plant Model Assessment of a Cooling Transient in Trillo Nuclear Power Plant. International Agreement Report.  

National Technical Information Service (NTIS)

This report presents the methodology to change from a 0-D kinetics core in a RELAP5/Mod3.3 full plant model of Trillo NPP to a coupled RELAP5/PARCS 3-D core. The coupled plant model is assessed against a real cooling transient that deformed the core power...

G. Verdu J. C. Martinez-Murillo M. Novo R. Miro T. Barrachina

2011-01-01

453