Note: This page contains sample records for the topic cooled superconducting power from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Performance tests of high temperature superconducting power cable cooling system  

Microsoft Academic Search

A high temperature superconducting power cable requires forced flow cooling. Liquid nitrogen is circulated by a pump and cooled down by a subcooling system. Typical operating temperature range is expected to be between 65 K and 80 K. The circulating liquid nitrogen is subcooled by liquid nitrogen boiling on the shell side of a subcooler heat exchanger, and then it

Deukyong Koh; Hankil Yeom; Yongju Hong; Kwansoo Lee

2004-01-01

2

Counter flow cooling characteristics with liquid nitrogen for superconducting power cables  

Microsoft Academic Search

Counter flow cooling is one of effective cooling systems for superconducting power transmission cables to save space. In designing of HTc superconducting power cables, investigating cooling characteristics with liquid nitrogen is important. We have conducted counter flow cooling tests of a 100-m long duplex-counter-flow tube with liquid nitrogen and obtained basic data of initial cooling and temperature distributions along the

Mitsuho Furuse; Shuichiro Fuchino; Noboru Higuchi

2002-01-01

3

Micro Power Grid System With SMES and Superconducting Cable Modules Cooled by Liquid Hydrogen  

Microsoft Academic Search

For future power system, a micro power grid system, which is mainly composed of several power modules, such as superconducting (SC) cable, superconducting magnetic energy storage (SMES) system, hydrogen system, fuel cell (FC) system, renewable energy modules, and power converter modules, is expected. In the grid system, hydrogen mainly produced by renewable energy is liquefied for cooling down of the

Tomonori Nakayama; Tsuyoshi Yagai; Makoto Tsuda; Takataro Hamajima

2009-01-01

4

Power applications for superconductivity  

Microsoft Academic Search

A new class of materials that conduct electricity with virtually no resistance losses is being used on some of the key elements of a superconducting power grid. Several prototype devices are being tested or are nearing testing on utility systems. Electric wires that become superconducting when cooled to the affordable operating-temperature realm of liquid nitrogen - as well as coils,

1996-01-01

5

Superconducting magnet cooling system  

DOEpatents

A device is provided for cooling a conductor to the superconducting state. The conductor is positioned within an inner conduit through which is flowing a supercooled liquid coolant in physical contact with the conductor. The inner conduit is positioned within an outer conduit so that an annular open space is formed therebetween. Through the annular space is flowing coolant in the boiling liquid state. Heat generated by the conductor is transferred by convection within the supercooled liquid coolant to the inner wall of the inner conduit and then is removed by the boiling liquid coolant, making the heat removal from the conductor relatively independent of conductor length.

Vander Arend, Peter C. (Center Valley, PA); Fowler, William B. (St. Charles, IL)

1977-01-01

6

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

7

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

8

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

9

The integration of cryogenic cooling systems with superconducting electronic systems  

Microsoft Academic Search

The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types

Michael A

2003-01-01

10

Feasibility of Hydrogen Cooled Superconducting Magnets  

Microsoft Academic Search

It looks feasible to realize hydrogen cooled superconducting magnets with High Tc Superconductors (HTS) and newly discovered magnesium di-boride (MgB2). As is well known, liquid and slush hydrogen between 15~20 K, could be not only an excellent refrigerant for HTS and MgB2, but also a clean energy transporter without exhaust of carbon di-oxide. HTS cooled by liquid hydrogen at 22

Hiromi Hirabayashi; Yasuhiro Makida; Shinichi Nomura; Takakazu Shintomi

2006-01-01

11

STOCHASTIC COOLING POWER REQUIREMENTS.  

SciTech Connect

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

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

2004-07-05

12

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

13

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

14

The integration of cryogenic cooling systems with superconducting electronic systems  

SciTech Connect

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

Green, Michael A.

2003-07-01

15

Cooling system for superconducting magnet  

SciTech Connect

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

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

1998-12-15

16

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

17

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

18

Cool-down characteristic of conduction-cooled superconducting magnet by a cryocooler  

NASA Astrophysics Data System (ADS)

The initial cooling is crucial in conduction-cooled superconducting magnet system. Since a cryocooler is the only heat sink in conduction-cooled superconducting magnet system, the initial cool-down time is strongly dependent upon the refrigeration capacity of cryocooler. In this paper, the process of estimation of initial cool-down time is presented. The procedure includes the modeling of properties of low temperature superconductor, the dimensions of superconducting magnet, the cryogenic loads, the thermal link between magnet and cryocooler, and the available refrigerating capacity of a cryocooler. The method is applied to the 3 T superconducting magnet cooled by a two-stage GM cryocooler, showing that the results of proposed method have a good agreement with those of experiment. The effects of superconducting magnet size and secondary thermal link on the cool-down characteristic are also discussed.

Choi, Y. S.; Kim, D. L.; Shin, D. W.

2011-11-01

19

Cooling of superconducting devices by liquid storage and refrigeration unit  

DOEpatents

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

20

Conceptual study of superconducting urban area power systems  

NASA Astrophysics Data System (ADS)

Efficient transmission, distribution and usage of electricity are fundamental requirements for providing citizens, societies and economies with essential energy resources. It will be a major future challenge to integrate more sustainable generation resources, to meet growing electricity demand and to renew electricity networks. Research and development on superconducting equipment and components have an important role to play in addressing these challenges. Up to now, most studies on superconducting applications in power systems have been concentrated on the application of specific devices like for example cables and current limiters. In contrast to this, the main focus of our study is to show the consequence of a large scale integration of superconducting power equipment in distribution level urban power systems. Specific objectives are to summarize the state-of-the-art of superconducting power equipment including cooling systems and to compare the superconducting power system with respect to energy and economic efficiency with conventional solutions. Several scenarios were considered starting from the replacement of an existing distribution level sub-grid up to a full superconducting urban area distribution level power system. One major result is that a full superconducting urban area distribution level power system could be cost competitive with existing solutions in the future. In addition to that, superconducting power systems offer higher energy efficiency as well as a number of technical advantages like lower voltage drops and improved stability.

Noe, Mathias; Bach, Robert; Prusseit, Werner; Willén, Dag; Gold-acker, Wilfried; Poelchau, Juri; Linke, Christian

2010-06-01

21

Conduction-Cooled Superconducting Magnet for Material Control Application  

Microsoft Academic Search

The conduction-cooled superconducting magnet with operating current of 180 A is designed, fabricated, and tested for material control application. The superconducting magnet has the effective standard warm bore of 52 mm and the maximum central field of 3 Tesla. Since magnetic field gradient should be larger at the end rather than at the center of the magnet for material control,

Yeon Suk Choi; Dong Lak Kim; Byoung Seob Lee; Hyung Suk Yang; Thomas A. Painter

2009-01-01

22

Superconducting power: meeting the challenges  

Microsoft Academic Search

Superconductivity has the potential to bring a more fundamental change to electric power technologies than has occurred since electricity use became widespread over a century ago. The potential is for an energy revolution as profound as the impact fiber optics has had on communications. The fiber optic “information superhighway” was constructed by replacing copper wires with a higher capacity alternative.

J. G. Daley; R. A. Hawsey; J. S. Badin

2001-01-01

23

Cryogenic system with the sub-cooled liquid nitrogen for cooling HTS power cable  

Microsoft Academic Search

A 10m long, three-phase AC high-temperature superconducting (HTS) power cable had been fabricated and tested in China August 2003. The sub-cooled liquid nitrogen (LN2) was used to cool the HTS cable. The sub-cooled LN2 circulation was built by means of a centrifugal pump through a heat exchanger in the sub-cooler, the three-phase HTS cable cryostats and a LN2 gas–liquid separator.

Y. F. Fan; L. H. Gong; X. D. Xu; L. F. Li; L. Zhang; L. Y. Xiao

2005-01-01

24

Applications of Superconductivity in Electric Power Systems.  

National Technical Information Service (NTIS)

Major applications of superconductivity to power systems are considered. The state of the art of materials and refrigeration developments that are necessary for these applications is reviewed. Specific applications including superconducting cables for pow...

W. E. Keller

1976-01-01

25

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); Lowe, Kirk T. (Knoxville, TN)

2010-09-14

26

Cryogenic Engineering for Superconducting Power Transmission Systems.  

National Technical Information Service (NTIS)

The successful introduction of helium-cooled (superconducting) transmission systems into electric utility networks will open a vast market for cryogenic engineering components and services. If only 10 percent of the anticipated investment in transmission ...

E. B. Forsyth

1976-01-01

27

A helium thermosiphon cooling loop for the APS superconducting undulator  

NASA Astrophysics Data System (ADS)

A thermosiphon cooling system is being pursued as part of the superconducting undulator magnet development at Argonne National Laboratory. Analyses carried out at the University of Wisconsin-Madison address several unique features for the helium-filled cooling loop including sub-cooling associated with the hydrostatic head, the impact of a heat load deposited primarily along the horizontal channel, and two-phase flow characterization at extremely low quality conditions. Results of the analyses are compared with experimental measurements for a full-scale cooling loop. Both the analyses and measurements address the design objective of maintaining the superconducting windings well below their current sharing temperature by exploring the flow induced heat transfer to the single and two-phase regions of the helium cooling loop.

Potratz, Daniel; Pfotenhauer, John; Hasse, Quentin; Ivanyushenkov, Yury; Moog, Elizabeth; Kustom, Robert

2012-06-01

28

Thermosiphon cooling of superconducting field windings in a cryoturbogenerator  

NASA Astrophysics Data System (ADS)

Cooling systems for superconducting field windings of cryoturbogenerators are examined from the standpoint of cryostabilization. Several possible designs based on the thermosiphon effect are considered and the most promising system is selected. The calculation method for an open-circuit thermosiphon is developed, which gives good agreement with experimental results. It is shown that cryostabilization of superconducting windings is possible under certain conditions, which provides very high reliability of the cryoturbogenerator operation.

Babenko, F. M.; Gavrilov, R. V.

29

Experimental investigation on ejecting low-temperature cooling superconducting magnets  

NASA Astrophysics Data System (ADS)

With the development of the high-temperature superconducting (HTS) materials and refrigeration technologies, using ejecting refrigeration to cool the superconducting materials becomes the direction of HTS applications. In this paper, an experimental study has been carried out on the basis of the theory of analyzing the ejecting low-temperature cooling superconducting magnet. The relationship between area ratios and refrigeration performance at different system pressures was derived. In addition, the working fluid flow and suction chamber pressure of the ejector with different area ratios at various inlet pressures have been examined to obtain the performance of ejectors under different working conditions. The result shows that the temperature of liquid nitrogen can be reduced to 70 K by controlling the inlet water pressure when the pressurized water at 20 °C is used to eject the saturated liquid nitrogen, which can provide the stable operational conditions for the HTS magnets cooling.

Liu, Bin; Zhang, Qiang; Tong, Ming-wei; Hu, Peng; Wu, Shuang-ying; Cai, Qin; Qin, Zeng-hu

2013-10-01

30

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

31

System and method for cooling a superconducting rotary machine  

SciTech Connect

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

Ackermann, Robert Adolf (Schenectady, NY); Laskaris, Evangelos Trifon (Schenectady, NY); Huang, Xianrui (Clifton Park, NY); Bray, James William (Niskayuna, NY)

2011-08-09

32

System and method for cooling a super-conducting device  

DOEpatents

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

33

Development of a 500 kVA-class oxide-superconducting power transformer operated at liquid-nitrogen temperature 1 An extended version of the following paper presented in ICEC16\\/ICMC (Kitakyushu, 1996). Funaki, K. et al. Design and construction of a 500 kVA-class oxide superconducting power transformer cooled by liquid nitrogen Proc. of ICEC16\\/ICMC (1997) Part 2 1009-1012 1  

Microsoft Academic Search

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 785mm in diameter and 1210mm in height, that has a room-temperature space for an iron core with the diameter of 314mm. The primary and secondary windings are three-strand and six-strand parallel conductors of a

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

1998-01-01

34

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

Microsoft Academic Search

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

Michael A Green

2003-01-01

35

The electrical aspects of the choice of former in a high Tc superconducting power cable  

Microsoft Academic Search

Centrally located in a superconducting power cable the former supplies a rigid means onto which to wind the superconducting tapes and enables a continuous supply of cooling power via a flow of liquid cryogen through it. Therefore, the choice of former has a broad impact on the construction and design of a cable. The diameter of the former determines the

C. Traeholt; A. Kuhle; S. K. Olsen; O. Tonnesen

1999-01-01

36

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

37

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

38

Research on large superconducting generators cools off in US  

SciTech Connect

Now that utilities are dropping plans to build large generating units, research and development on large superconducting generators is ending in the US. Interest in superconducting generators was due to their potential capital cost savings of 50% and smaller size. Interviews with Westinghouse, General Electric, and the Electric Power Research Institute indicate that, while some military-related work will continue, utility-related work will wait until load growth warrants continued research and testing.

Smock, R.

1984-06-01

39

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

40

Surface cooled, vacuum impregnated superconducting magnet systems: Design, construction, applications  

NASA Astrophysics Data System (ADS)

The design and construction of three superconducting magnet systems for applications in the fields of medical imaging, plasma physics and nuclear physics are described. All three systems have vacuum impregnated, intrinsically stable coils with cooling at the outer surfaces of the winding package with liquid helium, and are all coupled in some way to closed cycle cooling systems. General theories are discussed. The techniques used in both the design and the construction of the different magnet systems, are given. The use of numerical methods for the calculation of thermal and mechanical properties of superconducting coil systems, is emphasized. The experimental results obtained with the Delft magnetic resonance imaging system are described and examples of images showing sagittal sections of the human head, successfully produced with this system, are given.

Dam, Jacobus Adrianus Maria; Pieterman, Karel

41

Cryogenic engineering for superconducting power transmission systems  

Microsoft Academic Search

The successful introduction of helium-cooled (superconducting) transmission systems into electric utility networks will open a vast market for cryogenic engineering components and services. If only 10 percent of the anticipated investment in transmission facilities in the U.S. after 1990 is made in helium-cooled systems this will represent a potential annual market of over $120,000,000 for the manufacturers of cryogenic components.

Forsyth

1976-01-01

42

Conceptual Design of an All Superconducting Mini Power Plant Model  

Microsoft Academic Search

The development of all superconducting (AS) plants (ASP), as for example AS mini power plants (MPP), or AS substations is a new trend in power applications of superconductivity. Superconductivity can contribute significantly to increase the advantages of MPPs. Exceeding the stage of the development of individual superconducting power devices (SPD), more and more concern is being focused around ASPs consisting

István Vajda

2002-01-01

43

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

44

Fundamental Power Couplers for Superconducting Cavities  

Microsoft Academic Search

Fundamental power couplers (FPC's) for superconducting cavities must meet very strict requirements to perform at high power levels (hundreds of kilowatts) and in a variety of conditions (CS, pulsed, travelling wave, standing wave) without adversely affecting the performance of the cavities they are powering. Producing good coupler designs and achieving operational performances in accelerator environments are challenging tasks that have

Isidoro E. Campisi

2001-01-01

45

Experimental investigation on the detachable thermosiphon for conduction-cooled superconducting magnets  

Microsoft Academic Search

A detachable thermosiphon, as a transient thermal switch for conduction-cooled superconducting magnet, is designed, fabricated and tested. A thermosiphon between the first and second stages of a cryocooler can reduce the cool-down time of a conduction-cooled superconducting magnet by using the large cooling capacity of the first stage. The thermosiphon is a very efficient heat transfer device until all the

Sangkwon Jeong; Youngkwon Kim; Changhyun Noh; Seokho Kim; Hongbeom Jin

2006-01-01

46

Optimal cool-down time of a 4 K superconducting magnet cooled by a two-stage cryocooler  

NASA Astrophysics Data System (ADS)

A cool-down time is one of the major factors in many cryocooler applications, especially for the design of conduction-cooled superconducting devices. Cool-down time means a time cooling a thermal mass from a room-temperature to cryogenic-temperature within a stipulated amount of time. The estimation of cool-down time seeks the elapsed time to cool the thermal object by a cryocooler during initial cool-down process. This procedure includes the dimension and properties of thermal object, heat transfer analysis for cryogenic load, thermal interface between cold mass and cryocooler, and available refrigeration capacity of cryocooler. The proposed method is applied to the specific cooling system for 3 T superconducting magnet cooled by a two-stage GM cryocooler. The result is compared with that of experiment, showing that proposed method has a good agreement with experiment. In addition, the initial cool-down time can be shortened by employing thermal link between the cold mass and first-stage of cryocooler. Through a rigorous modeling and analysis taking into account the effect of thermal link size, it is concluded that there exists an optimal cool-down time during initial cooling in conduction-cooled superconducting magnet system.

Choi, Yeon Suk; Kim, Dong Lak; Shin, Dong Won

2012-01-01

47

Electromagnetic Phenomena in Superconducting Magnet for Fusion Facility -Pool-Cooled Superconducting Coil-  

NASA Astrophysics Data System (ADS)

The features of superconducting coils for nuclear fusion devices include large size, high field, and high current density. A large conductor is needed for such a large coil to suppress the voltage increase. Since the ability of pool-cooling becomes relatively less with the increase of conductor size, new technologies are necessary to achieve both sufficient mechanical strength and cryogenic stability with high current density. A composite conductor of the 20 kA class was developed for the LHD helical coils. The conductor consists of a pure aluminum stabilizer, a copper sheath, and NbTi/Cu strands. New electromagnetic phenomena, which are Hall current and slow current diffusion into the stabilizer, deteriorate the cryogenic stability. The mechanism and countermeasures are described. Furthermore, a perspective on pool-cooled coils is discussed.

Imagawa, Shinsaku

48

Magnesium diboride wire application to high power superconducting dc cables  

NASA Astrophysics Data System (ADS)

In 1967, R. L. Garwin and J. Matisoo considered the possibility of constructing a 100 GW, 1000 km, dc superconducting transmission line based on the then newly discovered type II material, Nb_3Sn, refrigerated by liquid helium at 4.2 K.^1 Their paper is viewed by many as the seminal study on the practicality of superconductivity for use in electric transmission cables, and influenced the design of the high temperature superconducting cables now undergoing demonstration worldwide refrigerated by liquid nitrogen, although at much lower power capacities due to the high cost of high temperature superconducting wire. However, the recent discovery of the 39 K MgB2 superconductor and its promise of cheap, high performance wire may enable the multi-gigawatt capacity transmission line Garwin-Matisoo envisioned. In this presentation, we will rescale their study for MgB2 cooled by liquid hydrogen at 21 K, which will be used as an additional energy delivery agent as well as a cryogen. ^1R. L. Garwin and J. Matisoo, Proc. IEEE 55, 538 (1967).

Grant, Paul M.

2003-03-01

49

Superconducting helical solenoid systems for muon cooling experiment at Fermilab  

SciTech Connect

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

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

2007-08-01

50

Development of Superconducting Magnets with Current Leads without Gas Cooling  

NASA Astrophysics Data System (ADS)

The superconducting magnets (SCM) of electromagnetic vibration apparatus for MAGLEV ground coils operate in a persistent current mode for long periods of time. In addition, almost all of the time, the current lead of the SCM acts as a route for heat leak to the inside; therefore, the authors have developed low-heat-load current lead equipment. This equipment consists of a high-temperature superconductor (HTS) lead and the low-duty metallic lead allows the SCM to magnetize and demagnetize without a gas cooling system. This realizes a simplification of work procedure and reliable operations for magnetizing and demagnetizing the SCM. This result is also valuable for further improving the SCM of the MAGLEV vehicle.

Ogata, Masafumi; Nagashima, Ken; Miyazaki, Yoshiki; Iwamatsu, Masaru

51

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

52

Ice pond cooling system for power plants  

SciTech Connect

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 presented. This scheme was applied to a 1000 MW nuclear power plant that requires a constant condenser cooling water flow of 1337 cfs.

Miller, A.C.; Pena, J.A.; Urbsanski, J.; Kerr, S.N.

1983-09-01

53

Optimization of cryostabilized superconducting generator windings cooled by the thermosiphon method  

NASA Astrophysics Data System (ADS)

The problem of optimum parameter choice for the superconducting field winding when using the thermosophon cooling method has been discussed. As an optimum criterion, the magnetic flow within the superconducting field winding at a given outer radius of rim cylinder is chosen. The restrictions it imposes on the superconducting field winding cryostabilization and mechanical strength of its supporting elements are taken into consideration. The parameters to be optimized are: the inner and outer radii of the superconducting field winding, superconducting field winding current, ratio of the superconductor area to the matrix area in the multifilamentary composite conductor, cooling channel dimensions, and dimensions of the superconducting field winding supporting elements. The optimum magnetic flows for the stabilized and non-stabilized windings and for windings made of normal metal are compared.

Gavrilov, R. V.; Zhitomirsky, I. S.

54

Experimental study of gas-cooled current leads for superconducting magnets. [ESCAR  

Microsoft Academic Search

Design details and experimental test results from several design variations of the gas-cooled, copper current leads used in conjunction with the superconducting dipole magnets for ESCAR (Experimental Superconducting Accelerator Ring) are reported. Thermal acoustic oscillations, which were experienced with an initial design, were eliminated in subsequent designs by a reduction of the hydraulic diameter. The occurrence of these oscillations is

1978-01-01

55

A 10 T cryo-cooled superconducting magnet with 100 mm room temperature bore  

Microsoft Academic Search

A cryo-cooled NbTi\\/Nb3Sn superconducting magnet has been fabricated. It generated 10T field in the center of a 100 mm room temperature bore. A 4K GM refrigerator, using Er3Ni regenerator material, cooled the magnet without help of liquid helium. Heat generated in coils is removed through the heat conduction copper cylinder attached on the outer wall of each coil. Bi(2212) superconducting

M. Urata; K. Koyanagi; T. Kuriyama; K. Yamamoto; S. Nakayama; T. Yazawa; S. Nomura; Y. Yamada; H. Nakagome; S. Murase; H. Maeda; O. Horigami

1996-01-01

56

Research and development of super-conductive cable and AC power equipment  

NASA Astrophysics Data System (ADS)

Super-conducting AC power equipment project started as a national project in 2000 fiscal year by METI and NEDO. This project is to research and develop the basic technology of super-conductive cable (high temperature super-conductive cable, HTS-cable), fault current limiter (FCL) and transformer. Main subjects are to study the 3 kA Super-conducive conductor, cooling technology of 500 m HTS-cable, manufacturing technology of 66 kV/1 kA class SN type of FCL, high voltage technology of AC magnet and pulse magnet, and power system analysis of super-conductive cable and AC equipments. The paper describes the background of this project, target of each research subject, schedule of research and development, and major results of research activity in 2001.

Ueda, K.; Ozawa, Y.; Wachi, Y.; Kikuchi, A.; Nakatsuka, T.; Iwadate, K.

2002-10-01

57

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

58

Power electronics substrate for direct substrate cooling  

DOEpatents

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

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

2012-05-01

59

Cryogenic System for a High Temperature Superconducting Power Transmission Cable  

SciTech Connect

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

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

1999-07-12

60

Superconductive energy storage inductor-converter units for power systems  

Microsoft Academic Search

Large magnets with superconductive windings could serve to perform a power system function analogous to pumped storage hydro. A conventional Graetz bridge converter as used in dc transmission provides an ideal interface between the three-phase power system and the superconductive magnet or inductor. Such Inductor-Converter or I-C units, when properly controlled, provide significant power system benefits. Power reversibility is achievable

H. A. Peterson; N. Mohan; R. W. Boom

1975-01-01

61

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

62

On the efficiency at maximum cooling power  

NASA Astrophysics Data System (ADS)

The efficiency at maximum power (EMP) of heat engines operating as generators is one corner stone of finite-time thermodynamics, the Curzon-Ahlborn efficiency \\eta_CA being considered as a universal upper bound. Yet, no valid counterpart to \\eta_CA has been derived for the efficiency at maximum cooling power (EMCP) for heat engines operating as refrigerators. In this letter we analyse the reasons of the failure to obtain such a bound and we demonstrate that, despite the introduction of several optimisation criteria, the maximum cooling power condition should be considered as the genuine equivalent of maximum power condition in the finite-time thermodynamics frame. We then propose and discuss an analytic expression for the EMCP in the specific case of exoreversible refrigerators.

Apertet, Y.; Ouerdane, H.; Michot, A.; Goupil, C.; Lecoeur, Ph.

2013-08-01

63

Power from mine cooling water  

SciTech Connect

Mining is a heavy user of electric power in the daily activities associated with underground operations. These activities include excavation, ground stabilization, haulage, and ore processing. It is well known in the mining industry that as mines go deeper (>1000 m), the mining environment becomes hotter. The higher temperatures and humidities encountered at these depths require air conditioning systems in addition to the normal mine ventilation system. Refrigeration equipment further increases the demand for power. These refrigeration systems can be located on the surface or on the underground working levels of the mine. Regardless of location, relatively large quantities of water are required to be brought into the mine either as direct chilled water or as chiller service water. The large head associated with this water represents a significant amount of of available potential energy. Current United States mining practices have not generally placed a significant value on this available energy. In many instances, the incoming water is allowed to flow inside steel pipelines to the desired depth, and at that point, the available potential energy is dissipated by friction and momentum transfer. The water is then stored for redistribution around the mine.

Torbin, R.N.; Thimons, E.

1986-03-01

64

Stability analysis of air-core superconducting power transformer  

Microsoft Academic Search

The air-core superconducting power transformer is being investigated as a transformer having the function of a shunt reactor. From the results of the authors' previous analysis, the magnetic field acting on the superconducting wires of an air-core transformer under load includes the rotating component besides the alternating component. Since this rotating component has a possibility of affecting the wire stability,

Hiroshi Yamaguchi; Teruo Kataoka

1997-01-01

65

Hybrid Wet\\/Dry Cooling for Power Plants (Presentation)  

Microsoft Academic Search

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

C. Kutscher; A. Buys; C. Gladden

2006-01-01

66

Steam-Electric Power-Plant-Cooling Handbook  

SciTech Connect

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

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

1982-02-01

67

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.

68

Paramagnetic moment in field-cooled superconducting plates: Paramagnetic Meissner effect  

SciTech Connect

We calculate the magnetic moment for thin superconducting plates after field cooling. We consider the situation when the whole magnetic flux is trapped within the strip and compressed due to inhomogeneous cooling. We demonstrate that the magnetic moment in such a state is paramagnetic. For a thin superconducting strip we found exact solutions for the field and current distributions at any degree of flux compression. The cases of complete and partial Bean states were considered. For a thin superconducting disk we found an approximate solution for the case of weak compression and a complete Bean state. The mechanism considered can explain the paramagnetic Meissner effect observed recently in some high-{ital T}{sub {ital c}} superconductors and in Nb.

Koshelev, A.E. [Material Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)]|[Institute of Solid State Physics, Chernogolovka, Moscow District, 142432 (Russian Federation); Larkin, A.I. [Material Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)]|[Landau Institute for Theoretical Physics, Moscow 117940 (Russian Federation)

1995-11-01

69

Power producing dry cooling apparatus and method  

SciTech Connect

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

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

1981-09-29

70

Experimental investigation on the detachable thermosiphon for conduction-cooled superconducting magnets  

NASA Astrophysics Data System (ADS)

A detachable thermosiphon, as a transient thermal switch for conduction-cooled superconducting magnet, is designed, fabricated and tested. A thermosiphon between the first and second stages of a cryocooler can reduce the cool-down time of a conduction-cooled superconducting magnet by using the large cooling capacity of the first stage. The thermosiphon is a very efficient heat transfer device until all the working fluid in it freezes (off-state). After the working fluid freezes and the second stage temperature becomes lower than that of the first stage, however, the thermosiphon then becomes a conduction heat leak path between two stages of the cryocooler. Considering a very small cooling capacity of the second stage of the cryocooler around 4.2 K, the conduction heat loss is not negligible. Therefore, a detachable thermosiphon, made of a metal bellows, is considered to be able to eliminate such a conduction heat leak. The mock-up magnet is cooled down with the thermosiphon and the thermodynamic states of the thermosiphon and the mock-up magnet are precisely examined during the whole cool-down process. At off-state, the thermosiphon is detached mechanically from the magnet. In this way, the conduction heat leak path through the thermosiphon wall is completely eliminated. This paper describes the detailed transient operation of the detachable thermosiphon using nitrogen as the working fluid.

Jeong, Sangkwon; Kim, Youngkwon; Noh, Changhyun; Kim, Seokho; Jin, Hongbeom

2006-10-01

71

Power conditioning systems for superconductive magnetic energy storage  

Microsoft Academic Search

Two power conditioning systems for superconductive magnetic energy storage (SMES) are presented. One power conditioning system is based on a hybrid current sourced inverter (CSI), the second is a combination of a DC chopper with a voltage sourced inverter (VSI). Both of these systems have independent control of real and reactive power. These systems have a significant reduction in MVA

R. H. Lasseter; S. G. Jalali

1991-01-01

72

Partial Discharge Performance of Lapped Plastic Insulation for Superconducting Power Transmission Cables and the Dielectric Strength of Supercritical Helium Gas.  

National Technical Information Service (NTIS)

Brookhaven National Laboratory (BNL) has been working on a project to develop a superconducting power transmission cable since 1972. A flexible ac cable with Nb sub 3 Sn superconductor force-cooled by supercritical helium was the design selected. A lapped...

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

1978-01-01

73

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

74

High-Tc superconducting materials for electric power applications  

Microsoft Academic Search

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.

David Larbalestier; Alex Gurevich; D. Matthew Feldmann; Anatoly Polyanskii

2001-01-01

75

High power density superconducting motor for control applications  

NASA Astrophysics Data System (ADS)

A high dynamics superconducting low power motor for control applications has been considered for design. The rotor is cylindrical with machined bulks that generate the field by trapping flux in a four poles configuration. The toothless iron armature is wound by copper, acting iron only as magnetic screen. Details of the magnetic assembling, cryogenics and electrical supply conditioning will be reported. Improvements due to the use of a superconducting set are compared with performances of equivalent conventional motors.

López, J.; Granados, X.; Lloberas, J.; Torres, R.; Grau, J.; Maynou, R.; Bosch, R.

2008-02-01

76

Thermal management of high power dissipation electronic packages: from air cooling to liquid cooling  

Microsoft Academic Search

Performance-driven electronic packaging demands for thermal solutions of high power dissipation such as enhanced air cooling or, alternatively, liquid cooling technologies. This paper reports the characterization of air-cooled vapor chamber heat sink (VCHS) and liquid cooled heat sinks (LCHS) for electronic packages with a targeted power dissipation of 140W. The test vehicle flip chip plastic BGA package (FC-PBGA) involves a

H. Y. Zhang; D. Pinjala; Poi-Siong Teo

2003-01-01

77

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

SciTech Connect

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

Jensch, K.; Lange, R.; Petersen, B. [Deutsches Elektronen Synchrotron (DESY), Hamburg, 22607 (Germany)

2004-06-23

78

Liquid helium cooling of the MFTF superconducting magnets  

SciTech Connect

During acceptance testing of the Mirror Fusion Test Facility (MFTF), we measured these tests: liquid helium heat loads and flow rates in selected magnets. We used the data from these tests to estimate helium vapor quality in the magnets so that we could determine if adequate conductor cooling conditions had occurred. We compared the measured quality and flow with estimates from a theoretical model developed for the MFTF magnets. The comparison is reasonably good, considering influences that can greatly affect these values. This paper describes the methods employed in making the measurements and developing the theoretical estimates. It also describes the helium system that maintained the magnets at required operating conditions.

VanSant, J.H.; Zbasnik, J.P.

1986-09-01

79

Cooling of hybrid neutron stars and hypothetical self-bound objects with superconducting quark cores  

Microsoft Academic Search

We study the consequences of superconducting quark cores (with color-flavor-locked phase as representative example) for the evolution of temperature profiles and cooling curves in quark-hadron hybrid stars and in hypothetical self-bound objects having no hadron shell (quark core neutron stars). The quark gaps are varied from 0 to Deltaq =50 MeV. For hybrid stars we find time scales of 1\\/5,

D. Blaschke; H. Grigorian; D. N. Voskresensky

2001-01-01

80

Performance of a conduction-cooled high-temperature superconducting bearing  

Microsoft Academic Search

We report rotational loss measurements for a high-temperature superconducting (HTS) bearing whose cooling consists of a thermal conduction path to the cold head of a cryocooler. Losses have been measured for rotational rates up to 14,500rpm at different HTS temperatures. The rotational losses decrease with decreasing HTS temperature. For temperatures that can be obtained in a liquid-nitrogen thermosiphon system, at

M. Strasik; J. R. Hull; P. E. Johnson; J. Mittleider; K. E. McCrary; C. R. McIver; A. C. Day

2008-01-01

81

Development of a forced-cooled superconducting coil with high average current density (DPC-TJ)  

Microsoft Academic Search

A forced-cooled superconducting coil (DPC-TJ) using a double walled cable-in-conduit, so called Preformed Armor Type CICC, is currently developed. The DPC-TJ is an advanced coil with high average current density of 40 A\\/mm², large operating current of 24 kA and high field of 12T. The DPC-TJ coil has several advantages such as mechanical rigidity, negligible degradation of critical current, sound

T. Hamajima; A. Tanaka; H. Shiraki; M. Shibui; Y. Sanada; M. Naganuma; M. Shimada; T. Fujioka; M. Nishi; H. Nakajima; K. Koizumi; Y. Takahashi; T. Ando; H. Tsuji; S. Shimamoto

1989-01-01

82

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

83

Cooling Concepts for High Power Density Magnetic Devices  

Microsoft Academic Search

In the area of power electronics there is a general trend to higher power densities. In order to increase the power density the systems must be designed optimally concerning topology, semiconductor selection, etc. and the volume of the components must be decreased. The decreasing volume comes along with a reduced surface for cooling. Consequently, new cooling methods are required. In

J. Biela; J. W. Kolar

2007-01-01

84

Cooling Concepts for High Power Density Magnetic Devices  

Microsoft Academic Search

In the area or power electronics there is a general trend to higher power densities. In order to increase the power density the systems must be designed optimally concerning topology, semiconductor selection, etc. and the volume of the components must be decreased. The decreasing volume comes along with a reduced surface for cooling. Consequently, new cooling methods are required. In

Juergen Biela; Johann W. Kolar

2008-01-01

85

Assessment of Evaporative Cooling Enhancement Methods for Air-Cooled Geothermal Power Plants.  

National Technical Information Service (NTIS)

Many binary-cycle geothermal power plants are air cooled because insufficient water is available to provide year-round water cooling. The performance of air-cooled geothermal plants is highly dependent on the dry bulb temperature of the air (much more so ...

C. Kutscher D. Costenaro

2002-01-01

86

Opportunities for superconductivity in the electric power industry  

Microsoft Academic Search

The US Federal Energy Policy Act of 1992 has fostered the rapid evolution of a competitive electric power industry. Its implementation by the Federal Energy Regulatory Commission (FERC) and the various state public utility commissions has created an opportunity for vastly expanded application of superconducting devices in transmission and distribution systems. Historically, the entrance of new technologies into the electric

Thomas L. Mann; John C. Zeigler; Thomas R. Young

1997-01-01

87

The Energy and Environmental Benefits of Superconducting Power Products  

Microsoft Academic Search

Superconductivity has the potential to bring a more fundamental change to electric power technologies than has occurred since electricity use became widespread nearly a century ago. The potential is for an energy revolution as profound as the impact fiber optics has had on communications. The fiber optic ‘information superhighway’ was constructed by replacing copper wires with a higher capacity alternative.

Robert A. Hawsey; Satoshi Morozumi

2005-01-01

88

Construction and tests of a heart scanner based on superconducting sensors cooled by small stirling cryocoolers  

NASA Astrophysics Data System (ADS)

At the University of Twente, a heart scanner has been designed and constructed that uses superconducting devices (superconducting quantum interference devices (SQUIDs)) to measure the magnetic field of the heart. A key feature is the elimination of liquid cryogens by incorporating cryocoolers. In the design, two coolers are operated in counter-phase to reduce the mechanical interference. In addition to the application of ferromagnetic shields around the compressors, the magnetic cooler interference is reduced by placing the SQUID magnetometers coplanar with respect to the coolers. In this way, the cooler noise was reduced to a level below the intrinsic sensor noise: 0.16 pT/?Hz. A temperature of 60 K was realised with a cool-down time of about 2 h. The corresponding heat load to the coolers is roughly 0.9 W. Magnetocardiograms were recorded inside a magnetically shielded room.

Rijpma, A. P.; Blom, C. J. H. A.; Balena, A. P.; de Vries, E.; Holland, H. J.; ter Brake, H. J. M.; Rogalla, H.

2000-01-01

89

Ion Source Specific Power Limitations Connected with Cooled Electrode Deformation.  

National Technical Information Service (NTIS)

Considered are specific power limitations related to the deformation of water-cooled electrodes in the ion-optical system (IOS) of power ion sources for producing fast atoms and for injecting them into thermonuclear machines. Calculated was dependence of ...

N. N. Flerov

1979-01-01

90

Hybrid Cooling Systems for Low-Temperature Geothermal Power Production  

Microsoft Academic Search

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

A. Ashwood; D. Bharathan

2011-01-01

91

Hybrid Cooling Systems for Low-Temperature Geothermal Power Production  

SciTech Connect

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

Ashwood, A.; Bharathan, D.

2011-03-01

92

The water-cooled heavy-current power supply units  

Microsoft Academic Search

Heavy-current power supply units with 400 A and 800 A load currents and 2 V and 5 V output voltages are presented. The general power consumption of a computer is 100 kW. Both in computer assemblies and in power supply units, water cooling is used. During computer power supply development, the following principal problems are solved: minimal power supply components

J. Mkrtchian; L. N. Reznikov; V. Mkrtchian

1995-01-01

93

Modular He-cooled divertor for power plant application  

Microsoft Academic Search

Gas cooled divertor concepts are regarded as a suitable option for fusion power plants because of an increased thermal efficiency for power conversion systems and the use of a coolant compatible with all blanket systems. A modular helium cooled divertor concept is proposed with an improved heat transfer. The concept employs small tiles made of tungsten and brazed to a

Eberhard Diegele; R. Krüssmann; S. Malang; P. Norajitra; G. Rizzi

2003-01-01

94

New power-conditioning systems for superconducting magnetic energy storage  

NASA Astrophysics Data System (ADS)

This dissertation presents the development of new power-conditioning systems for superconducting magnetic energy storage (SMES), which can regulate fast and independently the active and reactive powers demanded in the ac network. Three new power-conditioning systems were developed through a systematic approach to match the requirements of the superconducting coil and the ac power network. Each of these new systems is composed of ten 100-MW modules connected in parallel to handle the large current through the superconducting coil. The first system, which was published in the IEEE Transactions on Energy Conversion, consists of line-commutated 24-pulse converter, a thyristor-switched tap-changing transformer, and a thyristor-switched capacitor bank. The second system, which was accepted for publication in the IEEE Transactions on Energy Conversion, consists of a 12-pulse GTO (gate turn-off thyristor) converter and a thyristor-switched tap-changing transformer. The third system, which was submitted to the International Journal of Energy System, consists of a dc chopper and a voltage-source PWM (pulse width modulation) converter. The operational concept of each new system is verified through mathematical analyses and computer simulations. The dynamic interaction of each new system with the ac network and the superconducting coil is analyzed using a simulation model with EMTP (electro-magnetic transients program). The analysis results prove that each new system is feasible and realizable. Each system can regulate the active and reactive powers of the utility network rapidly and independently, and each offer a significant reduction of the system rating by reducing the reactive power demand in the converter. Feasible design for each new system was introduced using a modular design approach based on the 1000 MW/5000 MWH plant, incorporating commercially available components and proven technologies.

Han, Byung Moon

1992-06-01

95

New power-conditioning systems for superconducting magnetic energy storage  

SciTech Connect

This dissertation presents the development of new power-conditioning systems for superconducting magnetic energy storage (SMES), which can regulate fast and independently the active and reactive powers demanded in the ac network. Three new power-conditioning systems were developed through a systematic approach to match the requirements of the superconducting coil and the ac power network. Each of these new systems is composed of ten 100-MW modules connected in parallel to handle the large current through the superconducting coil. The first system, which was published in the IEEE Transactions on EnergyConversion, consists of line-commutated 24-pulse converter, a thyristor-switched tap-changing transformer, and a thyristor-switched capacitor bank. The second system, which was accepted for publication in the IEEE Transactions on Energy Conversion, consists of a 12-pulse GTO (gate turn-off thyristor) converter and a thyristor-switched tap-changing transformer. The third system, which was submitted to the International Journal of Energy System, consists of a dc chopper and a voltage-source PWM (pulse width modulation) converter. The operational concept of each new system is verified through mathematical analyses and computer simulations. The dynamic interaction of each new system with the ac network and the superconducting coil is analyzed using a simulation model with EMTP (electro-magnetic transients program). The analysis results prove that each new system is feasible and realizable. Each system can regulate the active and reactive powers of the utility network rapidly and independently, and each offer a significant reduction of the system rating by reducing the reactive power demand in the converter. Feasible design for each new system was introduced using a modular design approach based on the 1000 MW/5000 MWH plant, incorporating commercially available components and proven technologies.

Han, B.M.

1992-01-01

96

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

97

Potential impact of superconductivity on power quality enhancement  

SciTech Connect

Electric power quality problems are estimated to cost US 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.

1992-01-01

98

Assessment of Evaporative Cooling Enhancement Methods for Air-Cooled Geothermal Power Plants: Preprint  

Microsoft Academic Search

Many binary-cycle geothermal power plants are air cooled because insufficient water is available to provide year-round water cooling. The performance of air-cooled geothermal plants is highly dependent on the dry bulb temperature of the air (much more so than fossil fuel plants that operate at higher boiler temperatures), and plant electric output can drop by 50% or more on hot

C. Kutscher; D. Costenaro

2002-01-01

99

Case study on the US superconducting power transmission program  

SciTech Connect

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

Hammel, E.F.

1996-02-01

100

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

101

Development of a forced-cooled superconducting coil with high average current density (DPC-TJ)  

SciTech Connect

A forced-cooled superconducting coil (DPC-TJ) using a double walled cable-in-conduit, so called Preformed Armor Type CICC, is currently developed. The DPC-TJ is an advanced coil with high average current density of 40 A/mm/sup 2/, large operating current of 24 kA and high field of 12T. The DPC-TJ coil has several advantages such as mechanical rigidity, negligible degradation of critical current, sound electrical insulation and excellent winding tolerance, compared with a conventional forced-cooled coil. The development of the superconducting strand with an aim of improving the critical current density and resistivity was performed. The Nb tube processed (NbTi) Sn strand fulfills the requirement that the critical current density is more than 600 A/mm/sup 2/ at 12T and RRR is higher than 50. The DPC-TJ is now being fabricated at Toshiba Corporation and will be tested in the DPC facility at the Japan Atomic Energy Research Institute.

Hamajima, T.; Tanaka, A.; Shiraki, H.; Shibui, M.; Sanada, Y.; Naganuma, M.; Shimada, M.; Fujioka, T.; Nishi, M.; Nakajima, H.

1989-03-01

102

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

103

Laboratory research on combined cooling, heating and power (CCHP) systems  

Microsoft Academic Search

Combined cooling, heating and power (CCHP) systems offer the potential for a significant increase in fuel use efficiency by generating electricity onsite and recycling the exhaust gas for heating, cooling, or dehumidifying. A challenge for CCHP system is the efficient integration of distributed generation (DG) equipment with thermally-activated (TA) technologies. The China Ministry of Science and Technology and Tsinghua University

L. Fu; X. L. Zhao; S. G. Zhang; Y. Jiang; H. Li; W. W. Yang

2009-01-01

104

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

105

Thermodynamic performance optimization of a combined power\\/cooling cycle  

Microsoft Academic Search

A combined thermal power and cooling cycle has already been proposed in which thermal energy is used to produce work and to generate a sub-ambient temperature stream that is suitable for cooling applications. The cycle uses ammonia–water mixture as working fluid and is a combination of a Rankine cycle and absorption cycle. The very high ammonia vapor concentration, exiting turbine

M. Pouraghaie; K. Atashkari; S. M. Besarati; N. Nariman-zadeh

2010-01-01

106

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

107

Focus section on superconducting power systems  

Microsoft Academic Search

This focus section of Superconductor Science and Technology looks at the properties, technology and applications of (RE)BCO and MgB2 based superconductors for power engineering systems. Both bulk and conductor forms of material are addressed, including elements of materials fabrication and processing, and the measurement of their applied properties for various levels of system application. The areas of research include ac

D A Cardwell; N Amemiya; R Fair

2012-01-01

108

Legionnaires' Disease Bacteria in Power Plant Cooling Systems: Phase 2.  

National Technical Information Service (NTIS)

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 fac...

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

1985-01-01

109

Flexible two-phase thermosyphon for power electronic cooling  

Microsoft Academic Search

A two phase thermosyphon system for power electronic cooling is presented. The designed evaporator can house multiple power electronics modules, it collects the generated vapor to a common flexible tube that drives the vapor to a plate heat exchanger condenser. The system was tested and simulated for a total power loss of 12.5 kW. The condenser was installed at a

Francesco Agostini; Bruno Agostini

2011-01-01

110

Portable self-contained power and cooling system  

Microsoft Academic Search

A portable power and cooling system is described comprising: a drive unit including a combustion section, a scroll-type expander section, a scroll-type air compressor section, and a power output drive shaft, the expander and air compressor sections connected together for synchronousmovement via said power output drive shaft; said combustion section including a combustion air inlet and a combustion gas outlet,

1993-01-01

111

Voltage-driven superconducting weak link as a refrigerator for cooling of nanomechanical vibrations  

NASA Astrophysics Data System (ADS)

We consider a new type of cooling mechanism for a suspended nanowire acting as a weak link between two superconductive electrodes. By applying a bias voltage over the system, we show that the system can be viewed as a refrigerator for the nanomechanical vibrations, where energy is continuously transferred from the vibrational degrees of freedom to the extended quasiparticle states in the leads through the periodic modulation of the inter-Andreev level separation. The necessary coupling between the electronic and mechanical degrees of freedom responsible for this energy-transfer can be achieved both with an external magnetic or electrical field, and is shown to lead to an effective cooling of the vibrating nanowire. Using realistic parameters for a suspended nanowire in the form of a metallic carbon nanotube we analyze the evolution of the density matrix and demonstrate the possibility of cooling the system down to a stationary vibron population of ~0.1. Furthermore, it is shown that the stationary occupancy of the vibrational modes of the nanowire can be directly probed using the dc current responsible for carrying away the absorbed energy from the vibrating nanowire.

Sonne, G.; Peña-Aza, M. E.; Shekhter, R. I.; Gorelik, L. Y.; Jonson, M.

2010-10-01

112

Experimental Study on the Electrical Breakdown Characteristics of Sub-Cooled Liquid Nitrogen for Designing a High Voltage Superconducting Machine  

Microsoft Academic Search

The electrical breakdown characteristics of liquid nitrogen should be investigated for developing of a high voltage superconducting machine. This paper deals with the experimental study for the verification of dielectric characteristics of sub-cooled in accordance with utilization factors. AC dielectric experiments were carried out by using sphere-plane electrode systems. The utilization factors of simulated electrode systems were controlled by gap

Jin Bae Na; Hyoungku Kang; Young Jin Hwang; Seong Eun Yang; Dong Keun Park; Duck Kweon Bae; Tae Kuk Ko

2010-01-01

113

Assessment of Evaporative Cooling Enhancement Methods for Air-Cooled Geothermal Power Plants: Preprint  

SciTech Connect

Many binary-cycle geothermal power plants are air cooled because insufficient water is available to provide year-round water cooling. The performance of air-cooled geothermal plants is highly dependent on the dry bulb temperature of the air (much more so than fossil fuel plants that operate at higher boiler temperatures), and plant electric output can drop by 50% or more on hot summer days, compared to winter performance. This problem of reduced summer performance is exacerbated by the fact that electricity has a higher value in the summer. This paper describes a spreadsheet model that was developed to assess the cost and performance of four methods for using supplemental evaporative cooling to boost summer performance: (1) pre-cooling with spray nozzles, (2) pre-cooling with Munters media, (3) a hybrid combination of nozzles and Munters media, and (4) direct deluge cooling of the air-cooled condenser tubes. Although all four options show significant benefit, deluge cooling has the potential to be the most economic. However, issues of scaling and corrosion would need to be addressed.

Kutscher, C.; Costenaro, D.

2002-08-01

114

Actively cooled pump limiters and power scrape-off length measurements in Tore-Supra  

NASA Astrophysics Data System (ADS)

Tore-Supra is a superconducting tokamak aimed at studying long plasma pulses (>30 s). It is equipped with two types of pump limiters (PL). A provisional type, semi-inertially cooled between shots, has been used for plasma scrape-off characterization. The e-folding length ?q for power deposition on these components has been unfolded (1.0power level up to 4 MW and of toroidal magnetic field (1.5cooled during shots, its thermal constant being less than 2 s. Experiments using this ITER relevant technology are presented. Three of the actively cooled limiters have been successfully tested in a steady state regime with a surface temperature less than 1000°C (Ip=1.6 MA). The design value for power removal on this type of limiters has been obtained. Peak power fluxes of 10 MW/m2 (3.5 MW/m2 on average) have been estimated. This represents a breakthrough for high heat flux components since critical heat flux and burnout with subcooled flow boiling are major aspects for this kind of design.

Guilhem, D.; Seigneur, A.; Chappuis, P.; Chatelier, M.; Demichelis, C.; Deschamps, P.; Grosman, A.; Hess, W.; Lecoustey, P.; Loarer, T.; Poutchy, L.; Schlosser, J.

1992-12-01

115

Mixing and noise in diffusion and phonon cooled superconducting hot-electron bolometers  

NASA Astrophysics Data System (ADS)

We report a systematic, comprehensive set of measurements on the dynamics and noise processes in diffusion and phonon-cooled superconducting hot-electron bolometer mixers which will serve as ultralow noise detectors in THz heterodyne receivers. The conversion efficiency and output noise of devices of varying lengths were measured with radio frequency between 8 and 40 GHz. The devices studied consist of 100-Å-thin film Nb bridges connected to thick (1000 Å), high conductivity normal metal (Au) leads. The lengths of the devices studied range from 0.08 to 3 ?m. For devices longer than the electron-phonon interaction length Le-ph?D?e-ph, with D the diffusion constant and ?e-ph-1 the electron-phonon interaction rate, the hot electrons are cooled dominantly by the electron-phonon interaction, which in Nb is too slow for practical applications. If the device length is less than ?Le-ph(~1 ?m at 4.2 K), then out diffusion of heat into the high conductivity leads dominates the cooling process. In this limit, the intermediate frequency (IF) bandwidth is found to vary as L-2, with L the bridge length, as expected for diffusion cooling. The shortest device has an IF bandwidth greater than 6 GHz, the largest reported for a low-Tc superconducting bolometric mixer. The dominant component of the output noise decreases with frequency in the same manner as the conversion efficiency, consistent with a model based on thermal fluctuations. The noise bandwidth is larger than the gain bandwidth, and the mixer noise is low, ranging from 100 to 530 K (double sideband). The crossover from phonon dominated to diffusion dominated behavior is also demonstrated using noise thermometry measurements in the normal state. Scalar measurements of the device differential impedance in the intermediate state agree with a theoretical model which takes into account the thermal and electrical dynamics. We also present detailed comparisons with theoretical predictions of the output noise and conversion efficiency.

Burke, P. J.; Schoelkopf, R. J.; Prober, D. E.; Skalare, A.; Karasik, B. S.; Gaidis, M. C.; McGrath, W. R.; Bumble, B.; Leduc, H. G.

1999-02-01

116

Steam powered heating/cooling systems  

SciTech Connect

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 supply line from the boiler to the generator section of the absorption machine; a condensate return line from the generator section of the absorption machine through the steam trap to the condensate tank; a return line from the condensate tank to the boiler; and outlet supply line from the absorption section of the absorption machine to the work; a return line from the work to the absorption section of the absorption machine; and a condensate return pump on the return line from the condensate tank to the boiler.

Perry, J.E.

1987-05-19

117

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

118

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

119

Conductor requirements for high-temperature superconducting utility power transformers  

SciTech Connect

High-temperature superconducting (HTS) coated conductors in utility power transformers must satisfy a set of operating requirements that are driven by two major considerations-HTS transformers must be economically competitive with conventional units, and the conductor must be robust enough to be used in a commercial manufacturing environment. The transformer design and manufacturing process will be described in order to highlight the various requirements that it imposes on the HTS conductor. Spreadsheet estimates of HTS transformer costs allow estimates of the conductor cost required for an HTS transformer to be competitive with a similarly performing conventional unit.

Pleva, E. F. [Waukesha Electric Systems, Waukesha, WI; Mehrotra, V. [Waukesha Electric Systems, Waukesha, WI; Schwenterly, S W [ORNL

2010-01-01

120

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

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045...Powerplant Cooling § 23.1045 Cooling test procedures for turbine engine powered airplanes. (a) Compliance...

2013-01-01

121

Delayed gamma power measurement for sodium-cooled fast reactors  

Microsoft Academic Search

Previous works on pressurized water reactors show that the nitrogen 16 activation product can be used to measure thermal power. Power monitoring using a more stable indicator than ex-core neutron measurements is required for operational sodium-cooled fast reactors, in order to improve their economic efficiency at the nominal operating point. The fluorine 20 and neon 23 produced by (n,?) and

R. Coulon; S. Normand; G. Ban; E. Barat; T. Montagu; T. Dautremer; H.-P. Brau; V. Dumarcher; M. Michel; L. Barbot; T. Domenech; K. Boudergui; J.-M. Bourbotte; P. Jousset; G. Barouch; S. Ravaux; F. Carrel; N. Saurel; A.-M. Frelin-Labalme; H. Hamrita; V. Kondrasovs

2011-01-01

122

Performance evaluations of steam power plants with dry cooling towers  

SciTech Connect

A theoretical model is presented to design dry cooling tower systems and to evaluate their off-design performances. The influence of the more important design parameters on the tower dimensions is shown. A preliminary ''optimum'' size is predicted by means of a computer code using a simplified cost model. Moreover the influence of the designed cooling system on the performance of thermoelectric and/or nuclear power plants is analysed.

Fortunato, B.; Magi, V.

1984-08-01

123

Gas-cooled reactor power systems for space  

NASA Astrophysics Data System (ADS)

Large amounts of electric power are required for some of the systems envisioned in support of SDI. Since various applications are being considered, and an overall power architecture study has not been completed, the required power levels and corresponding operating times for specific systems are not known. The characteristics of six designs for power levels of 2, 10 and 20 MWe for operating time of 1 and 7 yrs are described. The operating conditions for these arbitrary designs were chosen to minimize system specific mass. Both gas and liquid cooled reactors are considered. The designs discussed draw heavily on the Pluto project experience. Gas cooled thermal reactors coupled with Brayton cycle power conversion appear to provide reasonable multimegawatt space power systems. An advanced radiation design must be developed which can meet the mass limit assumed. The inherent high temperature capability of the reactors considered removes the reactor as a limiting condition on system performance.

Walter, Carl E.

124

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

125

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

126

Current control system of the power supplies for LHD superconducting coils  

Microsoft Academic Search

The LHD is a fusion experimental facility using a large-scale superconducting coil system. The coil system includes six sets of superconducting coils, and six DC power supplies are used to charge them. For the current controllers of these power supplies, high accuracy of current control, fast response and robustness of the system are required. This paper describes the current control

Hirotaka Chikaraishi; Sigeyuki Takami; Tomoyuki Inoue; Satoru Sakakibara; Keisuke Matsuoka; Toshifumi Ise; Daisuke Eto; Tomoyuki Haga

2004-01-01

127

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

128

Review of High Power Density Superconducting Generators: Present State and Prospects for Incorporating YBCO Windings.  

National Technical Information Service (NTIS)

This work focuses on the development of high power density generators for airborne applications by bridging the chasm between generator and high temperature superconducting (HTS) wire developmental efforts. Benefits of HTS power generation include improve...

G. L. Rhoads M. D. Sumption P. N. Barnes

2005-01-01

129

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.

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

2013-11-01

130

A cryocooler cooled 6T NbTi superconducting magnet with room temperature bore of 220mm  

SciTech Connect

The authors are developing a cryocooler cooled 6T superconducting magnet without liquid helium and/or liquid nitrogen. This magnet, which is directly cooled by two 4K Gifford-McMahon (GM) cryocoolers in vacuum, consists of a graded NbTi coil, Bi-based oxide superconducting current leads and a persistent current switch. The coil is made using two types of NbTi wires and a copper bobbin. The coil with an inner diameter of 260mm, an outer diameter of 329mm, and a height of 334 mm, is impregnated with grease to ensure a good heat conduction. The operating current for a central field of 6T in the 220mm room temperature bore is 152A. A mechanical persistent current switch is used to limit the load from the switch into the 4K GM cryocooler. Designed temperature of the magnet is 4.9 K at the operating current of 152 A.

Watazawa, K.; Sakuraba, J.; Hata, F.; Hasebe, T.; Chong, C.K.; Yamada, Y. [Sumitomo Heavy Industries, Ltd., Hiratsuka (Japan); Watanabe, K.; Awaji, S.; Fukase, T. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research

1996-07-01

131

Performance enhancement of conventional combined cycle power plant by inlet air cooling, inter-cooling and LNG cold energy utilization  

Microsoft Academic Search

This paper has proposed an integrated advanced thermal power system to improve the performance of the conventional combined cycle power plant. Both inlet air cooling and inter-cooling are utilized within the proposed system to limit the decrease of the air mass flow contained in the given volume flow as well as reduce the compression power required. The latent heat of

Xiaojun Shi; Brian Agnew; Defu Che; Jianmin Gao

2010-01-01

132

Peak power and cooling energy savings of shade trees  

Microsoft Academic Search

In summer of 1992, we monitored peak power and cooling energy savings from shade trees in two houses in Sacramento, CA. The collected data include air-conditioning electricity use, indoor and outdoor dry bulb temperatures and humidities, roof and ceiling surface temperatures, inside and outside wall temperatures, insolation, and wind speed and direction. Shade trees at the two monitored houses yielded

Hashem Akbari; Dan M. Kurn; Sarah E. Bretz; James W. Hanford

1997-01-01

133

Brackish groundwater for power plant cooling in California  

Microsoft Academic Search

An investigation which assessed the potential use of brackish groundwater in California as cooling water for thermal power plants is reported. Information is included on California groundwater resources; the occurrence of brackish groundwater basins; characteristics of these basins; technical, economic, legal, and environmental aspects of proposed use of brackish groundwater; how to confirm the groundwater supplies; and assessment of brackish

V. H. Scott; J. C. Scalmanini; K. A. Popko

1978-01-01

134

Demonstration of a two-phase cooled power transformer  

SciTech Connect

This report describes the design, manufacture, test installation and operation of a 138/13.8 kV, 65 MVA two-phase cooled power transformer developed by Westinghouse. The transformer was installed on the Consolidated Edison system in the Seaport Substation in 1986 and is presently in service. The demonstration installation and operation experience is described.

Savio, L.J. (Consolidated Edison Co. of New York, Inc., New York, NY (USA))

1990-04-01

135

Floating Power Optimization Studies for the Cooling System of a Geothermal Power Plant.  

National Technical Information Service (NTIS)

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 fl...

C. J. Shaffer

1977-01-01

136

Design and performance of the JAERI superconducting linac for high-power free-electron laser  

Microsoft Academic Search

A superconducting rf linac has been required to realize high-duty operation and low-electricity consumption for a high-average-power and high-efficiency free-electron laser (FEL). The JAERI FEL superconducting linac consists of a 250 kV electron gun, a subharmonic normal-conducting buncher (SHB) of 83.3 MHz, and two single-cell and two five-cell superconducting cavities of 499.8 MHz. The gun was typically operated around 200

Masaru Sawamura; Ryoji Nagai; Nobuhiro Kikuzawa; Masayoshi Sugimoto; Nobuyuki Nishimori; Eisuke J. Minehara

1999-01-01

137

Magnetic field and electromagnetic force analysis of 3-phase air-core superconducting power transformer  

Microsoft Academic Search

The superconducting windings of the air-core superconducting power transformer have possibilities of being exposed to a higher magnetic field than those of the iron-core transformer because of no special paths for magnetic flux. Thus, in this paper, the magnetic field and electromagnetic force acting on the windings of an experimental 3-phase air-core superconducting transformer are analyzed. From the results, it

Hiroshi Yamaguchi; Teruo Kataoka; Hiroki Matsuoka; Tomohide Mouri; Shoji Nishikata; Y. Sato

2001-01-01

138

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

139

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

Code of Federal Regulations, 2013 CFR

... 1 2013-01-01 2013-01-01 false Cooling test procedures for reciprocating engine powered...AND COMMUTER CATEGORY AIRPLANES Powerplant Cooling § 23.1047 Cooling test procedures for reciprocating engine...

2013-01-01

140

Feasibility of Alternative Cooling Systems for Power Plants in the Northern Great Plains.  

National Technical Information Service (NTIS)

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

141

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

Code of Federal Regulations, 2010 CFR

...AIRPLANES Powerplant Cooling § 23.1047 Cooling test procedures for reciprocating engine powered...applicable performance requirements that are critical to cooling. [Amdt. 23-51, 61 FR 5137, Feb. 9, 1996] Liquid...

2010-01-01

142

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

Code of Federal Regulations, 2010 CFR

...AIRPLANES Powerplant Cooling § 23.1047 Cooling test procedures for reciprocating engine powered...applicable performance requirements that are critical to cooling. [Amdt. 23-51, 61 FR 5137, Feb. 9, 1996] Liquid...

2009-01-01

143

Behavior of power-limited transverse stochastic cooling systems  

SciTech Connect

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

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

1988-07-01

144

Thermal Stress Calculations for Heatpipe-Cooled Reactor Power Systems  

NASA Astrophysics Data System (ADS)

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 includes a single heatpipe surrounded by 3-6 clad fuel pins. As part of this development effort, a partial array of a candidate heatpipe-cooled reactor is to be tested in the SAFE-100 experimental program at the Marshall Space Flight Center. The partial array comprises 19 3-pin modules, which are powered by resistance heaters. This paper describes the analyses that were performed in support of this test program, to assess thermal and structural performance and to specify the test conditions needed to simulate reactor operating conditions.

Kapernick, Richard J.; Guffee, Ray M.

2003-01-01

145

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

146

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

SciTech Connect

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

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

2007-01-01

147

Superconducting power transmission line materials research and conductor development. Final report  

Microsoft Academic Search

The feasibility of transferring the conductor technology developed on tubes to more practical tape conductors was investigated and a variety of studies aimed at improving the basic understanding of the important superconducting properties crucial to superconducting power transmission line (SPTL) applications were continued. The major objectives were: to produce one to three meter long tapes of multi-layered prototype NbâSn tape

T. H. Geballe; M. R. Beasley

1977-01-01

148

Why cryogenically cooled, thin crystals handle extremely high power densities  

SciTech Connect

Recently, a new type of cryogenically cooled high heat load monochromator was proposed and, developed at Argonne National Laboratory and tested at European Synchrotron Radiation Facility (ESRF.) These tests showed that powers of 153 W and power densities of 450 W/mm{sup 2} cause only negligible strain. These powers and power densities are larger than will be absorbed by the first crystal on an undulator beamline at the Advanced Photon Source (APS). In our earlier work we suggested that the crystal might show strain at much lower values of the powers and power densities. We now can explain the ESRF results in terms of the unique role the negative thermal expansion coefficient of Si plays in minimizing strain.

Knapp, G.S.; Jennings, G.; Beno, M.A.

1995-09-01

149

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

150

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

151

Computer simulations of the power supply for the superconducting coils of HELIAS Stellarator Fusion Reactor  

Microsoft Academic Search

The goal of HELIAS fusion power plant is to deliver electric power to the grid. For magnetic confinement of the hot plasma a superconducting coil system is used. Power supplies are necessary to provide charge and discharge and to stabilize the coil current during operation. Computer simulations of the power supplies have been done with the SIMPLORER code. The computation

A. Wieczorek; E. Harmeyer; G. Linhofer

152

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

Microsoft Academic Search

The FLASH user facility providing free electron laser radiation is built based on the TTF project at DESY. Fermilab has the responsibility for the design and processing of a third harmonic, 3.9 GHz, superconducting cavity which is powered via a coaxial power coupler. Six power couplers have been manufactured at CPI after successful design of the power coupler including RF

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

2007-01-01

153

The Fundamental Power Coupler for the Spallation Neutron Source (SNS) Superconducting Cavities  

SciTech Connect

The SNS linac contains superconducting cavities with phase velocities .61 and .81 for the acceleration of H- ions. Each of the 6-cell cavities, resonant at 805 MHz at 2 degrees K, is powered by a 550 kW pulsed klystron via a coaxial coupler. The specifications for the coupler require that it withstand the full klystron power in full reflection for the duration of the RF pulse (1.3+1.5(decay) ms) at a repetition rate of 60 pps, with an average power of 48 kW. The coupler must provide a Qext of 7.3 x 105 for the medium beta and high beta cavities, respectively. A design derived from proven experience at other laboratories (primarily at KEK, for Tristan and KEK-B cavities at 508 MHz) has been adopted for the production of the 50 omega prototype couplers. The couplers include a planar coaxial window with matching compensation elements, cooled by conduction via a water system from the air side of the inner conductor. The coupler's outer conductor between the window and the cavity is actively cooled by a helium circuit with input at 5 degrees K and output at about 165 degrees K. Vacuum, arcing, infrared, and electron current monitoring and interlocking is done through several ports located near the window. The coaxial coupler is matched to a WR975 waveguide through a door-knob transition, also derived from the KEK design. Numerical calculations have been performed on the electromagnetic properties of the coupler and on the multipacting behavior of the coaxial line and window. A capacitor for DC bias will be used to control multipacting. The first coupler prototypes have been produced by industry and the results of the RF testing on them at room temperature will be presented.

I.E. Campisi; E. Daly; P. Kneisel; W. Schneider; M. Stirbet; K.M. Wilson

2001-06-01

154

Effects of power-plant cooling systems on marine phytoplankton  

Microsoft Academic Search

The large quattities of marine phytoplankton passing through the cooling systems of two Southern California coastal power plants were found to be greatly reduced in numbers (41.7%) and in volume (33.7%). The biomass killed from June, 1972 to May, 1973 amounted to approximately 1,700 tons of organic carbon. Phytoplankton mortalities were most pronounced from October to December when intake waters

F. J.-P. Briand; F. J. P

1975-01-01

155

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

SciTech Connect

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

Burgett, W.; Christianson, M.; Coombes, R. [and others

1992-10-01

156

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

157

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

158

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

159

High power rapidly tunable system for laser cooling  

NASA Astrophysics Data System (ADS)

Laser cooling experiments require light sources that can be rapidly tuned in frequency and power. Keeping as much power as possible increases the number of trapped atoms. We present a configuration that combines the capabilities of rapid frequency tuning with power amplification in a robust system. A double pass acousto-optic modulator (AOM) changes the frequency of the laser beam while keeping the alignment approximately constant. We decouple the modulation and amplification sections using an optical fiber and we keep the power out of the fiber constant by feed-forward on the amplitude modulation of the AOM. The tapered amplifier is in a double pass configuration and requires an input of only 1 mW to obtain 1 W out. A second modulator controls the intensity after the amplifier and generates additional beams that we use, for example, to do absorption imaging. We demonstrate the transfer of atoms to a dipole trap using the system.

Gomez, Eduardo; Valenzuela Jimenez, Victor Manuel; Hernandez Diaz, Lorenzo

2012-06-01

160

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{percent}Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars. {copyright} {ital 1999 American Institute of Physics.}

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

1999-01-01

161

A gas-cooled reactor surface power system  

NASA Astrophysics Data System (ADS)

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.

1999-01-01

162

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 nitide clad in Nb 1 %Zr, which has been extensively tested under the SP-I 00 program The fiel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fbel and stabilizing the geometty against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality cannot occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.

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

1998-11-09

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

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

165

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.

166

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

167

Development of 1 kA class HTS coil for superconducting power transformers  

NASA Astrophysics Data System (ADS)

The winding technology with high current capacity is one of the important factors in power application of 20 MVA/66 kV-class superconducting power transformers. High-current power transformer is achieved by transposed conductors made of Rare Earth-based superconducting coated conductors. By transpositions, the improvement of uniformity of strand current distribution makes it possible to reduce the total number of strands and AC loss of coils. In this study, the high-Tc superconducting coil was made by transposed 24 strands of 5 mm-wide Rare Earth-based superconducting coated conductors and operated at a current of 1 kA. The test results of AC and DC current characteristics and AC loss are reported.

Okamoto, H.; Hayashi, H.; Iwakuma, M.; Iijima, Y.; Saito, T.; Izumi, T.; Yamada, Y.; Shiohara, Y.

2009-10-01

168

LOSS REDUCTION BY USING A SUPERCONDUCTING INDUCTOR IN AN ACTIVE POWER FILTER  

Microsoft Academic Search

Shunt active power filters are widely used for the compensation of harmonics in industrial processes to improve the power quality. A current-source active power filter has a better current- control capability but is less efficient, compared to a voltage-source active power filter. The use of a superconducting inductor can reduce the power loss to increase the efficiency of a current-source

C Chao; C Grantham

169

Water-cooled, in-cavity apertures for high power operation of FEL oscillators  

NASA Astrophysics Data System (ADS)

In an oscillator FEL, higher-order harmonic radiation from wigglers can cause serious damage to the downstream FEL resonator mirror and limit the maximum electron beam current for FEL operation due to thermal overload. These problems can be effectively dealt with for FELs driven by helical wigglers using a system to block off-axis wiggler harmonic radiation. In this paper, we report a new scheme to block the off-axis radiation from helical wigglers using a set of motorized, water-cooled, in-cavity apertures. These apertures can reduce the wiggler harmonic radiation power load on the downstream FEL resonator mirror by two orders of magnitude or more. With these apertures, we were able to operate the Duke FEL with record high intracavity power in infrared and visible wavelengths and extend FEL operation into ultraviolet wavelengths with a large electron beam current. The technique for limiting wiggler harmonic radiation using in-cavity apertures is expected to be useful for other types of FEL oscillators including high average power FEL oscillators driven by superconducting linacs.

Huang, S.; Li, J.; Wu, Y. K.

2009-07-01

170

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

SciTech Connect

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

Reyes, A.P.; Ahrens, E.T.; Hammel, P.C.; Heffner, R.H.; Thompson, J.D.; Canfield, P.C.; Fisk, Z. (Los Alamos National Lab., NM (United States)); Schirber, J.E. (Sandia National Labs., Albuquerque, NM (United States))

1992-01-01

171

A Study on Starting Method of Superconducting Generator in Combined-Cycle Power Plant  

NASA Astrophysics Data System (ADS)

In the combined-cycle power plant generators are started by using the igniting arrangement up to the ignition rotational speed of the gas turbine. On the other hand, in case of using the superconducting generator, it is difficult to apply the igniting arrangement used to generate electricity on the combined cycle for the structure as it is. Then, we examined the induction motor starting method of superconducting generator by using the 70MW class quick response excitation superconducting model generator and the VVVF power supply. In the result of examination, we confirmed to be able to raise the rotational speed from 6 to 360rpm. Moreover, it was clarified to be able to start 200MW class superconducting generator by the induction motor start method with the analysis.

Imai, Yoshihiro; Tokumasu, Tadashi; Nagamura, Hidehiro; Miyaike, Kiyoshi; Matsumoto, Hisakazu; Hasegawa, Hiroshi; Kusafuka, Hiroshi; Shibuya, Masatoyo; Takahashi, Ryukichi

172

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

SciTech Connect

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 the Legionella profile of these waters. Simple predictive relationships were not found. At incubation temperatures of 32/sup 0/ and 37/sup 0/C, waters from a power plant where infectious Legionella were not observed stimulated the growth of stock Legionella cultures more than did waters from plants where infectious Legionella were prevalent. This observation is consistent with Phase I results, which showed that densities of Legionella were frequently reduced in closed-cycle cooling systems despite the often higher infectivity of Legionella in closed-cycle waters. In contrast, water from power plants where infectious Legionella were prevalent supported the growth of indigenous Legionella pneumophila at 42/sup 0/C, while water from a power plant where infectious Legionella were absent did not support growth of indigenous Legionella. Some Legionella are able to withstand a water temperature of 85/sup 0/C for several hours, thus proving more tolerant than was previously realized. Finally, the observation that water from two power plants where infectious Legionella were prevalent usually supported the growth of Group A Legionella at 45/sup 0/C indicates the presence, of soluble Legionella growth promoters in these waters. This test system could allow for future identification and control of these growth promoters and, hence, of Legionella. 25 refs., 23 figs., 10 tabs.

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

1985-04-01

173

Conceptual design of an indirect-cooled superconducting magnet for the LHD-type fusion reactor FFHR  

Microsoft Academic Search

The large helical device (LHD) has demonstrated that LHD-type reactors are well suited for steady-state power plants. This paper presents a conceptual design of the superconductor and coil for the LHD-type helical reactor (FFHR) superconducting magnet. The magnet of the FFHR consists of continuous windings with a large diameter, twisted configuration and large magnetic energy. The magnet system has a

K. Takahata; T. Mito; H. Tamura; S. Imagawa; A. Sagara

2007-01-01

174

Commissioning Tests of the Bonneville Power Administration 30 MJ Superconducting Magnetic Energy Storage Unit  

Microsoft Academic Search

A 30 MJ (8.4 kWh) Superconducting Magnetic Energy Storage (SMES) unit with a 10 MW converter has been installed and commissioned at the Bonneville Power Administration (BPA) substation in Tacoma, Washington. This is the first large-scale application in the US of superconductivity in an electric utility system. The unit, which is capable of absorbing and releasing up to 10 MJ

H. J. Boenig; J. F. Hauer

1985-01-01

175

Development of High-speed and Low-power Microprocessors using Superconductive Circuits  

NASA Astrophysics Data System (ADS)

Superconductive single flux quantum (SFQ) circuits, which perform their circuit operations by controlling propagations of flux quanta in connected superconducting rings, can operate at the frequency of several tens GHz with ultra low power dissipation. The SFQ circuit is thought to be an attractive candidate for fundamental elements of future high-end information processing systems. This paper reports the development of SFQ microprocessors for high-end computation systems.

Yamanashi, Yuki; Yoshikawa, Nobuyuki; Tanaka, Masamitsu; Fujimaki, Akira

176

Conceptual design of air-core superconducting power transformer for cable transmission system  

Microsoft Academic Search

The air-core superconducting transformer, which has a large magnetizing current, has been proposed as a power transformer that has the function as a shunt reactor. In this paper, the basic design procedure for the air-core superconducting transformer is presented. By using this procedure, 500\\/â(3kV)--66\\/â(3kV)--300 MVA single phase air-core transformer is designed for a model cable transmission system. Then, the performance

Hiroshi Yamaguchi; Yukihiko Sato; Teruo Kataoka

1996-01-01

177

Reduction of greenhouse-gas emissions by utilization of superconductivity in electric-power generation  

Microsoft Academic Search

The reduction of greenhouse-gas (GHG) emissions is becoming a topical issue due to the Kyoto Protocol which requires the European Union (EU) to reduce its emissions by 8% from the 1990 levels by between 2008 and 2012. The main source for GHG-emissions is energy production. Superconducting electrical machinery is starting to emerge into the market of power devices. High-temperature superconducting

Teemu Hartikainen; Jorma Lehtonen; Risto Mikkonen

2004-01-01

178

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

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

Superconducting magnets for an MHD test facility and base load power plant  

Microsoft Academic Search

The development of Magnetohydrodynamic (MHD) power generation in the U.S. may involve the construction of an Engineering Test Facility (ETF) as a step toward a base load or full-scale power plant. This paper describes the superconducting magnet requirements for the ETF and base load plants and gives the results to date in a program involving production of magnet reference designs

Z. Stekly; R. Thome; W. Punchard

1977-01-01

181

DC Power System for Superconducting Coils of Fusion Plasma Test Facility LHD  

Microsoft Academic Search

The Large Helical Device (LHD) is an experimental facility for fusion plasma using a large scale mutually coupled superconducting coil system and it is now operating at the National Institute for Fusion Science. This paper introduces the design and the operation results of the dc power systems to drive these coils. First, the outline of the LHD and the power

Hirotaka Chikaraishi; Sigeyuki Takami; Tomoyuki Inoue; Satoru Sakakibara; Toshifumi Ise; Tomoyuki Haga; Hiroyuki Niwa

2006-01-01

182

Poloidal Field Power Supply Systems for the HT-7U Steady-State Superconducting Tokamak  

SciTech Connect

The paper gives a description of the poloidal field power supplies and the control system of the HT-7U superconducting tokamak required to energize the magnetic field coils for plasma excitation and confinement. An original configuration of alternating-current/direct-current (dc) converter, thyristor dc circuit breaker, and power supply control system are introduced in detail.

Fu, P.; Liu, Z.Z.; Xu, J.Z.; Gao, G.; Wen, J.L.; Cao, Y.; Song, Z.Q.; Tang, L.J.; Wang, L.S.; Liang, X.Y. [Institute of Plasma Physics (China)

2002-07-15

183

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

184

Reduction of field emission in superconducting cavities with high power pulsed RF  

Microsoft Academic Search

A systematic study is presented of the effects of pulsed high power RF processing (HPP) as a method of reducing field emission (FE) in superconducting radio frequency (SRF) cavities to reach higher accelerating gradients for future particle accelerators. The processing apparatus was built to provide up to 150 kW peak RF power to 3 GHz cavities, for pulse lengths from

J. Graber; C. Crawford; J. Kirchgessner; H. Padamsee; D. Rubin; P. Schmueser

1994-01-01

185

Thermal stress calculations for heatpipe-cooled reactor power systems  

NASA Astrophysics Data System (ADS)

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, Richard J.; Guffee, Ray M.

2002-01-01

186

Variable CW RF power coupler for 345 MHz superconducting cavities  

Microsoft Academic Search

This paper reports the development of a CW variable coupler for 345 MHz spoke-loaded superconducting (SC) cavities. The coupler inserts an 80 K copper loop into a 5 cm (2 inch) interior diameter coupling port on several types of spoke-loaded cavity operating at 2 K or 4 K. The coupling loop can be moved during operation to vary the coupling

K. W. Shepard; Z. A. Conway; J. D. Fuerst; M. P. Kelly; G. J. Waldschmidt; A. M. Porcellato

2007-01-01

187

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

SciTech Connect

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

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

2007-06-01

188

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

189

Power module and cooling system thermal performance evaluation for HEV application  

Microsoft Academic Search

To further reduce system costs and package volumes of hybrid electric vehicles (HEVs), it is important to optimize the power module and associated cooling system. This paper reports the thermal performance evaluation and analysis of three commercial power modules with different cooling systems. Experiments and simulations were conducted to help further optimization of design. Results show that power electronics can

Puqi Ning; Zhenxian Liang; Fred Wang; Laura Marlino

2012-01-01

190

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

191

Effect of superfluid helium at the inner coil face on cooling and stability in superconducting accelerator magnets  

NASA Astrophysics Data System (ADS)

For the upcoming luminosity upgrade of CERN's Large Hadron Collider, a main issue is to increase the effective heat removal from the superconducting cables in the final focusing quadrupole magnets. The focus here is on the effect of superfluid helium in the thin annular space between the windings and the beam pipe, which is studied using finite element modeling. Below the lambda temperature the effect of helium is described by an effective thermal conductivity. The temperature distribution is strongly dependent on the heat flux and therefore on the dimensions of the cooling channels and the spatial distribution of the heat source. Especially the influence of the so-called ground-insulation flaps, partly blocking helium flow in the annulus is of interest. For a high energy deposition, the flaps are a limiting factor. A solution is to implement a corrugated edged flap, such that openings exist, while sufficient electrical insulation is maintained.

Bielert, Erwin; Verweij, Arjan; ten Kate, H. H. J.

2012-06-01

192

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

SciTech Connect

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

Green, Michael A.

2007-08-27

193

Volt-ampere rating of air-core superconducting power transformers  

Microsoft Academic Search

The authors point out that air-core superconducting power transformers have the potential of serving not only as power transformers but also as shunt reactors when used in power transmission systems having large capacitances. Here, the rated primary volt-amperes, volt-amperes as a shunt reactor, and related quantities are analyzed and their relations to the magnetic coupling factor and magnetizing reactance of

Teruo Kataoka; Hiroshi Yamaguchi; Yukihiko Sato; Shin-ichi HAYASHI; Hajime Morimoto

1993-01-01

194

Performance test of a refrigerator cooled magnet fabricated using Bi2212 multilayer superconducting tapes  

Microsoft Academic Search

A stacked pancake coil was fabricated by Ag-alloy sheathed Bi-2212 multilayer tapes and tested using a refrigerator. The magnet consisted of ten double pancakes wound with 100 m class tapes. The Ic values of the tapes varied from 80 A to 150 A at 4.2 K and 10 T because of the scattering of the thickness in the superconducting layers.

T. Hasegawa; Y. Hikichi; T. Koizumi; N. Ohtani; H. Kurnakura; H. Kitaguchi; K. Togano

1999-01-01

195

Fabrication of a working Bi2223 superconducting magnet cooled by liquid nitrogen  

Microsoft Academic Search

A practical Bi-2223 superconducting magnet, working in liquid nitrogen (L.N2), was designed and fabricated. Bi-2223 tape with a critical current of 147A was prepared by a controlled overpressure (CT-OP) process at 77.3K in self-field. Ten double-pancake coils were resistively connected by copper terminals. The bore diameter was 54mm?, the magnet outer diameter was 122mm?, the height of the magnet was

E. S. Otabe; M. Kiuchi; T. Matsushita; K. Fujino; K. Ohmatsu; B. Ni

2009-01-01

196

Princeton fusion power plant superconducting magnet system and costs  

Microsoft Academic Search

Details are given of the superconducting magnet system consisting of toroidal field, divertor, ohmic heating, equilibrium field and control field magnets, all of which are wound of NbSn conductor. The toroidal field coils are of the moment-free, D type. The toroidal field magnet is comprised of 48 discrete D coils, 12m x 19m bore. The magnet which is operated at

J. File

1975-01-01

197

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

198

Instabilities above critical current region in Bi2223\\/Ag superconducting coils cooled by liquid nitrogen  

Microsoft Academic Search

A sudden drop of the coil voltage and a hysteresis of I–V curve were observed in measurement of one-layer Bi-2223\\/Ag coils cooled by liquid nitrogen at currents well above critical current region. Their temporal behavior indicates, that the improvement of the cooling and corresponding decrease of temperature after the jump takes place. To study this phenomenon we measured I–V curves

F Chovanec; P Usak

2002-01-01

199

Economic assessment of backfitting power plants with closed-cycle cooling systems  

Microsoft Academic Search

A method for assessing the economic consequences of backfitting electric power plants with conventional closed cycle cooling systems is stipulated. 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 to reproduce the operating characteristics of different types

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

1976-01-01

200

Portable self-contained power and cooling system  

SciTech Connect

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

McCullough, J.E.

1993-07-20

201

The status of R and D for superconducting power transmission systems  

NASA Astrophysics Data System (ADS)

Many research groups in the US, Europe and the USSR worked on the development of superconducting power transmission systems in 1960's, 1970's and early 1980's. The superconducting material used was niobium or niobium-tin. A wide variety of conductor configurations, dielectric insulation and cryogenic enclosures were investigated. Systems studies to evaluate technical and economic factors were performed. Two large outdoor test facilities were constructed which provided data of interest to potential utility company users. Virtually all these projects are now closed down, mainly due to technical difficulties with the particular design chosen or due to the realization that the next development phase, the transfer of the technology into industry, will be very expensive compared to the original R and D costs. At present no funding agency sets a high priority on the development of superconducting power transmission systems.

Forsyth, E. B.

202

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.  

Code of Federal Regulations, 2010 CFR

...cooling systems for light-water nuclear power reactors. 50.46 Section 50...cooling systems for light-water nuclear power reactors. (a)(1)(i...or pressurized light-water nuclear power reactor fueled with...

2010-01-01

203

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.  

Code of Federal Regulations, 2010 CFR

...cooling systems for light-water nuclear power reactors. 50.46 Section 50...cooling systems for light-water nuclear power reactors. (a)(1)(i...or pressurized light-water nuclear power reactor fueled with...

2009-01-01

204

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

205

Gas-cooled reactor for space power systems  

NASA Astrophysics Data System (ADS)

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 time of 1 yr. 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 percent are obtained with 12 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

206

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

207

Comparison power generation by using thermoelectric modules between cooling module and power module for low temperature application  

Microsoft Academic Search

The paper presents comparison thermoelectric power generation between cooling and power modules. In order to investigate which type of TE module is suitable for the power generation at low temperature of hot side of TE, four TE modules were considered: two TE cooling modules (TE model TEC1-12708 and MT2-1.-127) and two TE power modules (TE model TEP1-1264-3.4 and TEG1-1260-5.1) for

S. Maneewan; B. Zeghmati

2007-01-01

208

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

209

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

NASA Astrophysics Data System (ADS)

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

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

2004-06-01

210

Method for estimating future markets for high-temperature superconducting power devices  

Microsoft Academic Search

This paper describes a spreadsheet model for estimating the impact of high-temperature superconducting (HTS) power devices on the national electric grid. The distribution of losses in the national grid is carefully traced and those losses that HTS can eliminate are identified. The energy savings achievable by the many sizes of HTS generators, transformers, cables, and motors are then computed and

Thomas P. Sheahen; Benjamin W. McConnell; Joseph W. Mulholland

2002-01-01

211

One-phase dual converter for two quadrant power control of superconducting magnets  

SciTech Connect

This paper presents the results of theoretical and experimental development of a new dc-ac-dc converter for superconducting magnet power supplies. The basic operating principles of the circuit are described followed by a theoretical treatment of the dynamics and control of the system. The successful results of the first experimental operation and control of such a circuit are presented and discussed.

Ehsani, M.; Kustom, R.I.; Boom, R.W.

1985-01-01

212

Energy and Environmental Assessment of On-Site Power and Cooling for Data Centers  

Microsoft Academic Search

High density data centers consume mega watts of electricity for both computing and cooling. Because of the fast paced growth of data center energy demand, effective energy conservation measures must be implemented. The use of the on-site combined power generation and cooling systems for data centers that are located on campuses is discussed and compared to grid powered data centers.

Hamza S. Erden; H. Ezzat Khalifa

2011-01-01

213

Energy and environmental assessment of on-site power and cooling for data centers  

Microsoft Academic Search

High density data centers consume mega watts of electricity for both computing and cooling. Because of the fast paced growth of data center energy demand, effective energy conservation measures must be implemented. The use of on-site combined power generation and cooling systems for data centers that are located on campuses is discussed and compared to grid-powered data centers. The placement

Hamza S. Erden; H. Ezzat Khalifa

2012-01-01

214

High power failure of superconducting microwave filters: Investigation by means of thermal imaging  

SciTech Connect

We have investigated power handling of high-temperature superconducting microstrip filters employing highly sensitive thermal imaging. At low power, the images show small heating effects localized to areas with high current densities ({Delta}{ital T}{lt}0.5 K), consistent with the known surface resistance and simulations of the current distribution. The breakdown at high-power levels, however, is always nucleated by a frequency independent local hot spot ({ital T}{approx_gt}{ital T}{sub {ital c}}). Scanning electron microscopy analysis of this area reveals a flaw in the superconducting material, presumably reducing the local critical current. The maximum power handling of these filters is, therefore, still open to improvement. {copyright} {ital 1996 American Institute of Physics.}

Hampel, G.; Kolodner, P.; Gammel, P.L.; Polakos, P.A.; de Obaldia, E.; Mankiewich, P.M. [Bell Laboratories, Lucent Technologies Inc., Murray Hill, New Jersey 07974 (United States); Anderson, A.; Slattery, R. [MIT/Lincoln Laboratory, Lexington, Massachusetts 02173 (United States); Zhang, D.; Liang, G.C.; Shih, C.F. [Conductus, Inc., Sunnyvale, California 94086 (United States)

1996-07-01

215

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

216

Superconducting magnets for an MHD test facility and base load power plant  

Microsoft Academic Search

The development MHD power generation in the U.S. may involve the construction of an Engineering Test Facility (ETF) as a step toward a base-load or full-scale power plant. This paper describes the superconducting-magnet requirements for the ETF and base-load plants and gives the results to date in a program involving production of magnet reference designs for the two systems. Each

Z. J. J. Stekly; R. J. Thome; W. F. B. Punchard

1977-01-01

217

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

218

Stochastic Method for the Operation of a Power System With Wind Generators and Superconducting Magnetic Energy Storages (SMESs)  

Microsoft Academic Search

Various energy storage systems have been adopted in power systems for economic and reliability reasons. In order to maintain the reliability of power systems, reserve power needs to be scheduled against possible generation unit outages. The varia- tion of wind power outputs also requires additional reserve power in addition to the reserve for the possible generation unit outages. Superconducting Magnetic

Jaehee Lee; Ji-Hui Kim; Sung-Kwan Joo

2011-01-01

219

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

220

Development Project of Supercritical-water Cooled Power Reactor  

SciTech Connect

A Supercritical-water Cooled Power Reactor (SCPR) development project (Feb. 2001- Mar. 2005) is being performed by a joint team consisting of Japanese universities and nuclear venders with a national fund. The main objective of this project is to provide technical information essential to demonstration of SCPR technologies through concentrating three sub-themes: 'plant conceptual design', 'thermohydraulics', and 'material and water chemistry'. The target of the 'plant conceptual design sub-theme' is simplify the whole plant systems compared with the conventional LWRs while achieving high thermal efficiency of more than 40 % without sacrificing the level of safety. Under the 'thermohydraulics sub-theme', heat transfer characteristics of supercritical-water as a coolant of the SCPR are examined experimentally and analytically focusing on 'heat transfer deterioration'. The experiments are being performed using fron-22 for water at a fossil boiler test facility. The experimental results are being incorporated in LWR analytical tools together with an extended steam/R22 table. Under the 'material and water chemistry sub-theme', material candidates for fuel claddings and internals of the SCPR are being screened mainly through mechanical tests, corrosion tests, and simulated irradiation tests under the SCPR condition considering water chemistry. In particular, stress corrosion cracking sensitivity is being investigated as well as uniform corrosion and swelling characteristics. Influences of water chemistry on the corrosion product characteristics are also being examined to find preferable water condition as well as to develop rational water chemistry controlling methods. (authors)

Kataoka, K.; Shiga, S. [Toshiba Corporation, 8, Shinsugita-cho, Isogo-ku, Yokohama, 235-8517 (Japan); Moriya, K. [Hitachi, Ltd. (Japan); Oka, Y. [Univ. of Tokyo (Japan); Yoshida, S. [Kyushu Univ. (Japan); Takahashi, H. [Hokkaido Univ. (Japan)

2002-07-01

221

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

222

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.

223

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)

2011-01-19

224

Microwave-Induced Cooling of a Superconducting Persistent-Current Qubit  

NASA Astrophysics Data System (ADS)

We present the experimental demonstration of microwave-induced cooling of a persistent-current qubit. Our qubit is a multi-level artificial atom. Thermal population of the first-excited qubit state is driven to a higher-excited state, from which it preferentially relaxes to the qubit ground state. Cooling is realized, because the driving-induced population transfer to the ground state is faster than the thermal repopulation of the excited state. We achieve effective qubit temperatures < 3 mK, a factor 10x-100x lower than the dilution refrigerator ambient temperature. This talk will present and discuss these experimental results. [1] S.O. Valenzuela, W.D. Oliver, D.M. Berns, et al., Science (2006).

Valenzuela, Sergio; Oliver, William; Berns, David; Berggren, Karl; Levitov, Leonid; Orlando, Terry

2007-03-01

225

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

226

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

227

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

NASA Astrophysics Data System (ADS)

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

Hegazy, Ahmed Sabry

228

Receiver measurements at 1267 GHz using a diffusion-cooled superconducting transition-edge bolometer  

Microsoft Academic Search

We report receiver noise temperature measurements using a quasioptically coupled diffusion-cooled hot-electron bolometer mixer at a local oscillator frequency of 1267 GHz, and an intermediate frequency of 1.4 GHz. A best double-sideband (DSB) receiver noise temperature of 1880 K was measured, with an estimated mixer noise of 945 K (DSB), and a conversion efficiency including coupling losses of -19 dB

A. Skalare; W. R. McGrath; B. Bumble; H. G. LeDuc

1997-01-01

229

A study of the operating conditions and power performance characteristics of power units upon increasing the cooling capacity of their chimney-type cooling towers  

NASA Astrophysics Data System (ADS)

The operating conditions and power performance characteristics of the Armenian nuclear power station’s Unit 2 equipped with a K-220-4.3 turbine and of the Razdan district power station’s units equipped with K-200-12.8 and K-300-23.5 turbines are studied. The effect from increasing the cooling capacity of chimney-type cooling towers obtained by installing built-in rotary vertical panels instead of the existing louver-type devices is evaluated.

Muradyan, A. K.; Arshakyan, D. T.

2007-11-01

230

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

231

Electric Power Saving Fan Options For Cow Cooling  

Microsoft Academic Search

Summer heat stress lowers dairy cow feed intake and productive performance. Unless measures are taken to improve cow comfort this stress can also lead to animal health problems. Various cooling methods have been used successfully to alleviate this problem (Shultz 1986 and Armstrong 1993). These methods focus on increasing feed intake, while cooling the cow and the immediate environment around

Thomas A. Shultz; Paul Williams

232

On the power handling capability of high temperature superconductive filters  

SciTech Connect

This paper presents high power test results for high temperature superconductor (HTS) filters having six different configurations. The results demonstrate the possibility of realizing narrow band HTS filters that are capable of handling 30--50 W at 77 K. The paper also introduces a procedure for comparing the power handling capability of HTS filters with different RF characteristics. Issues related to thermal design of high power HTS filters are discussed in detail.

Mansour, R.R.; Jolley, B.; Ye, S.; Thomson, F.S.; Dokas, V. [Com Dev Ltd., Cambridge, Ontario (Canada). Corporate R and D Dept.

1996-07-01

233

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

234

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.  

Code of Federal Regulations, 2013 CFR

...core cooling systems for light-water nuclear power reactors. 50.46 Section 50.46 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING...core cooling systems for light-water nuclear power reactors....

2013-01-01

235

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

Federal Register 2010, 2011, 2012, 2013

...Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory...Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors,'' in which the NRC made editorial...

2013-10-25

236

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

Microsoft Academic Search

Diffusion-cooled Nb hot-electron bolometer (HEB) mixers have the potential to simultaneously achieve high intermediate frequency (IF) bandwidths and low mixer noise temperatures for operation at THz frequencies (above the superconductive gap energy). We have measured the IF signal bandwidth at 630 GHz of Nb devices with lengths L = 0.3, 0.2, and 0.1 pm in a quasioptical mixer configuration employing

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

1999-01-01

237

Performance test of current lead cooled by a cryocooler in low temperature superconducting magnet system  

NASA Astrophysics Data System (ADS)

In a low temperature superconducting magnet system, heat leakage through current leads is one of the major factors in cryogenic load. The semi-retractable current lead is a good option because the conductive heat leakage can be eliminated after the excitation of the magnet. It is composed of a normal metal element, conducting the current from room temperature to intermediate temperature, and an HTS element, conducting the current down to liquid helium temperature. The normal metal element is disengaged from the HTS element through the multi-contact connector without disturbance to the insulating vacuum space and without requiring complete removal of the normal metal element. The intermediate block with a lockable set point is thermally connected to the first stage of cryocooler and carries current through a strip of louvered material. The electrical contact resistance of multi-contact connector in the intermediate block is measured during magnet charging process. The effects of current level as well as operating temperature on the heat generation in the joint block are also discussed.

Choi, Yeon Suk; Kim, Myung Su

2013-11-01

238

A hybrid superconducting fault current limiter for enhancing transient stability in Korean power systems  

NASA Astrophysics Data System (ADS)

Additional power generation sites have been limited in Korea, despite the fact load demands are gradually increasing. In order to meet these increasing demands, Korea's power system company has begun constructing new generators at existing sites. Thus, multi-unit plants can create problems in terms of transient stability when a large disturbance occurs. This paper proposes a hybrid superconducting fault current limiter (SFCL) application to enhance the transient stability of multi-unit power plants. SFCLs reduce fault currents, and limitation currents decrease the imbalance of the mechanical and electrical torque of the generators, resulting in an improvement in transient stability.

Seo, Sangsoo; Kim, Seog-Joo; Moon, Young-Hwan; Lee, Byongjun

2013-11-01

239

Mixed cryogen cooling systems for HTS power applications: A status report of progress in Korea University  

NASA Astrophysics Data System (ADS)

A cooling system employing a solid cryogen (SC), such as solid nitrogen (SN2), was recently reported for high-temperature superconducting (HTS) applications. However, thermal contact between the SC and the HTS can be degraded by repeated overcurrent runs, resulting in 'thermal dry-out'. Novel cryogens, SC with small amounts of liquid cryogen, have been suggested to overcome this problem. Such cooling systems rely on the small amount of liquid cryogen to facilitate heat exchange so as to fully exploit the heat capacity of the solid cryogen. This paper presents a description and summary of recent activities at Korea University related to cooling systems employing mixed cryogens of solid-liquid nitrogen, solid argon-liquid nitrogen, and solid nitrogen-liquid neon.

Song, Jung-Bin; Lee, Haigun

2012-12-01

240

Analysis of an improved solar-powered cooling system utilizing open-cycle absorbent regeneration  

Microsoft Academic Search

A solar-powered cooling system which promises high system C.O.P.'s and low collector costs is analyzed. It consists of a desiccant and an absorption cooling system operating in series to both dry and cool the air. A common solution of lithium chloride is used as the absorbant. The lithium chloride solution is regenerated by evaporating the excess water to the atmosphere

1978-01-01

241

Actively cooled plasma facing components for long pulse high power operation  

Microsoft Academic Search

This paper reviews the development of heat removal technology for plasma facing components (PFCs) and focuses on water-cooled PFCs for near term, high power applications and the use of the tungsten (W), carbon (C), and beryllium (Be) as the preferred armor materials. There are also brief summaries of developments in helium-cooled PFCs and applications of free liquid surfaces. Water-cooled PFCs

R. E. Nygren

2002-01-01

242

Power applications of high-temperature superconductivity: Variable speed motors, current switches, and energy storage for end use.  

National Technical Information Service (NTIS)

The objective of this project is to conduct joint research and development activities related to certain electric power applications of high-temperature superconductivity (HTS). The new superconductors may allow development of an energy-efficient switch t...

R. A. Hawsey B. B. Banerjee P. M. Grant

1996-01-01

243

Radiation cooled medium power arcjet experiments and thermal analysis  

NASA Astrophysics Data System (ADS)

This paper reports the investigations and test results of a 5-20 kW thermal arcjet thruster. The objective is to gain more insight into the operating conditions and to develop a flight oriented device with high efficiency and high specific impulse. A 5-20 kW radiation cooled arcjet thruster has been developed and tested at several mass flow rates with hydrogen, simulated hydrazine (a mixture of hydrogen and nitrogen) and ammonia as propellant. The influence of the injection swirl is investigated and test results with different cathode gaps are presented. The nozzle geometry and the electrode configuration are the same as in a previously investigated water-cooled version. The characteristics of these two devices with different cooling systems are compared. A numerical temperature analysis of the radiation cooled thruster has been performed with a finite element programming system. The results are compared with temperature measurements, obtained with a pyrometer at the radiation cooled anode and with thermocouples on the housing of the thruster. It is shown that the heat load at the anode is higher than with the water-cooled device and that a great amount of this heat is transferred into the propellant by heat conduction.

Glocker, Bernd; Auweter-Kurtz, Monika

1992-07-01

244

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

SciTech Connect

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

None

2010-10-01

245

Highly efficient and high-power industrial FELs driven by a compact, stand-alone and zero-boil-off superconducting RF linac  

NASA Astrophysics Data System (ADS)

In order to realize a tunable, highly efficient, high average power, high peak power and ultra-short pulse free-electron laser (FEL) as a Supertool (Laser, Supertool of the 1980s, Ticker & Fields, New Heaven, CT, 1982) of the 21st century, for all, the JAERI FEL group and I have developed an industrial FEL driven by a compact, stand-alone and zero-boil-off superconducting RF linac (Nucl. Instr. and Meth. 445 (2000)183) with an energy-recovery geometry as a conceptual design. Our discussions on the Supertool will cover market requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil-off cryostat concept, non-stop cooling, and operational experience over these 9 years, and our discovery of the new, highly efficient, high-power, and ultra-short pulse lasing mode (Phys. Rev. Lett. 86 (2001) 5707), and the energy-recovery geometry.

Minehara, E. J.

2002-05-01

246

Observation of voltage fluctuations in a Superconducting Magnet during MHD power generation  

Microsoft Academic Search

Fluctuating voltage signals on the potential taps of the ANL 5.0 T MHD Superconducting Dipole Magnet have been observed during MHD power generation at the U-25B Facility at the High Temperature Institute (IVTAN) Moscow, USSR. Various other thermodynamic and electrical parameters of the U-25B flow train have been recorded, and statistical analysis concerning correlations between the phenomena with a view

R. P. Smith; R. C. Niemann; M. R. Kraimer; T. E. Zinneman

1979-01-01

247

Observation of voltage fluctuations in a superconducting magnet during MHD power generation  

Microsoft Academic Search

Fluctuating voltage signals on the potential taps of the ANL 5.0 T MHD Superconducting Dipole Magnet have been observed during MHD power generation at the U-25B Facility at the High Temperature Institute (IVTAN) Moscow, USSR. Various other thermodynamic and electrical parameters of the U-25B flow train have been recorded, and statistical analysis concerning correlations between the phenomena with a view

R. P. Smith; R. C. Niemann; M. R. Kraimer; T. E. Zinneman

1978-01-01

248

Observation of voltage fluctuations in a superconducting magnet during MHD power generation  

Microsoft Academic Search

Fluctuating voltage signals on the potential taps of the ANL 5.0 T MHD Superconducting Dipole Magnet have been observed during MHD power generation at the U-25B Facility at the High Temperature Institute (IVTAN) Moscow, USSR. Various other thermodynamic and electrical parameters of the U-25B flow train have been recorded, and statistical analysis concerning correlations between the phenomena with a view

R. P. Smith; R. C. Niemam; M. R. Kraimer; T. E. Zinneman

1979-01-01

249

Hydraulic model study of the cooling lake for the La Salle County Nuclear Power Plant  

Microsoft Academic Search

A hydraulic model study of the cooling lake of the La Salle County Nuclear Power Station of Commonwealth Edison was performed. Two sizes of lake were investigated. In both cases various configurations of the internal, baffle-dike layout were studied to determine the configuration giving the best cooling performance. The experiments were performed by injecting a solution of Rhodamine WT fluorescent

J. C. Tatinclaux; S. C. Jain; W. W. Sayre

1973-01-01

250

Water Recycle/Reuse Possibilities: Power Plant Boiler and Cooling Systems.  

National Technical Information Service (NTIS)

The report contains the methodology to evaluate, in economic terms, potential power plant boiler and cooling system water recycle/reuse programs. Drum type boiler systems and closed cycle cooling systems are used as the basis for the programs' water requi...

G. R. Nelson

1974-01-01

251

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

NASA Astrophysics Data System (ADS)

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, Al2O3, Cu, MgO, Nb, and Si.

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

2012-12-01

252

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.

Binping Xiao, Michael Kelley, Charles Reece, H. Phillips

2012-12-01

253

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

254

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

National Technical Information Service (NTIS)

The results of an investigation of sources of municipal waste water for potential use as cooling water in California power plants and the major factors which affect this practice are presented. Municipal treatment facilities in California with discharge v...

T. McDonald

1980-01-01

255

State of the Art Power Couplers for Superconducting RF Cavities  

Microsoft Academic Search

Simulations are now routinely performed that allow the prediction of electromagnetic, multipacting, thermal, and mechanical properties of couplers. From these studies, better designs have been conceived which can minimize potential problems ahead of construction. Judicious use of materials and the implementation of clean practices and of careful conditioning have gradually increased the power levels at which couplers can safely operate.

Isidoro E. Campisi

2002-01-01

256

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

SciTech Connect

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 MWt lithium cooled reactor, generating potassium vapor that would drive a power turbine. The facility is a large containment vessel originally intended to test the EGCR. Large, contained, and shielded spaces are available for testing, assembly, disassembly, and post-test examination.

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

1992-08-01

257

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

258

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

259

A Comparison of Hybrid Electric Vehicle Power Electronics Cooling Options  

Microsoft Academic Search

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 105degC coolant and dissipate 200

M. O'Keefe; K. Bennion

2007-01-01

260

High Power Cable with Internal Water Cooling 400 KV.  

National Technical Information Service (NTIS)

The project was planned for a duration of 4 years. Afterwards it has been extended over 6 years and finally stopped after 3 1/2 years. Therefore, of course results of field tests with an internally cooled 400 kV cable are not available. Nevertheless, this...

W. Rasquin B. Harjes

1982-01-01

261

High power density self-cooled lithium-vanadium blanket.  

National Technical Information Service (NTIS)

A self-cooled lithium-vanadium blanket concept capable of operating with 2 MW/m(sup 2) surface heat flux and 10 MW/m(sup 2) neutron wall loading has been developed. The blanket has liquid lithium as the tritium breeder and the coolant to alleviate issues ...

Y. Gohar S. Majumdar D. Smith

1999-01-01

262

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

263

First High Power Test Results for 2.1 GHz Superconducting Photonic Band Gap Accelerator Cavities  

NASA Astrophysics Data System (ADS)

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 15MV/m and an unloaded quality factor Q0 of 4×109 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 TM01-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.

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

2012-10-01

264

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

265

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

266

Use of LHP for cooling power electronic components  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

267

Vaporizable dielectric fluid cooling for IGBT power semiconductors  

Microsoft Academic Search

An electrical drive utilizing a common dielectric fluid as the coolant in two-phase operation for cooling 1700V 450A Isolated Gate Bipolar Transistor semiconductor modules has been proposed and demonstrated as a proof-of-concept system. While water as a coolant is very common for such drive systems, a variety of liquids are used in commercial, industrial, aerospace, and military electronics systems. Use

David L. Saums

2010-01-01

268

Monolayer graphene dispersion and radiative cooling for high power LED  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

269

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

270

Design and construction of a rigid cryogenic envelope with low heat loss for a superconducting power transmission line  

Microsoft Academic Search

A research program to develop a superconducting cable for the purpose of establishing the technical and economic feasibility of superconducting ac power transmission is discussed. The program plan calls for a technical effort to provide the necessary conductor, dielectric, and cryogenic data needed to design a single-phase laboratory model and a field-installed prototype cable, the testing of the single-phase laboratory

H. Morihara; D. J. Webster; K. C. Kather

1975-01-01

271

Superconducting inductive pulsed power supply for electromagnetic launchers: Design aspects and experimental investigation of laboratory set-up  

SciTech Connect

The principle of the superconducting inductive energy storage and of superconducting pulse switching is reviewed. Design criteria are discussed by introducing two different laboratory set-ups. Special emphasis will be laid on the methods of charging the energy storage and on the pulse switching. The layout and dimensioning of an experimental pulsed power supply with an energy capacity of 4 MJ are described. First experimental results are presented and future development steps are discussed.

Weck, W.; Ehrhart, P.; Mueller, A.; Reiner, G. [Magnet-Motor GmbH, Starnberg (Germany)

1997-01-01

272

Economics of Conserving Water by Use of Alternative Cooling Methods for Large Nuclear, Fossil, and Combined Cycle Power Plants.  

National Technical Information Service (NTIS)

Computer analyses were performed to determine the water requirements for power plant cooling systems. Further analyses determined the change in energy production costs resulting from the use of cooling methods which reduce annual water requirements. The s...

J. P. Rossie

1978-01-01

273

Improving the performance of power-limited transverse stochastic cooling systems  

SciTech Connect

We present the formulas relevant to the behavior of (transverse) stochastic cooling systems which operate under the not uncommon condition that performance is limited by available output power, and contrast the operation of such systems with non-power-limited ones. In particular, we show that for power-limited systems, the two most effective improvements are the use of pickups/kickers which operate in both planes simultaneously and/or plunging of the cooling system electrodes, and present an example where increasing bandwidth is counter-productive. We apply our results to the proposed upgrade of the Fermilab {bar p} source. 4 refs., 1 fig., 2 tabs.

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

1989-08-01

274

Cooling ponds, lakes, and reservoirs: a positive factor in power plant siting  

Microsoft Academic Search

A specific area of power plant siting now concerns thermal effluents. Some regulations governing these discharges are reviewed. With the EPA now directed to weigh costs and benefits in determining whether a particular level of effluent reduction is economically achievable and reasonable as required by the FWPCA, cooling ponds, lakes, and reservoirs should be reevaluated as alternate methods of power

1977-01-01

275

Municipal waste water as a source of cooling water for California electric power plants  

Microsoft Academic Search

The results of an investigation of sources of municipal waste water for potential use as cooling water in California power plants and the major factors which affect this practice are presented. Municipal treatment facilities in California with discharge volumes deemed adequate to supply new power plants are identified. Also included is a summary of the experiences of several utilities in

1980-01-01

276

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

277

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

278

Narrow channel heat sink for cooling of high powered electronic components  

Microsoft Academic Search

The authors show the results of narrow channel heat sinks used for cooling of high powered components. The results of the experimental simulation for various air delivery methods are reported. The results show the difference in the thermal performance of the heat sink with top clearance versus ducted systems. In addition, effects of component layout power variation and air velocity

K. Azar; R. S. McLeod; R. E. Caron

1992-01-01

279

Alternating current loss characteristics in (bismuth,lead)SCCO and yttrium barium copper oxide superconducting tapes  

Microsoft Academic Search

Alternating current (AC) loss and current carrying capacity are two of the most crucial considerations in large-scale power applications of high temperature superconducting (HTS) conductors. AC losses result in an increased thermal load for cooling machines, and thus increased operating costs. Furthermore, AC losses can stimulate quenching phenomena or at least decrease the stability margin for superconducting devices. Thus, understanding

Doan Ngoc Nguyen

2007-01-01

280

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

281

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

282

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

283

Reduction of field emission in superconducting cavities with high power pulsed RF  

NASA Astrophysics Data System (ADS)

A systematic study is presented of the effects of pulsed high power RF processing (HPP) as a method of reducing field emission (FE) in superconducting radio frequency (SRF) cavities to reach higher accelerating gradients for future particle accelerators. The processing apparatus was built to provide up to 150 kW peak RF power to 3 GHz cavities, for pulse lengths from 200 ?s to 1 ms. Single-cell and nine-cell cavities were tested extensively. The thermal conductivity of the niobium for these cavities was made as high as possible to ensure stability against thermal breakdown of superconductivity. HPP proves to be a highly successful method of reducing FE loading in nine-cell SRF cavities. Attainable continuous wave (CW) fields increase by as much as 80% from their pre-HPP limits. The CW accelerating field achieved with nine-cell cavities improved from 8-15 MV/m with HPP to 14-20 MV/m. The benefits are stable with subsequent exposure to dust-free air. More importantly, HPP also proves effective against new field emission subsequently introduced by cold and warm vacuum ``accidents'' which admitted ``dirty'' air into the cavities. Clear correlations are obtained linking FE reduction with the maximum surface electric field attained during processing. In single cells the maximums reached were Epeak = 72 MV/m and Hpeak = 1660 Oe. Thermal breakdown, initiated by accompanying high surface magnetic fields is the dominant limitation on the attainable fields for pulsed processing, as well as for final CW and long pulse operation. To prove that the surface magnetic field rather than the surface electric fields is the limitation to HPP effectiveness, a special two-cell cavity with a reduced magnetic to electric field ratio is successfully tested. During HPP, pulsed fields reach Epeak = 113 MV/m (Hpeak = 1600 Oe) and subsequent CW low power measurement reached Epeak = 100 MV/m, the highest CW field ever measured in a superconducting accelerator cavity.

Graber, J.; Crawford, C.; Kirchgessner, J.; Padamsee, H.; Rubin, D.; Schmueser, P.

1994-11-01

284

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

SciTech Connect

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

Gary Vine

2010-12-01

285

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

Microsoft Academic Search

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

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

2006-01-01

286

Thermodynamic analysis of an existing coal-fired power plant for district heating\\/cooling application  

Microsoft Academic Search

In a conventional coal-fired power plant, which is only designed for electricity generation, 2\\/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating\\/cooling demand of their locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired

Hasan Huseyin Erdem; Ahmet Dagdas; Suleyman Hakan Sevilgen; Burhanettin Cetin; Ali Volkan Akkaya; Bahri Sahin; Ismail Teke; Cengiz Gungor; Selcuk Atas

2010-01-01

287

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

Microsoft Academic Search

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,

Curtis William Ayers; J. C. Conklin; J. S. Hsu; K. T. Lowe

2007-01-01

288

A new power-conditioning system for superconducting magnetic energy storage  

SciTech Connect

A new power-conditioning system for superconducting magnetic energy storage, which can independently regulate the active and reactive power of the utility network, is presented. The conceived system is composed of ten 100-MW modules connected in parallel. Each 100-MW module consists of a tap changing transformer and a 12-pulse, force-commutated converter. This system offers a significant reduction of the system rating by reducing the reactive power demand in the converter with control of the tap-changing ratio and the converter firing angle. The operational concept of this system is verified through mathematical analysis and computer simulation. The dynamic interaction between this system and the ac network is analyzed using a simulation model with EMTP. The analysis results prove that the new system concept is feasible. This system can be built with commercially available components and proven technologies.

Han, B.M.; Karady, G.G. (Arizona State Univ., Tempe, AZ (United States))

1993-06-01

289

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

290

Cooling of high power LEDs through ventilating ambient air to front surface of chip  

NASA Astrophysics Data System (ADS)

In this study, a novel cooling strategy through ventilating ambient air to the front surface of the hot chips of the high power light-emitting diodes (LEDs) was proposed to tackle the ever tough issues facing the conventional thermal management approaches. Preliminary thermal resistance analysis, numerical simulation and conceptual experiments were carried out to evaluate the cooling performance thus enabled. In the system analysis, a thermal network model was established to characterize the thermal resistance of an ordinary high power LED light and that of the newly proposed light module. Through ventilating the high speed ambient airflow directly onto the chip surface, the thermal resistance of the whole light could be evidently reduced and additional pathway was thus opened for releasing heat from the chips. Further, three-dimensional finite volume simulations were adopted to investigate the temperature distribution of the new light. It was found that even without heat sink or active cooling at the back part of the LED light, the new method via cooling the front part still works well. Lastly, a conceptual experiment was performed, which again demonstrated that cooling the LED at its front surface suggests an effective way to maintain the safe running of LED light within an allowable temperature scale just as cooling the light at the back part. The present method initiates a new way for future thermal management of high power LEDs.

Ma, Lu; Yang, Yang; Liu, Jing

2013-01-01

291

COOLING SYSTEM FOR THE MERIT HIGH-POWER TARGET EXPERIMENT  

SciTech Connect

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

Haug, F.; Pereira, H.; Silva, P.; Pezzetti, M.; Pavlov, O.; Pirotte, O.; Metselaar, J.; Efthymiopoulos, I.; Fabich, A.; Lettry, J. [CERN, CH-1211, Geneva, 23 (Switzerland); Kirk, H. G. [BNL, Upton, NY 11973 (United States); McDonald, K. T. [Princeton University, Princeton, NJ 08544 (United States); Titus, P. [NW22-225 MIT Plasma Science and Fusion Center, 185 Albany Street, Cambridge MA 02139 (United States); Bennett, J. R. J. [CCLRC, RAL, Chilton, OX11 0QX (United Kingdom)

2010-04-09

292

Power applications of high-temperature superconductivity: Variable speed motors, current switches, and energy storage for end use  

SciTech Connect

The objective of this project is to conduct joint research and development activities related to certain electric power applications of high-temperature superconductivity (HTS). The new superconductors may allow development of an energy-efficient switch to control current to variable speed motors, superconducting magnetic energy storage (SMES) systems, and other power conversion equipment. Motor types that were considered include induction, permanent magnet, and superconducting ac motors. Because it is impractical to experimentally alter certain key design elements in radial-gap motors, experiments were conducted on an axial field superconducting motor prototype using 4 NbTi magnets. Superconducting magnetic energy storage technology with 0.25--5 kWh stored energy was studied as a viable solution to short duration voltage sag problems on the customer side of the electric meter. The technical performance characteristics of the device wee assembled, along with competing technologies such as active power line conditioners with storage, battery-based uninterruptible power supplies, and supercapacitors, and the market potential for SMES was defined. Four reports were prepared summarizing the results of the project.

Hawsey, R.A. [Oak Ridge National Lab., TN (United States); Banerjee, B.B.; Grant, P.M. [Electric Power Research Inst., Palo Alto, CA (United States)

1996-08-01

293

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

294

Prototype Low Temperature Low Power Cryocooler.  

National Technical Information Service (NTIS)

Over the past several years considerable interest has developed for low power, low cost mechanical cryocoolers for use in cooling SQUIDS and other superconducting devices. In 1977 Dr. Jim Zimmerman of National Bureau of Standards, Boulder, CO described a ...

W. G. Pierce

1982-01-01

295

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

Microsoft Academic Search

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

Mehmet Kanoglu

1999-01-01

296

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...

297

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

SciTech Connect

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

Mann, Ron; Chavez, Miguel, E.

2012-06-27

298

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

SciTech Connect

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

Reyes, A.P.; Ahrens, E.T.; Hammel, P.C.; Heffner, R.H.; Thompson, J.D.; Canfield, P.C.; Fisk, Z. [Los Alamos National Lab., NM (United States); Schirber, J.E. [Sandia National Labs., Albuquerque, NM (United States)

1992-10-01

299

High power density self-cooled lithium-vanadium blanket.  

SciTech Connect

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

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

1999-07-01

300

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

301

Design and construction of a high temperature superconducting power cable cryostat for use in railway system applications  

NASA Astrophysics Data System (ADS)

The primary objective of the current effort was to design and test a cryostat using a prototype five-meter long high temperature Bi2Sr2Ca2Cu3Oy (Bi-2223) superconducting dc power cable for railway systems. To satisfy the safety regulations of the Govt of Japan a mill sheet covered by super-insulation was used inside the walls of the cryostat. The thicknesses of various walls in the cryostat were obtained from a numerical analysis. A non-destructive inspection was utilized to find leaks under vacuum or pressure. The cryostat target temperature range was around 50 K, which is well below liquid nitrogen temperature, the operating temperature of the superconducting cable. The qualification testing was carried out from 77 down to 66 K. When using only the inner sheet wire, the maximum current at 77.3 K was 10 kA. The critical current (Ic) value increased with decreasing temperature and reached 11.79 kA at 73.7 K. This is the largest dc current reported in a Bi2Sr2Ca2Cu3Oy or YBa2Cu3Oy (Y-123) superconducting prototype cable so far. These results verify that the developed DC superconducting cable is reliable and fulfils all the requirements necessary for successful use in various power applications including railway systems. The key issues for the design of a reliable cryogenic system for superconducting power cables for railway systems are discussed.

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

2013-10-01

302

Emerging Issues and Needs in Power Plant Cooling Systems  

Microsoft Academic Search

The majority of the electricity generated in the United States is produced by steam- driven turbine-generators. A very important step in this power generation process is the condensation of exhaust steam from the final, low-pressure turbine. When the steam condenses, the rapid decrease in vapor-to-liquid specific volumes creates a vacuum at the turbine outlet (monitored as turbine backpressure) that increases

Wayne C. Micheletti; John M. Burns

303

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

304

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

305

IMPROVING AIR-COOLED CONDENSER PERFORMANCE USING WINGLETS AND OVAL TUBES IN A GEOTHERMAL POWER PLANT  

Microsoft Academic Search

Two concepts for improving the heat transfer performance of the air-cooled condensers used in binary geothermal power plants are being developed and tested at the INEEL. These concepts involve (1) replacing the circular tubes with oval tubes and (2) adding strategically located vortex generators (winglets) in the fins. These concepts can be used individually or in unison. Depending on the

M. S. Sohal; J. E. O'Brien

2001-01-01

306

HEAT TRANSFER AND FLUID DYNAMIC RESEARCH AS APPLIED TO FOG COOLED POWER REACTORS  

Microsoft Academic Search

An up-to-date critical review is presented of the state of heat transfer ; and fluid dynamic research on two-phase gas\\/ liquid systems as applied to the fog ; cooled power reactor concept. Detailed accounts are included of recent ; experiments with steam-water mixtures in complex geometries including 19 rod ; cluster assemblies. Areas where further research is required are mentioned.

1962-01-01

307

CoolSpots: reducing the power consumption of wireless mobile devices with multiple radio interfaces  

Microsoft Academic Search

CoolSpots enable a wireless mobile device to automatically switch between multiple radio interfaces, such as WiFi and Bluetooth, in order to increase battery lifetime. The main contribution of this work is an exploration of the policies that enable a system to switch among these interfaces, each with diverse radio characteristics and different ranges, in order to save power - supported

Trevor Pering; Yuvraj Agarwal; Rajesh K. Gupta; Roy Want

2006-01-01

308

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

309

Characterization of Chlorination By-products in Cooling Effluents of Coastal Nuclear Power Stations  

Microsoft Academic Search

In power stations, the cooling effluents are chlorinated to avoid excessive biofouling. Yet, this disinfecting treatment leads to the formation of halogenated by-products. In spite of possible toxicity of such compounds towards aquatic organisms, there is an evident lack of information on the formation of halogenated compounds in chlorinated seawater samples. So, this study was undertaken to identify and quantify

Anne-Sophie Allonier; Michel Khalanski; ValÉrie Camel; Alain Bermond

1999-01-01

310

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

311

A New System to Produce Cooling and Power Using Solar Thermal Energy  

Microsoft Academic Search

A new system to produce cooling and power with the energy obtained from low-temperature as a thermal resource is presented in this work. This resource can be obtained from concentrating solar thermal energy (parabolic trough). This system belongs to the broader class of low temperature, Rankine cycles, which have been shown to be one of the most effective means for

Z. S. Abdel-Rehim

2011-01-01

312

Hydraulic Model Study of the Cooling Lake for the La Salle County Nuclear Power Plant.  

National Technical Information Service (NTIS)

A hydraulic model study of the cooling lake of the La Salle County Nuclear Power Station of Commonwealth Edison was performed. Two sizes of lake were investigated. In both cases various configurations of the internal, baffle-dike layout were studied to de...

J. C. Tatinclaux S. C. Jain W. W. Sayre

1973-01-01

313

Solar-powered housing unit - Simulation of solar heating and cooling in Saudi Arabia  

Microsoft Academic Search

A report is given on the initiation of a project to investigate the feasibility of a solar-powered residence in the Eastern Province of Saudi Arabia. As a first step, the operation of such a house will be simulated by digital computer, concentrating primarily on a system which includes space heating and cooling and a hot water supply for domestic use.

R. W. Jones; A. Kremheller; I. R. Titze

1976-01-01

314

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

315

Rotor packing of an atomic-power-station centrifugal cooling pump  

Microsoft Academic Search

Centrifugal cooling pumps have to be highly reliable because of the complex conditions under which they operate in atomic power stations. Fabrication of reliable shaft packings is therefore a major task. Of the known mechanical, hydrostatic and other types of face packings, the requirements are best met by the face packing with a self-adjusted gap. The working parameters and the

N. V. Penedrii; B. N. Perminov

1983-01-01

316

BRENDA: a dynamic simulator for a sodium-cooled fast reactor power plant  

Microsoft Academic Search

This report is a users' manual for one version of BRENDA (Breeder Reactor Nuclear Dynamic Analysis), which is a digital program for simulating the dynamic behavior of a sodium-cooled fast reactor power plant. This version, which contains 57 differential equations, represents a simplified model of the Clinch River Breeder Reactor Project (CRBRP). BRENDA is an input deck for DARE P

D. L. Hetrick; G. W. Sowers

1978-01-01

317

Loss of ‘Core cooling’ at low power and cold condition of VVER-1000\\/V320  

Microsoft Academic Search

This paper presents the results of thermal–hydraulic calculation of accident scenarios that involve the loss of critical safety function (CSF) “Core cooling” for VVER-1000\\/V320 units at Kozloduy nuclear power plant done during the development of symptom based emergency operating procedures (SB EOPs) for this plant at low power and cold condition. The main purpose of this analysis is to provide

P. P. Groudev; E. L. Georgieva

2010-01-01

318

Solar-powered systems for cooling, dehumidification and air-conditioning  

Microsoft Academic Search

This paper describes current trends in solar-powered air conditioning, which has seen renewed interest in recent years due to the growing awareness of global warming and other environmental problems. Closed-cycle heat-powered cooling devices are based mainly on absorption chillers, a proven technology employing LiBr–water as the working fluid pair. Recent developments in gas-fired systems of this type make available double-

Gershon Grossman

2002-01-01

319

Cool water gasification: Combined-cycle power plant: Availability analysis: Final report  

Microsoft Academic Search

The Cool Water Coal Gasification Plant represents a jointly funded private industry program to design, build, and operate a 120-MW coal-based power plant to demonstrate new integrated gasification combined-cycle (IGCC) technology on a commercial scale. The UNIRAM availability assessment software program, developed by ARINC Research Corporation for the Electric Power Research Institute (EPRI), was used to assess the availability of

Johnson

1988-01-01

320

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

Microsoft Academic Search

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,

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

2010-01-01

321

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

322

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

323

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

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

Hawsey, R.A.

2000-06-13

324

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

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

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

2000-04-01

325

Control of Superconducting Magnetic Energy Storage Units in Multi-Machine Power Systems  

NASA Astrophysics Data System (ADS)

A new scheme, in which a synchronous generator connected to the SMES busbar is used as a feedback generator, is proposed to control superconducting magnetic energy storage (SMES) units in multi-machine power systems, in this dissertation. The speed and the load angle changes of the feedback generator are used to calculate the necessary real power transfers to the SMES, while the necessary reactive power transfers are calculated from the voltage changes of the common busbar. Expressions are derived for the direct and quadrature axis components of the current drawn by the SMES, for unequal firing angles in the converter bridge, and the relationships of the two currents to the total real and reactive power transfers to the SMES are shown. The expressions derived are valid for small or large systems, under steady state or transient conditions, and it is shown through computer simulations in a small power system that, the proposed scheme is quite effective in stabilizing electromechanical oscillations caused by small as well as large disturbances. It is also shown that, the SMES can improve the power output of wind turbine induction generators, and also stabilize the oscillations caused by wind power losses in a steam turbine generator system, and thereby eliminate the need to use diesel turbine generators for the same purpose. Finally, equations are derived to represent the synchronous machine in terms of its d-q circuits, while it is connected to the network which is described by complex quantities, and the formulations done for the proposed scheme are extended to study the use of SMES units with proposed control in power systems of large and complex configurations. The proposed scheme of control is simple, and does not call for a special design of a controller requiring simplifying assumptions such as the presence of an infinite busbar or steady state operating conditions on the system, and therefore, would help in the widespread use of SMES units in electric utilities.

Ranaweera, Aruna

326

Performance of a modified zeolite 13X-water adsorptive cooling module powered by exhaust waste heat  

Microsoft Academic Search

A modified adsorption cooling module with a working pair of 13X zeolite-water used for engineering truck air-conditioning driven by engine waste heat is presented in this paper. The cooling powers at different evaporating temperatures for the module were first tested, and the cycle operating characteristics of the module at different cooling powers were then analyzed and discussed. The performance of

Wei-Dong Wu; Hua Zhang; Chuan-lin Men

2011-01-01

327

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

328

Optimal Design of Superconducting Motor to Improve Power Density Using 3D EMCN and Response Surface Methodology  

Microsoft Academic Search

This paper proposes an effective design process for 1 MW HTS superconducting motor by using 3-dimensional equivalent magnetic circuit network method (3D EMCN) and response surface methodology (RSM). During the process, 3D EMCN is used with a simplified 3D analysis model to get electric parameters in short time. RSM is used for the motor optimal design to improve power density.

Ji-Young Lee; Sung-Il Kim; Jung-Pyo Hong; Young-Sik Jo; Myung-Hwan Sohn; Seung-Kyu Baik; Young-Kil Kwon

2006-01-01

329

Potential impact of high temperature superconducting cables on grid reliability and available transfer capacity: power flow simulation results  

Microsoft Academic Search

This paper describes analyses of the potential impact on an electric utility system of high temperature superconducting (HTS) cables. Requirements for energy savings with HTS cables were investigated via parametric analysis of the energy use of an HTS cable, a conventional overhead conductor, and a conventional underground cable operating at similar voltage. Power flow simulations were performed for a portion

Emile Ettedgui; Santiago Grijalva; Richard Silberglitt; Christopher Wakefield

2002-01-01

330

Economic Operation of Long Distances Power Networks Using On-line Control of Superconducting Magnetic Energy Storage  

Microsoft Academic Search

This paper investigates a two-purpose application for the superconducting magnetic energy storage (SMES) in order to remove its economic barriers for a wide spread promotion in power systems. A practical realization of the control method using the locally measurable signals is considered. A simulation case study is conducted to verify the performance of the proposed application. The results prove that

Seyed Mohammad; SADEGH ZADEH

2007-01-01

331

Operation of the 30 MJ Superconducting Magnetic Energy Storage System in the Bonneville Power Administration Electrical Grid.  

National Technical Information Service (NTIS)

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...

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

1984-01-01

332

Operation of the 30 MJ superconducting magnetic energy storage system in the Bonneville Power Administration electrical grid  

Microsoft Academic Search

The 30 MJ superconducting magnetic energy storage (SMES) system was installed in the Bonneville Power Administration (BPA) Tacoma Substation in 1982-83. 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.

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

1985-01-01

333

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

Microsoft Academic Search

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

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

1984-01-01

334

Conceptual design of superconducting magnet systems for the Argonne Tokamak experimental power reactor  

Microsoft Academic Search

The conceptual design of a 10-tesla, pure-tension superconducting toroidal field (TF) coil system was developed in sufficient detail to define a realistic design for the TF coil system that could be built based upon the current state of technology with minimum technological extrapolations. A conceptual design study on the superconducting ohmic heating (OH) coils and the superconducting equilibrium field (EF)

S. T. Wang; L. R. Turner; F. E. Mills; D. W. Demichele; P. Smelser; S. H. Kim

1976-01-01

335

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

336

Organohalogen products from chlorination of cooling water at nuclear power stations  

SciTech Connect

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

Bean, R.M.

1983-10-01

337

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

338

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

339

A high power, radiation cooled, rotating toroidal target for neutrino production  

NASA Astrophysics Data System (ADS)

A rotating toroid is considered as a target for the production of pions by intense high energy proton beams for a neutrino factory. The toroid rotates in vacuum and the power is radiated to the water-cooled walls of the vacuum chamber. It is shown that steady powers of over 100 MW can be dissipated by thermal radiation at temperatures of ~2500 K, using a suitable refractory material such as tantalum or tungsten. Under pulsed beam conditions, the thermal stresses induced in the toroid will reduce the power capabilities. .

Bennett, J. R. J.

2000-11-01

340

Some thoughts on a high-power, radiation cooled, rotating toroidal target for neutrino production  

NASA Astrophysics Data System (ADS)

A rotating toroid is considered as a target for the production of pions by intense high-energy proton beams for a neutrino factory. The toroid rotates in vacuum and the power is radiated to the water-cooled walls of the vacuum chamber. It is shown that steady powers of over 100MW can be dissipated by thermal radiation at temperatures of /~2500K using a suitable refractory material such as tantalum or tungsten. Under pulsed beam conditions, the thermal stresses induced in the toroid will reduce the power capabilities.

Bennett, J. R. J.

2000-08-01

341

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

342

Design and operation of the 30-MJ superconducting magnetic-storage system on the Bonneville Power Administration bus  

SciTech Connect

A superconducting magnetic-energy-storage (SMES) unit is suitable for power-system stabilization because it can provide positive damping by absorbing or releasing energy with a relatively fast response time, 10 ms. In the fall of 1982, an SMES unit was installed at the Tacoma Substation of the Bonneville Power Administration as an experiment in monitoring, predicting and improving system stability. This paper reports principally on the system testing.

Schermer, R.I.; Barron, M.H.; Boenig, H.J.; Brown, R.R.; Criscuolo, A.L.; Cumming, C.J.; Dean, J.W.; Hassenzahl, W.V.; Rogers, J.D.; Seamons, M.J.

1983-01-01

343

Theoretical analysis and experimental results on super-conducting magnetic energy storage (SMES) in dynamic simulation test of power system  

Microsoft Academic Search

This paper introduces a double-DSPs controlled power conditioning system (PCS) for superconducting magnetic energy storage (SMES), which is used for experimental study in dynamic simulation tests of power system. Considering of realization, voltage source converter (VSC) with a chopper is adopted in the experimental sample. The VSC in the PCS is a four-quadrant AC\\/DC converter and chopper is a two-quadrant

Hui Zhang; Yong Kang; Pengcheng Zhu; Xuejuan kong; Ping Liu; Jian Chen

2001-01-01

344

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

SciTech Connect

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

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

1985-04-01

345

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

346

Brackish groundwater as an alternative source of cooling water for nuclear power plants in Israel  

NASA Astrophysics Data System (ADS)

Because of a high population density in the coastal plain, any future nuclear power plants will be located in the sparsely settled Negev desert Since this part of Israel has no surface water, the only alternatives to cooling water are piped-in Mediterranean. Water and local, brackish groundwater One particular aquifier was examined for its potential to provide the required amount of cooling water over the lifetime of the plant, without causing a drastic lowering of the regional water table It was concluded that given the assumed range of aquifer properties, extraction of brackish water for cooling purposes will not result in large changes in the regional water table, furthermore, it could possibly halt the gradual deterioration of the quality of the water supply of the city of Beer Sheva

Arad, A.; Olshina, A.

1984-09-01

347

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

SciTech Connect

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

C. McGowin; M. DiFilippo; L. Weintraub

2006-06-30

348

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

SciTech Connect

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

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

2012-05-20

349

Superconducting fiber  

NASA Astrophysics Data System (ADS)

In this study, we demonstrated superconductivity in a fiber with a lead core and fused silica cladding. The fibers were fabricated via a melt-draw technique and maintained overall diameters ranging from 200-900 ?m and core diameters of 100-800 ?m. Superconductivity of this fiber design was validated via the traditional four probe test method in a bath of liquid helium at temperatures on the order of 4 K. The superconducting fiber paves the way for applications in power transmission, magnetic sensing, and fundamental studies in the fields of electromagnetism.

Homa, D.; Liang, Y.; Pickrell, G.

2013-08-01

350

Metastable superconducting phases  

NASA Astrophysics Data System (ADS)

Various methods of increasing the superconducting transition temperature of metal superconductors are examined. In particular, attention is given to the use of high pressures, superhigh cooling rates, and shock waves for stabilizing the optimum compositions and structures of promising superconducting compounds, such as A15-type phases. The use of alloying and metastable supersaturation of solid solutions based on superconducting phases to increase the transition temperature of superconductors and to obtain new superconducting materials are also discussed. Thin-film superconducting materials with a transition temperatuure of 21 have been obtained by rapid quenching; high-pressure synthesis has made it possible to obtain bulk materials with a transition temperature of 19 K.

Savitskii, E. M.; Efimov, Iu. V.; Bychkova, M. I.; Giller, I. D.; Miasnikova, E. A.; Sumarokov, V. N.; Frolova, T. M.

351

Engineering evaluation of magma cooling-tower demonstration at Nevada Power Company's Sunrise Station. Final report  

SciTech Connect

The Magma Cooling Tower (MCT) process utilizes a falling film heat exchanger integrated into an induced draft cooling tower to evaporate wastewater. A hot water source such as return cooling water (90/sup 0/F to 110/sup 0/F) provides the energy for evaporation. Water quality control is maintained by removing potential scaling constituents to make concentration of the wastewater possible without scaling heat transfer surfaces. A pilot-scale demonstration test of the MCT process was performed from March 1979 through June 1979 at Nevada Power Company's Sunrise Station in Las Vegas, Nevada. The pilot unit extracted heat from the powerplant cooling system to evaporate cooling tower blowdown. Two water quality control methods were employed: makeup/sidestream softening and fluidized bed crystallization. The 11-week softening mode test was successful. The unit operated without biofouling or scaling at 100,000 ppM TDS levels under a wide range of operating conditions. Successful operation was not demonstrated in the 10-day crystallization mode test; calcium sulfate (CaSO/sub 4/) scaling occurred on the last day of the test at a maximum brine concentration of less than 40,000 ppM. An economic and technical comparison with other zero-discharge technologies showed that, for application at Sunrise, the MCT process had competitive capital, operating, and levelized annual costs. No major technical problems were encountered that would preclude the commercial application of a properly designed MCT unit operating in the softening mode.

Not Available

1980-11-01

352

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

353

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

354

Current Limiting Experiment of Transformer Type Superconducting Fault Current Limiter With Rewound Structure Using BSCCO Wire in Small Model Power System  

Microsoft Academic Search

Superconducting fault current limiters (SFCLs) are expected to improve the reliability and stability of power systems. We have proposed new design of a transformer type SFCL whose primary and secondary superconducting coil has rewound struc- ture. The fundamental characteristics of the proposed SFCL were investigated using a small model designed and made with BSCCO wire. This paper describes on the

Sayaka Oda; Sho Noda; Hideyoshi Nishioka; Masato Mori; Jumpei Baba; Yasuyuki Shirai

2011-01-01

355

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

SciTech Connect

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

Li, Z. [Bob Lawrence and Associates, Inc., Alexandria, VA (United States)

1998-05-01

356

Parameterizing the deformation of LN2-cooled silicon monochromator crystals with modified linear power density funtion  

NASA Astrophysics Data System (ADS)

The very low emittance and low energy spread source of a future Cornell energy recovery linac (ERL) will be equipped with long undulators of large numbers of short period magnets. The power density in the undulator radiation central cone will be much higher than that from normal undulators at current 3rd generation sources. The deformation of liquid nitrogen (LN2) cooled silicon crystal monochromators for ERL beamlines is evaluated by parameterizing the thermal problem with a modified linear power density function based on a simplified analytical model. This provides a clear and "universal" description of thermal deformation under different thermal footprints, variable loads and is independent of specific facility. The characteristics of thermal deformation of LN2-cooled Si crystals for Cornell ERL undulators is also given using finite element analysis (FEA).

Huang, Rong; Bilderback, Donald H.

2012-10-01

357

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

358

Peak power and cooling energy savings of high-albedo roofs  

Microsoft Academic Search

In the summers of 1991 and 1992, we monitored peak power and cooling energy savings from high-albedo coatings at one house and two school bungalows in Sacramento, California. We collected data on air-conditioning electricity use, indoor and outdoor temperatures and humidities, roof and ceiling surface temperatures, inside and outside wall temperatures, insolation, and wind speed and direction. Applying a high-albedo

Hashem Akbari; Sarah Bretz; Dan M. Kurn; James Hanford

1997-01-01

359

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

SciTech Connect

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 the electrodialytic devices can be used for regeneration of sodium-cation filters.

Vysotski, S.P.

1980-05-01

360

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

361

Operation and Control Simulation of a Modular High Temperature Gas Cooled Reactor Nuclear Power Plant  

Microsoft Academic Search

Issues in the operation and control of the multi-modular nuclear power plant are complicated. The high temperature gas cooled reactor pebble-bed module (HTR-PM) plant with two-module will be built as a demonstration plant in China. To investigate the operation and control characteristics of the plant, a simplified dynamic model is developed and mathematically formulated based upon the fundamental conversation of

Haipeng Li; Xiaojin Huang; Liangju Zhang

2008-01-01

362

Digital Simulaiion of a Commercial Scale High Temperature Gas-Cooled Reactor (HTGR) Steam Power Plant  

Microsoft Academic Search

A nonlinear dynamic model of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant was derived in state-space form from fundamental principles. The plant model is 40th order, time-invariant, deterministic and continuous-time. Numerical results were obtained by digital simulation. Steady-state performance of the nonlinear model was verified with plant heat balance data at 100, 75 and 50 percent

Asok Ray; H. Frederick Bowman

1978-01-01

363

Development of practical high temperature superconducting wire for electric power application  

NASA Astrophysics Data System (ADS)

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.

1995-04-01

364

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

365

Achieving more reliable operation of turbine generators at nuclear power plants by improving the water chemistry of the generator stator cooling system  

NASA Astrophysics Data System (ADS)

Ways of improving the water chemistry used in the turbine generator stator's cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.

Tyapkov, V. F.; Chudakova, I. Yu.; Alekseenko, O. A.

2011-08-01

366

Achieving more reliable operation of turbine generators at nuclear power plants by improving the water chemistry of the generator stator cooling system  

Microsoft Academic Search

Ways of improving the water chemistry used in the turbine generator stator's cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.

V. F. Tyapkov; I. Yu. Chudakova; O. A. Alekseenko

2011-01-01

367

Alternating Current Loss Characteristics in (Bi,Pb)2SrCa2Cu3O10 and YBa2Cu307-? Superconducting Tapes  

Microsoft Academic Search

Alternating current (AC) loss and current carrying capacity are two of the most crucial considerations in large-scale power applications of high temperature superconducting (HTS) conductors. AC losses result in an increased thermal load for cooling machines, and thus increased operating costs. Furthermore, AC losses can stimulate quenching phenomena or at least decrease the stability margin for superconducting devices. Thus, understanding

Doan Ngoc Nguyen

2007-01-01

368

Conductively cooled high-power high-brightness bars and fiber-coupled arrays  

NASA Astrophysics Data System (ADS)

Solid-state-laser and fiber laser pumping, reprographics, medical and materials processing applications require high power, high-brightness bars and fiber-coupled arrays. Conductively cooled laser diode bars allow customers to simplify system design and reduce operational size, weight, and costs. We present results on next generation high brightness, high reliability bars and fiber-coupled arrays at 790-830 nm, 940 nm and 980 nm wavelengths. By using novel epitaxial structures, we have demonstrated highly reliable 808 nm, 30% fill-factor conductively cooled bars operating at 60W CW mode, corresponding to a linear power density (LPD) of 20 mW/&mum. At 25°C, the bars have shown greater than 50% wall-plug-efficiency (WPE) when operating at 60W. Our novel approach has also reduced the fast-axis divergence FWHM from 31° to less than 24°. These bars have a 50% brightness improvement compared to our standard products with this geometry. At 980nm, we have demonstrated greater than 100W CW from 20% fill-factor conductively cooled bars, corresponding to a LPD of 50 mW/µm. At 25°C, the WPE for 976nm bars consistently peaks above 65% and remains greater than 60% at 100W. We coupled the beam output from those high-brightness bars into fiber-array-packages ("FAPs"), and we also achieved high-brightness and high-efficiency FAPs. We demonstrated 60W from a 600µm core-diameter fiber-bundle with a high WPE of 55%, and a low numerical aperture of 0.115. The brightness of such FAPs is four times higher than our standard high-power 40W FAP products at Coherent. Ongoing life test data suggests an extrapolated lifetime greater than 10,000 hours at 80W CW operating-condition based on 30%FF conductively cooled bar geometry.

Zhou, Hailong; Mondry, Mark; Fouksman, Michael; Weiss, Eli; Anikitchev, Serguei; Kennedy, Keith; Li, Jun; Zucker, Erik; Rudy, Paul; Kongas, Jukka; Haapamaa, Jouko; Lehkonen, Sami

2005-03-01

369

A study on the electrical insulation properties of solid nitrogen for cooling of the high temperature superconducting systems  

Microsoft Academic Search

Recently, for improvement of the magnetic field of high temperature superconductor (HTS) apparatus, many studies on operating in the temperature range of 20–65K with liquid helium or the thermal conducting method using cryocooler are actively reviewed. Also, the cooling method of using solid nitrogen as cryogen is currently being suggested. Since nitrogen has a very large specific heat in solid

J. H. Choi; J. W. Choi; H. Lee; J. B. Song; H. J. Kim; K. C. Seong; S. H. Kim

2009-01-01

370

A study on the electrical insulation properties of solid nitrogen for cooling of the high temperature superconducting systems  

Microsoft Academic Search

Recently, for improvement of the magnetic field of high temperature superconductor (HTS) apparatus, many studies on operating in the temperature range of 20-65 K with liquid helium or the thermal conducting method using cryocooler are actively reviewed. Also, the cooling method of using solid nitrogen as cryogen is currently being suggested. Since nitrogen has a very large specific heat in

J. H. Choi; J. W. Choi; H. Lee; J. B. Song; H. J. Kim; K. C. Seong; S. H. Kim

2009-01-01

371

Diamond cooling of high-power diode-pumped Nd:YVO4 and Nd:YAG lasers  

Microsoft Academic Search

We have demonstrated the feasibility of cooling high power solid-state lasers with diamond windows, whose thermal conductivity is about two orders of magnitude higher than sapphire's, the material conventionally used for this purpose. Since pumping and cooling were along the same axis, a Cartesian thermal gradient was achieved, while the zigzag scheme was used to minimize thermal lensing. An output

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

2005-01-01

372

High Temperature Superconducting Underground Power Cable (The 'Albany Cable Project'). Final Report. Period of Performance: November 1, 2002-December 31, 2009.  

National Technical Information Service (NTIS)

The purpose of this project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m an...

C. Weber R. Farrell

2009-01-01

373

SOLERAS - Solar Cooling Engineering Field Tests Project: United Technologies Research Center. Design guidelines for solar heating/cooling/power generation systems  

SciTech Connect

This report documents the methodology, design guidelines and analytical tools for the preliminary technical/economic evaluation of solar heating/cooling/power generation systems. In particular, it provides the theoretical framework, data bases and software tools for: determining the preliminary economic feasibility of solar-powered configurations compared with grid-supplied electric power and/or competing fossil fuels; selecting the optimum system configuration with respect to solar collector area and ''solar-side'' thermal storage capacity. Implementation of the methodology described in this report can be facilitated by the use of the accompanying IBM PC-compatible computer program ''SOLERAS''. This report represents the final task of the multi-year SOLERAS Program -- jointly sponsored by the US Department of Energy and the King Abdulaziz City for Science and Technology -- which involved the development and field-testing of a solar-powered cooling system in Phoenix, AZ. 11 refs., 37 figs.

Not Available

1987-01-01

374

Conceptual system design of a 5 MWh\\/100 MW superconducting flywheel energy storage plant for power utility applications  

Microsoft Academic Search

The authors have designed a 5 MWh\\/100 MW superconducting flywheel energy storage plant. The plant consists of 10 flywheel modules rated at 0.5 MWh\\/10 MW each. Module weight is 30 t, size is ? 3.5 m×6.5 m high. A synchronous type motor-generator is used for power input\\/output. Each flywheel system consists of four disk modules made from a carbon fibre

H. J. Bornemann; M. Sander

1997-01-01

375

Minnesota Project: District Heating and Cooling Through Power Plant Retrofit and Distribution Network. Final Report. Phase 1.  

National Technical Information Service (NTIS)

Appendices are presented for the Minnesota Project: District Heating and Cooling Through Power Plant Retrofit and Distribution Network. These are: SYNTHA results (SYNTHA II is a proprietary program of the SYNTHA Corporation); Market Survey Questionnaire: ...

1980-01-01

376

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

SciTech Connect

The use of dry cooling systems in power plants is a relatively new development and limited to only a few applications worldwide. The locations in question are those at which wet cooling system could not be used economically due to a shortage of making-up water. The power plants using dry cooling systems which have been built to date world- wide, and which have a power generation capacity of over 100 MWe are listed. It is evident from this that there is a predominance of indirect cooling systems. Although the actual investment costs for the direct system are lower, the reasons for selecting an indirect system for Kendal power station was essentially for conservative reasons. A long term comparison of the two different systems is made considering all influences including weather, long term durability, and availability. The two systems have seldom before been assessed correctly from an economic stand point.

Trage, B. (Blacke-Durr AG, Ratingen (DE)); Ham, A.J. (ESKOM, Johannesburg (ZA)); Vicary, T.C. (Zurn Balcke-Durr, Inc., Tampa, FL (US))

1990-01-01

377

Multifarious Power Plant Water Intake Structure (MWIS). A Design Concept to Reduce the Environmental Effects of Cooling Water Intake Structures.  

National Technical Information Service (NTIS)

The design for the Multifarious Power Plant Water Intake Structure (MWIS) was developed to reduce the entrainment and impingement of aquatic organisms in water intakes requiring large volumes of cooling water. Its uniqueness is based upon the operation of...

B. Chezar

1976-01-01

378

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

379

Operating characteristics of cooling underground power cables using up sloped long heat pipes in conduit  

NASA Astrophysics Data System (ADS)

Long heat pipes for cooling electric power cables in conduit pipe are required to operate not only in the down slope but also in the up slope. The stable operation of the heat pipe is attained by separating the vapor flow path and the liquid flow path completely, and returning the working fluid condensed by the radiator to the evaporation section end by utilizing a difference in the pressure head. Evaporating section consisting of corrugated metallic pipes and carbon fiber wicks were employed for liquid film evaporation and holding liquid uniformly along an axial length of the pipe. Long heat pipes with a length 100 m, outside diameter 70 mm, and up slope 1/100 were made experimentally and tested. They operated in the normal heat pipe mode, carrying heat 9kW. Further the heat pipes were layed in some cable conduits providing adequate cooling effect.

Oka, K.; Tsuchihashi, H.; Nishimura, Y.; Mohtai, T.; Mochizuki, M.; Mashiko, K.; Yamanouchi, H.

380

Transport and deposition of activation products in a helium cooled fusion power plant  

SciTech Connect

The transport and deposition of neutron activation products in a helium cooled tokamak fusion power plant are investigated. Stainless steel is used as coolant channel material for a helium/steam system. The important gamma emitting nuclides /sup 56/Mn, /sup 54/Mn, /sup 57/Co, /sup 58/Co, /sup 60/Co, /sup 51/Cr, and /sup 99/Mo are considered. The dominant release mechanism identified is direct daughter recoil emission from (n,x) type reactions. Corrosion and evaporation are discussed. The radionuclide inventory released by these mechanisms is predicted to exceed 1 x 10/sup 4/ Ci for a reference reactor design after only several days of operation, and approach 3.5 x 10/sup 4/ Ci in equilibrium. A mass transport model is then used to predict the deposition pattern of this inventory in the reactor cooling system.

Bickford, W.E.

1980-09-01

381

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

PubMed

We study a thermal engine model for which Newton's cooling law is obeyed during heat transfer processes. The thermal efficiency and its bounds at maximum output power are derived and discussed. This model, though quite simple, can be applied not only to Carnot engines but also to four other types of engines. For the long thermal contact time limit, new bounds, tighter than what were known before, are obtained. In this case, this model can simulate Otto, Joule-Brayton, Diesel, and Atkinson engines. While in the short contact time limit, which corresponds to the Carnot cycle, the same efficiency bounds as that from Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)] are derived. In both cases, the thermal efficiency decreases as the ratio between the heat capacities of the working medium during heating and cooling stages increases. This might provide instructions for designing real engines. PMID:22400551

Yan, H; Guo, Hao

2012-01-27

382

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

383

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

384

An approach for electrical self-stabilization of high-temperature superconducting wires for power applications  

NASA Astrophysics Data System (ADS)

Electrical and thermal stability of high-temperature superconducting (HTS) wires/tapes are essential in applications involving efficient production, distribution, and storage of electrical energy. We have developed a conductive buffer layer structure composed of bilayer La0.7Sr0.3MnO3/Ir on a textured Ni-W alloy metal tape to functionally shunt the HTS layer to the underlying substrate. The key feature is the Ir layer, which serves as a barrier to both inward diffusion of oxygen and outward diffusion of metal substrate cations during fabrication. Electrical and microstructural property characterizations of YBa2Cu3O7-? films on short prototype conductors demonstrate self-field critical current density values, Jc, exceeding 2×106 A/cm2 at 77 K and excellent electrical coupling to the underlying metal substrate, with no unwanted insulating oxide interfaces. Implementing this approach in power technologies would significantly increase the engineering current density of the conductor and reduce overall process costs.

Aytug, T.; Paranthaman, M.; Zhai, H. Y.; Gapud, A. A.; Leonard, K. J.; Martin, P. M.; Goyal, A.; Thompson, J. R.; Christen, D. K.

2004-10-01

385

Astronomical demonstration of superconducting bolometer arrays  

Microsoft Academic Search

We have built a prototype submillimeter spectrometer, FIBRE, which is based on a helium-cooled scanning Fabry-Perot and superconducting transition edge sensor bolometers (TES). SQUID multiplexers are used to read out the individual detector pixels. The spectral resolving power of the instrument is provided by the Fabry-Perot spectrometer. The outgoing light from the Fabry-Perot passes onto a low resolution grating for

Johannes G. Staguhn; Dominic J. Benford; Francois Pajot; Troy J. Ames; James A. Chervenak; Erich N. Grossman; Kent D. Irwin; Bruno Maffei; S. H. Moseley Jr.; Thomas G. Phillips; Carl D. Reintsema; Cyrille Rioux; Richard A. Shafer; George M. Voellmer

2003-01-01

386

Superconducting cable and superconducting fault current limiter at Puji Substation  

Microsoft Academic Search

We have undertaken research and development of superconducting cables and superconducting fault current limiters and have made significant progress in the last six years. At Puji substation of Southern China Power Grid, a 35 kV superconducting cable system was installed and energized in 2004. In 2007, a 35 kV superconducting fault current limiter (FCL) was installed in the substation. After

Y. Xin; H. Hui; W. Z. Gong; F. Ye; J. Z. Wang; B. Tian; A. L. Ren; M. R. Zi

2009-01-01

387

Superconducting mirror for laser gyroscope  

SciTech Connect

This paper describes an apparatus for reflecting a light beam. It comprises: a mirror assembly comprising a substrate and a superconductive mirror formed on such substrate, wherein: the substrate is optically transparent to the light beam and has a thickness of from about 0.5 to about 1.0 millimeter, and the superconductive mirror has a thickness of from about 0.5 to about 1.0 microns; means for cooling the superconductive mirror; means for measuring the temperature of the superconductive mirror; means for determining the reflectivity of the superconductive mirror; and means for varying the reflectivity of the superconductive mirror.

Wang, X.

1991-05-14

388

Design Strategy and Constraints for Medium-Power Lead-Alloy-Cooled Actinide Burners  

SciTech Connect

We outline the strategy and constraints adopted for the design of medium-power lead-alloy-cooled actinide-burning reactors that strive for a lower cost than accelerator-driven systems and for robust safety. Reduced cost is pursued through the use of (1) a modular design and maximum power rating to capitalize on an economy of scale within the constraints imposed by modularity, (2) a very compact and simple supercritical-CO{sub 2} power cycle, and (3) simplifications of the primary system allowed by the use of lead coolant. Excellent safety is pursued by adopting the integral fast reactor approach of achieving a self-controllable reactor that responds to all key abnormal occurrences, including anticipated transients without scrams, by a safe shutdown without exceeding core integrity limits. The three concepts developed are the fertile-free actinide burner for incineration of all transuranics from light water reactor (LWR) spent fuel, the fertile-free minor actinide (MA) burner for preferential burning of MAs working in tandem with LWRs or gas-cooled thermal reactors, and the actinide burner with thorium fuel aimed also at reducing the electricity generation costs through longer-cycle operation.

Hejzlar, Pavel [Massachusetts Institute of Technology (United States); Buongiorno, Jacopo [Idaho National Engineering and Environmental Laboratory (United States); MacDonald, Philip E. [Idaho National Engineering and Environmental Laboratory (United States); Todreas, Neil E. [Massachusetts Institute of Technology (United States)

2004-09-15

389

Design Strategy and Constraints for Medium-Power Lead-Alloy-Cooled Actinide  

SciTech Connect

We outline the strategy and constraints adopted for the design of medium-power lead-alloy-cooled actinide-burning reactors that strive for a lower cost than accelerator-driven systems and for robust safety. Reduced cost is pursued through the use of (1) a modular design and maximum power rating to capitalize on an economy of scale within the constraints imposed by modularity, (2) a very compact and simple supercritical-CO2 power cycle, and (3) simplifications of the primary system allowed by the use of lead coolant. Excellent safety is pursued by adopting the integral fast reactor approach of achieving a self-controllable reactor that responds to all key abnormal occurrences, including anticipated transients without scrams, by a safe shutdown without exceeding core integrity limits. The three concepts developed are the fertile-free actinide burner for incineration of all transuranics from light water reactor (LWR) spent fuel, the fertile-free minor actinide (MA) burner for preferential burning of MAs working in tandem with LWRs or gas-cooled thermal reactors, and the actinide burner with thorium fuel aimed also at reducing the electricity generation costs through longer-cycle operation.

Pavel Hejzlar; Jacopo Buongiorno; Philip MacDonald; Neil Todreas

2004-09-01

390

Closed Loop Cooling Systems for HTS Applications  

NASA Astrophysics Data System (ADS)

Stirling Cryogenics & Refrigeration BV has developed a complete range of closed loop cooling systems for High Temperature Superconducting applications. Several solutions are available depending on the requirements of the application to be cooled. Using liquid nitrogen as a working medium, a temperature as low as 65K can be used. The cooling power at 65K can be in the range of several hundred watts to several kilowatts. The distribution of the cooling power can be done by using the latent heat of evaporation or by using the heat capacity of sub-cooled liquid. The latter requires a fully automated pumping cryostat, containing all the components required for a controlled cool down of the application, sub cooling of the working fluid, transport of the liquid through the application and precise temperature regulation. For low temperature applications, two-stage cryocoolers provide cooling power at 20K and 80K temperature regions. Distribution of cooling capacity can eg. be done by forced flow of gaseous helium or by reliquefaction of neon.

Willems, D.; Dioguardi, F.; den Heijer, R.

2006-04-01

391

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

392

Presence of pathogenic amoebae in power plant cooling waters. Final report, October 15, 1977-September 30, 1979. [Naegleria fowleri  

SciTech Connect

Cooling-water-associated algae and sediments from five northern and five southern or western electric power plants were tested for the presence of pathogenic amoebae. In addition, water algae and sediments from five northern and five southern/western sites not associated with power plants were tested. There was a significant correlation at northern power plants between the presence of thermophilic, pathogenic amoebae in cooling waters and thermal additions. Presence of the pathogenic did not correlate with salinity, pH, conductivity, or a variety of various chemical components of the cooling waters. Selected pathogenic isolates were tested serologically and were classified as Naegleria fowleri. Although thermal additions were shown to be contributing factor in predisposing cooling waters to the growth of pathogenic amoebae, the data suggest the involvement of other currently undefined parameters associated with the presence of the pathogenic amoebae. 35 refs., 21 tabs.

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

1981-03-01

393

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

394

Legionnaires' disease bacteria in power plant cooling systems: downtime report. Final report  

SciTech Connect

Legionnaires' disease bacteria (Legionella) are a normal part of the aquatic community that, when aerosolized, can be pathogenic to man. The downtime study was designed to determine the degree to which Legionella populations are aerosolized during cleaning and maintenance operations in a closed-cycle steam-electric power plant. Both high-volume and impinger air samples were collected prior to and during downtime operations. Emphasis was placed on sampling inside or adjacent to water boxes, condensers, and cooling towers. Control air samples were taken upwind from the plant site. Water and sludge samples were also collected at various locations. In the laboratory, the concentrations of Legionella were determined using the direct fluorescent antibody method. All positive air samples, and other selected air samples, were injected into guinea pigs to detect infectious Legionella. Legionella could be detected in only 12 of the 127 air samples collected. These were predominantly L. pneumophila, serogroups 1-6. In contrast to the air samples, most of the water and sludge samples were positive for Legionella, again predominantly L. pneumophila, serogroups 1-6. The highest Legionella concentrations were found in sludge samples associated with condenser tube cleaning. Among the water samples, the highest Legionella concentrations were found in cooling towers, immediately after the tower basins were cleaned and refilled, and in condenser tubes. Two of the three cooling tower water samples collected prior to downtime operations were infectious for guinea pigs. 16 refs., 4 figs., 11 tabs.

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

1985-11-01

395

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

396

The cooling pond of the Chernobyl Nuclear Power Plant: A groundwater remediation case history  

NASA Astrophysics Data System (ADS)

The cooling pond of the Chernobyl nuclear power plant was heavily contaminated as a result of the reactor accident in April 1986. From 1989 to 1993 the cooling pond represented one of the major sources of 90Sr migration from the Chernobyl site to the Dnieper River. Several attempts have been made to contain radioactive contamination within the pond. Overestimation of releases via groundwater pathway and design mistakes led to unsuccessful remedial actions in 1986 and in later periods. In addition, remediation criteria based solely on comparison of contaminant concentrations in groundwater with drinking water standards were not effective from the health risk perspective, because the public was not directly exposed to contaminated groundwater; the exclusion zone surrounding the site acted as an institutional control to prevent public access. In light of recent estimates of low risks due to radionuclide transport outside the exclusion zone, a "no action" approach may represent the most reasonable strategy for the near-term management of the cooling pond.

Bugai, Dmitri A.; Waters, Robert D.; Dzhepo, Sergei P.; Skalsk'ij, Alexander S.

1997-04-01

397

Thermal modeling and cooling analysis of high-power lithium ion cells  

NASA Astrophysics Data System (ADS)

The heat generation model and three-dimensional computational fluid dynamics model for lithium ion cells were established with boundary conditions defined. In order to provide a better insight about the behaviors of high-power lithium ion cells under realistic discharge conditions, the temperature difference of the cells and an active thermal management system with a pure air-cooling mode were analyzed and predicted with the factors affecting the unevenness of temperature field discussed. The results show a significant effect of the cooling flow rate on the temperature rise of the cells for all discharge rates. Average surface temperatures are relatively uniform at lower discharge rate that makes it easier to control the temperature of the pack. Cell temperatures are expected to rise significantly toward the end of discharge and they show non-uniformity at higher discharge rates. Adequate air flow rate of active cooling is required at high discharge rate and high ambient temperature for practical pack thermal management system.

Zhang, Zhuqian; Jia, Li; Zhao, Nan; Yang, Lixin

2011-12-01

398

Superconducting Power Transmission Line Materials Research and Conductor Development. Final Report.  

National Technical Information Service (NTIS)

The feasibility of transferring the conductor technology developed on tubes to more practical tape conductors was investigated and a variety of studies aimed at improving the basic understanding of the important superconducting properties crucial to super...

T. H. Geballe M. R. Beasley

1977-01-01

399

High-temperature (250 °C \\/ 500 °F) 19?000 rpm BLDC fan for forced air-cooling of advanced automotive power electronics  

Microsoft Academic Search

In an increasing number of application areas and industry sectors, such as the automotive, aerospace, military or oil and gas industry, a trend towards higher ambient temperature rating from 120 °C upward for electrical machines and power electronic converters can be observed. Forced air-cooling of power electronic converters offers reduced complexity of the cooling circuit compared to water-cooling. For high

Benjamin Wrzecionko; Andreas Looser; Johann W. Kolar; Michael Casey

2011-01-01

400

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

401

Design and test of a simplified and reliable cryogenic system for high speed superconducting generator applications  

NASA Astrophysics Data System (ADS)

Under the contract with Air Force Research Lab (AFRL), General Electric has successfully tested a high speed, superconducting generator for a Multimegawatt Electric Power System (MEPS). As the first successful full-power test of a superconducting generator for the Air Force, the demonstration tested the generator's load up to 1.3 MW and over 10,000 rpm. A key component of the generator system is a closed loop cryo-refrigeration system to cool the field excitation coil at liquid neon temperature. This paper reports the design and tests of the cryogenic system, including the liquid neon dewar, cryogenic cooling loop for the high temperature superconducting (HTS) field coil and the cryostat. Performance data during both short-term load run and long-term non-load run were presented. Also, some key issues to design a reliable cryogenic system for a superconducting generator were discussed.

Zhang, T.; Haran, K.; Laskaris, E. T.; Bray, J. W.

2011-07-01

402

A study on the electrical insulation properties of solid nitrogen for cooling of the high temperature superconducting systems  

NASA Astrophysics Data System (ADS)

Recently, for improvement of the magnetic field of high temperature superconductor (HTS) apparatus, many studies on operating in the temperature range of 20-65 K with liquid helium or the thermal conducting method using cryocooler are actively reviewed. Also, the cooling method of using solid nitrogen as cryogen is currently being suggested. Since nitrogen has a very large specific heat in solid state, it is expected that it can enable long-time operation without a continuous supply of cooling energy. However, there is still insufficient data on the characteristics of solid nitrogen such as thermodynamic properties and liquid-solid phase transition. Especially, there was almost no study done on the electrical insulation properties of solid nitrogen so far. In this study, solid nitrogen to find the electrical characteristics was made by using cryocooler and cryostat, and investigated the flashover discharge and breakdown. The results of this study will be useful as a basic data for electrical insulation design of the HTS system such as SMES using solid nitrogen as cryogen.

Choi, J. H.; Choi, J. W.; Lee, H.; Song, J. B.; Kim, H. J.; Seong, K. C.; Kim, S. H.

2009-10-01

403

Cryogenic engineering and fusion power  

Microsoft Academic Search

In order to reduce the consumption of power for the magnets of a fusion power plant to acceptable proportions, it is necessary that fusion reactors must use either cryogenically cooled or superconducting coils. The cryogenic aspects of reactor design are discussed. It is found that the most difficult cryogenic engineering problems of fusion reactors are mainly those caused by the

C. E. Taylor

1974-01-01

404

Powering of cool filaments in cluster cores by buoyant bubbles - I. Qualitative model  

NASA Astrophysics Data System (ADS)

Cool-core clusters (e.g. Perseus or M87) often possess a network of bright gaseous filaments, observed in radio, infrared, optical and X-ray bands. We propose that these filaments are powered by the reconnection of the magnetic field in the wakes of buoyant bubbles. Active galactic nucleus (AGN)-inflated bubbles of relativistic plasma rise buoyantly in the cluster atmosphere, stretching and amplifying the field in the wake to values of ? = 8?Pgas/B2 ˜ 1. The field lines in the wake have opposite directions and are forced together as the bubble motion stretches the filament. This setup bears strong similarity to the coronal loops on the Sun or to the Earth's magnetotail. The reconnection process naturally explains both the required level of local dissipation rate in filaments and the overall luminosity of filaments. The original source of power for the filaments is the potential energy of buoyant bubbles, inflated by the central AGN.

Churazov, E.; Ruszkowski, M.; Schekochihin, A.

2013-09-01

405

Powering of cool filaments in cluster cores by buoyant bubbles - I. Qualitative model  

NASA Astrophysics Data System (ADS)

Cool-core clusters (e.g. Perseus or M87) often possess a network of bright gaseous filaments, observed in radio, infrared, optical and X-ray bands. We propose that these filaments are powered by the reconnection of the magnetic field in the wakes of buoyant bubbles. Active galactic nucleus (AGN)-inflated bubbles of relativistic plasma rise buoyantly in the cluster atmosphere, stretching and amplifying the field in the wake to values of ? = 8?Pgas/B2 ˜ 1. The field lines in the wake have opposite directions and are forced together as the bubble motion stretches the filament. This setup bears strong similarity to the coronal loops on the Sun or to the Earth's magnetotail. The reconnection process naturally explains both the required level of local dissipation rate in filaments and the overall luminosity of filaments. The original source of power for the filaments is the potential energy of buoyant bubbles, inflated by the central AGN.

Churazov, E.; Ruszkowski, M.; Schekochihin, A.

2013-11-01

406

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

SciTech Connect

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 profiles (density, viability, and infectivity for guinea pigs) were obtained. Legionella were detected in nearly all samples. Water from closed-cycle cooling systems frequently had lower densities of Legionella than the ambient water. Nonetheless, infectious Legionella, as defined by their isolation from inoculated guinea pigs, were significantly more likely to be found in samples from the plant-exposed water of closed-cycle plants than in samples from once-through plants or in ambient samples. A new species (L. oakridgensis) was initially isolated from two of the sites, and it has since been found to have a widespread distribution. Two other organisms found to cause illness in guinea pigs may also be new species. Phase II of the project involves investigating possible cause/effect relationships between physicochemical variables and Legionella. This work may contribute toward eventual control techniques for this pathogen.

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

1983-06-01

407

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

408

A Closed Neon Liquefier System for Testing Superconducting Devices  

NASA Astrophysics Data System (ADS)

A Neon liquefier system has been developed by Southampton University (UK) and EDISON (Italy) with the aim to provide a facility for testing HTS superconducting devices using Magnesium Diboride materials, in the range 25-30K. The system consists of a liquid Neon cryostat coupled to a two stages cryocooler and a recovery system. The first stage of the cryocooler is connected to the thermal shield of the cryostat and a copper station positioned at mid point along the access neck to the liquid Neon bath to reduce heat leak and to provide pre-cooling of samples. The second stage, capable of 20W cooling power at 22K, is used to provide the cooling power for liquefaction and to refrigerate the liquid Neon bath and the superconducting device/sample during the steady state operation. The recovery system has been designed to automatically compress excess boil-off generated by a quench or a transient heating into a storage gas container. Transport measurement up to 900A can be carried out in the Ne cryostat using purposely build hybrid current leads. These leads have a copper upper section cooled by liquid Nitrogen and a superconducting lower section of Ag/AuBi2223 tapes. In this paper we report on the performance of the system and the initial measurement of superconducting samples.

Bianchetti, M.; Al-Mosawi, M. K.; Yang, Y.; Beduz, C.; Giunchi, G.

2006-04-01

409

The maximal cooling power of magnetic and thermoelectric refrigerators with La(FeCoSi)13 alloys  

NASA Astrophysics Data System (ADS)

Using our data on magnetic entropy change ?Sm, adiabatic temperature change ?Tad and heat capacity CH for La(FeCoSi)13 alloys, the upper limit of heat Qc transferred per cycle, and the lowest limit of consumed work Wc were established for magnetic refrigerators operating in ??0H=1.9 T. In order to estimate the cooling power, attributable to thermoelectric refrigerators with La(FeCoSi)13, thermal conductivity ?, resistivity ?, and Seebeck coefficient ? were measured and the maximal cooling power QL, the input power Pi, and coefficient of performance have been calculated.

Skokov, K. P.; Karpenkov, A. Yu.; Karpenkov, D. Yu.; Gutfleisch, O.

2013-05-01

410

Evaluation of the Impact of Off-Design Operation on an Air-Cooled Binary Power Plant  

Microsoft Academic Search

Geothermal power plants are designed and constructed to provide a rated power output at specific resource and ambient conditions. Due to both diurnal and seasonal changes in the ambient air temperature, as well as a decline in resource productivity over time, plants seldom operate at these ''design'' conditions. This paper examines the impact of ''off- design'' operation of an air-cooled

Greg L. Mines; Gregory Lee

2002-01-01

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

Technical and economic assessment of the use of ammonia expanders for energy recovery in air-cooled power plants  

Microsoft Academic Search

Binary cycle power plants have been the subject of much discussion among engineers and scientists for nearly 100 years. Current economic and environmental concerns have stimulated new interest and research. Ammonia has been recommended by other studies as the leading contender for use as simply the heat rejection medium in an air-cooled power plant. This study investigates the technical feasibility

S. G. Hauser; G. J. Hane; B. M. Johnson

1982-01-01

413

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

414

User's guide for the BNW-III optimization code for modular dry/wet-cooled power plants  

SciTech Connect

This user's guide describes BNW-III, a computer code developed by the Pacific Northwest Laboratory (PNL) as part of the Dry Cooling Enhancement Program sponsored by the US Department of Energy (DOE). The BNW-III code models a modular dry/wet cooling system for a nuclear or fossil fuel power plant. The purpose of this guide is to give the code user a brief description of what the BNW-III code is and how to use it. It describes the cooling system being modeled and the various models used. A detailed description of code input and code output is also included. The BNW-III code was developed to analyze a specific cooling system layout. However, there is a large degree of freedom in the type of cooling modules that can be selected and in the performance of those modules. The costs of the modules are input to the code, giving the user a great deal of flexibility.

Braun, D.J.; Faletti, D.W.

1984-09-01

415

Preparation of high-Tc superconducting thick films and power conducting tubes by a low-pressure plasma spraying  

SciTech Connect

Superconducting thick films of YBaCuO and BiSrCaCuO systems have been prepared using a low-pressure plasma spraying technique. The chemical composition of the deposits was very close to that of the spraying powders. After the post-annealing, films showed zero resistance temperatures: Tc of -- 90K for YBaCuO and -- 60K for BiSrCaCuO, respectively. The superconducting power tubes were successfully produced by a low-pressure plasma spraying. 100 - 200..mu..m thick YBaCuO superconducting films were deposited on the outer surface of the Ni-plated Cu tubes. After the post- annealing at 930/sup 0/C for 1 hr, the films exhibited Tc of 85 - 90K. An improved film preparation process, where a flux layer is coated on the Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub x/ matrix layer by a low-pressure plasma spraying, has been developed. Enhanced critical currents have been achieved through this process.

Tachikawa, K.; Ono, M.; Shinbo, Y.; Suzuk, T.; Kabasawa, M.; Kosuge, S.

1989-03-01

416

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

417

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

418

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

419

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

420

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

421

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

422

Diamond cooling of high-power diode-pumped Nd:YVO4 and Nd:YAG lasers  

NASA Astrophysics Data System (ADS)

We have demonstrated the feasibility of cooling high power solid-state lasers with diamond windows, whose thermal conductivity is about two orders of magnitude higher than sapphire's, the material conventionally used for this purpose. Since pumping and cooling were along the same axis, a Cartesian thermal gradient was achieved, while the zigzag scheme was used to minimize thermal lensing. An output power of 200Watt was achieved from a single Nd:YVO4 slab in a zigzag configuration when pumped with 600Watt diodes at 808nm. The maximum output power previously reported in the literature with Nd:YVO4 using conventional cooling schemes is only about 100W. A 2.3x4x24mm3 slab was pumped from its broad side (4x24 mm2) through a 0.3mm thick optical diamond window placed in close contact with the lasing crystal. The diamond window, held in a water-cooled copper housing acted as a heat conductor. The other broad side of the crystal was cooled directly by its water-cooled copper housing. The output of a two-head configuration was 295Watt. By using a RTP Q-switch, 124Watt average power was obtained at 15kHz with a pulse width of 17nsec, pumping at 650Watt. An additional larger head was developed to pump a Nd:YAG slab. The concept of the pumping and cooling is identical to the Nd:YVO4 laser head. An output power of 1000Watt was achieved from a single Nd:YAG slab when pumped with 2500Watt diodes at 808nm. The slab dimensions are 3×12×90mm3.

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

2005-06-01

423

Specifications and performance experience of pool boiling cooled magnets  

Microsoft Academic Search

Large superconducting magnets have three kinds of conductor-cooling methods; liquid helium pool boiling cooling, two-phase helium indirect cooling, or supercritical helium internal cooling. Practical superconducting magnets in their thirty years' history have had a lot of failure experiences. Electrical breakdown of insulation is the most fatal for pool boiling cooled magnets, because those magnets are unable to be utilized again,

T. Satow

1998-01-01

424

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

425

Presence of pathogenic amoebae in power plant cooling waters. Final report, October 15, 1977September 30, 1979. [Naegleria fowleri  

Microsoft Academic Search

Cooling-water-associated algae and sediments from five northern and five southern or western electric power plants were tested for the presence of pathogenic amoebae. In addition, water algae and sediments from five northern and five southern\\/western sites not associated with power plants were tested. There was a significant correlation at northern power plants between the presence of thermophilic, pathogenic amoebae in

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

1981-01-01

426

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

427

Estimating the cost of large superconducting thin solenoid magnets  

NASA Astrophysics Data System (ADS)

The cost of thin superconducting solenoid magnets can be estimated if one knows the magnet stored energy, the magnetic field volume product or the overall mass of the superconducting coil and its cryostat. This report shows cost data collected since 1979 for large superconducting solenoid magnets used in high energy physics. These magnets are characterized in most cases by the use of indirect two phase helium cooling and a superconductor stabilizer of very pure aluminum. This correlation can be used for making a preliminary cost estimate of proposed one of a kind superconducting magnets. The magnet costs quoted include the power supply and quench protection system but the cost of the helium refrigerator and helium distribution system is not included in the estimated cost.

Green, M. A.; St. Lorant, S. J.

1993-07-01

428

Legionnaires' Disease Bacteria in power plant cooling systems: downtime report. Final report  

SciTech Connect

Legionnaires' Disease Bacteria (Legionella) are a normal part of the aquatic community that, when aerosolized, can be pathogenic to man. The downtime study was designed to determine the degree to which Legionella populations are aerosolized during cleaning and maintenance operations in a closed-cycle steam-electric power plant. Both high-volume and impinger air samples were collected prior to and during downtime operations. Emphasis was placed on sampling inside or adjacent to water boxes, condensers, and cooling towers. Control air samples were taken upwind from the plant site. Water and sludge samples were also collected at various locations. In the laboratory, the concentrations of Groups A, B, and C Legionella were determined using the direct fluorescent antibody method. All positive air samples, and other selected air samples, were injected into guinea pigs to detect infectious Legionella. Legionella could be detected in only 12 of the 126 air samples collected. These were predominantly Group A Legionella (L. pneumophila, serogroups 1 to 6). All 12 positive samples had been collected in the vicinity of water boxes, condensers, detention ponds, and cooling towers during downtime operations where aerosolization of Legionella populations would be expected. None of the air samples yielded infectious Legionella when injected into guinea pigs. Detection of Legionella in air samples taken during downtime was significantly more likely than detection during normal operating conditions (p <0.01). 13 refs., 4 figs., 10 tabs.

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

1985-04-01

429

Dry Cooling of Power Generating Stations: A Summary of the Economic Evaluation of Several Advanced Concepts Via a Design Optimization Study and a Conceptual Design and Cost Estimate.  

National Technical Information Service (NTIS)

Due to enhanced concern about water supplies and water use priorities, dry cooling systems for thermal power plants are receiving increased consideration, even though electric power from dry-cooled power plants currently costs 10 to 15 percent more than p...

B. M. Johnson R. T. Allemann D. W. Faletti B. C. Fryer F. R. Zaloudek

1976-01-01

430

A three domain controller for a high frequency high power four quadrant power converter for superconducting magnets  

Microsoft Academic Search

The paper describes the implementation of a controller that orchestrates the functioning of three subsystems that implement a high energy converter (±1500 A, ±15 V) that supplies a superconducting magnet to be used in particle accelerators. The performance of the whole system, in accordance to specifications, is documented with experimental results

J. A. Carrasco; E. J. Dede; J. M. Benavent; F. Bordry; A. Dupaquier; A. Ferreres

1997-01-01

431

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

432

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

433

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

SciTech Connect

We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

2002-05-30

434

Nuclear technology and potential ripple effect of superconducting magnets for fusion power plant  

Microsoft Academic Search

In a fusion reactor plant, a neutral beam injector (NBI) will be operated for a long time, and it will allow neutron streaming from NBI ports to outside of the plasma vacuum vessel. This fact requires that the superconducting magnets develop nuclear technology to maintain high performance and to reduce activation of the magnet components. In this report, the background

Arata Nishimura; Takeo Muroga; Takao Takeuchi; Takeo Nishitani; Atsuhiko Morioka

2006-01-01

435

Power tests of a string of magnets comprising a full cell of the Superconducting Super Collider  

Microsoft Academic Search

In this paper we describe the operation and testing of a string of magnets comprising a full cell of the Superconducting Super Collider (SSC). The full cell configuration composed of ten dipoles, two quadrupoles, and three spool pieces is the longest SSC magnet string ever tested. Although the tests of the full cell were undertaken after the SSC project was

W S Burgett; L. Cromer; D R Haenni; M. Hentges; T S Jaffery; P. Kraushaar; M. Levin; A McInturff; G T Mulholland; D Richter; W Robinson; D Voy; J G Weisend; J Zatopek

1995-01-01

436

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

437

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.

438

Hybrid superconducting magnetic suspensions  

SciTech Connect

Superconductors, especially high T{sub c} ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO.

Tixador, P.; Hiebel, P.; Brunet, Y. [CNRS-CRTBT/LEG, Grenoble (France); Chaud, X.; Gautier-Picard, P. [CNRS-EPM-Matformag, Grenoble (France)

1996-07-01

439

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. ...

440

The helium cryogenic plant for the CMS superconducting magnet  

NASA Astrophysics Data System (ADS)

A new helium refrigeration plant with a cooling capacity of 800 W at 4.45 K, 4500 W between 60 K and 80 K, and 4 g/s liquefaction simultaneously has been designed and is presently being constructed by Air Liquide for CERN. The refrigeration plant will provide the cooling power for the cool down and the operation of the CMS (Compact Muon Solenoid) superconducting coil whose cold mass weighs 225 t. The refrigeration plant will at first be installed in a surface building for the tests of the superconducting magnet. On completion of the tests the cold box will be moved to its final underground position next to the CMS experimental cavern. This paper presents the process design, describes the main components and explains their selection. .

Perini?, G.; Caillaud, A.; Dagut, F.; Dauguet, P.; Hirel, P.

2002-05-01

441

Absorption chiller crystallization control strategies for integrated cooling heating and power systems  

Microsoft Academic Search

The concept of an air-cooled absorption chiller system is attractive because the cooling tower and the associated installation and maintenance issues can be avoided. However, crystallization of the LiBr–H2O solution then becomes the main challenge in the operation of the chiller, since the air-cooled absorber tends to operate at a higher temperature and concentration level than the water-cooled absorber due

Xiaohong Liao; Reinhard Radermacher

2007-01-01

442

Properties of the Carrol system and a machine design for solar-powered, air cooled, absorption space cooling  

NASA Astrophysics Data System (ADS)

The name Carrol was selected as a convenient shorthand designation for a prime candidate chemical system comprising ethylene glycol-lithium bromide as an absorbent mixture with water as a refrigerant. The instrumentation, methods of handling data and numerical results from a systematic determination of Carrol property data required to design an air cooled absorption machine based on this chemical system are described. These data include saturation temperature, relative enthalpy, density, specific heat capacity, thermal conductivity, viscosity and absorber film heat transfer coefficient as functions of solution temperature and Carrol concentration over applicable ranges. For each of the major components of the absorption chiller, i.e., generator, chiller, absorber, condenser, heat exchanger, purge and controls, the report contains an assembly drawing and the principal operating characteristics of that component.

1981-05-01

443

Study of using microfiltration and reverse osmosis membrane technologies for reclaiming cooling water in the power industry.  

PubMed

A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times. PMID:17710919

Li, J; Xu, Z Y; An, H G; Liu, L Q

2007-07-01

444

Power Tests of a String of Magnets Comprising a Full Cell of the Superconducting Super Collider  

SciTech Connect

In this paper we describe the operation and testing of a string of magnets comprising a full cell of the Superconducting Super Collider (SSC). The full cell configuration composed of ten dipoles, two quadrupoles, and three spool pieces is the longest SSC magnet string ever tested. Although the tests of the full cell were undertaken after the SSC project was marked for termination, their completion was deemed necessary and useful to future efforts at other accelerator laboratories utilizing Superconducting magnets. The focus of this work is on the electrical and cryogenic performance of the string components and the quench protection system with an emphasis on solving some of the questions concerning electrical performance raised during the previous two experimental runs involving a half cell configuration.

Burgett, W.; Cromer, L.; Haenni, D.; Hentges, M.; Jaffrey, T.; Kraushaar, P.; Levin, M.; Mulholland, G.; Richter, D.; Robinson, W.; Weisend II, J.; Zapotek, J.

1995-06-28

445

High-Temperature Superconductivity  

NASA Astrophysics Data System (ADS)

A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

Tanaka, Shoji

2006-12-01

446

Feasibility Study of a Multipurpose Refrigerator for a Superconducting Cable Test Facility.  

National Technical Information Service (NTIS)

A major problem in simultaneously cooling a number of test sections of super-conducting power transmission cables is the wide variation in cable operating pressures and temperatures. It is feasible to couple a single large refrigerator to the cables with ...

T. R. Strobridge

1975-01-01

447

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

448

Microbiologically influenced stress corrosion cracking failure of admiralty brass condenser tubes in a nuclear power plant cooled by freshwater  

Microsoft Academic Search

The failure of admiralty brass condenser tubes in a nuclear power plant was investigated. Metallurgical analyses had indicated that stress corrosion cracking (SCC) could have caused the failure. Studies were carried out to see if bacteria could have played a role in bringing about the conditions which resulted in SCC of the tubes. Cooling water (Ranapratap Sagar lake, Kota, Rajasthan)

T. S Rao; K. V. K Nair

1998-01-01

449

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...

450

Diamagnetic forces in superconducting magnets  

Microsoft Academic Search

We have previously reported damage to two large superconducting solenoids caused by axial expansion forces and radial compression forces. These forces, which can be greater than and are of opposite sense to the classical Lorentz forces, we have attributed to the diamagnetism of the composite superconductors. Some irregularities experienced in the operation of force cooled superconducting magnet systems appear to

R. Stevenson; D. Atherton

1975-01-01

451

Superconducting wire with improved strain characteristics  

DOEpatents

A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

Luhman, T.; Klamut, C.J.; Suenaga, M.; Welch, D.

1979-12-19

452

Superconducting wire with improved strain characteristics  

DOEpatents

A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.

Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (E. Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

1982-01-01

453

Superconducting wire with improved strain characteristics  

DOEpatents

A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (East Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

1982-01-01

454

Design study of the cooling scheme for SMES system in ASPCS by using liquid hydrogen  

NASA Astrophysics Data System (ADS)

From the point of view of environment and energy problems, the renewable energies have been attracting attention. However, fluctuating power generation by the renewable energies affects the stability of the power network. Thus, we propose a new electric power storage and stabilization system, Advanced Superconducting Power Conditioning System (ASPCS), in which a Superconducting Magnetic Energy Storage (SMES) and a hydrogen-energy-storage converge on a liquid hydrogen station for fuel cell vehicles. The ASPCS proposes that the SMES coils wound with MgB2 conductor are indirectly cooled by thermo-siphon circulation of liquid hydrogen to use its cooling capability. The conceptual design of cooling scheme of the ASPCS is presented.

Makida, Yasuhiro; Shintomi, Takakazu; Asami, Takuya; Suzuki, Goro; Takao, Tomoaki; Hamajima, Takataro; Tsuda, Makoto; Miyagi, Daisuke; Munakata, Kouhei; Kajiwara, Masataka

2013-11-01

455

The computational-and-experimental investigation into the head-flow characteristic of the two-stage ejector for the emergency core cooling system of the NPP with a water-moderated water-cooled power reactor  

NASA Astrophysics Data System (ADS)

The results of the computational-and-experimental investigation into the two-stage ejector for the emergency cooling system of the core of the water-moderated water-cooled power reactor. The results of experimental investigations performed for the ejector model at the JSC "EREC" and the result of calculations performed using the REMIX CFD code are presented.

Parfenov, Yu. V.

2013-09-01

456

Superconducting wind turbine generators  

Microsoft Academic Search

We have examined the potential of 10 MW superconducting direct drive generators to enter the European offshore wind power market and estimated that the production of about 1200 superconducting turbines until 2030 would correspond to 10% of the EU offshore market. The expected properties of future offshore turbines of 8 and 10 MW have been determined from an up-scaling of

A. B. Abrahamsen; N. Mijatovic; E. Seiler; T. Zirngibl; C. Træholt; P. B. Nørgård; N. F. Pedersen; N. H. Andersen; J. Østergård

2010-01-01

457

Assessment of the suitability of agricultural waste water for geothermal power plant cooling in the Imperial Valley. I. Water quality  

SciTech Connect

Evaluation of the quality of agricultural waste water is the first step in assessing the sitability of agricultural waste water for geothermal power plant cooling. In this study samples of agricultural waste water from the New and Alamo rivers located in the Imperial Valley of California are analyzed. Determinations of standard water quality parameters, solids content, and inorganic compositions of the solids are made. The results are compared with data on samples of irrigation water and steam condensate also obtained from sites in the Imperial Valley. The data are evaluated in relation to cooling tower operation, waste generation, and waste disposal.

Morris, W.F.; Rigdon, L.P.

1981-09-01

458

Feasibility Analysis of the Positioning of Superconducting Fault Current Limiters for the Smart Grid Application Using Simulink and SimPowerSystem  

Microsoft Academic Search

One of the most important topics regarding the ap- plication of superconducting fault current limiters (SFCL) for up- coming smart grid is related to its possible effect on the reduction of abnormal fault current and the suitable location in the micro grids. Due to the grid connection of the micro grids with the cur- rent power grids, excessive fault current

Umer A. Khan; J. K. Seong; S. H. Lee; S. H. Lim; B. W. Lee

2011-01-01

459

The short-circuit characteristics of a DC reactor type superconducting fault current limiter with fault detection and signal control of the power converter  

Microsoft Academic Search

In general case of DC reactor type superconducting fault current limiter (SFCL), a fault current gradually increases during the fault. It takes above 5 cycles to cut off the fault in the existing power system installed the conventional circuit breakers (CBs). Therefore, the fault current increases during the fault even if the SFCL is installed. This paper proposes a technique

Min Cheol Ahn; Hyoungku Kang; Duck Kweon Bae; Dong Keun Park; Yong Soo Yoon; Sang Jin Lee; Tae Kuk Ko

2005-01-01

460

Optimization of electron cooling by SIN tunnel junctions  

NASA Astrophysics Data System (ADS)

We report on the optimization of electron cooling by SIN tunnel junctions due to the advanced geometry of superconducting electrodes and very effective normal metal traps for more efficient removal of quasiparticles at temperatures from 25 to 500 mK. The maximum decrease in electron temperature of about 200 mK has been observed at bath temperatures 300-350 mK. We used four-junction geometry with Al-AlOx-Cr/Cu tunnel junctions and Au traps. Efficient electron cooling was realized due to the improved geometry of the cooling tunnel junctions (quadrant shape of the superconducting electrode) and optimized Au traps just near the junctions ({\\approx }0.5~\\micmu {\\mathrm {m}} ) to reduce reabsorption of quasiparticles after removing them from normal metal. The maximum cooling effect was increased from a temperature drop of d T = -56 mK (ordinary cross geometry) to -130 mK (improved geometry of superconducting electrodes) and to d T = -200 mK (improved geometry of superconducting electrodes and effective Au traps). The heating peak (instead of cooling) near the zero voltage across cooling junctions has been observed in practice for all samples at temperatures below 150 mK. For higher cooling voltages close to the superconducting gap, the heating was converted to cooling with decreased amplitude. The leakage resistance of the tunnel junctions gives a reasonable explanation of the heating peak. The phonon reabsorption due to the recombination of quasiparticles in superconducting electrodes gives an additional improvement in the theoretical fitting but could not explain the heating peak. An anomalous zero-bias resistance peak has been observed for all tested structures. The peak is explained by Coulomb blockade of tunnelling in transistor-type structures with relatively small tunnel junctions. The work on electron cooling is devoted to the development of a cold-electron bolometer (CEB) with capacitive coupling by SIN tunnel junctions to the antenna for sensitive detection in the terahertz region. Direct electron cooling of an absorber plays a crucial role in supersensitive detection in the presence of a realistic background power load.

Kuzmin, L.; Agulo, I.; Fominsky, M.; Savin, A.; Tarasov, M.

2004-05-01