Science.gov

Sample records for power generation cycles

  1. Nuclear power generation and fuel cycle report 1996

    SciTech Connect

    1996-10-01

    This report presents the current status and projections through 2015 of nuclear capacity, generation, and fuel cycle requirements for all countries using nuclear power to generate electricity for commercial use. It also contains information and forecasts of developments in the worldwide nuclear fuel market. Long term projections of U.S. nuclear capacity, generation, and spent fuel discharges for two different scenarios through 2040 are developed. A discussion on decommissioning of nuclear power plants is included.

  2. Solar powered Stirling cycle electrical generator

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.

    1991-01-01

    Under NASA's Civil Space Technology Initiative (CSTI), the NASA Lewis Research Center is developing the technology needed for free-piston Stirling engines as a candidate power source for space systems in the late 1990's and into the next century. Space power requirements include high efficiency, very long life, high reliability, and low vibration. Furthermore, system weight and operating temperature are important. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, non-contacting gas bearings, and can be hermetically sealed. These attributes of the free-piston Stirling engine also make it a viable candidate for terrestrial applications. In cooperation with the Department of Energy, system designs are currently being completed that feature the free-piston Stirling engine for terrestrial applications. Industry teams were assembled and are currently completing designs for two Advanced Stirling Conversion Systems utilizing technology being developed under the NASA CSTI Program. These systems, when coupled with a parabolic mirror to collect the solar energy, are capable of producing about 25 kW of electricity to a utility grid. Industry has identified a niche market for dish Stirling systems for worldwide remote power application. They believe that these niche markets may play a major role in the introduction of Stirling products into the commercial market.

  3. Solar powered Stirling cycle electrical generator

    NASA Astrophysics Data System (ADS)

    Shaltens, Richard K.

    1991-03-01

    Under NASA's Civil Space Technology Initiative (CSTI), the NASA Lewis Research Center is developing the technology needed for free-piston Stirling engines as a candidate power source for space systems in the late 1990's and into the next century. Space power requirements include high efficiency, very long life, high reliability, and low vibration. Furthermore, system weight and operating temperature are important. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, non-contacting gas bearings, and can be hermetically sealed. These attributes of the free-piston Stirling engine also make it a viable candidate for terrestrial applications. In cooperation with the Department of Energy, system designs are currently being completed that feature the free-piston Stirling engine for terrestrial applications. Industry teams were assembled and are currently completing designs for two Advanced Stirling Conversion Systems utilizing technology being developed under the NASA CSTI Program. These systems, when coupled with a parabolic mirror to collect the solar energy, are capable of producing about 25 kW of electricity to a utility grid. Industry has identified a niche market for dish Stirling systems for worldwide remote power application. They believe that these niche markets may play a major role in the introduction of Stirling products into the commercial market.

  4. Coal-gasification combined-cycle power generation

    SciTech Connect

    Roberts, J.A.

    1984-06-01

    Rolls-Royce has joined forces with Foster Wheeler to offer a modern power plant that integrates the benefits of coal gasification with the efficiency advantages of combined-cycle power generation. Powered by fuel gas from two parallel Lurgi slagging gasifiers, the 150-MW power station employs two Rolls-Royce SK60 gas-turbine generating sets. The proposed plant is designed for continuous power generation and should operate efficiently down to one-third of its rated capacity. Rolls estimates that the installed cost for this station would be lower than that for a conventional coal-fired station of the same output with comparable operating costs. Cooling water requirements would be less than half those of a coal-fired station.

  5. Fuel cycle comparison of distributed power generation technologies.

    SciTech Connect

    Elgowainy, A.; Wang, M. Q.; Energy Systems

    2008-12-08

    The fuel-cycle energy use and greenhouse gas (GHG) emissions associated with the application of fuel cells to distributed power generation were evaluated and compared with the combustion technologies of microturbines and internal combustion engines, as well as the various technologies associated with grid-electricity generation in the United States and California. The results were primarily impacted by the net electrical efficiency of the power generation technologies and the type of employed fuels. The energy use and GHG emissions associated with the electric power generation represented the majority of the total energy use of the fuel cycle and emissions for all generation pathways. Fuel cell technologies exhibited lower GHG emissions than those associated with the U.S. grid electricity and other combustion technologies. The higher-efficiency fuel cells, such as the solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC), exhibited lower energy requirements than those for combustion generators. The dependence of all natural-gas-based technologies on petroleum oil was lower than that of internal combustion engines using petroleum fuels. Most fuel cell technologies approaching or exceeding the DOE target efficiency of 40% offered significant reduction in energy use and GHG emissions.

  6. ''An assessment of integrated gasification combined cycle power generation''

    SciTech Connect

    Hauber, D.A.; Kirk, R.J.; Pietruszkiewicz, J.; Smith, R.S.

    1983-11-01

    This paper presents the results of a comparative study of various selected technologies for coal-fired electric power generation with emphasis on the generation of power using the Integrated Gasification Combined Cycle (IGCC) Concept. This study was managed by Argonne National Laboratory for the U.S. Department of Energy, Office of Coal Utilization. All of the power plant conceptual designs were prepared as grassroots plants with a nominal output of 500 MWe, located in the east-central region of the United States. The designs were based upon a uniform set of design, performance, economic criteria and a 1990 state-of-the-art reference frame. Three IGCC power plant concepts were studied (Texaco, BGC/Lurgi, and Westinghouse gasification processes) and compared with conventional pulverized coal-fired power plants. Each of the IGCC plant concepts were designed to produce a medium-Btu fuel gas which was treated in a SELEXOL processing facility to remove sulfur from the fuel gas in order to meet NSPS SO/sub 2/ emission control requirements. The IGCC power generation facilities for each concept used advanced gas turbines with a rotor inlet temperature of 2,150/sup 0/F. Conventional heat recovery steam generators produced high pressure superheated steam which was expanded through a non-reheat steam turbine exhausting to a conventional condenser. The basic designs, estimated performance, and economics for the IGCC plants are presented for both eastern and western coals with varying sulfur removals and are compared with conventional power plants of the same outputs. A consistent set of technical and economic ground rules was employed in making the comparisons. Each of the base case concepts that were studied were found to be cost competitive under the economic ground rules.

  7. Assessment of integrated gasification combined cycle power generation

    SciTech Connect

    Huber, D.A.; Kirk, R.J.; Pietruszkiewicz, J.; Smith, R.S.

    1983-01-01

    This paper presents the results of a comparative study of various selected technologies for coal-fired electric power generation with emphasis on the generation of power using the Integrated Gasification Combined Cycle (IGCC) Concept. All of the power plant conceptual designs were prepared as grassroots plants with a nominal output of 500 MWe, located in the east-central region of the United States. The designs were based upon a uniform set of design, performance, economic criteria and a 1990 state-of-the-art reference frame. Three IGCC power plant concepts were studied (Texaco, BGC/Lurgi, and Westinghouse gasification processes) and compared with conventional pulverized coal-fired power plants. Each of the IGCC plant concepts were designed to produce a medium-Btu fuel gas which was treated in a SELEXOL processing facility to remove sulfur from the fuel gas in order to meet NSPS SO/sub 2/ emission control requirements. The IGCC power generation facilities for each concept used advanced gas turbines with a rotor inlet temperature of 2150/sup 0/F. Conventional heat recovery steam generators produced high pressure superheated steam which was expanded through a non-reheat steam turbine exhausting to a conventional condenser. The basic designs, estimated performance, and economics for the IGCC plants are presented for both eastern and western coals with varying sulfur removals and are compared with conventional power plants of the same outputs. A consistent set of technical and economic ground rules was employed in making the comparisons. Each of the base case concepts that were studied were found to be cost competitive under the economic ground rules. 8 figures, 12 tables.

  8. Nuclear power generation and fuel cycle report 1997

    SciTech Connect

    1997-09-01

    Nuclear power is an important source of electric energy and the amount of nuclear-generated electricity continued to grow as the performance of nuclear power plants improved. In 1996, nuclear power plants supplied 23 percent of the electricity production for countries with nuclear units, and 17 percent of the total electricity generated worldwide. However, the likelihood of nuclear power assuming a much larger role or even retaining its current share of electricity generation production is uncertain. The industry faces a complex set of issues including economic competitiveness, social acceptance, and the handling of nuclear waste, all of which contribute to the uncertain future of nuclear power. Nevertheless, for some countries the installed nuclear generating capacity is projected to continue to grow. Insufficient indigenous energy resources and concerns over energy independence make nuclear electric generation a viable option, especially for the countries of the Far East.

  9. Membranes for H2 generation from nuclear powered thermochemical cycles.

    SciTech Connect

    Nenoff, Tina Maria; Ambrosini, Andrea; Garino, Terry J.; Gelbard, Fred; Leung, Kevin; Navrotsky, Alexandra; Iyer, Ratnasabapathy G.; Axness, Marlene

    2006-11-01

    In an effort to produce hydrogen without the unwanted greenhouse gas byproducts, high-temperature thermochemical cycles driven by heat from solar energy or next-generation nuclear power plants are being explored. The process being developed is the thermochemical production of Hydrogen. The Sulfur-Iodide (SI) cycle was deemed to be one of the most promising cycles to explore. The first step of the SI cycle involves the decomposition of H{sub 2}SO{sub 4} into O{sub 2}, SO{sub 2}, and H{sub 2}O at temperatures around 850 C. In-situ removal of O{sub 2} from this reaction pushes the equilibrium towards dissociation, thus increasing the overall efficiency of the decomposition reaction. A membrane is required for this oxygen separation step that is capable of withstanding the high temperatures and corrosive conditions inherent in this process. Mixed ionic-electronic perovskites and perovskite-related structures are potential materials for oxygen separation membranes owing to their robustness, ability to form dense ceramics, capacity to stabilize oxygen nonstoichiometry, and mixed ionic/electronic conductivity. Two oxide families with promising results were studied: the double-substituted perovskite A{sub x}Sr{sub 1-x}Co{sub 1-y}B{sub y}O{sub 3-{delta}} (A=La, Y; B=Cr-Ni), in particular the family La{sub x}Sr{sub 1-x}Co{sub 1-y}Mn{sub y}O{sub 3-{delta}} (LSCM), and doped La{sub 2}Ni{sub 1-x}M{sub x}O{sub 4} (M = Cu, Zn). Materials and membranes were synthesized by solid state methods and characterized by X-ray and neutron diffraction, SEM, thermal analyses, calorimetry and conductivity. Furthermore, we were able to leverage our program with a DOE/NE sponsored H{sub 2}SO{sub 4} decomposition reactor study (at Sandia), in which our membranes were tested in the actual H{sub 2}SO{sub 4} decomposition step.

  10. DESIGN OF HYBRID POWER GENERATION CYCLES EMPLOYING AMMONIA-WATER-CARBON DIOXIDE MIXTURES

    SciTech Connect

    Ashish Gupta

    2002-06-01

    A power cycle generates electricity from the heat of combustion of fossil fuels. Its efficiency is governed by the cycle configuration, the operating parameters, and the working fluid. Typical. designs use pure water as the fluid. in the last two decades, hybrid cycles based on ammonia-water, and carbon-dioxide mixtures as the working fluid have been proposed. These cycles may improve the power generation efficiency of Rankine cycles by 15%. Improved efficiency is important for two reasons: it lowers the cost of electricity being produced, and by reducing the consumption of fossil fuels per unit power, it reduces the generation of environmental pollutants. The goal of this project is to develop a computational optimization-based method for the design and analysis of hybrid bottoming power cycles to minimize the usage of fossil fuels. The development of this methodology has been achieved by formulating this task as that of selecting the least cost power cycle design from all possible configurations. They employ a detailed thermodynamic property prediction package they have developed under a DOE-FETC grant to model working fluid mixtures. Preliminary results from this work suggest that a pure NH{sub 3} cycle outperforms steam or the expensive Kalina cycle.

  11. Electric power generating plant having direct-coupled steam and compressed-air cycles

    DOEpatents

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  12. Electric power generating plant having direct coupled steam and compressed air cycles

    DOEpatents

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  13. Innovative open air brayton combined cycle systems for the next generation nuclear power plants

    NASA Astrophysics Data System (ADS)

    Zohuri, Bahman

    The purpose of this research was to model and analyze a nuclear heated multi-turbine power conversion system operating with atmospheric air as the working fluid. The air is heated by a molten salt, or liquid metal, to gas heat exchanger reaching a peak temperature of 660 0C. The effects of adding a recuperator or a bottoming steam cycle have been addressed. The calculated results are intended to identify paths for future work on the next generation nuclear power plant (GEN-IV). This document describes the proposed system in sufficient detail to communicate a good understanding of the overall system, its components, and intended uses. The architecture is described at the conceptual level, and does not replace a detailed design document. The main part of the study focused on a Brayton --- Rankine Combined Cycle system and a Recuperated Brayton Cycle since they offer the highest overall efficiencies. Open Air Brayton power cycles also require low cooling water flows relative to other power cycles. Although the Recuperated Brayton Cycle achieves an overall efficiency slightly less that the Brayton --- Rankine Combined Cycle, it is completely free of a circulating water system and can be used in a desert climate. Detailed results of modeling a combined cycle Brayton-Rankine power conversion system are presented. The Rankine bottoming cycle appears to offer a slight efficiency advantage over the recuperated Brayton cycle. Both offer very significant advantages over current generation Light Water Reactor steam cycles. The combined cycle was optimized as a unit and lower pressure Rankine systems seem to be more efficient. The combined cycle requires a lot less circulating water than current power plants. The open-air Brayton systems appear to be worth investigating, if the higher temperatures predicted for the Next Generation Nuclear Plant do materialize.

  14. TECHNOECONOMIC APPRAISAL OF INTEGRATED GASIFICATION COMBINED-CYCLE POWER GENERATION

    EPA Science Inventory

    The report is a technoeconomic appraisal of the integrated (coal) gasification combined-cycle (IGCC) system. lthough not yet a proven commercial technology, IGCC is a future competitive technology to current pulverized-coal boilers equipped with SO2 and NOx controls, because of i...

  15. A NOVEL SOLAR THERMAL COMBINED CYCLE FOR DISTRIBUTED POWER GENERATION

    EPA Science Inventory

    Impacts of this work will be seen in the areas of energy, poverty alleviation, improvement of quality of health care provision and quality of life, business development, and education. We will be directly preventing installation of polluting diesel generators while improving ...

  16. The importance of combined cycle generating plants in integrating large levels of wind power generation

    SciTech Connect

    Puga, J. Nicolas

    2010-08-15

    Integration of high wind penetration levels will require fast-ramping combined cycle and steam cycles that, due to higher operating costs, will require proper pricing of ancillary services or other forms of compensation to remain viable. Several technical and policy recommendations are presented to help realign the generation mix to properly integrate the wind. (author)

  17. Preheating of fluid in a supercritical Brayton cycle power generation system at cold startup

    DOEpatents

    Wright, Steven A.; Fuller, Robert L.

    2016-07-12

    Various technologies pertaining to causing fluid in a supercritical Brayton cycle power generation system to flow in a desired direction at cold startup of the system are described herein. A sensor is positioned at an inlet of a turbine, wherein the sensor is configured to output sensed temperatures of fluid at the inlet of the turbine. If the sensed temperature surpasses a predefined threshold, at least one operating parameter of the power generation system is altered.

  18. Microfabricated rankine cycle steam turbine for power generation and methods of making the same

    NASA Technical Reports Server (NTRS)

    Frechette, Luc (Inventor); Muller, Norbert (Inventor); Lee, Changgu (Inventor)

    2009-01-01

    In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

  19. Closed Cycle Magnetohydrodynamic Nuclear Space Power Generation Using Helium/Xenon Working Plasma

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Harada, N.

    2005-01-01

    A multimegawatt-class nuclear fission powered closed cycle magnetohydrodynamic space power plant using a helium/xenon working gas has been studied, to include a comprehensive system analysis. Total plant efficiency was expected to be 55.2 percent including pre-ionization power. The effects of compressor stage number, regenerator efficiency, and radiation cooler temperature on plant efficiency were investigated. The specific mass of the power generation plant was also examined. System specific mass was estimated to be 3 kg/kWe for a net electrical output power of 1 MWe, 2-3 kg/kWe at 2 MWe, and approx.2 kg/KWe at >3 MWe. Three phases of research and development plan were proposed: (1) Phase I-proof of principle, (2) Phase II-demonstration of power generation, and (3) Phase III-prototypical closed loop test.

  20. Optimization of Brayton Cycle Power Generation for In-Space Electric Propulsion Application

    NASA Technical Reports Server (NTRS)

    Woodcock, Gordon

    2003-01-01

    A Brayton cycle was analyzed and optimized over the power range 60 - 140 kWe, for application to electric propulsion systems. A gas-cooled reactor heat source with exit temperature 1150 K was assumed. Power generation system specific masses (alpha) from 36 kg/kWe at 60 kWe to 22 kg/kWe at 140 kWe were obtained. These masses do not include the thrust production system, which is predicted to add 6 to 8 kg/kWe. Cycle efficiencies varied from 32% at 60 kWe to 36% at 140 kWe. Cycle minimum temperature, cycle pressure ratio, and heat exchanger design parameters were varied for the optimization. Optimization parameters and methods are described.

  1. Experimental studies on closed cycle MHD power generation with Fuji-1 facility

    SciTech Connect

    Okuno, Yoshihiro; Kabashima, Shigeharu; Okamura, Tetsuji; Yoshikawa, Kunio; Tsuji, Kiyoshi; Suekane, Tetsuya; Shioda, Susumu; Yamasaki, Hiroyuki; Hasegawa, Yasuo

    1996-12-31

    Experimental studies on closed cycle MHD power generation with Fuji-1 blow-down facility at Tokyo Institute of Technology are presented. Recently, a new disk generator (Disk-F4) has been installed and a new seed injection system has been introduced from IVTAN (Institute of High Temperature in Russia). The design concept of the new generator channel is focused mainly on the reliability of high power generation. The Mach number at the generator inlet and the thermal input are increased up to {approximately}2.8 and {approximately}3.0 MW, respectively. In the new seeding system, a melted seed material is pushed by a piston dozator, instead of gas-pressure-driven in the previous system. The controllability of seed fraction is markedly improved, and the large fluctuation as has been observed previously is diminished. In the power generation experiments with the new components, the maximum power output of 502kW and the enthalpy extraction ratio of 16.7% have been obtained. These values at the present stage are lower than the maximum values previously achieved in the facility. However, the reliable high power generation can be expected with the new generator. The behavior of plasma and fluid under high MHD interaction taking place in the generator channel is also discussed.

  2. Investigation of rocket-powered, open-cycle, magnetohydrodynamic generators for high, pulsed power needs in space. Master's thesis

    SciTech Connect

    Power, J.W.

    1986-11-01

    This investigation examined the possibility of using a rocket-powered magnetohydrodynamic generator for pulse power in space of 300 megawatts (MW). The result is a preliminary design of an MHD generator using an open cycle disk channel and a single superconducting solenoid coil. The disk channel acts as a thrust deflector, and internal vanes counteract induced vorticity. The use of a solid-fuel-wafer grain design rocket motor is proposed for increased electrical conductivity and pulse operation of the generator. Using conservative parameters, a generator design capable of being carried on one or two space-shuttle launches is developed with estimated mass of 24,450 kg and estimated power output of 1346 MW. The nominal operation time before refurbishment is 115 seconds; the restriction operation time is deterioration of the channel throat. This design exceeds present nuclear and solar-cell power systems in power output per unit mass.

  3. A Supercritical CO{sub 2} Cycle- a Promising Power Conversion System for Generation IV Reactors

    SciTech Connect

    Hejzlar, Pavel; Dostal, Vaclav; Driscoll, Michael J.

    2006-07-01

    Advances in power conversion systems (PCS) for Generation IV power plants are of high importance because of their impact on plant specific capital cost reduction, which can be more significant than the cost savings achieved through the modifications of the nuclear island itself. One such PCS candidate, especially attractive for reactor outlet temperatures in the range of 550 to 650 deg C, is applicable to lead-alloy, sodium, or liquid salt-cooled reactors, as well as direct-cycle CO{sub 2} cooled reactors. The efficiencies achievable in this medium temperature range exceed those of conventional Brayton cycles and supercritical steam Rankine cycles and are comparable to those of conventional helium Brayton cycles at turbine inlet temperatures of 800 to 900 deg C. The S-CO{sub 2} recompression cycle under evaluation at MIT, is described with its advantages, drawbacks and R and D needs. The cycle is shown to excel in efficiency, simplicity and compactness which projects to cost savings, and in lower sensitivity of efficiency to core bypass flow, component pressure losses and flow maldistribution in recuperators. On the other hand, the cycle is highly recuperative and thus requires very compact heat exchangers, poses challenges to design of piping for large units, and its control and part load operation is more complicated. (authors)

  4. Studies of cycles for liquid-metal magnetohydrodynamic generation of power

    NASA Technical Reports Server (NTRS)

    Lee, K.; Petrick, M.

    1969-01-01

    Studies of liquid-metal magnetohydrodynamic power cycles indicate that the overall efficiency of a binary cycle, employing a liquid-metal topping cycle and a bottoming steam cycle, may reach 60 percent. Details of analyses and data on cycles are presented, and the commercial potential of the binary cycle is discussed.

  5. Thermal analysis of a simple-cycle gas turbine in biogas power generation

    SciTech Connect

    Yomogida, D.E.; Thinh, Ngo Dinh

    1995-09-01

    This paper investigates the technical feasibility of utilizing small simple-cycle gas turbines (25 kW to 125 kW) for biogas power generation through thermal analysis. A computer code, GTPower, was developed to evaluate the performance of small simple-cycle gas turbines specifically for biogas combustion. The 125 KW Solar Gas Turbine (Tital series) has been selected as the base case gas turbine for biogas combustion. After its design parameters and typical operating conditions were entered into GTPower for analysis, GTPower outputted expected values for the thermal efficiency and specific work. For a sensitivity analysis, the GTPower Model outputted the thermal efficiency and specific work. For a sensitivity analysis, the GTPower Model outputted the thermal efficiency and specific work profiles for various operating conditions encountered in biogas combustion. These results will assist future research projects in determining the type of combustion device most suitable for biogas power generation.

  6. Power and entropy generation of an extended irreversible Brayton cycle: optimal parameters and performance

    NASA Astrophysics Data System (ADS)

    Herrera, Carlos A.; Sandoval, Jairo A.; Rosillo, Miguel E.

    2006-08-01

    Finite time thermodynamics is used to solve a new model of an extended Brayton cycle with variable-temperature heat reservoirs and finite size heat exchangers. The model takes into account external and internal entropy generation and handles heat recovery and heat leaks to the environment in a novel way. The extended system considerations are very important for minimizing entropy generation and maximizing second law efficiency, profit and ecological criterion. An optimization analysis was developed on this new model to determine its maximum power and minimum entropy generation, and amid the most important findings were the global maximum net power, global minimum entropy generation, optimum global heat exchangers size distribution, best working fluid specific heat ratio and optimal fluid heat capacities, some of these never having been published previously.

  7. Integrated air separation plant-integrated gasification combined cycle power generator

    SciTech Connect

    Allam, R.J.; Topham, A.

    1992-01-21

    This patent describes an integrated gasification combined cycle power generation system, comprising an air separation unit wherein air is compressed, cooled, and separated into an oxygen and nitrogen enriched fractions, a gasification system for generating a fuel gas, an air compressor system for supplying compressed air for use in combusting the fuel gas, a combustion zone for effecting combustion of the compressed air and the fuel gas, and a gas turbine for effecting the generation of power from the resulting combusted gases from the combustion zone in the combined cycle power generation system. It comprises independently compressing feed air to the air separation unit to pressures of from 8 to 20 bar from the compressor system used to compress air for the combustion zone; cryogenically separating the air in the air separation unit having at least one distillation column operating at pressures of between 8 and 20 bar and producing an oxygen enriched fraction consisting of low purity oxygen, and; utilizing at least a portion of the low purity oxygen for effecting gasification of a carbon containing fuel source by partial oxidation in the gasification system and thereby generating a fuel gas stream; removing at least a portion of a nitrogen enriched fraction from the air separation unit and boosting its pressures to a pressure substantially equal to that of the fuel gas stream; and expanding at least another portion of the nitrogen enriched fraction in an expansion engine.

  8. Life cycle analysis of geothermal power generation with supercritical carbon dioxide

    NASA Astrophysics Data System (ADS)

    Frank, Edward D.; Sullivan, John L.; Wang, Michael Q.

    2012-09-01

    Life cycle analysis methods were employed to model the greenhouse gas emissions and fossil energy consumption associated with geothermal power production when supercritical carbon dioxide (scCO2) is used instead of saline geofluids to recover heat from below ground. Since a significant amount of scCO2 is sequestered below ground in the process, a constant supply is required. We therefore combined the scCO2 geothermal power plant with an upstream coal power plant that captured a portion of its CO2 emissions, compressed it to scCO2, and transported the scCO2 by pipeline to the geothermal power plant. Emissions and energy consumption from all operations spanning coal mining and plant construction through power production were considered, including increases in coal use to meet steam demand for the carbon capture. The results indicated that the electricity produced by the geothermal plant more than balanced the increase in energy use resulting from carbon capture at the coal power plant. The effective heat rate (BTU coal per total kW h of electricity generated, coal plus geothermal) was comparable to that of traditional coal, but the ratio of life cycle emissions from the combined system to that of traditional coal was 15% when 90% carbon capture efficiency was assumed and when leakage from the surface was neglected. Contributions from surface leakage were estimated with a simple model for several hypothetical surface leakage rates.

  9. Cycle Evaluations of Reversible Chemical Reactions for Solar Thermochemical Energy Storage in Support of Concentrating Solar Power Generation Systems

    SciTech Connect

    Krishnan, Shankar; Palo, Daniel R.; Wegeng, Robert S.

    2010-07-25

    The production and storage of thermochemical energy is a possible route to increase capacity factors and reduce the Levelized Cost of Electricity from concentrated solar power generation systems. In this paper, we present the results of cycle evaluations for various thermochemical cycles, including a well-documented ammonia closed-cycle along with open- and closed-cycle versions of hydrocarbon chemical reactions. Among the available reversible hydrocarbon chemical reactions, catalytic reforming-methanation cycles are considered; specifically, various methane-steam reforming cycles are compared to the ammonia cycle. In some cases, the production of an intermediate chemical, methanol, is also included with some benefit being realized. The best case, based on overall power generation efficiency and overall plant capacity factor, was found to be an open cycle including methane-steam reforming, using concentrated solar energy to increase the chemical energy content of the reacting stream, followed by combustion to generate heat for the heat engine.

  10. Closed Brayton Cycle (CBC) Power Generation from an Electric Systems Perspective

    NASA Astrophysics Data System (ADS)

    Halsey, David G.; Fox, David A.

    2006-01-01

    Several forms of closed cycle heat engines exist to produce electrical energy suitable for space exploration or planetary surface applications. These engines include Stirling and Closed Brayton Cycle (CBC). Of these two, CBC has often been cited as providing the best balance of mass and efficiency for deep space or planetary power systems. Combined with an alternator on the same shaft, the hermetically sealed system provides the potential for long life and reliable operation. There is also a list of choices for the type of alternator. Choices include wound rotor machines, induction machines, switched reluctance machines, and permanent magnet generators (PMGs). In trades involving size, mass and efficiency the PMG is a favorable solution. This paper will discuss the consequences of using a CBC-PMG source for an electrical power system, and the system parameters that must be defined and controlled to provide a stable, useful power source. Considerations of voltage, frequency (including DC), and power quality will be discussed. Load interactions and constraints for various power types will also be addressed. Control of the CBC-PMG system during steady state operation and startup is also a factor.s

  11. Life cycle assessment of fuel selection for power generation in Taiwan.

    PubMed

    Yang, Ying-Hsien; Lin, Sue-Jane; Lewis, Charles

    2007-11-01

    Life cycle assessment (LCA) was applied to performance data from 1997-2002 to evaluate the environmental impacts of the energy input, airborne emission, waterborne emission, and solid waste inventories for Taiwan's electric power plants. Eco-indicator 95 was used to compare the differences among the generation processes and fuel purification. To better understand the environmental trends related to Taiwan's electric power industry, three fuel scenarios were selected for LCA system analysis. Results indicate that there are differences in characteristic environmental impact among the 13 power plants. Scenario simulation provided a basis for minimizing environmental impacts from fuel selection targets. Fuel selection priority should be a gas-fired combined cycle substituted for a coal-fired steam turbine to be more environmentally friendly, particularly in the areas of the greenhouse effect, acidification, winter smog, and solid waste. Furthermore, based purely on economic and environmental criteria, it is recommended that the gas-fired combined cycle be substituted for the oil-fired steam turbine. PMID:18069462

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

    SciTech Connect

    Daniel S. Wendt; Greg L. Mines

    2010-09-01

    As geothermal resources that are more expensive to develop are utilized for power generation, there will be increased incentive to use more efficient power plants. This is expected to be the case with Enhanced Geothermal System (EGS) resources. These resources will likely require wells drilled to depths greater than encountered with hydrothermal resources, and will have the added costs for stimulation to create the subsurface reservoir. It is postulated that plants generating power from these resources will likely utilize the binary cycle technology where heat is rejected sensibly to the ambient. The consumptive use of a portion of the produced geothermal fluid for evaporative heat rejection in the conventional flash-steam conversion cycle is likely to preclude its use with EGS resources. This will be especially true in those areas where there is a high demand for finite supplies of water. Though they have no consumptive use of water, using air-cooling systems for heat rejection has disadvantages. These systems have higher capital costs, reduced power output (heat is rejected at the higher dry-bulb temperature), increased parasitics (fan power), and greater variability in power generation on both a diurnal and annual basis (larger variation in the dry-bulb temperature). This is an interim report for the task ‘Air-Cooled Condensers in Next- Generation Conversion Systems’. The work performed was specifically aimed at a plant that uses commercially available binary cycle technologies with an EGS resource. Concepts were evaluated that have the potential to increase performance, lower cost, or mitigate the adverse effects of off-design operation. The impact on both cost and performance were determined for the concepts considered, and the scenarios identified where a particular concept is best suited. Most, but not all, of the concepts evaluated are associated with the rejection of heat. This report specifically addresses three of the concepts evaluated: the use of

  13. Heat recovery steam generator outlet temperature control system for a combined cycle power plant

    SciTech Connect

    Martens, A.; Myers, G.A.; McCarty, W.L.; Wescott, K.R.

    1986-04-01

    This patent describes a command cycle electrical power plant including: a steam turbine and at least one set comprising a gas turbine, an afterburner and a heat recovery steam generator having an attemperator for supplying from an outlet thereof to the steam turbine superheated steam under steam turbine operating conditions requiring predetermined superheated steam temperature, flow and pressure; with the gas turbine and steam turbine each generating megawatts in accordance with a plant load demand; master control means being provided for controlling the steam turbine and the heat recovery steam generator so as to establish the steam operating conditions; the combination of: first control means responsive to the gas inlet temperature of the heat recovery steam generator and to the plant load demand for controlling the firing of the afterburner; second control means responsive to the superheated steam predetermined temperature and to superheated steam temperature from the outlet for controlling the attemperator between a closed and an open position; the first and second control means being operated concurrently to maintain the superheated steam outlet temperature while controlling the load of the gas turbine independently of the steam turbine operating conditions.

  14. MTCI/ThermoChem steam reforming process for solid fuels for combined cycle power generation

    SciTech Connect

    Mansour, M.N.; Voelker, G.; Dural-Swamy, K.

    1995-12-31

    Manufacturing and Technology Conversion International, Inc. (MTCI) has developed a novel technology to convert solid fuels including biomass, coal, municipal solid waste (MSW) and wastewater sludges into usable syngas by steam reforming in an indirectly heated, fluid-bed reactor. MTCI has licensed and patented the technology to ThermoChem, Inc. Both MTCI and ThermoChem have built two modular commercial-scale demonstration units: one for recycle paper mill rejects (similar to refuse-derived fuel [RDF]), and another for chemical recovery of black liquor. ThermoChem has entered into an agreement with Ajinkyatara Cooperative Sugar Factory, India, for building a 10 MW combined cycle power generation facility based on bagasse and agro-residue gasification.

  15. Optical generation of single-cycle 10 MW peak power 100 GHz waves.

    PubMed

    Wu, Xiaojun; Calendron, Anne-Laure; Ravi, Koustuban; Zhou, Chun; Hemmer, Michael; Reichert, Fabian; Zhang, Dongfang; Cankaya, Huseyin; Zapata, Luis E; Matlis, Nicholas H; Kärtner, Franz X

    2016-09-01

    We demonstrate the generation of 100 GHz single-cycle pulses with up to 10 MW of peak power using optical rectification and broadband phase matching via the tilted pulse front (TPF) technique in lithium niobate. The optical driver is a cryogenically cooled Yb:YAG amplifier providing tens of mJ energy, ~5 ps long laser pulses. We obtain a high THz pulse energy up to 65 µJ with 31.6 MV/m peak electric field when focused close to its diffraction limit of 2.5 mm diameter. A high optical-to-THz energy conversion efficiency of 0.3% at 85 K is measured in agreement with numerical simulations. This source is of great interest for a broad range of applications, such as nonlinear THz field-matter interaction and charged particle acceleration for ultrafast electron diffraction and table-top X-ray sources. PMID:27607709

  16. Comparative Evaluation of Biomass Power Generation Systems in China Using Hybrid Life Cycle Inventory Analysis

    PubMed Central

    Liu, Huacai; Yin, Xiuli; Wu, Chuangzhi

    2014-01-01

    There has been a rapid growth in using agricultural residues as an energy source to generate electricity in China. Biomass power generation (BPG) systems may vary significantly in technology, scale, and feedstock and consequently in their performances. A comparative evaluation of five typical BPG systems has been conducted in this study through a hybrid life cycle inventory (LCI) approach. Results show that requirements of fossil energy savings, and greenhouse gas (GHG) emission reductions, as well as emission reductions of SO2 and NOx, can be best met by the BPG systems. The cofiring systems were found to behave better than the biomass-only fired system and the biomass gasification systems in terms of energy savings and GHG emission reductions. Comparing with results of conventional process-base LCI, an important aspect to note is the significant contribution of infrastructure, equipment, and maintenance of the plant, which require the input of various types of materials, fuels, services, and the consequent GHG emissions. The results demonstrate characteristics and differences of BPG systems and help identify critical opportunities for biomass power development in China. PMID:25383383

  17. Life Cycle GHG Emissions from Conventional Natural Gas Power Generation: Systematic Review and Harmonization (Presentation)

    SciTech Connect

    Heath, G.; O'Donoughue, P.; Whitaker, M.

    2012-12-01

    This research provides a systematic review and harmonization of the life cycle assessment (LCA) literature of electricity generated from conventionally produced natural gas. We focus on estimates of greenhouse gases (GHGs) emitted in the life cycle of electricity generation from conventionally produced natural gas in combustion turbines (NGCT) and combined-cycle (NGCC) systems. A process we term "harmonization" was employed to align several common system performance parameters and assumptions to better allow for cross-study comparisons, with the goal of clarifying central tendency and reducing variability in estimates of life cycle GHG emissions. This presentation summarizes preliminary results.

  18. Efficiency Study of a Commercial Thermoelectric Power Generator (TEG) Under Thermal Cycling

    NASA Astrophysics Data System (ADS)

    Hatzikraniotis, E.; Zorbas, K. T.; Samaras, I.; Kyratsi, Th.; Paraskevopoulos, K. M.

    2010-09-01

    Thermoelectric generators (TEGs) make use of the Seebeck effect in semiconductors for the direct conversion of heat to electrical energy. The possible use of a device consisting of numerous TEG modules for waste heat recovery from an internal combustion (IC) engine could considerably help worldwide efforts towards energy saving. However, commercially available TEGs operate at temperatures much lower than the actual operating temperature range in the exhaust pipe of an automobile, which could cause structural failure of the thermoelectric elements. Furthermore, continuous thermal cycling could lead to reduced efficiency and lifetime of the TEG. In this work we investigate the long-term performance and stability of a commercially available TEG under temperature and power cycling. The module was subjected to sequential hot-side heating (at 200°C) and cooling for long times (3000 h) in order to measure changes in the TEG’s performance. A reduction in Seebeck coefficient and an increase in resistivity were observed. Alternating-current (AC) impedance measurements and scanning electron microscope (SEM) observations were performed on the module, and results are presented and discussed.

  19. Electrical power generating system

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1983-01-01

    A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

  20. Application of Organic Rankine Cycles (ORCs) to decentralized power generation, preliminary study

    NASA Astrophysics Data System (ADS)

    Huovilainen, Reino; Alamaeki, Jarmo; Tarjanne, Risto

    The study concentrates on MW-class ORC processes that could be utilized in connection with different kind of power plants. The use of an ORC-process may offer potential for improvements in two ways; first, an ORC-process can be suitable with low-grade thermal sources where water based power generation is not feasible. Second, an increase in power generation efficiency is achieved. The connection of an ORC-process to following plants were investigated; a gas burning heat-only boiler, a solid fuel boiler, a steam and gas turbine (co-generation) unit, a steam turbine and a heating reactor. In each case the following economical factors for adding an ORC-process were calculated; the cost for electricity, the return of investment (ROI) and the pay-back period. The most favorable cases to utilize an ORC-process are a heating reactor, a steam turbine and a gas turbine based co-generation plant. In connection with heat-only plants a better economy were achieved than with co-generation plants. The results indicate that there can be found economically promising applications for ORC-processes in industry and power plants. It is evident that those cases should be investigated more in detail. ORC-processes allow power generation in new circumstances and can increase the efficiency of power plants. More emphasis should be paid for the R and D of this relatively new technology.

  1. Reliability and availability assessments of selected domestic combined-cycle power-generating plants

    NASA Astrophysics Data System (ADS)

    Brown, H. W.; Gardner, N. J.

    1982-08-01

    This report presents the results of reliability and availability assessment performed with the cooperation of seven utilities operating combined-cycle power plants in service since 1974 to evaluate: combined-cycle unit equivalent availability and equivalent forced outage rates; system and component mean time between failures (MTBF) and mean downtime (MDT); and gas turbine reliability correlations with service hours, starting frequency, fuel type, and service factor. A data base was developed for 45 plant components or systems for the period 1978 through 1980; this led to recommendations for improving outage data collection for the purpose of reliability analysis. In addition reliability, availability, and maintainability prediction models for several commercial combined cycle plant designs were developed and validated.

  2. Reliability and availability assessments of selected domestic combined-cycle power-generating plants. Final report

    SciTech Connect

    Brown, H.W.; Gardner, N.J.

    1982-08-01

    This report presents the results of reliability and availability assessments performed with the cooperation of seven utilities operating combined-cycle power plants in service since 1974 to evaluate: combined-cycle unit equivalent availability and equivalent forced outage rates; system and component mean time between failures (MTBF) and mean downtime (MDT); and gas turbine reliability correlations with service hours, starting frequency, fuel type, and service factor. A data base was developed for 45 plant components or systems for the period 1978 through 1980; this led to recommendations for improving outage data collection for the purpose of reliability analysis. In addition reliability, availability, and maintainability prediction models for several commercial combined-cycle plant designs were developed and validated.

  3. Harmonization of Initial Estimates of Shale Gas Life Cycle Greenhouse Gas Emissions for Electric Power Generation

    NASA Astrophysics Data System (ADS)

    Heath, G.; O'Donoughue, P.; Arent, D.; Bazilian, M.

    2014-12-01

    Recent technological advances in the recovery of unconventional natural gas, particularly shale gas, have served to dramatically increase domestic production and reserve estimates for the United States and internationally. This trend has led to lowered prices and increased scrutiny on production practices. Questions have been raised as to how greenhouse gas (GHG) emissions from the life cycle of shale gas production and use compares with that of conventionally produced natural gas or other fuel sources such as coal. Recent literature has come to different conclusions on this point, largely due to differing assumptions, comparison baselines, and system boundaries. Through a meta-analytical procedure we call harmonization, we develop robust, analytically consistent, and updated comparisons of estimates of life cycle GHG emissions for electricity produced from shale gas, conventionally produced natural gas, and coal. On a per unit electrical output basis, harmonization reveals that median estimates of GHG emissions from shale gas-generated electricity are similar to those for conventional natural gas, with both approximately half that of the central tendency of coal. Sensitivity analysis on the harmonized estimates indicates that assumptions regarding liquids unloading and estimated ultimate recovery (EUR) of wells have the greatest influence on life cycle GHG emissions, whereby shale gas life cycle GHG emissions could approach the range of best performing coal-fired generation under certain scenarios. Despite clarification of published estimates through harmonization, these initial assessments should be confirmed through methane emissions measurements at components and in the atmosphere and through better characterization of EUR and practices.

  4. Combination flash-bottoming cycle geothermal power generation: A case history

    SciTech Connect

    Gallup, D.L.

    1996-12-31

    High- and low-enthalpy, liquid-dominated geothermal resources are commonly exploited by steam flash and binary power cycles, respectively. Cooled brine from both flash and binary power cycles, respectively. Cooled brine from both flash and binary power plants is typically reinjected into the geothermal reservoir to replenish the aquifer, maintain reservoir pressure and to protect the environment. Silica tends to precipitate from geothermal brine at almost every stage of brine processing as the temperature is reduced, either as hydrous, amorphous opal or as metal silicate. Silica scale deposition in flash plants and brine reinjection systems is commonly controlled by disposing of brine at temperatures above which silica/silicate is saturated or only slightly over-saturated. A significant amount of heat remains in high temperature injection brine that may otherwise be extracted. In 1994, binary cycle units comprising 16 MWe were installed at the Bulalo, Philippines geothermal field utilizing flashed waste brine that was previously injected directly to the reservoir. The binary bottoming cycle consists of six energy converters each employing a preheater and a vaporizer. The brine temperature is reduced across the heat exchangers from 450{degree} to 408{degree}. During the heat recovery process, over-saturation of silica in the injection brine increases from < 10 to > 100%, and scaling rates are predicted to increase thirty-fold from 0.1 to 3 mm/yr. Siliceous scaling in heat exchangers, cooled injection brine piping, injection wells and near-wellbore formation is inhibited by acidification of brine sent to the binary plant. The heat recovery process, incorporating silica scale control by pH modification, has successfully operated at the Bulalo field for two years. Silica scaling, as a result of flashing and cooling brine has been reduced to less than 1 mm/yr.

  5. THERMODYNAMIC ANALYSIS OF AMMONIA-WATER-CARBON DIOXIDE MIXTURES FOR DESIGNING NEW POWER GENERATION CYCLES

    SciTech Connect

    Ashish Gupta

    2003-01-15

    This project was undertaken with the goal of developing a computational package for the thermodynamic properties of ammonia-water-carbon dioxide mixtures at elevated temperature and pressure conditions. This objective was accomplished by modifying an existing set of empirical equations of state for ammonia-water mixtures. This involved using the Wagner equation of state for the gas phase properties of carbon dioxide. In the liquid phase, Pitzer's ionic model was used. The implementation of this approach in the form of a computation package that can be used for the optimization of power cycles required additional code development. In particular, this thermodynamic model consisted of a large set of non-linear equations. Consequently, in the interest of computational speed and robustness that is required when applied to optimization problems, analytic gradients were incorporated in the Newton solver routines. The equations were then implemented using a stream property predictor to make initial guesses of the composition, temperature, pressure, enthalpy, entropy, etc. near a known state. The predictor's validity is then tested upon the convergence of an iteration. It proved difficult to obtain experimental data from the literature that could be used to test the accuracy of the new thermodynamic property package, and this remains a critical need for future efforts in the area. It was possible, however, to assess the feasibility of using this complicated property prediction package for power cycle design and optimization. Such feasibility was first demonstrated by modification of our Kalina cycle optimization code to use the package with either a deterministic optimizer, MINOS, or a stochastic optimizer using differential evolution, a genetic-algorithm-based technique. Beyond this feasibility demonstration, a new approach to the design and optimization of power cycles was developed using a graph theoretic approach.

  6. Coal-gasification/MHD/steam-turbine combined-cycle (GMS) power generation

    SciTech Connect

    Lytle, J.M.; Marchant, D.D.

    1980-11-01

    The coal-gasification/MHD/steam-turbine combined cycle (GMS) refers to magnetohydrodynamic (MHD) systems in which coal gasification is used to supply a clean fuel (free of mineral matter and sulfur) for combustion in an MHD electrical power plant. Advantages of a clean-fuel system include the elimination of mineral matter or slag from all components other than the coal gasifier and gas cleanup system; reduced wear and corrosion on components; and increased seed recovery resulting from reduced exposure of seed to mineral matter or slag. Efficiencies in some specific GMS power plants are shown to be higher than for a comparably sized coal-burning MHD power plant. The use of energy from the MHD exhaust gas to gasify coal (rather than the typical approach of burning part of the coal) results in these higher efficiencies.

  7. Thermal Cycling Behavior of Zinc Antimonide Thin Films for High Temperature Thermoelectric Power Generation Applications.

    PubMed

    Shim, Hyung Cheoul; Woo, Chang-Su; Han, Seungwoo

    2015-08-19

    The zinc antimonide compound ZnxSby is one of the most efficient thermoelectric materials known at high temperatures due to its exceptional low thermal conductivity. For this reason, it continues to be the focus of active research, especially regarding its glass-like atomic structure. However, before practical use in actual surroundings, such as near a vehicle manifold, it is imperative to analyze the thermal reliability of these materials. Herein, we present the thermal cycling behavior of ZnxSby thin films in nitrogen (N2) purged or ambient atmosphere. ZnxSby thin films were prepared by cosputtering and reached a power factor of 1.39 mW m(-1) K(-2) at 321 °C. We found maximum power factor values gradually decreased in N2 atmosphere due to increasing resistivity with repeated cycling, whereas the specimen in air kept its performance. X-ray diffraction and electron microscopy observations revealed that fluidity of Zn atoms leads to nanoprecipitates, porous morphologies, and even growth of a coating layer or fiber structures on the surface of ZnxSby after repetitive heating and cooling cycles. With this in mind, our results indicate that proper encapsulation of the ZnxSby surface would reduce these unwanted side reactions and the resulting degradation of thermoelectric performance. PMID:26226167

  8. Results of closed cycle MHD power generation test with a helium-cesium working fluid

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.

    1977-01-01

    The cross sectional dimensions of the MHD channel in the NASA Lewis closed loop facility were reduced to 3.8 x 11.4 cm. Tests were run in this channel using a helium-cesium working fluid at stagnation pressures of 160,000 n/M2, stagnation temperatures of 2000-2060 K and an entrance Mach number of 0.36. In these tests Faraday open circuit voltages of 200 V were measured which correspond to a Faraday field of 1750 V/M. Power generation tests were run for different groups of electrode configurations and channel lengths. Hall fields up to 1450 V/M were generated. Power extraction per electrode of 183 W and power densities of 1.7 MW/M3 were obtained. A total power output of 2 kW was generated for tests with 14 electrodes. The power densities obtained in this channel represent a factor of 3 improvement over those previously reported for the M = 0.2 channel.

  9. Results of closed cycle MHD power generation tests with a helium-cesium working fluid

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.

    1977-01-01

    The cross-sectional dimensions of the MHD channel in the NASA Lewis closed loop facility have been reduced to 3.8 x 11.4 cm. Tests were run in this channel using a helium-cesium working fluid at stagnation pressures of 1.6 x 10 to the 5th N/sq m, stagnation temperatures of 2000-2060 K and an entrance Mach number of 0.36. In these tests Faraday open circuit voltages of 200 V were measured which correspond to a Faraday field of 1750 V/m. Power generation tests were run for different groups of electrode configurations and channel lengths. Hall fields up to 1450 V/m were generated. Power extraction per electrode of 183 W and power densities of 1.7 MW/cu m have been obtained. A total power output of 2 kW was generated for tests with 14 electrodes. The power densities obtained in this channel represent a factor of 3 improvement over those reported for the m = 0.2 channel at the last EAM Symposium.

  10. Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power

    SciTech Connect

    Brown, L.C.; Funk, J.F.; Showalter, S.K.

    1999-12-15

    OAK B188 Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power There is currently no large scale, cost-effective, environmentally attractive hydrogen production process, nor is such a process available for commercialization. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Fossil fuels are polluting and carbon dioxide emissions from their combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. Almost 800 literature references were located which pertain to thermochemical production of hydrogen from water and over 100 thermochemical watersplitting cycles were examined. Using defined criteria and quantifiable metrics, 25 cycles have been selected for more detailed study.

  11. High-potential Working Fluids for Next Generation Binary Cycle Geothermal Power Plants

    SciTech Connect

    Zia, Jalal; Sevincer, Edip; Chen, Huijuan; Hardy, Ajilli; Wickersham, Paul; Kalra, Chiranjeev; Laursen, Anna Lis; Vandeputte, Thomas

    2013-06-29

    A thermo-economic model has been built and validated for prediction of project economics of Enhanced Geothermal Projects. The thermo-economic model calculates and iteratively optimizes the LCOE (levelized cost of electricity) for a prospective EGS (Enhanced Geothermal) site. It takes into account the local subsurface temperature gradient, the cost of drilling and reservoir creation, stimulation and power plant configuration. It calculates and optimizes the power plant configuration vs. well depth. Thus outputs from the model include optimal well depth and power plant configuration for the lowest LCOE. The main focus of this final report was to experimentally validate the thermodynamic properties that formed the basis of the thermo-economic model built in Phase 2, and thus build confidence that the predictions of the model could be used reliably for process downselection and preliminary design at a given set of geothermal (and/or waste heat) boundary conditions. The fluid and cycle downselected was based on a new proprietary fluid from a vendor in a supercritical ORC cycle at a resource condition of 200�C inlet temperature. The team devised and executed a series of experiments to prove the suitability of the new fluid in realistic ORC cycle conditions. Furthermore, the team performed a preliminary design study for a MW-scale turbo expander that would be used for a supercritical ORC cycle with this new fluid. The following summarizes the main findings in the investigative campaign that was undertaken: 1. Chemical compatibility of the new fluid with common seal/gasket/Oring materials was found to be problematic. Neoprene, Viton, and silicone materials were found to be incompatible, suffering chemical decomposition, swelling and/or compression set issues. Of the materials tested, only TEFLON was found to be compatible under actual ORC temperature and pressure conditions. 2. Thermal stability of the new fluid at 200�C and 40 bar was found to be acceptable after 399

  12. A Supercritical CO{sub 2} Gas Turbine Power Cycle for Next-Generation Nuclear Reactors

    SciTech Connect

    Dostal, Vaclav; Driscoll, Michael J.; Hejzlar, Pavel; Todreas, Neil E.

    2002-07-01

    Although proposed more than 35 years ago, the use of supercritical CO{sub 2} as the working fluid in a closed circuit Brayton cycle has so far not been implemented in practice. Industrial experience in several other relevant applications has improved prospects, and its good efficiency at modest temperatures (e.g., {approx}45% at 550 deg. C) make this cycle attractive for a variety of advanced nuclear reactor concepts. The version described here is for a gas-cooled, modular fast reactor. In the proposed gas-cooled fast breeder reactor design of present interest, CO{sub 2} is also especially attractive because it allows the use of metal fuel and core structures. The principal advantage of a supercritical CO{sub 2} Brayton cycle is its reduced compression work compared to an ideal gas such as helium: about 15% of gross power turbine output vs. 40% or so. This also permits the simplification of use of a single compressor stage without inter-cooling. The requisite high pressure ({approx}20 MPa) also has the benefit of more compact heat exchangers and turbines. Finally, CO{sub 2} requires significantly fewer turbine stages than He, its principal competitor for nuclear gas turbine service. One disadvantage of CO{sub 2} in a direct cycle application is the production of N-16, which will require turbine plant shielding (albeit much less than in a BWR). The cycle efficiency is also very sensitive to recuperator effectiveness and compressor inlet temperature. It was found necessary to split the recuperator into separate high-and low-temperature components, and to employ intermediate re-compression, to avoid having a pinch-point in the cold end of the recuperator. Over the past several decades developments have taken place that make the acceptance of supercritical CO{sub 2} systems more likely: supercritical CO{sub 2} pipelines are in use in the western US in oil-recovery operations; 14 advanced gas-cooled reactors (AGR) are employed in the UK at CO{sub 2} temperatures up to

  13. Harmonization of initial estimates of shale gas life cycle greenhouse gas emissions for electric power generation

    PubMed Central

    Heath, Garvin A.; O’Donoughue, Patrick; Arent, Douglas J.; Bazilian, Morgan

    2014-01-01

    Recent technological advances in the recovery of unconventional natural gas, particularly shale gas, have served to dramatically increase domestic production and reserve estimates for the United States and internationally. This trend has led to lowered prices and increased scrutiny on production practices. Questions have been raised as to how greenhouse gas (GHG) emissions from the life cycle of shale gas production and use compares with that of conventionally produced natural gas or other fuel sources such as coal. Recent literature has come to different conclusions on this point, largely due to differing assumptions, comparison baselines, and system boundaries. Through a meta-analytical procedure we call harmonization, we develop robust, analytically consistent, and updated comparisons of estimates of life cycle GHG emissions for electricity produced from shale gas, conventionally produced natural gas, and coal. On a per-unit electrical output basis, harmonization reveals that median estimates of GHG emissions from shale gas-generated electricity are similar to those for conventional natural gas, with both approximately half that of the central tendency of coal. Sensitivity analysis on the harmonized estimates indicates that assumptions regarding liquids unloading and estimated ultimate recovery (EUR) of wells have the greatest influence on life cycle GHG emissions, whereby shale gas life cycle GHG emissions could approach the range of best-performing coal-fired generation under certain scenarios. Despite clarification of published estimates through harmonization, these initial assessments should be confirmed through methane emissions measurements at components and in the atmosphere and through better characterization of EUR and practices. PMID:25049378

  14. Harmonization of initial estimates of shale gas life cycle greenhouse gas emissions for electric power generation.

    PubMed

    Heath, Garvin A; O'Donoughue, Patrick; Arent, Douglas J; Bazilian, Morgan

    2014-08-01

    Recent technological advances in the recovery of unconventional natural gas, particularly shale gas, have served to dramatically increase domestic production and reserve estimates for the United States and internationally. This trend has led to lowered prices and increased scrutiny on production practices. Questions have been raised as to how greenhouse gas (GHG) emissions from the life cycle of shale gas production and use compares with that of conventionally produced natural gas or other fuel sources such as coal. Recent literature has come to different conclusions on this point, largely due to differing assumptions, comparison baselines, and system boundaries. Through a meta-analytical procedure we call harmonization, we develop robust, analytically consistent, and updated comparisons of estimates of life cycle GHG emissions for electricity produced from shale gas, conventionally produced natural gas, and coal. On a per-unit electrical output basis, harmonization reveals that median estimates of GHG emissions from shale gas-generated electricity are similar to those for conventional natural gas, with both approximately half that of the central tendency of coal. Sensitivity analysis on the harmonized estimates indicates that assumptions regarding liquids unloading and estimated ultimate recovery (EUR) of wells have the greatest influence on life cycle GHG emissions, whereby shale gas life cycle GHG emissions could approach the range of best-performing coal-fired generation under certain scenarios. Despite clarification of published estimates through harmonization, these initial assessments should be confirmed through methane emissions measurements at components and in the atmosphere and through better characterization of EUR and practices. PMID:25049378

  15. Power Plant Cycling Costs

    SciTech Connect

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  16. Steam Generator Component Model in a Combined Cycle of Power Conversion Unit for Very High Temperature Gas-Cooled Reactor

    SciTech Connect

    Oh, Chang H; Han, James; Barner, Robert; Sherman, Steven R

    2007-06-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP), Very High Temperature Gas-Cooled Reactor (VHTR) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. A combined cycle is considered as one of the power conversion units to be coupled to the very high-temperature gas-cooled reactor (VHTR). The combined cycle configuration consists of a Brayton top cycle coupled to a Rankine bottoming cycle by means of a steam generator. A detailed sizing and pressure drop model of a steam generator is not available in the HYSYS processes code. Therefore a four region model was developed for implementation into HYSYS. The focus of this study was the validation of a HYSYS steam generator model of two phase flow correlations. The correlations calculated the size and heat exchange of the steam generator. To assess the model, those calculations were input into a RELAP5 model and its results were compared with HYSYS results. The comparison showed many differences in parameters such as the heat transfer coefficients and revealed the different methods used by the codes. Despite differences in approach, the overall results of heat transfer were in good agreement.

  17. Electrical power generating system. [for windpowered generation

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1981-01-01

    An alternating current power generation system adopted to inject power in an already powered power line is discussed. The power generating system solves to adjustably coup an induction motor, as a generator, to an ac power line wherein the motor and power line are connected through a triac. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced. The principal application will be for windmill powered generation.

  18. Status of power generation experiments in the NASA Lewis closed cycle MHD facility

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.; Nichols, L. D.

    1971-01-01

    The design and operation of the closed cycle MHD facility is discussed and results obtained in recent experiments are presented. The main components of the facility are a compressor, recuperative heat exchanger, heater, nozzle, MHD channel with 28 pairs of thoriated tungsten electrodes, cesium condenser, and an argon cooler. The facility has been operated at temperatures up to 2100 K with a cesium-seeded argon working fluid. At low magnetic field strengths, the open circuit voltage, Hall voltage and short circuit current obtained are 90, 69, and 47 percent of the theoretical equilibrium values, respectively. Comparison of this data with a wall and boundary layer leakage theory indicates that the generator has shorting paths in the Hall direction.

  19. Model predictive control system and method for integrated gasification combined cycle power generation

    DOEpatents

    Kumar, Aditya; Shi, Ruijie; Kumar, Rajeeva; Dokucu, Mustafa

    2013-04-09

    Control system and method for controlling an integrated gasification combined cycle (IGCC) plant are provided. The system may include a controller coupled to a dynamic model of the plant to process a prediction of plant performance and determine a control strategy for the IGCC plant over a time horizon subject to plant constraints. The control strategy may include control functionality to meet a tracking objective and control functionality to meet an optimization objective. The control strategy may be configured to prioritize the tracking objective over the optimization objective based on a coordinate transformation, such as an orthogonal or quasi-orthogonal projection. A plurality of plant control knobs may be set in accordance with the control strategy to generate a sequence of coordinated multivariable control inputs to meet the tracking objective and the optimization objective subject to the prioritization resulting from the coordinate transformation.

  20. Closed cycle MHD power generation experiments in the NASA Lewis Facility

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.; Nichols, L. D.

    1974-01-01

    Many modifications were made in the MHD facility. These include a redesign of the MHD duct interior, addition of mixing bars, increased electrical isolation of all the high temperature components from each other and from ground, and experimentation with various cesium seed vaporization and injection techniques. With the exception of the cesium system which needs further improvement the above modifications were quite successful and resulted in improvements in generator performance. The facility was run for a total of 400 hours in the past year, with 70 hours of this operation at temperatures of 2000 K or more with hot generator walls. With the exception of replacing one cracked brick in the MHD channel no repairs were required in the high temperature loop components for the duration of these tests. Uniform Faraday and Hall voltage profiles were obtained and the Faraday open circuit voltage varied from 90 to 100 percent of the ideal uBh. The magnitudes of the measured parameters are: Faraday open circuit voltage approximately 70 V, total Faraday current approximately 20 A, Hall voltage approximately 250 V, power output approximately 300 W, and power density .036 W/cu cm.

  1. Organic Fluids and Passive Cooling in a Supercritical Rankine Cycle for Power Generation from Low Grade Heat Sources

    NASA Astrophysics Data System (ADS)

    Vidhi, Rachana

    Low grade heat sources have a large amount of thermal energy content. Due to low temperature, the conventional power generation technologies result in lower efficiency and hence cannot be used. In order to efficiently generate power, alternate methods need to be used. In this study, a supercritical organic Rankine cycle was used for heat source temperatures varying from 125°C to 200°C. Organic refrigerants with zero ozone depletion potential and their mixtures were selected as working fluid for this study while the cooling water temperature was changed from 10-25°C. Operating pressure of the cycle has been optimized for each fluid at every heat source temperature to obtain the highest thermal efficiency. Energy and exergy efficiencies of the thermodynamic cycle have been obtained as a function of heat source temperature. Efficiency of a thermodynamic cycle depends significantly on the sink temperature. At areas where water cooling is not available and ambient air temperature is high, efficient power generation from low grade heat sources may be a challenge. Use of passive cooling systems coupled with the condenser was studied, so that lower sink temperatures could be obtained. Underground tunnels, buried at a depth of few meters, were used as earth-air-heat-exchanger (EAHE) through which hot ambient air was passed. It was observed that the air temperature could be lowered by 5-10°C in the EAHE. Vertical pipes were used to lower the temperature of water by 5°C by passing it underground. Nocturnal cooling of stored water has been studied that can be used to cool the working fluid in the thermodynamic cycle. It was observed that the water temperature can be lowered by 10-20°C during the night when it is allowed to cool. The amount of water lost was calculated and was found to be approximately 0.1% over 10 days. The different passive cooling systems were studied separately and their effects on the efficiency of the thermodynamic cycle were investigated. They were

  2. Rotary Stirling-Cycle Engine And Generator

    NASA Technical Reports Server (NTRS)

    Chandler, Joseph A.

    1990-01-01

    Proposed electric-power generator comprises three motor generators coordinated by microprocessor and driven by rotary Stirling-cycle heat engine. Combination offers thermodynamic efficiency of Stirling cycle, relatively low vibration, and automatic adjustment of operating parameters to suit changing load on generator. Rotary Stirling cycle engine converts heat to power via compression and expansion of working gas between three pairs of rotary pistons on three concentric shafts in phased motion. Three motor/generators each connected to one of concentric shafts, can alternately move and be moved by pistons. Microprocessor coordinates their operation, including switching between motor and generator modes at appropriate times during each cycle.

  3. Regulation of pyruvate dehydrogenase activity and citric acid cycle intermediates during high cardiac power generation

    PubMed Central

    Sharma, Naveen; Okere, Isidore C; Brunengraber, Daniel Z; McElfresh, Tracy A; King, Kristen L; Sterk, Joseph P; Huang, Hazel; Chandler, Margaret P; Stanley, William C

    2005-01-01

    A high rate of cardiac work increases citric acid cycle (CAC) turnover and flux through pyruvate dehydrogenase (PDH); however, the mechanisms for these effects are poorly understood. We tested the hypotheses that an increase in cardiac energy expenditure: (1) activates PDH and reduces the product/substrate ratios ([NADH]/[NAD+] and [acetyl-CoA]/[CoA-SH]); and (2) increases the content of CAC intermediates. Measurements were made in anaesthetized pigs under control conditions and during 15 min of a high cardiac workload induced by dobutamine (Dob). A third group was made hyperglycaemic (14 mm) to stimulate flux through PDH during the high work state (Dob + Glu). Glucose and fatty acid oxidation were measured with 14C-glucose and 3H-oleate. Compared with control, the high workload groups had a similar increase in myocardial oxygen consumption ( and cardiac power. Dob increased PDH activity and glucose oxidation above control, but did not reduce the [NADH]/[NAD+] and [acetyl-CoA]/[CoA-SH] ratios, and there were no differences between the Dob and Dob + Glu groups. An additional group was treated with Dob + Glu and oxfenicine (Oxf) to inhibit fatty acid oxidation: this increased [CoA-SH] and glucose oxidation compared with Dob; however, there was no further activation of PDH or decrease in the [NADH]/[NAD+] ratio. Content of the 4-carbon CAC intermediates succinate, fumarate and malate increased 3-fold with Dob, but there was no change in citrate content, and the Dob + Glu and Dob + Glu + Oxf groups were not different from Dob. In conclusion, compared with normal conditions, at high myocardial energy expenditure (1) the increase in flux through PDH is regulated by activation of the enzyme complex and continues to be partially controlled through inhibition by fatty acid oxidation, and (2) there is expansion of the CAC pool size at the level of 4-carbon intermediates that is largely independent of myocardial fatty acid oxidation. PMID:15550462

  4. Conceptual design of closed Brayton cycle for coal-fired power generation

    NASA Technical Reports Server (NTRS)

    Shah, R. P.; Corman, J. C.

    1977-01-01

    The objectives to be realized in developing a closed cycle gas turbine are (1) to exploit high temperature gas turbine technology while maintaining a working fluid which is free from combustion gas contamination, (2) to achieve compact turbo-equipment designs through pressurization of the working fluid, and (3) to obtain relatively simple cycle configurations. The technical/economic performance of a specific closed cycle gas turbine system was evaluated through the development of a conceptual plant and system design. This energy conversion system is designed for electric utility service and to utilize coal directly in an environmentally acceptable manner.

  5. Closed cycle MHD power generation experiments using a helium-cesium working fluid in the NASA Lewis Facility

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.

    1976-01-01

    The MHD channel in the NASA Lewis Research Center was redesigned and used in closed cycle power generation experiments with a helium-cesium working fluid. The cross sectional dimensions of the channel were reduced to 5 by 16.5 cm to allow operation over a variety of conditions. Experiments have been run at temperatures of 1900-2100 K and Mach numbers from 0.3 to 0.55 in argon and 0.2 in helium. Improvements in Hall voltage isolation and seed vaporization techniques have resulted in significant improvements in performance. Typical values obtained with helium are Faraday open circuit voltage 141 V (92% of uBh) at a magnetic field strength of 1.7 T, power outputs of 2.2 kw for tests with 28 electrodes and 2.1 kw for tests with 17 electrodes. Power densities of 0.6 MW/cu m and Hall fields of about 1100 V/m were obtained in the tests with 17 electrodes, representing a factor of 18 improvement over previously reported results. The V-I curves and current distribution data indicate that while near ideal equilibrium performance is obtained under some conditions, no nonequilibrium power has been generated to date.

  6. Evaluation of technical feasibility of closed-cycle non-equilibrium MHD power generation with direct coal firing. Final report, Task I

    SciTech Connect

    Not Available

    1981-11-01

    Program accomplishments in a continuing effort to demonstrate the feasibility of direct coal-fired, closed-cycle MHD power generation are reported. This volume contains the following appendices: (A) user's manual for 2-dimensional MHD generator code (2DEM); (B) performance estimates for a nominal 30 MW argon segmented heater; (C) the feedwater cooled Brayton cycle; (D) application of CCMHD in an industrial cogeneration environment; (E) preliminary design for shell and tube primary heat exchanger; and (F) plant efficiency as a function of output power for open and closed cycle MHD power plants. (WHK)

  7. Life cycle environmental and economic tradeoffs of using fast pyrolysis products for power generation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bio-oils produced from small-scale pyrolysis technology may have economic and environmental benefits for both densifying agricultural biomass and supplying local bio-energy markets (e.g., Renewable Portfolio Standards). This study presents a life cycle assessment (LCA) of a farm-scale bio-oil produ...

  8. A Gradient of ATP Affinities Generates an Asymmetric Power Stroke Driving the Chaperonin TRIC/CCT Folding Cycle

    PubMed Central

    Reissmann, Stefanie; Joachimiak, Lukasz A.; Chen, Bryan; Meyer, Anne S.; Nguyen, Anthony; Frydman, Judith

    2012-01-01

    SUMMARY The eukaryotic chaperonin TRiC/CCT uses ATP cycling to fold many essential proteins that other chaperones cannot fold. This 1 MDa hetero-oligomer consists of two identical stacked rings assembled from eight paralogous subunits, each containing a conserved ATP-binding domain. Here, we report a dramatic asymmetry in the ATP utilization cycle of this ring-shaped chaperonin, despite its apparently symmetric architecture. Only four of the eight different subunits bind ATP at physiological concentrations. ATP binding and hydrolysis by the low-affinity subunits is fully dispensable for TRiC function in vivo. The conserved nucleotide-binding hierarchy among TRiC subunits is evolutionarily modulated through differential nucleoside contacts. Strikingly, high-and low-affinity subunits are spatially segregated within two contiguous hemispheres in the ring, generating an asymmetric power stroke that drives the folding cycle. This unusual mode of ATP utilization likely serves to orchestrate a directional mechanism underlying TRiC/CCT’s unique ability to fold complex eukaryotic proteins. PMID:23041314

  9. A power and load priority control concept as applied to a Brayton cycle turbo-electric generator.

    NASA Technical Reports Server (NTRS)

    Kelsey, E. L.; Young, R. N.

    1972-01-01

    This paper describes a system to regulate the speed and power output of a Brayton Cycle Power System under varying load. A typical user load profile is applied and a simple load priority and parasitic load is used for system regulation. Power storage is provided by batteries with charge and discharge converters to demonstrate support capability. The breadboard system is tested with the Brayton Cycle Demonstrator at the National Aeronautics and Space Administration, Manned Space Craft Center, Houston, Texas.

  10. Closed cycle MHD power generation experiments in the NASA Lewis facility

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.; Nichols, L. D.

    1974-01-01

    Discussion of the performance improvements achieved through some modifications made in the closed cycle MHD facility. These modifications include a redesign of the MHD duct interior, addition of mixing bars, increased electrical isolation, and experimentation with various cesium seed vaporization and injection techniques. Uniform Faraday and Hall voltage profiles were obtained, and the Faraday open circuit voltage varied from 90 to 100% of the ideal uBh.

  11. IMPACTS ON HUMAN HEALTH FROM THE COAL AND NUCLEAR FUEL CYCLES AND OTHER TECHNOLOGIES ASSOCIATED WITH ELECTRIC POWER GENERATION AND TRANSMISSION

    EPA Science Inventory

    The report evaluates major public health impacts of electric power generation and transmission associated with the nuclear fuel cycle and with coal use. Only existing technology is evaluated. For the nuclear cycle, effects of future use of fuel reprocessing and long-term radioact...

  12. Characteristics Evaluation of a CO2-Caputuring Power Generation System with Reheat Cycle Utilizing Regenerative Oxygen-Combustion Steam-Superheater

    NASA Astrophysics Data System (ADS)

    Pak, Pyong Sik

    A new CO2-capturing power generation system is proposed that can be easily realized by applying conventional technologies. In the proposed system, the temperature of middle-pressure steam in a thermal power plant is raised by utilizing oxygen-combusting regenerative steam-superheater. The generated CO2 by combusting fuel in the superheater can be easily separated and captured from the exhaust gas at condenser outlet, and is liquefied. The superheated steam is used to drive a steam turbine power generation system. By adopting a high efficient combined cycle power generation system as an example, it has been shown that the proposed system can increase power output by 10.8%, decrease the CO2 emission amount of the total integrated system by 18.6% with power generation efficiency drop of 2.36% compared with the original power plant without CO2-capture, when superheated steam temperature is 750°C

  13. System Mass Variation and Entropy Generation in 100-kWe Closed-Brayton-Cycle Space Power Systems

    SciTech Connect

    Barrett, Michael J.; Reid, Bryan M.

    2004-02-04

    State-of-the-art closed-Brayton-cycle (CBC) space power systems were modeled to study performance trends in a trade space characteristic of interplanetary orbiters. For working-fluid molar masses of 48.6, 39.9 and 11.9 kg/kmol, peak system pressures of 1.38 and 3.0 MPa and compressor pressure ratios ranging from 1.6 to 2.4, total system masses were estimated. System mass increased as peak operating pressure increased for all compressor pressure ratios and molar mass values examined. Minimum mass point comparison between 72% He at 1.38 MPa peak and 94% He at 3.0 MPa peak showed an increase in system mass of 14%. Converter flow loop entropy generation rates were calculated for 1.38 and 3.0 MPa peak pressure cases. Physical system behavior was approximated using a pedigreed NASA-Glenn modeling code, Closed Cycle Engine Program (CCEP), which included realistic performance prediction for heat exchangers, radiators and turbomachinery.

  14. System Mass Variation and Entropy Generation in 100-kWe Closed-Brayton-Cycle Space Power Systems

    NASA Astrophysics Data System (ADS)

    Barrett, Michael J.; Reid, Bryan M.

    2004-02-01

    State-of-the-art closed-Brayton-cycle (CBC) space power systems were modeled to study performance trends in a trade space characteristic of interplanetary orbiters. For working-fluid molar masses of 48.6, 39.9 and 11.9 kg/kmol, peak system pressures of 1.38 and 3.0 MPa and compressor pressure ratios ranging from 1.6 to 2.4, total system masses were estimated. System mass increased as peak operating pressure increased for all compressor pressure ratios and molar mass values examined. Minimum mass point comparison between 72% He at 1.38 MPa peak and 94% He at 3.0 MPa peak showed an increase in system mass of 14%. Converter flow loop entropy generation rates were calculated for 1.38 and 3.0 MPa peak pressure cases. Physical system behavior was approximated using a pedigreed NASA-Glenn modeling code, Closed Cycle Engine Program (CCEP), which included realistic performance prediction for heat exchangers, radiators and turbomachinery.

  15. System Mass Variation and Entropy Generation in 100-kWe Closed-Brayton-Cycle Space Power Systems

    NASA Technical Reports Server (NTRS)

    Barrett, Michael J.; Reid, Bryan M.

    2004-01-01

    State-of-the-art closed-Brayton-cycle (CBC) space power systems were modeled to study performance trends in a trade space characteristic of interplanetary orbiters. For working-fluid molar masses of 48.6, 39.9, and 11.9 kg/kmol, peak system pressures of 1.38 and 3.0 MPa and compressor pressure ratios ranging from 1.6 to 2.4, total system masses were estimated. System mass increased as peak operating pressure increased for all compressor pressure ratios and molar mass values examined. Minimum mass point comparison between 72 percent He at 1.38 MPa peak and 94 percent He at 3.0 MPa peak showed an increase in system mass of 14 percent. Converter flow loop entropy generation rates were calculated for 1.38 and 3.0 MPa peak pressure cases. Physical system behavior was approximated using a pedigreed NASA Glenn modeling code, Closed Cycle Engine Program (CCEP), which included realistic performance prediction for heat exchangers, radiators and turbomachinery.

  16. System Mass Variation and Entropy Generation in 100k We Closed-Brayton-Cycle Space Power Systems

    NASA Technical Reports Server (NTRS)

    Barrett, Michael J.; Reid, Bryan M.

    2004-01-01

    State-of-the-art closed-Brayton-cycle (CBC) space power systems were modeled to study performance trends in a trade space characteristic of interplanetary orbiters. For working-fluid molar masses of 48.6, 39.9, and 11.9 kg/kmol, peak system pressures of 1.38 and 3.0 MPa and compressor pressure ratios ranging from 1.6 to 2.4, total system masses were estimated. System mass increased as peak operating pressure increased for all compressor pressure ratios and molar mass values examined. Minimum mass point comparison between 72 percent He at 1.38 MPa peak and 94 percent He at 3.0 MPa peak showed an increase in system mass of 14 percent. Converter flow loop entropy generation rates were calculated for 1.38 and 3.0 MPa peak pressure cases. Physical system behavior was approximated using a pedigreed NASA Glenn modeling code, Closed Cycle Engine Program (CCEP), which included realistic performance prediction for heat exchangers, radiators and turbomachinery.

  17. Oscillating fluid power generator

    DOEpatents

    Morris, David C

    2014-02-25

    A system and method for harvesting the kinetic energy of a fluid flow for power generation with a vertically oriented, aerodynamic wing structure comprising one or more airfoil elements pivotably attached to a mast. When activated by the moving fluid stream, the wing structure oscillates back and forth, generating lift first in one direction then in the opposite direction. This oscillating movement is converted to unidirectional rotational movement in order to provide motive power to an electricity generator. Unlike other oscillating devices, this device is designed to harvest the maximum aerodynamic lift forces available for a given oscillation cycle. Because the system is not subjected to the same intense forces and stresses as turbine systems, it can be constructed less expensively, reducing the cost of electricity generation. The system can be grouped in more compact clusters, be less evident in the landscape, and present reduced risk to avian species.

  18. Thermal and environmental characteristics of the primary equipment of the 480-MW Razdan-5 power-generating plant operating as a combined-cycle plant

    NASA Astrophysics Data System (ADS)

    Sargsyan, K. B.; Eritsyan, S. Kh.; Petrosyan, G. S.; Avtandilyan, A. V.; Gevorkyan, A. R.; Klub, M. V.

    2015-01-01

    Results of thermal tests of 480-MW power-generating Unit 5 of Razdan Thermal Power Plant (hereinafter, Razdan-5 power unit) are presented. The tests were carried out by LvivORGRES after an integration trial of the power unit. The aim of the tests was thermal characterization of the steam boiler and the steam turbine when the power unit operates as a combined-cycle plant. The economic efficiency of the boiler and the turbine and the environmental characteristics of the power unit are determined and the calculated and the actual values are compared. The specific heat gross and net rates required for the power unit to generate the electric power are established.

  19. How to quantify uncertainty and variability in life cycle assessment: the case of greenhouse gas emissions of gas power generation in the US

    NASA Astrophysics Data System (ADS)

    Hauck, M.; Steinmann, Z. J. N.; Laurenzi, I. J.; Karuppiah, R.; Huijbregts, M. A. J.

    2014-07-01

    This study quantified the contributions of uncertainty and variability to the range of life-cycle greenhouse gas (LCGHG) emissions associated with conventional gas-fired electricity generation in the US. Whereas uncertainty is defined as lack of knowledge and can potentially be reduced by additional research, variability is an inherent characteristic of supply chains and cannot be reduced without physically modifying the system. The life-cycle included four stages: production, processing, transmission and power generation, and utilized a functional unit of 1 kWh of electricity generated at plant. Technological variability requires analyses of life cycles of individual power plants, e.g. combined cycle plants or boilers. Parameter uncertainty was modeled via Monte Carlo simulation. Our approach reveals that technological differences are the predominant cause for the range of LCGHG emissions associated with gas power, primarily due to variability in plant efficiencies. Uncertainties in model parameters played a minor role for 100 year time horizon. Variability in LCGHG emissions was a factor of 1.4 for combined cycle plants, and a factor of 1.3 for simple cycle plants (95% CI, 100 year horizon). The results can be used to assist decision-makers in assessing factors that contribute to LCGHG emissions despite uncertainties in parameters employed to estimate those emissions.

  20. Geothermal Power Generation

    SciTech Connect

    2007-11-15

    The report provides an overview of the renewed market interest in using geothermal for power generation including a concise look at what's driving interest in geothermal power generation, the current status of geothermal power generation, and plans for the future. Topics covered in the report include: an overview of geothermal power generation including its history, the current market environment, and its future prospects; an analysis of the key business factors that are driving renewed interest in geothermal power generation; an analysis of the challenges that are hindering the implementation of geothermal power generation projects; a description of geothermal power generation technologies; a review of the economic drivers of geothermal power generation project success; profiles of the major geothermal power producing countries; and, profiles of the major geothermal power project developers.

  1. Levelized Power Generation Cost Codes

    Energy Science and Technology Software Center (ESTSC)

    1996-04-30

    LPGC is a set of nine microcomputer programs for estimating power generation costs for large steam-electric power plants. These programs permit rapid evaluation using various sets of economic and technical ground rules. The levelized power generation costs calculated may be used to compare the relative economics of nuclear and coal-fired plants based on life-cycle costs. Cost calculations include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generationmore » cost. These programs can be used for quick analyses of power generation costs using alternative economic parameters, such as interest rate, escalation rate, inflation rate, plant lead times, capacity factor, fuel prices, etc. The two major types of electric generating plants considered are pressurized water reactor (PWR) and pulverized coal-fired plants. Data are also provided for the Large Scale Prototype Breeder (LSPB) type liquid metal reactor.« less

  2. Comparative life cycle assessment of biogas plant configurations for a demand oriented biogas supply for flexible power generation.

    PubMed

    Hahn, Henning; Hartmann, Kilian; Bühle, Lutz; Wachendorf, Michael

    2015-03-01

    The environmental performance of biogas plant configurations for a demand - oriented biogas supply for flexible power generation is comparatively assessed in this study. Those configurations indicate an increased energy demand to operate the operational enhancements compared to conventional biogas plants supplying biogas for baseload power generation. However, findings show that in contrast to an alternative supply of power generators with natural gas, biogas supplied on demand by adapted biogas plant configurations saves greenhouse gas emissions by 54-65 g CO(2-eq) MJ(-1) and primary energy by about 1.17 MJ MJ(-1). In this regard, configurations with flexible biogas production profit from reduced biogas storage requirements and achieve higher savings compared to configurations with continuous biogas production. Using thicker biogas storage sheeting material reduces the methane permeability of up to 6m(3) d(-1) which equals a reduction of 8% of the configuration's total methane emissions. PMID:25553565

  3. Evaluation of technical feasibility of closed-cycle non-equilibrium MHD power generation with direct coal firing. Final report, Task 1

    SciTech Connect

    Not Available

    1981-11-01

    Program accomplishments in a continuing effort to demonstrate the feasibility of direct coal fired, closed cycle, magnetohydrodynamic power generation are detailed. These accomplishments relate to all system aspects of a CCMHD power generation system including coal combustion, heat transfer to the MHD working fluid, MHD power generation, heat and cesium seed recovery and overall systems analysis. Direct coal firing of the combined cycle has been under laboratory development in the form of a high slag rejection, regeneratively air cooled cyclone coal combustor concept, originated within this program. A hot bottom ceramic regenerative heat exchanger system was assembled and test fired with coal for the purposes of evaluating the catalytic effect of alumina on NO/sub x/ emission reduction and operability of the refractory dome support system. Design, procurement, fabrication and partial installation of a heat and seed recovery flow apparatus was accomplished and was based on a stream tube model of the full scale system using full scale temperatures, tube sizes, rates of temperature change and tube geometry. Systems analysis capability was substantially upgraded by the incorporation of a revised systems code, with emphasis on ease of operator interaction as well as separability of component subroutines. The updated code was used in the development of a new plant configuration, the Feedwater Cooled (FCB) Brayton Cycle, which is superior to the CCMHD/Steam cycle both in performance and cost. (WHK)

  4. Life Cycle Greenhouse Gas Emissions of Trough and Tower Concentrating Solar Power Electricity Generation: Systematic Review and Harmonization

    SciTech Connect

    Burkhardt, J. J.; Heath, G.; Cohen, E.

    2012-04-01

    In reviewing life cycle assessment (LCA) literature of utility-scale concentrating solar power (CSP) systems, this analysis focuses on reducing variability and clarifying the central tendency of published estimates of life cycle greenhouse gas (GHG) emissions through a meta-analytical process called harmonization. From 125 references reviewed, 10 produced 36 independent GHG emissions estimates passing screens for quality and relevance: 19 for parabolic trough (trough) technology and 17 for power tower (tower) technology. The interquartile range (IQR) of published estimates for troughs and towers were 83 and 20 grams of carbon dioxide equivalent per kilowatt-hour (g CO2-eq/kWh),1 respectively; median estimates were 26 and 38 g CO2-eq/kWh for trough and tower, respectively. Two levels of harmonization were applied. Light harmonization reduced variability in published estimates by using consistent values for key parameters pertaining to plant design and performance. The IQR and median were reduced by 87% and 17%, respectively, for troughs. For towers, the IQR and median decreased by 33% and 38%, respectively. Next, five trough LCAs reporting detailed life cycle inventories were identified. The variability and central tendency of their estimates are reduced by 91% and 81%, respectively, after light harmonization. By harmonizing these five estimates to consistent values for global warming intensities of materials and expanding system boundaries to consistently include electricity and auxiliary natural gas combustion, variability is reduced by an additional 32% while central tendency increases by 8%. These harmonized values provide useful starting points for policy makers in evaluating life cycle GHG emissions from CSP projects without the requirement to conduct a full LCA for each new project.

  5. MHD Power Generation

    ERIC Educational Resources Information Center

    Kantrowitz, Arthur; Rosa, Richard J.

    1975-01-01

    Explains the operation of the Magnetohydrodynamic (MHD) generator and advantages of the system over coal, oil or nuclear powered generators. Details the development of MHD generators in the United States and Soviet Union. (CP)

  6. Closed cycle MHD power generation experiments using a helium-cesium working fluid in the NASA Lewis Facility

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.

    1976-01-01

    A MHD channel, which was previously operated for over 500 hours of thermal operation, ten thermal cycles, and 200 cesium injection tests, was removed from the facility and redesigned. The cross sectional dimensions of the channel were reduced to 5 by 16.5 cm to allow operation over a variety of conditions. The redesigned channel has been operated for well over 300 hours, 10 thermal cycles, and 150 cesium injection tests with no problems. Experiments have been run at temperatures of 1900-2100 K and Mach numbers from 0.3 to 0.55 in argon and 0.2 in helium. The best results to date have been obtained in the helium tests. Power outputs of 2.2 kw for tests with 28 electrodes and 2.1 kw for tests with 17 electrodes were realized. Power densities of 0.6 MW/cu m and Hall fields of about 1,100 V/m were obtained in the tests with 17 electrodes.

  7. Next Generation Geothermal Power Plants

    SciTech Connect

    Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri

    1995-09-01

    A number of current and prospective power plant concepts were investigated to evaluate their potential to serve as the basis of the next generation geothermal power plant (NGGPP). The NGGPP has been envisaged as a power plant that would be more cost competitive (than current geothermal power plants) with fossil fuel power plants, would efficiently use resources and mitigate the risk of reservoir under-performance, and minimize or eliminate emission of pollutants and consumption of surface and ground water. Power plant concepts were analyzed using resource characteristics at ten different geothermal sites located in the western United States. Concepts were developed into viable power plant processes, capital costs were estimated and levelized busbar costs determined. Thus, the study results should be considered as useful indicators of the commercial viability of the various power plants concepts that were investigated. Broadly, the different power plant concepts that were analyzed in this study fall into the following categories: commercial binary and flash plants, advanced binary plants, advanced flash plants, flash/binary hybrid plants, and fossil/geothed hybrid plants. Commercial binary plants were evaluated using commercial isobutane as a working fluid; both air-cooling and water-cooling were considered. Advanced binary concepts included cycles using synchronous turbine-generators, cycles with metastable expansion, and cycles utilizing mixtures as working fluids. Dual flash steam plants were used as the model for the commercial flash cycle. The following advanced flash concepts were examined: dual flash with rotary separator turbine, dual flash with steam reheater, dual flash with hot water turbine, and subatmospheric flash. Both dual flash and binary cycles were combined with other cycles to develop a number of hybrid cycles: dual flash binary bottoming cycle, dual flash backpressure turbine binary cycle, dual flash gas turbine cycle, and binary gas turbine

  8. An integrated system combining chemical looping hydrogen generation process and solid oxide fuel cell/gas turbine cycle for power production with CO2 capture

    NASA Astrophysics Data System (ADS)

    Chen, Shiyi; Xue, Zhipeng; Wang, Dong; Xiang, Wenguo

    2012-10-01

    In this paper, the solid oxide fuel cell/gas turbine (SOFC/GT) cycle is integrated with coal gasification and chemical looping hydrogen generation (CLHG) for electric power production with CO2 capture. The CLHG-SOFC/GT plant is configurated and the schematic process is modeled using Aspen Plus® software. Syngas, produced by coal gasification, is converted to hydrogen with CO2 separation through a three-reactors CLHG process. Hydrogen is then fueled to SOFC for power generation. The unreacted hydrogen from SOFC burns in a combustor and drives gas turbine. The heat of the gas turbine exhaust stream is recovered in HRSG for steam bottoming cycle. At a system pressure of 20 bar and a cell temperature of 900 °C, the CLHG-SOFC/GT plant has a net power efficiency of 43.53% with no CO2 emissions. The hybrid power plant performance is attractive because of high energy conversion efficiency and zero-CO2-emission. Key parameters that influence the system performance are also discussed, including system operating pressure, cell temperature, fuel utilization factor, steam reactor temperature, CO2 expander exhaust pressure and inlet gas preheating.

  9. SOFC combined cycle systems for distributed generation

    SciTech Connect

    Brown, R.A.

    1997-05-01

    The final phase of the tubular SOFC development program will focus on the development and demonstration of pressurized solid oxide fuel cell (PSOFC)/gas turbine (GT) combined cycle power systems for distributed power applications. The commercial PSOFC/GT product line will cover the power range 200 kWe to 50 MWe, and the electrical efficiency for these systems will range from 60 to 75% (net AC/LHV CH4), the highest of any known fossil fueled power generation technology. The first demonstration of a pressurized solid oxide fuel cell/gas turbine combined cycle will be a proof-of-concept 250 kWe PSOFC/MTG power system consisting of a single 200 kWe PSOFC module and a 50 kWe microturbine generator (MTG). The second demonstration of this combined cycle will be 1.3 MWe fully packaged, commercial prototype PSOFC/GT power system consisting of two 500 kWe PSOFC modules and a 300 kWe gas turbine.

  10. Regenerative Heater Optimization for Steam Turbo-Generation Cycles of Generation IV Nuclear Power Plants with a Comparison of Two Concepts for the Westinghouse International Reactor Innovative and Secure (IRIS)

    SciTech Connect

    Williams, W.C.

    2002-08-01

    The intent of this study is to discuss some of the many factors involved in the development of the design and layout of a steam turbo-generation unit as part of a modular Generation IV nuclear power plant. Of the many factors involved in the design and layout, this research will cover feed water system layout and optimization issues. The research is arranged in hopes that it can be generalized to any Generation IV system which uses a steam powered turbo-generation unit. The research is done using the ORCENT-II heat balance codes and the Salisbury methodology to be reviewed herein. The Salisbury methodology is used on an original cycle design by Famiani for the Westinghouse IRIS and the effects due to parameter variation are studied. The vital parameters of the Salisbury methodology are the incremental heater surface capital cost (S) in $/ft{sup 2}, the value of incremental power (I) in $/kW, and the overall heat transfer coefficient (U) in Btu/ft{sup 2}-degrees Fahrenheit-hr. Each is varied in order to determine the effects on the cycles overall heat rate, output, as well as, the heater surface areas. The effects of each are shown. Then the methodology is then used to compare the optimized original Famiani design consisting of seven regenerative feedwater heaters with an optimized new cycle concept, INRC8, containing four regenerative heaters. The results are shown. It can be seen that a trade between the complexity of the seven stage regenerative Famiani cycle and the simplicity of the INRC8 cycle can be made. It is desired that this methodology can be used to show the ability to evaluate modularity through the value of size a complexity of the system as well as the performance. It also shows the effectiveness of the Salisbury methodology in the optimization of regenerative cycles for such an evaluation.

  11. Wind power generating system

    SciTech Connect

    Schachle, Ch.; Schachle, E. C.; Schachle, J. R.; Schachle, P. J.

    1985-03-12

    Normally feathered propeller blades of a wind power generating system unfeather in response to the actuation of a power cylinder that responds to actuating signals. Once operational, the propellers generate power over a large range of wind velocities. A maximum power generation design point signals a feather response of the propellers so that once the design point is reached no increase in power results, but the system still generates power. At wind speeds below this maximum point, propeller speed and power output optimize to preset values. The propellers drive a positive displacement pump that in turn drives a positive displacement motor of the swash plate type. The displacement of the motor varies depending on the load on the system, with increasing displacement resulting in increasing propeller speeds, and the converse. In the event of dangerous but not clandestine problems developing in the system, a control circuit dumps hydraulic pressure from the unfeathering cylinder resulting in a predetermined, lower operating pressure produced by the pump. In the event that a problem of potentially cladestine consequence arises, the propeller unfeathering cylinder immediately unloads. Upon startup, a bypass around the motor is blocked, applying a pressure across the motor. The motor drives the generator until the generator reaches a predetermined speed whereupon the generator is placed in circuit with a utility grid and permitted to motor up to synchronous speed.

  12. Magnetohydrodynamic power generation

    NASA Technical Reports Server (NTRS)

    Smith, J. L.

    1984-01-01

    Magnetohydrodynamic (MHD) Power Generation is a concise summary of MHD theory, history, and future trends. Results of the major international MHD research projects are discussed. Data from MHD research is included. Economics of initial and operating costs are considered.

  13. Combined cycle power plant incorporating coal gasification

    DOEpatents

    Liljedahl, Gregory N.; Moffat, Bruce K.

    1981-01-01

    A combined cycle power plant incorporating a coal gasifier as the energy source. The gases leaving the coal gasifier pass through a liquid couplant heat exchanger before being used to drive a gas turbine. The exhaust gases of the gas turbine are used to generate both high pressure and low pressure steam for driving a steam turbine, before being exhausted to the atmosphere.

  14. COMPREHENSIVE STANDARDS: THE POWER GENERATION CASE

    EPA Science Inventory

    This study presents an illustrative data base of material quantities and environmental effluents in the fuel cycles for alternative technologies of thermally generated power. The entire fuel cycle for each of the alternative ten technologies is outlined for a representative power...

  15. Low cost space power generation

    NASA Technical Reports Server (NTRS)

    Olsen, Randall B.

    1991-01-01

    The success of this study has given a method of fabricating durable copolymer films without size limitations. Previously, only compression molded samples were durable enough to generate electrical energy. The strengthened specimens are very long lived materials. The lifetime was enhanced at least a factor of 1,300 in full pyroelectric conversion cycle experiments compared with extruded, non-strengthened film. The new techniques proved so successful that the lifetime of the resultant copolymer samples was not fully characterized. The lifetime of these new materials is so long that accelerated tests were devised to probe their durability. After a total of more than 67 million high voltage electrical cycles at 100 C, the electrical properties of a copolymer sample remained stable. The test was terminated without any detectable degradation to allow for other experiments. One must be cautious in extrapolating to power cycle performance, but 67 million electrical cycles correspond to 2 years of pyroelectric cycling at 1 Hz. In another series of experiments at reduced temperature and electrical stress, a specimen survived over one-third of a billion electrical cycles during nearly three months of continuous testing. The radiation-limited lifetimes of the copolymer were shown to range from several years to millions of years for most earth orbits. Thus, the pyroelectric copolymer has become a strong candidate for serious consideration for future spacecraft power supplies.

  16. Peak power ratio generator

    DOEpatents

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  17. Peak power ratio generator

    DOEpatents

    Moyer, Robert D.

    1985-01-01

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  18. Supercritical Brayton Cycle Nuclear Power System Concepts

    SciTech Connect

    Wright, Steven A.

    2007-01-30

    Both the NASA and DOE have programs that are investigating advanced power conversion cycles for planetary surface power on the moon or Mars, and for next generation nuclear power plants on earth. The gas Brayton cycle offers many practical solutions for space nuclear power systems and was selected as the nuclear power system of choice for the NASA Prometheus project. An alternative Brayton cycle that offers high efficiency at a lower reactor coolant outlet temperature is the supercritical Brayton cycle (SCBC). The supercritical cycle is a true Brayton cycle because it uses a single phase fluid with a compressor inlet temperature that is just above the critical point of the fluid. This paper describes the use of a supercritical Brayton cycle that achieves a cycle efficiency of 26.6% with a peak coolant temperature of 750 K and for a compressor inlet temperature of 390 K. The working fluid uses a clear odorless, nontoxic refrigerant C318 perflurocarbon (C4F8) that always operates in the gas phase. This coolant was selected because it has a critical temperature and pressure of 388.38 K and 2.777 MPa. The relatively high critical temperature allows for efficient thermal radiation that keeps the radiator mass small. The SCBC achieves high efficiency because the loop design takes advantage of the non-ideal nature of the coolant equation of state just above the critical point. The lower coolant temperature means that metal fuels, uranium oxide fuels, and uranium zirconium hydride fuels with stainless steel, ferretic steel, or superalloy cladding can be used with little mass penalty or reduction in cycle efficiency. The reactor can use liquid-metal coolants and no high temperature heat exchangers need to be developed. Indirect gas cooling or perhaps even direct gas cooling can be used if the C4F8 coolant is found to be sufficiently radiation tolerant. Other fluids can also be used in the supercritical Brayton cycle including Propane (C3H8, Tcritical = 369 K) and Hexane (C6

  19. Supercritical Brayton Cycle Nuclear Power System Concepts

    NASA Astrophysics Data System (ADS)

    Wright, Steven A.

    2007-01-01

    Both the NASA and DOE have programs that are investigating advanced power conversion cycles for planetary surface power on the moon or Mars, and for next generation nuclear power plants on earth. The gas Brayton cycle offers many practical solutions for space nuclear power systems and was selected as the nuclear power system of choice for the NASA Prometheus project. An alternative Brayton cycle that offers high efficiency at a lower reactor coolant outlet temperature is the supercritical Brayton cycle (SCBC). The supercritical cycle is a true Brayton cycle because it uses a single phase fluid with a compressor inlet temperature that is just above the critical point of the fluid. This paper describes the use of a supercritical Brayton cycle that achieves a cycle efficiency of 26.6% with a peak coolant temperature of 750 K and for a compressor inlet temperature of 390 K. The working fluid uses a clear odorless, nontoxic refrigerant C318 perflurocarbon (C4F8) that always operates in the gas phase. This coolant was selected because it has a critical temperature and pressure of 388.38 K and 2.777 MPa. The relatively high critical temperature allows for efficient thermal radiation that keeps the radiator mass small. The SCBC achieves high efficiency because the loop design takes advantage of the non-ideal nature of the coolant equation of state just above the critical point. The lower coolant temperature means that metal fuels, uranium oxide fuels, and uranium zirconium hydride fuels with stainless steel, ferretic steel, or superalloy cladding can be used with little mass penalty or reduction in cycle efficiency. The reactor can use liquid-metal coolants and no high temperature heat exchangers need to be developed. Indirect gas cooling or perhaps even direct gas cooling can be used if the C4F8 coolant is found to be sufficiently radiation tolerant. Other fluids can also be used in the supercritical Brayton cycle including Propane (C3H8, Tcritical = 369 K) and Hexane (C6

  20. Combined-cycle power tower

    SciTech Connect

    Bohn, M S; Williams, T A; Price, H W

    1994-10-01

    This paper evaluates a new power tower concept that offers significant benefits for commercialization of power tower technology. The concept uses a molten nitrate salt centralreceiver plant to supply heat, in the form of combustion air preheat, to a conventional combined-cycle power plant. The evaluation focused on first commercial plants, examined three plant capacities (31, 100, and 300 MWe), and compared these plants with a solar-only 100-MWe plant and with gas-only combined-cycle plants in the same three capacities. Results of the analysis point to several benefits relative to the solar-only plant including low energy cost for first plants, low capital cost for first plants, reduced risk with respect to business uncertainties, and the potential for new markets. In addition, the concept appears to have minimal technology development requirements. Significantly, the results show that it is possible to build a first plant with this concept that can compete with existing gas-only combined-cycle plants.

  1. Design and calculated performance and cost of the ECAS Phase II open cycle MHD power generation system

    NASA Technical Reports Server (NTRS)

    Harris, L. P.

    1977-01-01

    A 2000 MWe MHD/steam plant for central station applications has been designed and costed as part of the Energy Conversion Alternatives Study (ECAS). This plant is fueled by Illinois No. 6 coal, rejects heat through mechanical draft wet cooling towers, and includes coal processing equipment, seed reprocessing, electrical inversion of the MHD generator output and emission controls to current EPA standards. It yields an estimated overall efficiency of 0.483 (7066 Btu/kWe-hr), a capital cost of $718 per kWe (1975 dollars), and a cost of electricity at 65% capacity factor of 32 mills per kWe-hr. If the assumed life and reliability could be achieved with these performance parameters, the MHD system should prove attractive.

  2. Future trends in power generation cost by power resource

    NASA Astrophysics Data System (ADS)

    1992-08-01

    The Japan Energy Economy Research Institute has been evaluating power generation cost by each power resource every year focusing on nuclear power generation. The Institute is surveying the cost evaluations by power resources in France, Britain and the U.S.A., the nuclear generation advanced nations. The OECD is making power generation cost estimation using a hypothesis which uniforms basically the conditions varying in different member countries. In model power generation cost calculations conducted by the Ministry of International Trade and Industry of Japan, nuclear power generation is the most economical system in any fiscal year. According to recent calculations performed by the Japan Energy Economy Research Institute, the situation is such that it is difficult to distinguish the economical one from others among the power generation systems in terms of generation costs except for thermal power generation. Economic evaluations are given on estimated power generation costs based on construction costs for nuclear and thermal power plants, nuclear fuel cycling cost, and fuel cost data on petroleum, LNG and coal. With regard to the future trends, scenario analyses are made on generation costs, that assume fluctuations in fuel prices and construction costs, the important factors to give economic influence on power generation.

  3. Spectrophotovoltaic orbital power generation

    NASA Technical Reports Server (NTRS)

    Onffroy, J. R.

    1980-01-01

    The feasibilty of a spectrophotovoltaic orbital power generation system that optically concentrates solar energy is demonstrated. A dichroic beam-splitting mirror is used to divide the solar spectrum into two wavebands. Absorption of these wavebands by GaAs and Si solar cell arrays with matched energy bandgaps increases the cell efficiency while decreasing the amount of heat that must be rejected. The projected cost per peak watt if this system is $2.50/W sub p.

  4. Wind power. [electricity generation

    NASA Technical Reports Server (NTRS)

    Savino, J. M.

    1975-01-01

    A historical background on windmill use, the nature of wind, wind conversion system technology and requirements, the economics of wind power and comparisons with alternative systems, data needs, technology development needs, and an implementation plan for wind energy are presented. Considerable progress took place during the 1950's. Most of the modern windmills feature a wind turbine electricity generator located directly at the top of their rotor towers.

  5. High power microwave generator

    DOEpatents

    Ekdahl, C.A.

    1983-12-29

    A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

  6. High power microwave generator

    DOEpatents

    Ekdahl, Carl A.

    1986-01-01

    A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

  7. Waterwheel power generator

    SciTech Connect

    Smith, J.

    1982-08-17

    An electrical power generation system includes a waterwheel contained within a housing enclosure above a water collection compartment, a water discharge nozzle in alignment with the waterwheel, means for delivering water to the discharge nozzle including a pump for returning water from the collection compartment, a portion of the output of the waterwheel being used to drive the pump, wherein the waterwheel includes fin elements having inclined water entrapping flange portions and is supported by means of an adjustable support to maintain the waterwheel dynamically balanced and in alignment with the discharge nozzle.

  8. GEOTHERMAL POWER GENERATION PLANT

    SciTech Connect

    Boyd, Tonya

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196oF resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  9. Power extraction from aeroelastic limit cycle oscillations

    NASA Astrophysics Data System (ADS)

    Dunnmon, J. A.; Stanton, S. C.; Mann, B. P.; Dowell, E. H.

    2011-11-01

    Nonlinear limit cycle oscillations of an aeroelastic energy harvester are exploited for enhanced piezoelectric power generation from aerodynamic flows. Specifically, a flexible beam with piezoelectric laminates is excited by a uniform axial flow field in a manner analogous to a flapping flag such that the system delivers power to an electrical impedance load. Fluid-structure interaction is modeled by augmenting a system of nonlinear equations for an electroelastic beam with a discretized vortex-lattice potential flow model. Experimental results from a prototype aeroelastic energy harvester are also presented. Root mean square electrical power on the order of 2.5 mW was delivered below the flutter boundary of the test apparatus at a comparatively low wind speed of 27 m/s and a chord normalized limit cycle amplitude of 0.33. Moreover, subcritical limit cycles with chord normalized amplitudes of up to 0.46 were observed. Calculations indicate that the system tested here was able to access over 17% of the flow energy to which it was exposed. Methods for designing aeroelastic energy harvesters by exploiting nonlinear aeroelastic phenomena and potential improvements to existing relevant aerodynamic models are also discussed.

  10. Photovoltaic power generation

    NASA Astrophysics Data System (ADS)

    Schwartz, Richard J.

    1993-03-01

    The wide acceptance and utilization of the photovoltaic generation of electrical power depends on our ability to reduce the cost of photovoltaic systems. This, in turn, largely hinges on our ability to decrease the cost of production of solar cells and panels while at the same time increasing their conversion efficiency. A short tutorial on solar cells is followed by a discussion of the types of solar cells that are presently being investigated for cost reduction and efficiency improvement. Many types of cells are under investigation as are a wide range of materials. Impressive efficiency improvements have been achieved for many types of cells that are potentially low cost in large-volume production.

  11. Generation of electrical power

    DOEpatents

    Hursen, Thomas F.; Kolenik, Steven A.; Purdy, David L.

    1976-01-01

    A heat-to-electricity converter is disclosed which includes a radioactive heat source and a thermoelectric element of relatively short overall length capable of delivering a low voltage of the order of a few tenths of a volt. Such a thermoelectric element operates at a higher efficiency than longer higher-voltage elements; for example, elements producing 6 volts. In the generation of required power, thermoelectric element drives a solid-state converter which is controlled by input current rather than input voltage and operates efficiently for a high signal-plus-noise to signal ratio of current. The solid-state converter has the voltage gain necessary to deliver the required voltage at the low input of the thermoelectric element.

  12. High efficiency carbonate fuel cell/turbine hybrid power cycle

    SciTech Connect

    Steinfeld, G.; Maru, H.C.; Sanderson, R.A.

    1996-07-01

    The hybrid power cycle studies were conducted to identify a high efficiency, economically competitive system. A hybrid power cycle which generates power at an LHV efficiency > 70% was identified that includes an atmospheric pressure direct carbonate fuel cell, a gas turbine, and a steam cycle. In this cycle, natural gas fuel is mixed with recycled fuel cell anode exhaust, providing water for reforming fuel. The mixed gas then flows to a direct carbonate fuel cell which generates about 70% of the power. The portion of the anode exhaust which is not recycled is burned and heat transferred through a heat exchanger (HX) to the compressed air from a gas turbine. The heated compressed air is then heated further in the gas turbine burner and expands through the turbine generating 15% of the power. Half the exhaust from the turbine provides air for the anode exhaust burner. All of the turbine exhaust eventually flows through the fuel cell cathodes providing the O2 and CO2 needed in the electrochemical reaction. Exhaust from the cathodes flows to a steam system (heat recovery steam generator, staged steam turbine generating 15% of the cycle power). Simulation of a 200 MW plant with a hybrid power cycle had an LHV efficiency of 72.6%. Power output and efficiency are insensitive to ambient temperature, compared to a gas turbine combined cycle; NOx emissions are 75% lower. Estimated cost of electricity for 200 MW is 46 mills/kWh, which is competitive with combined cycle where fuel cost is > $5.8/MMBTU. Key requirement is HX; in the 200 MW plant studies, a HX operating at 1094 C using high temperature HX technology currently under development by METC for coal gassifiers was assumed. A study of a near term (20 MW) high efficiency direct carbonate fuel cell/turbine hybrid power cycle has also been completed.

  13. Parabolic Trough Organic Rankine Cycle Power Plant

    SciTech Connect

    Canada, S.; Cohen, G.; Cable, R.; Brosseau, D.; Price, H.

    2005-01-01

    Arizona Public Service (APS) is required to generate a portion of its electricity from solar resources in order to satisfy its obligation under the Arizona Environmental Portfolio Standard (EPS). In recent years, APS has installed and operates over 4.5 MWe of fixed, tracking, and concentrating photovoltaic systems to help meet the solar portion of this obligation and to develop an understanding of which solar technologies provide the best cost and performance to meet utility needs. During FY04, APS began construction of a 1-MWe parabolic trough concentrating solar power plant. This plant represents the first parabolic trough plant to begin construction since 1991. The plant will also be the first commercial deployment of the Solargenix parabolic trough collector technology developed under contract to the National Renewable Energy Laboratory (NREL). The plant will use an organic Rankine cycle (ORC) power plant, provided by Ormat. The ORC power plant is much simpler than a conventional steam Rankine cycle power plant and allows unattended operation of the facility.

  14. Thermionic triode generates ac power

    NASA Technical Reports Server (NTRS)

    Kniazzeh, A. G. F.; Scharz, F. C.

    1970-01-01

    Electrostatic grid controls conduction cycle of thermionic diode to convert low dc output voltages to high ac power without undesirable power loss. An ac voltage applied to the grid of this new thermionic triode enables it to convert heat directly into high voltage electrical power.

  15. ZERO EMISSION POWER GENERATION TECHNOLOGY DEVELOPMENT

    SciTech Connect

    Ronald Bischoff; Stephen Doyle

    2005-01-20

    Clean Energy Systems (CES) was previously funded by DOE's ''Vision 21'' program. This program provided a proof-of-concept demonstration that CES' novel gas generator (combustor) enabled production of electrical power from fossil fuels without pollution. CES has used current DOE funding for additional design study exercises which established the utility of the CES-cycle for retrofitting existing power plants for zero-emission operations and for incorporation in zero-emission, ''green field'' power plant concepts. DOE funding also helped define the suitability of existing steam turbine designs for use in the CES-cycle and explored the use of aero-derivative turbines for advanced power plant designs. This work is of interest to the California Energy Commission (CEC) and the Norwegian Ministry of Petroleum & Energy. California's air quality districts have significant non-attainment areas in which CES technology can help. CEC is currently funding a CES-cycle technology demonstration near Bakersfield, CA. The Norwegian government is supporting conceptual studies for a proposed 40 MW zero-emission power plant in Stavager, Norway which would use the CES-cycle. The latter project is called Zero-Emission Norwegian Gas (ZENG). In summary, current engineering studies: (1) supported engineering design of plant subsystems applicable for use with CES-cycle zero-emission power plants, and (2) documented the suitability and availability of steam turbines for use in CES-cycle power plants, with particular relevance to the Norwegian ZENG Project.

  16. Variable pressure power cycle and control system

    DOEpatents

    Goldsberry, Fred L.

    1984-11-27

    A variable pressure power cycle and control system that is adjustable to a variable heat source is disclosed. The power cycle adjusts itself to the heat source so that a minimal temperature difference is maintained between the heat source fluid and the power cycle working fluid, thereby substantially matching the thermodynamic envelope of the power cycle to the thermodynamic envelope of the heat source. Adjustments are made by sensing the inlet temperature of the heat source fluid and then setting a superheated vapor temperature and pressure to achieve a minimum temperature difference between the heat source fluid and the working fluid.

  17. Energy Economic Data Base (EEDB) Program: Phase 9 Update (1987) report, AGCC5-A supplement: Advanced gas turbine combined cycle (natural gas based) power generating station

    SciTech Connect

    Not Available

    1989-05-01

    The purpose of this AGCC5-A supplement is to identify direct equipment, material and labor costs, and indirect costs in sufficient detail to be used as a baseline for comparing the costs of combined-cycle gas-fired power plants with the costs of alternatives. This information is needed to satisfy the cost evaluation requirements of the Oak Ridge National Laboratory (ORNL) and the US Department of Energy (DOE). 11 refs., 9 figs., 15 tabs.

  18. Apparatus and methods of reheating gas turbine cooling steam and high pressure steam turbine exhaust in a combined cycle power generating system

    DOEpatents

    Tomlinson, Leroy Omar; Smith, Raub Warfield

    2002-01-01

    In a combined cycle system having a multi-pressure heat recovery steam generator, a gas turbine and steam turbine, steam for cooling gas turbine components is supplied from the intermediate pressure section of the heat recovery steam generator supplemented by a portion of the steam exhausting from the HP section of the steam turbine, steam from the gas turbine cooling cycle and the exhaust from the HP section of the steam turbine are combined for flow through a reheat section of the HRSG. The reheated steam is supplied to the IP section inlet of the steam turbine. Thus, where gas turbine cooling steam temperature is lower than optimum, a net improvement in performance is achieved by flowing the cooling steam exhausting from the gas turbine and the exhaust steam from the high pressure section of the steam turbine in series through the reheater of the HRSG for applying steam at optimum temperature to the IP section of the steam turbine.

  19. Unalaska geothermal exploration project. Electrical power generation analysis. Final report

    SciTech Connect

    Not Available

    1984-04-01

    The objective of this study was to determine the most cost-effective power cycle for utilizing the Makushin Volcano geothermal resource to generate electricity for the towns of Unalaska and Dutch Harbor. It is anticipated that the geothermal power plant would be intertied with a planned conventional power plant consisting of four 2.5 MW diesel-generators whose commercial operation is due to begin in 1987. Upon its completion in late 1988, the geothermal power plant would primarily fulfill base-load electrical power demand while the diesel-generators would provide peak-load electrical power and emergency power at times when the geothermal power plant would be partially or completely unavailable. This study compares the technical, environmental, and economic adequacy of five state-of-the-art geothermal power conversion processes. Options considered are single- and double-flash steam cycles, binary cycle, hybrid cycle, and total flow cycle.

  20. Closed cycle osmotic power plants for electric power production

    NASA Astrophysics Data System (ADS)

    Reali, M.

    1980-04-01

    The paper deals with closed-cycle osmotic power plants (CCOPPs), which are not meant for the exploitation of natural salinity gradients but, rather, for the exploitation of those abundant heat sources having temperatures slightly higher than ambient temperature, e.g., geothermal fields, ocean temperature gradients, waste heat from power plants, and solar energy. The paper gives a general description of the CCOPP, along with some indications of its potential for energy generation. The concept of the CCOPP lies in producing electric power by means of the osmotic flows of suitable solvents and subsequently in separating them again from their solutes by means of thermal energy obtained from any available heat source. The discussion covers osmotic phenomena and the CCOPP, as well as important features of the CCOPP.

  1. Electrochemical power generator

    SciTech Connect

    Shirogami, T.; Ueno, M.

    1985-05-07

    An electrochemical power generator is disclosed which is composed of a plurality of unit cells stacked with interconnectors interposed therebetween; said unit cells being each composed of an anode consisting of a porous carbon plate having on its one surface a plurality of grooves constituting gas passages and on its other surface an anode catalyst layer; a cathode formed on its one surface with a cathode catalyst layer and applied on its other surface a hydrophobic material powder consisting of fluoropolymer resin; and an electrolyte layer interposed between the anode and the cathode in such a manner that its two surfaces are allowed to come into contact, respectively; said anode catalyst layer and said cathode catalyst layer, the electrolyte layer being prepared by causing an acidic electrolyte to be impregnated into an inorganic compound powder having heat resistance and chemical resistance; the interconnectors being each compressed of a high density carbon plate and having, on each surface coming into contact with the cathode, a plurality of grooves for gas passages, being used as an anode-active material, of a gas consisting mainly of hydrogen and, as a cathode-active material, of an oxidizing gas. First ribs and second ribs wider than said first ribs are formed between adjacent ones of the grooves of the anode substrate, and a catalyst is dispersed in the cathode substrate over a range extending from a boundary between a surface of contact of the cathode substrate with the cathode catalyst layer up to a point located inside the cathode substrate.

  2. Power enhancement of the Brayton cycle by steam utilization

    NASA Astrophysics Data System (ADS)

    Jesionek, Krzysztof; Chrzczonowski, Andrzej; Ziółkowski, Paweł; Badur, Janusz

    2012-09-01

    The paper presents thermodynamic analysis of the gas-steam unit of the 65 MWe combined heat and power station. Numerical analyses of the station was performed for the nominal operation conditions determining the Brayton and combined cycle. Furthermore, steam utilization for the gas turbine propulsion in the Cheng cycle was analysed. In the considered modernization, steam generated in the heat recovery steam generator unit is directed into the gas turbine combustion chamber, resulting in the Brayton cycle power increase. Computational flow mechanics codes were used in the analysis of the thermodynamic and operational parameters of the unit.

  3. Method and apparatus for thermal power generation

    DOEpatents

    Mangus, James D.

    1979-01-01

    A method and apparatus for power generation from a recirculating superheat-reheat circuit with multiple expansion stages which alleviates complex control systems and minimizes thermal cycling of system components, particularly the reheater. The invention includes preheating cold reheat fluid from the first expansion stage prior to its entering the reheater with fluid from the evaporator or drum component.

  4. Solar thermal organic rankine cycle for micro-generation

    NASA Astrophysics Data System (ADS)

    Alkahli, N. A.; Abdullah, H.; Darus, A. N.; Jalaludin, A. F.

    2012-06-01

    The conceptual design of an Organic Rankine Cycle (ORC) driven by solar thermal energy is developed for the decentralized production of electricity of up to 50 kW. Conventional Rankine Cycle uses water as the working fluid whereas ORC uses organic compound as the working fluid and it is particularly suitable for low temperature applications. The ORC and the solar collector will be sized according to the solar flux distribution in the Republic of Yemen for the required power output of 50 kW. This will be a micro power generation system that consists of two cycles, the solar thermal cycle that harness solar energy and the power cycle, which is the ORC that generates electricity. As for the solar thermal cycle, heat transfer fluid (HTF) circulates the cycle while absorbing thermal energy from the sun through a parabolic trough collector and then storing it in a thermal storage to increase system efficiency and maintains system operation during low radiation. The heat is then transferred to the organic fluid in the ORC via a heat exchanger. The organic fluids to be used and analyzed in the ORC are hydrocarbons R600a and R290.

  5. Advanced Coal-Based Power Generations

    NASA Technical Reports Server (NTRS)

    Robson, F. L.

    1982-01-01

    Advanced power-generation systems using coal-derived fuels are evaluated in two-volume report. Report considers fuel cells, combined gas- and steam-turbine cycles, and magnetohydrodynamic (MHD) energy conversion. Presents technological status of each type of system and analyzes performance of each operating on medium-Btu fuel gas, either delivered via pipeline to powerplant or generated by coal-gasification process at plantsite.

  6. A comparison of humid air turbine (HAT) cycle and combined-cycle power plants

    SciTech Connect

    Rao, A.D.; Francuz, V.J.; Shen, J.C.; West, E.W. )

    1991-03-01

    The Humid Air Turbine (HAT) cycle is a combustion turbine-based power generating cycle that provides an alternative to combined-cycle power generation. The HAT cycle differs from combined cycles in that it eliminates the steam turbine bottoming cycle by vaporizing water into the turbine's combustion air with heat obtained from the combustion turbine exhaust and other heat sources. This report presents the results of a study conducted by Fluor Daniel, Inc. for EPRI in which the HAT cycle was compared with combined-cycle plants in integration with the Texaco coal gasification process, and in natural gas-fired plants. The comparison of the coal gasification-based power plants utilizing the HAT cycle with Texaco coal gasification-based combined-cycle plants indicate that HAT cycle-based plants are less expensive and produce less environmental emissions. Whereas the combined-cycle plants require the use of expensive syngas coolers to achieve high efficiencies, the HAT cycle plants can achieve similar high efficiencies without the use of such equipment, resulting in a significant savings in capital cost and a reduction in levelized cost of electricity of up to 15%. In addition, HAT cycle plants produce very low levels of NO{sub x} emissions, possibly as little as 6 ppmv (dry, 15% O{sub 2} basis) without requiring the use of control technologies such as selective catalytic reduction. In natural gas-fired plants, the HAT cycle was calculated to have as much as a 4 percentage point gain in efficiency over the combined cycle and a potential for substantial reductions in NO{sub x} emissions, CO{sub 2} emissions, and water consumption. 71 figs., 74 tabs.

  7. Power generation systems and methods

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor); Chao, Yi (Inventor)

    2011-01-01

    A power generation system includes a plurality of submerged mechanical devices. Each device includes a pump that can be powered, in operation, by mechanical energy to output a pressurized output liquid flow in a conduit. Main output conduits are connected with the device conduits to combine pressurized output flows output from the submerged mechanical devices into a lower number of pressurized flows. These flows are delivered to a location remote of the submerged mechanical devices for power generation.

  8. Low chemical concentrating steam generating cycle

    DOEpatents

    Mangus, James D.

    1983-01-01

    A steam cycle for a nuclear power plant having two optional modes of operation. A once-through mode of operation uses direct feed of coolant water to an evaporator avoiding excessive chemical concentration buildup. A recirculation mode of operation uses a recirculation loop to direct a portion of flow from the evaporator back through the evaporator to effectively increase evaporator flow.

  9. LIFE CYCLE ASSESSMENT OF ELECTRICITY GENERATION ALTERNATIVES

    EPA Science Inventory

    This presentation summarizes various electricity and electricity/steam cogeneration alternatives. Among these alternatives, are fossil fuel and biomass power generation plants. These plants have different designs due to the need in fossil fuel (coal) plants to include process u...

  10. Spectrophotovoltaic orbital power generation

    NASA Technical Reports Server (NTRS)

    Knowles, G.; Carroll, J.

    1983-01-01

    A subscale model of a photovoltaic power system employing spectral splitting and 1000:1 concentration was fabricated and tested. The 10-in. aperture model demonstrated 15.5% efficiency with 86% of the energy produced by a GaAs solar cell and 14% of the energy produced by an Si cell. The calculated efficiency of the system using the same solar cells, but having perfect optics, would be approximately 20%. The model design, component measurements, test results, and mathematical model are presented.

  11. High power microwave generator

    SciTech Connect

    Minich, Roger W.

    1988-01-01

    A device (10) for producing high-powered and coherent microwaves is described. The device comprises an evacuated, cylindrical, and hollow real cathode (20) that is driven to inwardly field emit relativistic electrons. The electrons pass through an internally disposed cylindrical and substantially electron-transparent cylindrical anode (24), proceed toward a cylindrical electron collector electrode (26), and form a cylindrical virtual cathode (32). Microwaves are produced by spatial and temporal oscillations of the cylindrical virtual cathode (32), and by electrons that reflex back and forth between the cylindrical virtual cathode (32) and the cylindrical real cathode (20).

  12. Comparative analysis of CCMHD power plants. [Closed Cycle MHD

    NASA Technical Reports Server (NTRS)

    Alyea, F. N.; Marston, C. H.; Mantri, V. B.; Geisendorfer, B. G.; Doss, H.

    1981-01-01

    A study of Closed Cycle MHD (CCMHD) power generation systems has been conducted which emphasizes both advances in component conceptual design and overall system performance. New design data are presented for the high temperature, regenerative argon heaters (HTRH) and the heat recovery/seed recovery (HRSR) subsystem. Contamination of the argon by flue gas adsorbed in the HTRH is examined and a model for estimation of contamination effects in operating systems is developed. System performance and cost data have been developed for the standard CCMHD/steam cycle as powered by both direct fired cyclone combustors and selected coal gasifiers. In addition, a new CCMHD thermodynamic cycle has been identified.

  13. Spin Seebeck power generators

    SciTech Connect

    Cahaya, Adam B.; Tretiakov, O. A.; Bauer, Gerrit E. W.

    2014-01-27

    We derive expressions for the efficiency and figure of merit of two spin caloritronic devices based on the spin Seebeck effect (SSE), i.e., the generation of spin currents by a temperature gradient. The inverse spin Hall effect is conventionally used to detect the SSE and offers advantages for large area applications. We also propose a device that converts spin current into electric one by means of a spin-valve detector, which scales favorably to small sizes and approaches a figure of merit of 0.5 at room temperature.

  14. Power Systems Life Cycle Analysis Tool (Power L-CAT).

    SciTech Connect

    Andruski, Joel; Drennen, Thomas E.

    2011-01-01

    The Power Systems L-CAT is a high-level dynamic model that calculates levelized production costs and tracks environmental performance for a range of electricity generation technologies: natural gas combined cycle (using either imported (LNGCC) or domestic natural gas (NGCC)), integrated gasification combined cycle (IGCC), supercritical pulverized coal (SCPC), existing pulverized coal (EXPC), nuclear, and wind. All of the fossil fuel technologies also include an option for including carbon capture and sequestration technologies (CCS). The model allows for quick sensitivity analysis on key technical and financial assumptions, such as: capital, O&M, and fuel costs; interest rates; construction time; heat rates; taxes; depreciation; and capacity factors. The fossil fuel options are based on detailed life cycle analysis reports conducted by the National Energy Technology Laboratory (NETL). For each of these technologies, NETL's detailed LCAs include consideration of five stages associated with energy production: raw material acquisition (RMA), raw material transport (RMT), energy conversion facility (ECF), product transportation and distribution (PT&D), and end user electricity consumption. The goal of the NETL studies is to compare existing and future fossil fuel technology options using a cradle-to-grave analysis. The NETL reports consider constant dollar levelized cost of delivered electricity, total plant costs, greenhouse gas emissions, criteria air pollutants, mercury (Hg) and ammonia (NH3) emissions, water withdrawal and consumption, and land use (acreage).

  15. Solar power generating system

    SciTech Connect

    Watson, J.C.

    1981-08-18

    A volatile liquid is circulated through a normally closed circuit, including expansion tubes within an expansion chamber where the sun's rays are focused on the tubes to heat the liquid, transforming it to an expanding gas to drive a fluid-operated motor, also in the circuit. The motor may drive a mechanical load or an electric generator. The generator drives a pump which compresses the gas back to a liquid state and returns the same to a reservoir and to the inlets of the expansion tubes in the expansion chamber. An air reservoir which is pressurized by a pump driven by the fluid operated motor has its outlet connected to the motor inlet so that during periods of darkness or cloud cover in which the volatile liquid is not expanded into a gas, the pressurized air will be automatically fed into the motor to continue to drive the same. A gimbal system automatically controlled by sun tracking devices supports the expansion chamber to continually focus the sun's rays onto the expansion tubes, regardless of the relative position of the sun and the base on which the gimbal system is mounted.

  16. Wind Power Charged Aerosol Generator

    SciTech Connect

    Marks, A.M.

    1980-07-01

    This describes experimental results on a Charged Aerosol Wind/Electric Power Generator, using Induction Electric Charging with a water jet issuing under water pressure from a small diameter (25-100 ..mu..m) orifice.

  17. Tide operated power generating apparatus

    SciTech Connect

    Kertzman, H. Z.

    1981-02-03

    An improved tide operated power generating apparatus is disclosed in which a hollow float, rising and falling with the ocean tide, transmits energy to a power generator. The improvement comprises means for filling the float with water during the incoming tide to provide a substantial increase in the float dead weight during the outgoing tide. Means are further provided to then empty the float before the outgoing tide whereby the float becomes free to rise again on the next incoming tide.

  18. Carbon Cycling with Nuclear Power

    NASA Astrophysics Data System (ADS)

    Lackner, Klaus S.

    2011-11-01

    Liquid hydrocarbon fuels like gasoline, diesel or jet fuel are the most efficient ways of delivering energy to the transportation sector, in particular cars, ships and airplanes. Unfortunately, their use nearly unavoidably leads to the emission of carbon dioxide into the atmosphere. Unless an equivalent amount is removed from the air, the carbon dioxide will accumulate and significantly contribute to the man-made greenhouse effect. If fuels are made from biomass, the capture of carbon dioxide is a natural part of the cycle. Here, we discuss technical options for capturing carbon dioxide at much faster rates. We outline the basic concepts, discuss how such capture technologies could be made affordable and show how they could be integrated into a larger system approach. In the short term, the likely source of the hydrocarbon fuels is oil or gas; in the longer term, technologies that can provide energy to remove oxygen from carbon dioxide and water molecules and combine the remaining components into liquid fuels make it possible to recycle carbon between fuels and carbon dioxide in an entirely abiotic process. Here we focus on renewable and nuclear energy options for producing liquid fuels and show how air capture combined with fuel synthesis could be more economic than a transition to electric cars or hydrogen-fueled cars.

  19. Generation of Single-Cycle Light Pulses

    SciTech Connect

    Stuart, B C; Jovanovic, I; Armstrong, J P; Pyke, B; Crane, J K; Shuttlesworth, R

    2004-02-13

    Most optical pulses, even at the 10-femtosecond timescale, consist of several oscillations of the electric field. By producing and amplifying an ultra-broadband continuum, single cycle (e 3 fs) or shorter optical pulses may be generated. This requires a very challenging pulse-compression with sub-femtosecond accuracy. Production of these single-cycle pulses will lead to new generations of experiments in the areas of coherent control of chemical excitations and reactions, 0.1-fs high-order harmonic (XUV) generation for probing of materials and fast processes, and selective 3-D micron-scale material removal and modification. We activated the first stage of a planned three-stage optical parametric amplifier (OPA) that would ultimately produce sub-3 fs pulses. Active control with a learning algorithm was implemented to optimize the continuum generated in an argon-filled capillary and to control and optimize the final compressed pulse temporal shape. A collaboration was initiated to coherently control the population of different states upon dissociation of Rb{sub 2}. Except for one final optic, a pulse compressor and diagnostics were constructed to produce and characterize pulses in the 5-fs range from the first OPA stage.

  20. Taming power: Generative historical consciousness.

    PubMed

    Winter, David G

    2016-04-01

    Power is a necessary dimension of all human enterprises. It can inspire and illuminate, but it can also corrupt, oppress, and destroy. Therefore, taming power has been a central moral and political question for most of human history. Writers, theorists, and researchers have suggested many methods and mechanisms for taming power: through affiliation and love, intellect and reason, responsibility, religion and values, democratic political structures, and separation of powers. Historical examples and social science research suggest that each has some success, but also that each is vulnerable to being hijacked by power itself. I therefore introduce generative historical consciousness (GHC) as a concept and measure that might help to secure the benefits of power while protecting against its outrages and excesses. I conclude by discussing the role that GHC may have played in the peaceful resolution of the Cuban Missile Crisis of 1962. PMID:26011649

  1. Computational tool for simulation of power and refrigeration cycles

    NASA Astrophysics Data System (ADS)

    Córdoba Tuta, E.; Reyes Orozco, M.

    2016-07-01

    Small improvement in thermal efficiency of power cycles brings huge cost savings in the production of electricity, for that reason have a tool for simulation of power cycles allows modeling the optimal changes for a best performance. There is also a big boom in research Organic Rankine Cycle (ORC), which aims to get electricity at low power through cogeneration, in which the working fluid is usually a refrigerant. A tool to design the elements of an ORC cycle and the selection of the working fluid would be helpful, because sources of heat from cogeneration are very different and in each case would be a custom design. In this work the development of a multiplatform software for the simulation of power cycles and refrigeration, which was implemented in the C ++ language and includes a graphical interface which was developed using multiplatform environment Qt and runs on operating systems Windows and Linux. The tool allows the design of custom power cycles, selection the type of fluid (thermodynamic properties are calculated through CoolProp library), calculate the plant efficiency, identify the fractions of flow in each branch and finally generates a report very educational in pdf format via the LaTeX tool.

  2. Solid state pulsed power generator

    SciTech Connect

    Tao, Fengfeng; Saddoughi, Seyed Gholamali; Herbon, John Thomas

    2014-02-11

    A power generator includes one or more full bridge inverter modules coupled to a semiconductor opening switch (SOS) through an inductive resonant branch. Each module includes a plurality of switches that are switched in a fashion causing the one or more full bridge inverter modules to drive the semiconductor opening switch SOS through the resonant circuit to generate pulses to a load connected in parallel with the SOS.

  3. Comparison of geothermal power conversion cycles

    NASA Technical Reports Server (NTRS)

    Elliott, D. G.

    1976-01-01

    Geothermal power conversion cycles are compared with respect to recovery of the available wellhead power. The cycles compared are flash steam, in which steam turbines are driven by steam separated from one or more flash stages; binary, in which heat is transferred from the brine to an organic turbine cycle; flash binary, in which heat is transferred from flashed steam to an organic turbine cycle; and dual steam, in which two-phase expanders are driven by the flashing steam-brine mixture and steam turbines by the separated steam. Expander efficiencies assumed are 0.7 for steam turbines, 0.8 for organic turbines, and 0.6 for two-phase expanders. The fraction of available wellhead power delivered by each cycle is found to be about the same at all brine temperatures: 0.65 with one stage and 0.7 with four stages for dual stream; 0.4 with one stage and 0.6 with four stages for flash steam; 0.5 for binary; and 0.3 with one stage and 0.5 with four stages for flash binary.

  4. The Fourth Generation of Nuclear Power

    SciTech Connect

    Lake, James Alan

    2000-11-01

    The outlook for nuclear power in the U.S. is currently very bright. The economics, operations and safety performance of U.S. nuclear power plants is excellent. In addition, both the safety and economic regulation of nuclear power are being changed to produce better economic parameters for future nuclear plant operations and the licenses for plant operations are being extended to 60 years. There is further a growing awareness of the value of clean, emissions-free nuclear power. These parameters combine to form a firm foundation for continued successful U.S. nuclear plant operations, and even the potential In order to realize a bright future for nuclear power, we must respond successfully to five challenges: • Nuclear power must remain economically competitive, • The public must remain confident in the safety of the plants and the fuel cycle. • Nuclear wastes and spent fuel must be managed and the ultimate disposition pathways for nuclear wastes must be politically settled. • The proliferation potential of the commercial nuclear fuel cycle must continue to be minimized, and • We must assure a sustained manpower supply for the future and preserve the critical nuclear technology infrastructure. The Generation IV program is conceived to focus the efforts of the international nuclear community on responding to these challenges.

  5. Status of the integrated topping cycle and MHD generator testing

    SciTech Connect

    Pian, C.C.P.; Dunton, A.W.; Schmitt, E.W.; Morrison, D.J.

    1993-12-31

    The status of the Integrated Topping Cycle (ITC) MHD generator testing is presented. This generator is part of a 50 MW{sub t} prototypic powertrain that is currently undergoing proof-of-concept (POC) testing at the U.S. Department of Energy`s Component Development and Integration Facility in Butte, Montana. Test objectives are to establish component lifetimes at prototypic operating conditions and to verify the design performance parameters. The ITC generator has completed Design Verification Testing and is now well into the POC duration test. To date (May 1, 1993), over 360 hours of the planned 1000 hours of testing has been completed. Generator testing is being performed at conditions representative of commercial power plant operating conditions. Prototypic generator channel hardware is performing very well. Based on test results obtained thus far, the prognosis is excellent for meeting all of the POC test objectives.

  6. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    SciTech Connect

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  7. Coal Gasification for Power Generation, 3. edition

    SciTech Connect

    2007-11-15

    The report provides a concise look at the challenges faced by coal-fired generation, the ability of coal gasification to address these challenges, and the current state of IGCC power generation. Topics covered include: an overview of Coal Generation including its history, the current market environment, and the status of coal gasification; a description of gasification technology including processes and systems; an analysis of the key business factors that are driving increased interest in coal gasification; an analysis of the barriers that are hindering the implementation of coal gasification projects; a discussion of Integrated Gasification Combined Cycle (IGCC) technology; an evaluation of IGCC versus other generation technologies; a discussion of IGCC project development options; a discussion of the key government initiatives supporting IGCC development; profiles of the key gasification technology companies participating in the IGCC market; and, a detailed description of existing and planned coal IGCC projects.

  8. Results of the integrated topping cycle MHD generator testing

    SciTech Connect

    Pian, C.C.P.; Schmitt, E.W.

    1994-12-31

    The results of the Integrated Topping Cycle (ITC) MHD generator tests are presented. This generator is part of a 50 MW{sub t} prototypic powertrain which recently completed proof-of-concept (POC) testing at the U.S. Department of Energy`s Component Development and Integration Facility (CDIF) in Butte, Montana. POC duration testing was carried out at conditions representative of commercial power plant operation, in order to establish component lifetimes and to verify the design performance parameters. Over 500 hours of thermal and power testing was cumulated with the generator hardware before the program funding was terminated. A summary of the MHD generator performance characteristics and hardware evaluations is provided in the paper. A summary of the generator performance throughout the POC test series is presented. Included are comparisons of: (1) plasma electrical conductivities measured early in the Design Verification Test series and during the POC series, (2) measured generator performance with analytical predictions, and (3) internal wall leakage characteristics of the generator channel with and without iron oxide addition. The performance requirement of the ITC program, i.e., the demonstration of 1.5 MW{sub e} power output, was easily achieved. The ITC generator channel, nozzle, and diffuser accumulated more than 300 hours at nominal power conditions. The prototypic hardware performed well throughout the POC test series. Some problems did arise during the tests. but they were not life-threatening to the MHD generator. Corrective measures were implemented; they will be discussed in the full paper. The physical condition of the overall generator channel at the end of POC tests is good.

  9. Optimized working conditions for a thermoelectric generator as a topping cycle for gas turbines

    NASA Astrophysics Data System (ADS)

    Brady Knowles, C.; Lee, Hohyun

    2012-10-01

    This paper presents a model for a theoretical maximum efficiency of a thermoelectric generator integrated with a Brayton-cycle engine. The thermoelectric cycle is presented in two configurations as a topping cycle and a preheating topping cycle. For the topping cycle configuration, the thermoelectric generator receives heat from a high-temperature heat source and produces electrical work before rejecting heat to a Brayton cycle. For the preheating topping cycle, the rejected heat from the thermoelectric generator partially heats the compressed working fluid of the Brayton cycle before a secondary heater delivers heat to the working fluid directly from the heat source. The thermoelectric topping cycle efficiency increases as the temperature difference between the hot- and cold-side increases; however, this limits the heat transfer possible to the Brayton cycle, which in turn reduces power generation from the Brayton cycle. This model identifies the optimum operating parameters of the thermoelectric and Brayton cycles to obtain the maximum thermal efficiency of the combined cycle. In both configurations, efficiency gains are larger at low-temperature Brayton cycles. Although a thermoelectric generator (TEG) topping cycle enhances efficiency for a low temperature turbine, efficiency cannot exceed a high temperature gas turbine. Using a TEG topping cycle is limited to cases when space or price for a high temperature turbine cannot be justified. A design to achieve the preheating thermoelectric topping cycle is also presented.

  10. Gas Core Reactor with Magnetohydrodynamic Power System and Cascading Power Cycle

    SciTech Connect

    Smith, Blair M.; Anghaie, Samim

    2004-03-15

    The U.S. Department of Energy initiative Generation IV aim is to produce an entire nuclear energy production system with next-generation features for certification before 2030. A Generation IV-capable system must have superior sustainability, safety and reliability, and economic cost advantages in comparison with third generation light water reactors (LWRs). A gas core reactor (GCR) with magnetohydrodynamic (MHD) power converter and cascading power cycle forms the basis for a Generation IV concept that is expected to set the upper performance limits in sustainability and power conversion efficiency among all existing and proposed fission powered systems. A gaseous core reactor delivering thousands of megawatt fission power acts as the heat source for a high-temperature MHD power converter. A uranium tetrafluoride fuel mix, with {approx}95% mol fraction helium gas, provides a stable working fluid for the primary MHD Brayton cycle. The hot working fluid exiting a topping cycle MHD generator has sufficient heat to drive a conventional helium Brayton cycle with 35% thermal efficiency as well as a superheated steam Rankine cycle, with up to 40% efficiency, which recovers the waste heat from the intermediate Brayton cycle. A combined cycle efficiency of close to 70% can be achieved with only a modest MHD topping cycle efficiency. The high-temperature direct-energy conversion capability of an MHD dynamo combined with an already sophisticated steam-powered turbine industry knowledge base allows the cascading cycle design to achieve breakthrough first-law energy efficiencies previously unheard of in the nuclear power industry. Although simple in concept, the gas core reactor design has not achieved the state of technological maturity that established high-temperature gas-cooled reactors and high-temperature molten salt core reactors have pioneered. However, the GCR-MHD concept has considerable promise; for example, like molten salt reactors the fuel is continuously cycled

  11. Gas Core Reactor-MHD Power System with Cascading Power Cycle

    SciTech Connect

    Smith, Blair M.; Anghaie, Samim; Knight, Travis W.

    2002-07-01

    The US Department of Energy initiative Gen-IV aim is to produce an entire nuclear energy production system with next generation features for certification before 2030. A Generation 4 capable system must have superior sustainability, safety and reliability, and economic cost advantages in comparison with third generation light water reactors. A gas core reactor (GCR) with magnetohydrodynamic (MHD) power converter and cascading power cycle forms the basis for a Generation IV concept that is expected to set the upper performance limits in sustainability and power conversion efficiency among all existing and proposed fission powered systems. A gaseous core reactor delivering 1000's MW fission power acts as the heat source for a high temperature magnetohydrodynamic power converter. A uranium tetrafluoride fuel mix, with {approx}95% mole fraction helium gas, provides a stable working fluid for the primary MHD-Brayton cycle. A helium Brayton cycle extracts waste heat from the MHD generator with about 20% energy efficiency, but the low temperature side is still hot enough ({approx}1600 K) to drive a second conventional helium Brayton cycle with about 35% efficiency. There is enough heat at the low temperature side of the He-Brayton cycle to generate steam, and so another heat recovery cycle can be added, this time a Rankine steam cycle with up to 40% efficiency. The proof of concept does not require a tremendously efficient (first law) MHD cycle, the high temperature direct energy conversion capability of an MHD dynamo, combined with already sophisticated steam powered turbine industry knowledge base allows the cascading cycle design to achieve break-through first law energy efficiencies previously unheard of in the nuclear power industry. Although simple in concept, the gas core reactor design has not achieved the state of technological maturity that, say, molten salt or high-temperature gas-cooled reactors have pioneered. However, even on paper the GCR-MHD concept holds

  12. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Transient test cycle generation. 86...) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate Exhaust Test Procedures § 86.1333-90 Transient test cycle generation. (a) The heavy-duty transient engine cycles for...

  13. Desalination apparatus with power generation

    SciTech Connect

    Humiston, G.F.

    1981-11-24

    An apparatus for desalinating ocean waters by distillation and furnishing electrical power, utilizes an evaporator, barometric leg conduits, a closed condenser, ocean water circulating circuits for circulating warm surface water to the evaporator and cool ocean water to the condenser and using the mass flow of vapors evolved from the evaporator to drive a prime mover which in turn drives an electrical generator. A portion of the electrical power so-generated is used to control the operation of respective pumps and valves in the apparatus. The liquid level of the condensate water is controlled in a barometric leg condensate outlet conduit. The system is also provided with a vacuum pump at least for initiating a reduced pressure and particle separator channel means is provided to prevent liquid entrainment in the condenser.

  14. Clean power generation from coal

    SciTech Connect

    Butler, J.W.; Basu, P.

    2007-09-15

    The chapter gives an overview of power generation from coal, describing its environmental impacts, methods of cleaning coal before combustion, combustion methods, and post-combustion cleanup. It includes a section on carbon dioxide capture, storage and utilization. Physical, chemical and biological cleaning methods are covered. Coal conversion techniques covered are: pulverized coal combustion, fluidized-bed combustion, supercritical boilers, cyclone combustion, magnetohydrodynamics and gasification. 66 refs., 29 figs., 8 tabs.

  15. Magma energy for power generation

    SciTech Connect

    Dunn, J.C.

    1987-01-01

    Thermal energy contained in crustal magma bodies represents a large potential resource for the US and magma generated power could become a viable alternative in the future. Engineering feasibility of the magma energy concept is being investigated as part of the Department of Energy's Geothermal Program. This current project follows a seven-year Magma Energy Research Project where scientific feasibility of the concept was concluded.

  16. Power Supply Systems for Rapid Cycling Synchrotron

    NASA Astrophysics Data System (ADS)

    Watanabe, Yasuhiro; Adachi, Toshikazu; Someya, Hirohiko; Koseki, Shoichiro; Ogawa, Shinichi

    JAEA and KEK are jointly constructing a high intensity proton accelerator project J-PARC. Its main accelerator is 3GeV rapid cycling synchrotron (RCS). Two types of resonant excitation systems, parallel and cascade, are introduced to excite DC biased 25Hz AC currents through its main magnets. The parallel excitation is adopted for dipole magnets power supply system, and the cascade excitations are adopted for seven family quadrupole magnets systems. In this paper, two systems are investigated and analyzed, and it is explained why different types are adopted to each system. Authors believe that such hybrid exciting systems are most suitable for high power RCS.

  17. Thermoelectric power generator for variable thermal power source

    SciTech Connect

    Bell, Lon E; Crane, Douglas Todd

    2015-04-14

    Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

  18. Clean coal technologies in electric power generation: a brief overview

    SciTech Connect

    Janos Beer; Karen Obenshain

    2006-07-15

    The paper talks about the future clean coal technologies in electric power generation, including pulverized coal (e.g., advanced supercritical and ultra-supercritical cycles and fluidized-bed combustion), integrated gasification combined cycle (IGCC), and CO{sub 2} capture technologies. 6 refs., 2 tabs.

  19. High efficiency carbonate fuel cell/turbine hybrid power cycles

    SciTech Connect

    Steinfeld, G.

    1995-10-19

    Carbonate fuel cells developed by Energy Research Corporation, in commercial 2.85 MW size, have an efficiency of 57.9 percent. Studies of higher efficiency hybrid power cycles were conducted in cooperation with METC to identify an economically competitive system with an efficiency in excess of 65 percent. A hybrid power cycle was identified that includes a direct carbonate fuel cell, a gas turbine and a steam cycle, which generates power at a LHV efficiency in excess of 70 percent. This new system is called a Tandem Technology Cycle (TTC). In a TTC operating on natural gas fuel, 95 percent of the fuel is mixed with recycled fuel cell anode exhaust, providing water for the reforming of the fuel, and flows to a direct carbonate fuel cell system which generates 72 percent of the power. The portion of the fuel cell anode exhaust which is not recycled, is burned and heat is transferred to the compressed air from a gas turbine, raising its temperature to 1800{degrees}F. The stream is then heated to 2000{degrees}F in the gas turbine burner and expands through the turbine generating 13 percent of the power. Half the exhaust from the gas turbine flows to the anode exhaust burner, and the remainder flows to the fuel cell cathodes providing the O{sub 2} and CO{sub 2} needed in the electrochemical reaction. Exhaust from the fuel cells flows to a steam system which includes a heat recovery steam generator and stages steam turbine which generates 15 percent of the TTC system power. Studies of the TTC for 200-MW and 20-MW size plants quantified performance, emissions and cost-of-electricity, and compared the characteristics of the TTC to gas turbine combined cycles. A 200-MW TTC plant has an efficiency of 72.6 percent, and is relatively insensitive to ambient temperature, but requires a heat exchanger capable of 2000{degrees}F. The estimated cost of electricity is 45.8 mills/kWhr which is not competitive with a combined cycle in installations where fuel cost is under $5.8/MMBtu.

  20. Acoustic power absorption and enhancement generated by slow and fast MHD waves. Evidence of solar cycle velocity/intensity amplitude changes consistent with the mode conversion theory

    NASA Astrophysics Data System (ADS)

    Simoniello, R.; Finsterle, W.; García, R. A.; Salabert, D.; Jiménez, A.; Elsworth, Y.; Schunker, H.

    2010-06-01

    We used long duration, high quality, unresolved (Sun-as-a star) observations collected by the ground based network BiSON and by the instruments GOLF and VIRGO on board the ESA/NASA SOHO satellite to search for solar-cycle-related changes in mode characteristics in velocity and continuum intensity for the frequency range between 2.5 mHz <ν< 6.8 mHz. Over the ascending phase of solar cycle 23 we found a suppression in the p-mode amplitudes both in the velocity and intensity data between 2.5 mHz <ν< 4.5 mHz with a maximum suppression for frequencies in the range between 2.5 mHz <ν< 3.5 mHz. The size of the amplitude suppression is 13 ± 2 per cent for the velocity and 9 ± 2 per cent for the intensity observations. Over the range of 4.5 mHz <ν< 5.5 mHz the findings hint within the errors to a null change both in the velocity and intensity amplitudes. At still higher frequencies, in the so called High-frequency Interference Peaks (HIPs) between 5.8 mHz <ν< 6.8 mHz, we found an enhancement in the velocity amplitudes with the maximum 36 ± 7 per cent occurring for 6.3 mHz <ν< 6.8 mHz. However, in intensity observations we found a rather smaller enhancement of about 5 ± 2 per cent in the same interval. There is evidence that the frequency dependence of solar-cycle velocity amplitude changes is consistent with the theory behind the mode conversion of acoustic waves in a non-vertical magnetic field, but there are some problems with the intensity data, which may be due to the height in the solar atmosphere at which the VIRGO data are taken.

  1. Thermodynamics of combined-cycle electric power plants

    NASA Astrophysics Data System (ADS)

    Leff, Harvey S.

    2012-06-01

    Published data imply an average thermal efficiency of about 0.34 for U.S. electricity generating plants. With clever use of thermodynamics and technology, modern gas and steam turbines can be coupled, to effect dramatic efficiency increases. These combined-cycle power plants now reach thermal efficiencies in excess of 0.60. It is shown how the laws of thermodynamics make this possible.

  2. Coupling an induction motor type generator to ac power lines. [making windmill generators compatible with public power lines

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A system for coupling an induction motor type generator to an A.C. power line includes an electronic switch means that is controlled by a control system and is regulated to turn on at a relatively late point in each half cycle of its operation. The energizing power supplied by the line to the induction motor type generator is decreased and the net power delivered to the line is increased.

  3. Thermoelectric cooling and power generation

    PubMed

    DiSalvo

    1999-07-30

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

  4. Wind wheel electric power generator

    NASA Technical Reports Server (NTRS)

    Kaufman, J. W. (Inventor)

    1980-01-01

    Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

  5. Terms of reference (Mahreb power generation). Export trade information

    SciTech Connect

    Not Available

    1991-12-01

    The Government of Yemen has decided to use the Natural Gas discovered at Mareb for Power Generation by building a new power station plant with an initial installed capacity of 180MW plant utilizing open cycles gas turbines. The purpose of the study is to identify a least cost generation and transmission program (commencing with an initial 180MW open cycle gas turbine station) which will satisfy the forecast power demands of the Republic of Yemen (ROY) at minimum present value capital and operating cost over the period up to 2015 in accordance with agreed technical criteria.

  6. Advanced piggyback water power generator

    SciTech Connect

    Wiggs, B.R.

    1988-02-16

    A power generating system is described including: a central boat containing gearing and electric and/or power generation equipment, with a forward angled-back deflection screen and a rear non-angled deflection screen, with a smaller outrigger pontoon on each respective side of the central boat, with closed cell, waterproof, plastic foam filling in the central boat and pontoons, and with the bow of the respective outrigger pontoons angled so as to completely turn water away from, and to the outside of, the space and/or incoming water area between each such respective pontooon and the central boat. There are legs with cone shaped bottoms and with wheels attached, with the wheels extending slightly below the cone shaped bottoms; paddle wheels on each side of the central boat, between the central boat, and respective outrigger pontoons, with 90 degree spaced, flat, paddle blades, and with a solid, disk division vertically dividing each respective side paddle wheel in half and extending at right angles to, and from, the central axle, to the outside extreme end of the paddle blades, with each such half of the equally divided paddle wheel being constructed so that the 90 degree spaced paddle blades in one half are offset by 45 degrees from the 90 degree space paddle blades in the other half, and with the extreme ends of each such set of divided paddle wheels being enclosed via a similar solid.

  7. Energy Conversion Advanced Heat Transport Loop and Power Cycle

    SciTech Connect

    Oh, C. H.

    2006-08-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various

  8. Power output during women's World Cup road cycle racing.

    PubMed

    Ebert, Tammie R; Martin, David T; McDonald, Warren; Victor, James; Plummer, John; Withers, Robert T

    2005-12-01

    Little information exists on the power output demands of competitive women's road cycle racing. The purpose of our investigation was to document the power output generated by elite female road cyclists who achieved success in FLAT and HILLY World Cup races. Power output data were collected from 27 top-20 World Cup finishes (19 FLAT and 8 HILLY) achieved by 15 nationally ranked cyclists (mean +/- SD; age: 24.1+/-4.0 years; body mass: 57.9+/-3.6 kg; height: 168.7+/-5.6 cm; VO2max 63.6+/-2.4 mL kg(-1) min(-1); peak power during graded exercise test (GXT(peak power)): 310+/-25 W). The GXT determined GXT(peak power), VO2peak lactate threshold (LT) and anaerobic threshold (AT). Bicycles were fitted with SRM powermeters, which recorded power (W), cadence (rpm), distance (km) and speed (km h(-1)). Racing data were analysed to establish time in power output and metabolic threshold bands and maximal mean power (MMP) over different durations. When compared to HILLY, FLAT were raced at a similar cadence (75+/-8 vs. 75+/-4 rpm, P=0.93) but higher speed (37.6+/-2.6 vs. 33.9+/-2.7 km h(-1), P=0.008) and power output (192+/-21 vs. 169+/-17 W, P=0.04; 3.3+/-0.3 vs. 3.0+/-0.4 W kg(-1), P=0.04). During FLAT races, riders spent significantly more time above 500 W, while greater race time was spent between 100 and 300 W (LT-AT) for HILLY races, with higher MMPs for 180-300 s. Racing terrain influenced the power output profiles of our internationally competitive female road cyclists. These data are the first to define the unique power output requirements associated with placing well in both flat and hilly women's World Cup cycling events. PMID:16151832

  9. Miniature Gas-Turbine Power Generator

    NASA Technical Reports Server (NTRS)

    Wiberg, Dean; Vargo, Stephen; White, Victor; Shcheglov, Kirill

    2003-01-01

    A proposed microelectromechanical system (MEMS) containing a closed- Brayton-cycle turbine would serve as a prototype of electric-power generators for special applications in which high energy densities are required and in which, heretofore, batteries have been used. The system would have a volume of about 6 cm3 and would operate with a thermal efficiency >30 percent, generating up to 50 W of electrical power. The energy density of the proposed system would be about 10 times that of the best battery-based systems now available, and, as such, would be comparable to that of a fuel cell. The working gas for the turbine would be Xe containing small quantities of CO2, O2, and H2O as gaseous lubricants. The gas would be contained in an enclosed circulation system, within which the pressure would typically range between 5 and 50 atm (between 0.5 and 5 MPa). The heat for the Brayton cycle could be supplied by any of a number of sources, including a solar concentrator or a combustor burning a hydrocarbon or other fuel. The system would include novel heat-transfer and heat-management components. The turbine would be connected to an electric power generator/starter motor. The system would include a main rotor shaft with gas bearings; the bearing surfaces would be made of a ceramic material coated with nanocrystalline diamond. The shaft could withstand speed of 400,000 rpm or perhaps more, with bearing-wear rates less than 10(exp -)4 those of silicon bearings and 0.05 to 0.1 those of SiC bearings, and with a coefficient of friction about 0.1 that of Si or SiC bearings. The components of the system would be fabricated by a combination of (1) three-dimensional xray lithography and (2) highly precise injection molding of diamond-compatible metals and ceramic materials. The materials and fabrication techniques would be suitable for mass production. The disadvantages of the proposed system are that unlike a battery-based system, it could generate a perceptible amount of sound, and

  10. Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report

    NASA Technical Reports Server (NTRS)

    Fuller, Robert L.

    2010-01-01

    A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.

  11. Electronic load for testing power generating devices

    NASA Technical Reports Server (NTRS)

    Friedman, E. B.; Stepfer, G.

    1968-01-01

    Instrument tests various electric power generating devices by connecting the devices to the input of the load and comparing their outputs with a reference voltage. The load automatically adjusts until voltage output of the power generating device matches the reference.

  12. Open cycle gas fired MHD power plants

    SciTech Connect

    Medin, S.A. ); Negrini, F. )

    1991-01-01

    In this paper, the main objectives for the present development of gas fired MHD power generation are considered. The state of the world-wide natural gas consumption and its utilization for electricity production is analyzed. The experimental efforts in gas-fired MHD studies are briefly described. The essential features of the two major world gas-fired MHD project - the Ryazan MHDES-580 (U-500) power plant and the Italian 230 MWt retrofit are presented. New suggestions for improving the efficiency of MHD systems and the theoretical and experimental aspects of MHD development are discussed.

  13. Life cycle assessment of a biomass gasification combined-cycle power system

    SciTech Connect

    Mann, M.K.; Spath, P.L.

    1997-12-01

    The potential environmental benefits from biomass power are numerous. However, biomass power may also have some negative effects on the environment. Although the environmental benefits and drawbacks of biomass power have been debated for some time, the total significance has not been assessed. This study serves to answer some of the questions most often raised in regard to biomass power: What are the net CO{sub 2} emissions? What is the energy balance of the integrated system? Which substances are emitted at the highest rates? What parts of the system are responsible for these emissions? To provide answers to these questions, a life cycle assessment (LCA) of a hypothetical biomass power plant located in the Midwest United States was performed. LCA is an analytical tool for quantifying the emissions, resource consumption, and energy use, collectively known as environmental stressors, that are associated with converting a raw material to a final product. Performed in conjunction with a t echnoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. This study complements a technoeconomic analysis of the same process, reported in Craig and Mann (1996) and updated here. The process studied is based on the concept of power Generation in a biomass integrated gasification combined cycle (BIGCC) plant. Broadly speaking, the overall system consists of biomass production, its transportation to the power plant, electricity generation, and any upstream processes required for system operation. The biomass is assumed to be supplied to the plant as wood chips from a biomass plantation, which would produce energy crops in a manner similar to the way food and fiber crops are produced today. Transportation of the biomass and other materials is by both rail and truck. The IGCC plant is sized at 113 MW, and integrates an indirectly-heated gasifier with an industrial gas turbine and steam cycle. 63 refs., 34 figs., 32 tabs.

  14. Life cycle assessment of a biomass gasification combined-cycle power system

    SciTech Connect

    Mann, M.K.; Spath, P.L.

    1997-12-01

    The potential environmental benefits from biomass power are numerous. However, biomass power may also have some negative effects on the environment. Although the environmental benefits and drawbacks of biomass power have been debated for some time, the total significance has not been assessed. This study serves to answer some of the questions most often raised in regard to biomass power: What are the net CO{sub 2} emissions? What is the energy balance of the integrated system? Which substances are emitted at the highest rates? What parts of the system are responsible for these emissions? To provide answers to these questions, a life cycle assessment (LCA) of a hypothetical biomass power plant located in the Midwest United States was performed. LCA is an analytical tool for quantifying the emissions, resource consumption, and energy use, collectively known as environmental stressors, that are associated with converting a raw material to a final product. Performed in conjunction with a technoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. This study complements a technoeconomic analysis of the same process, reported in Craig and Mann (1996) and updated here. The process studied is based on the concept of power Generation in a biomass integrated gasification combined cycle (BIGCC) plant. Broadly speaking, the overall system consists of biomass production, its transportation to the power plant, electricity generation, and any upstream processes required for system operation. The biomass is assumed to be supplied to the plant as wood chips from a biomass plantation, which would produce energy crops in a manner similar to the way food and fiber crops are produced today. Transportation of the biomass and other materials is by both rail and truck. The IGCC plant is sized at 113 MW, and integrates an indirectly-heated gasifier with an industrial gas turbine and steam cycle. 63 refs., 34 figs., 32 tabs.

  15. Wave activated power generation system

    SciTech Connect

    Ono, Y.

    1983-08-09

    A wave activated power generation system of the float type is disclosed, comprising at least one piston-cylinder device having an anchored cylinder and a piston slidable in the cylinder and cooperating with the cylinder to form a pumping chamber above the piston and a low pressure chamber below the piston. The cylinder has an intake port and an exhaust port both formed at an upper port thereof to communicate with the pumping chamber and each provided with a check valve. A float is connected through a cable to the piston of the piston- cylinder device. A pair of fluid storages are connected to the intake port and the exhaust port of the pumping chamber, respectively. A waterwheel generator is driven by the fluid flowing from one of the fluid storages to another. A pressure regulating device is connected to the low pressure chamber so as to maintain the low pressure chamber at a pressure lower than the pressure in the pumping chamber, the difference in pressure ceaselessly applying a downward force on the piston to keep the cable in a tensed condition.

  16. The Kalina cycle and similar cycles for geothermal power production

    SciTech Connect

    Bliem, C.J.

    1988-09-01

    This report contains a brief discussion of the mechanics of the Kalina cycle and ideas to extend the concept to other somewhat different cycles. A modified cycle which has a potential heat rejection advantage but little or no performance improvement is discussed. Then, the results of the application of the Kalina cycle and the modified cycle to a geothermal application (360/degree/F resource) are discussed. The results are compared with published results for the Kalina cycle with high temperature sources and estimates about performance at the geothermal temperatures. Finally, the conclusions of this scoping work are given along with recommendations of the direction of future work in this area. 11 refs., 4 figs., 1 tab.

  17. Generator powered electrically heated diesel particulate filter

    DOEpatents

    Gonze, Eugene V; Paratore, Jr., Michael J

    2014-03-18

    A control circuit for a vehicle powertrain includes a switch that selectivity interrupts current flow between a first terminal and a second terminal. A first power source provides power to the first terminal and a second power source provides power to the second terminal and to a heater of a heated diesel particulate filter (DPF). The switch is opened during a DPF regeneration cycle to prevent the first power source from being loaded by the heater while the heater is energized.

  18. Evolutionary algorithm for vehicle driving cycle generation.

    PubMed

    Perhinschi, Mario G; Marlowe, Christopher; Tamayo, Sergio; Tu, Jun; Wayne, W Scott

    2011-09-01

    Modeling transit bus emissions and fuel economy requires a large amount of experimental data over wide ranges of operational conditions. Chassis dynamometer tests are typically performed using representative driving cycles defined based on vehicle instantaneous speed as sequences of "microtrips", which are intervals between consecutive vehicle stops. Overall significant parameters of the driving cycle, such as average speed, stops per mile, kinetic intensity, and others, are used as independent variables in the modeling process. Performing tests at all the necessary combinations of parameters is expensive and time consuming. In this paper, a methodology is proposed for building driving cycles at prescribed independent variable values using experimental data through the concatenation of "microtrips" isolated from a limited number of standard chassis dynamometer test cycles. The selection of the adequate "microtrips" is achieved through a customized evolutionary algorithm. The genetic representation uses microtrip definitions as genes. Specific mutation, crossover, and karyotype alteration operators have been defined. The Roulette-Wheel selection technique with elitist strategy drives the optimization process, which consists of minimizing the errors to desired overall cycle parameters. This utility is part of the Integrated Bus Information System developed at West Virginia University. PMID:22010377

  19. Indirect-fired gas turbine dual fuel cell power cycle

    SciTech Connect

    Micheli, P.L.; Williams, M.C.; Sudhoff, F.A.

    1998-04-01

    The present invention relates generally to an integrated fuel cell power plant, and more specifically to a combination of cycles wherein a first fuel cell cycle tops an indirect-fired gas turbine cycle and a second fuel cell cycle bottoms the gas turbine cycle so that the cycles are thermally integrated in a tandem operating arrangement. The United States Government has rights in this invention pursuant to the employer-employee relationship between the United States Department of Energy and the inventors.

  20. Potassium Rankine cycle nuclear power systems for spacecraft and lunar-mass surface power

    SciTech Connect

    Holcomb, R.S.

    1992-07-01

    The potassium Rankine cycle has high potential for application to nuclear power systems for spacecraft and surface power on the moon and Mars. A substantial effort on the development of Rankine cycle space power systems was carried out in the 1960`s. That effort is summarized and the status of the technology today is presented. Space power systems coupling Rankine cycle power conversion to both the SP-100 reactor and thermionic reactors as a combined power cycle are described in the paper.

  1. Status of Brayton Cycle Power Conversion Development at NASA GRC

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Shaltens, Richard K.; Dolce, James L.; Cataldo, Robert L.

    2002-01-01

    The NASA Glenn Research Center (GRC) is pursuing the development of Brayton cycle power conversion for various NASA initiatives. Brayton cycle power systems offer numerous advantages for space power generation including high efficiency, long life, high maturity, and broad scalability. Candidate mission applications include surface rovers and bases, advanced propulsion vehicles, and earth orbiting satellites. A key advantage is the ability for Brayton converters to span the wide range of power demands of future missions from several kilowatts to multi-megawatts using either solar, isotope, or reactor heat sources. Brayton technology has been under development by NASA since the early 1960's resulting in engine prototypes in the 2 to 15 kW-class that have demonstrated conversion efficiency of almost 30% and cumulative operation in excess of 40,000 hours. Present efforts at GRC are focusing on a 2 kW testbed as a proving ground for future component advances and operational strategies, and a 25 kW engine design as a modular building block for 100 kW-class electric propulsion and Mars surface power applications.

  2. Fossil fuel combined cycle power generation method

    DOEpatents

    Labinov, Solomon D [Knoxville, TN; Armstrong, Timothy R [Clinton, TN; Judkins, Roddie R [Knoxville, TN

    2008-10-21

    A method for converting fuel energy to electricity includes the steps of converting a higher molecular weight gas into at least one mixed gas stream of lower average molecular weight including at least a first lower molecular weight gas and a second gas, the first and second gases being different gases, wherein the first lower molecular weight gas comprises H.sub.2 and the second gas comprises CO. The mixed gas is supplied to at least one turbine to produce electricity. The mixed gas stream is divided after the turbine into a first gas stream mainly comprising H.sub.2 and a second gas stream mainly comprising CO. The first and second gas streams are then electrochemically oxidized in separate fuel cells to produce electricity. A nuclear reactor can be used to supply at least a portion of the heat the required for the chemical conversion process.

  3. Design considerations of a power supply system for fast cycling superconducting accelerator magnets of 2 Tesla b-field generated by a conductor of 100 kA current

    SciTech Connect

    Hays, Steve; Piekarz, Henryk; Pfeffer, Howie; Claypool, Brad; /Fermilab

    2007-06-01

    Recently proposed fast cycling accelerators for proton drivers (SF-SPS, CERN and SF-MR, SF-BOOSTER, FNAL) neutrino sources require development of new magnet technology. In support of this magnet development a power supply system will need to be developed that can support the high current and high rate of power swing required by the fast cycling (1 sec rise and fall in the SF-MR, 5Hz in Booster). This paper will outline a design concept for a +/- 2000 V and 100,000 A fast ramping power supply system. This power supply design is in support of a 6.44 km magnet system at 0.020 H and 330 m 5 Hz, 0.00534 H superconducting loads. The design description will include the layout and plan for extending the present FNAL Main Injector style ramping power supply to the higher currents needed for this operation. This will also include the design for a harmonic filter and power factor corrector that will be needed to control the large power swings caused by the fast cycle time. A conceptual design for the current regulation system and control will also be outlined. The power circuit design will include the bridge, filter and transformer plan based on existing designs.

  4. Models for generation of carbonate cycles

    SciTech Connect

    Read, J.F.; Grotzinger, J.P.; Bova, J.A.; Koerschner, W.F.

    1986-02-01

    Computer modeling provides a quantitative approach to a better understanding of actual carbonate cyclic sequences. To model carbonate cycles, the authors can use water-depth-dependent sedimentation rate for each facies, an initial lag time, linear subsidence, tidal range, and period and amplitude of sea-level oscillation about a horizontal datum. Tidal-flat-capped cycles up to a few meters thick result from low-amplitude sea-level oscillation of a few meters and short lag times. Nonerosive caps reflect sea-level lowering being balanced by subsidence, and basinward migration of the shoreline not exceeding tidal-flat progradation rate. When higher amplitude sea-level oscillations occur, the tidal flats are abandoned on the inner shelf during sea-level fall, because seaward movement of the strandline outpaces progradation rate of flats. Increased amplitude also results in sea-level falling faster than flats can subside, so that disconformities with thick vadose profiles develop. High-amplitude (100 m or more) oscillations result in incipient drowning of platforms and juxtaposition of deep-water facies against shallow-water facies within cycles. Sea level falls before the platform can build to the sea-level highstand, and the shoreline migrates much more rapidly than tidal flats can prograde; thus, cycles are disconformity-bounded and lack tidal-flat caps. 10 references.

  5. Recovered Energy Generation Using an Organic Rankine Cycle System

    SciTech Connect

    Leslie, Neil; Sweetser, Richard; Zimron, Ohad; Stovall, Therese K

    2009-01-01

    This paper describes the results of a project demonstrating the technical and economic feasibility of capturing thermal energy from a 35,000 hp (27 MW) gas turbine driving a natural gas pipeline compressor with a Recovered Energy Generation (REG) system to produce 5.5 MW of electricity with no additional fuel and near-zero emissions. The REG is based on a modified Organic Rankine Cycle (ORC). Other major system elements include a waste-heat-to-oil heat exchanger with bypass, oil-to-pentane heat exchanger with preheater, recuperator, condenser, pentane turbine, generator and synchronizing breaker and all power and control systems required for the automatic operation of the REG. When operating at design heat input available from the gas turbine exhaust, the REG system consistently delivered 5.5 MW or more output to the grid at up to 15 percent heat conversion efficiency. The REG system improved the overall energy efficiency by 28%, from 32% simple cycle efficiency to 41% for the combined system. Significant lessons learned from this project are discussed as well as measured performance and economic considerations.

  6. Rotary-Atomizer Electric Power Generator

    NASA Astrophysics Data System (ADS)

    Nguyen, Trieu; Tran, Tuan; de Boer, Hans; van den Berg, Albert; Eijkel, Jan C. T.

    2015-03-01

    We report experimental and theoretical results on a ballistic energy-conversion method based on a rotary atomizer working with a droplet acceleration-deceleration cycle. In a rotary atomizer, liquid is fed onto the center of a rotating flat surface, where it spreads out under the action of the centrifugal force and creates "atomized" droplets at its edge. The advantage of using a rotary atomizer is that the centrifugal force exerted on the fluid on a smooth, large surface is not only a robust form of acceleration, as it avoids clogging, but also easily allows high throughput, and produces high electrical power. We successfully demonstrate an output power of 4.9 mW and a high voltage up to 3120 V. At present, the efficiency of the system is still low (0.14%). However, the conversion mechanism of the system is fully interpreted in this paper, permitting a conceptual understanding of system operation and providing a roadmap for system optimization. This observation will open up a road for building power-generation systems in the near future.

  7. Combined fuel and air staged power generation system

    SciTech Connect

    Rabovitser, Iosif K; Pratapas, John M; Boulanov, Dmitri

    2014-05-27

    A method and apparatus for generation of electric power employing fuel and air staging in which a first stage gas turbine and a second stage partial oxidation gas turbine power operated in parallel. A first portion of fuel and oxidant are provided to the first stage gas turbine which generates a first portion of electric power and a hot oxidant. A second portion of fuel and oxidant are provided to the second stage partial oxidation gas turbine which generates a second portion of electric power and a hot syngas. The hot oxidant and the hot syngas are provided to a bottoming cycle employing a fuel-fired boiler by which a third portion of electric power is generated.

  8. Power generating system and method utilizing hydropyrolysis

    DOEpatents

    Tolman, R.

    1986-12-30

    A vapor transmission cycle is described which burns a slurry of coal and water with some of the air from the gas turbine compressor, cools and cleans the resulting low-Btu fuel gas, burns the clean fuel gas with the remaining air from the compressor, and extracts the available energy in the gas turbine. The cycle lends itself to combined-cycle cogeneration for the production of steam, absorption cooling, and electric power.

  9. Electronic power generators for ultrasonic frequencies

    NASA Technical Reports Server (NTRS)

    Ciovica, D.

    1974-01-01

    The design and construction of an ultrasonic frequency electronic power generator are discussed. The principle design elements of the generator are illustrated. The generator provides an inductive load with an output power of two kilowatts and a variable output frequency in the fifteen to thirty KiloHertz range. The method of conducting the tests and the results obtained with selected materials are analyzed.

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

    NASA Astrophysics Data System (ADS)

    Lior, N.; Koai, K.

    1984-11-01

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

  11. Supercritical Water Reactor Cycle for Medium Power Applications

    SciTech Connect

    BD Middleton; J Buongiorno

    2007-04-25

    and pipes were modeled with realistic assumptions using the PEACE module of Thermoflex. A three-dimensional layout of the plant was also generated with the SolidEdge software. The results of the engineering design are as follows: (i) The cycle achieves a net thermal efficiency of 24.13% with 350/460 C reactor inlet/outlet temperatures, {approx}250 bar reactor pressure and 0.75 bar condenser pressure. The steam quality at the turbine outlet is 90% and the total electric consumption of the pumps is about 2500 kWe at nominal conditions. (ii) The overall size of the plant is attractively compact and can be further reduced if a printed-circuit-heat-exchanger (vs shell-and-tube) design is used for the feedwater heater, which is currently the largest component by far. Finally, an analysis of the plant performance at off-nominal conditions has revealed good robustness of the design in handling large changes of thermal power and seawater temperature.

  12. Thermoelectric power generator with intermediate loop

    SciTech Connect

    Bell, Lon E; Crane, Douglas Todd

    2013-05-21

    A thermoelectric power generator is disclosed for use to generate electrical power from heat, typically waste heat. An intermediate heat transfer loop forms a part of the system to permit added control and adjustability in the system. This allows the thermoelectric power generator to more effectively and efficiently generate power in the face of dynamically varying temperatures and heat flux conditions, such as where the heat source is the exhaust of an automobile, or any other heat source with dynamic temperature and heat flux conditions.

  13. Thermoelectric power generator with intermediate loop

    DOEpatents

    Bel,; Lon E.; Crane, Douglas Todd

    2009-10-27

    A thermoelectric power generator is disclosed for use to generate electrical power from heat, typically waste heat. An intermediate heat transfer loop forms a part of the system to permit added control and adjustability in the system. This allows the thermoelectric power generator to more effectively and efficiently generate power in the face of dynamically varying temperatures and heat flux conditions, such as where the heat source is the exhaust of an automobile, or any other heat source with dynamic temperature and heat flux conditions.

  14. Pulse power applications of flux compression generators

    NASA Astrophysics Data System (ADS)

    Fowler, C. M.; Caird, R. S.; Erickson, D. J.; Freeman, B. L.

    Characteristics are presented for two different types of explosive driven flux compression generators and a megavolt pulse transformer. Status reports are given for rail gun and plasma focus programs for which the generators serve as power sources.

  15. Single generation cycles and delayed feedback cycles are not separate phenomena.

    PubMed

    Pfaff, T; Brechtel, A; Drossel, B; Guill, C

    2014-12-01

    We study a simple model for generation cycles, which are oscillations with a period of one or a few generation times of the species. The model is formulated in terms of a single delay-differential equation for the population density of an adult stage, with recruitment to the adult stage depending on the intensity of competition during the juvenile phase. This model is a simplified version of a group of models proposed by Gurney and Nisbet, who were the first to distinguish between single-generation cycles and delayed-feedback cycles. According to these authors, the two oscillation types are caused by different mechanisms and have periods in different intervals, which are one to two generation times for single-generation cycles and two to four generation times for delayed-feedback cycles. By abolishing the strict coupling between the maturation time and the time delay between competition and its effect on the population dynamics, we find that single-generation cycles and delayed-feedback cycles occur in the same model version, with a gradual transition between the two as the model parameters are varied over a sufficiently large range. Furthermore, cycle periods are not bounded to lie within single octaves. This implies that a clear distinction between different types of generation cycles is not possible. Cycles of all periods and even chaos can be generated by varying the parameters that determine the time during which individuals from different cohorts compete with each other. This suggests that life-cycle features in the juvenile stage and during the transition to the adult stage are important determinants of the dynamics of density limited populations. PMID:25453606

  16. Multi-layer canard cycles and translated power functions

    NASA Astrophysics Data System (ADS)

    Dumortier, Freddy; Roussarie, Robert

    The paper deals with two-dimensional slow-fast systems and more specifically with multi-layer canard cycles. These are canard cycles passing through n layers of fast orbits, with n⩾2. The canard cycles are subject to n generic breaking mechanisms and we study the limit cycles that can be perturbed from the generic canard cycles of codimension n. We prove that this study can be reduced to the investigation of the fixed points of iterated translated power functions.

  17. Combined cycle power unit with a binary system based on waste geothermal brine at Mutnovsk geothermal power plant

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.; Nikol'skii, A. I.; Semenov, V. N.

    2016-06-01

    The Russian geothermal power systems developed in the last few decades outperform their counterparts around the world in many respects. However, all Russian geothermal power stations employ steam as the geothermal fluid and discard the accompanying geothermal brine. In reality, the power of the existing Russian geothermal power stations may be increased without drilling more wells, if the waste brine is employed in combined cycle systems with steam and binary turbine units. For the example of the 50 MW Mutnovsk geothermal power plant, the optimal combined cycle power unit based on the waste geothermal brine is considered. It is of great interest to determine how the thermodynamic parameters of the secondary steam in the expansion unit and the pressure in the condenser affect the performance of the equipment in the combined cycle power unit at Mutnovsk geothermal power plant. For the utilization of the waste geothermal brine at Mutnovsk geothermal power plant, the optimal air temperature in the condensers of the combined cycle power unit is +5°C. The use of secondary steam obtained by flashing of the geothermal brine at Mutnovsk geothermal power plant 1 at a pressure of 0.2 MPa permits the generation of up to 8 MW of electric power in steam turbines and additional power of 5 MW in the turbines of the binary cycle.

  18. Integrated engine generator for aircraft secondary power

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.

    1972-01-01

    An integrated engine-generator for aircraft secondary power generation is described. The concept consists of an electric generator located inside a turbojet or turbofan engine and both concentric with and driven by one of the main engine shafts. The electric power conversion equipment and generator controls are located in the aircraft. When properly rated, the generator serves as an engine starter as well as a source of electric power. This configuration reduces or eliminates the need for an external gear box on the engine and permits reduction in the nacelle diameter.

  19. Solar power satellite life-cycle energy recovery consideration

    NASA Astrophysics Data System (ADS)

    Weingartner, S.; Blumenberg, J.

    The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead on monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on earth (rectenna) requires about 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production installation and operation, is about two years.

  20. Solar power satellite—Life-cycle energy recovery considerations

    NASA Astrophysics Data System (ADS)

    Weingartner, S.; Blumenberg, J.

    1995-05-01

    The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for a cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead of monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power plant components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on Earth (rectenna) requires in the order of 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production, installation and operation, is in the order of two years.

  1. System studies of coal fired-closed cycle MHD for central station power plants

    NASA Technical Reports Server (NTRS)

    Zauderer, B.

    1976-01-01

    This paper presents a discussion of the closed-cycle MHD results obtained in a recent study of various advanced energy-conversion power systems. The direct coal-fired MHD topping-steam bottoming cycle was established as the current choice for central station power generation. Emphasis is placed on the background assumptions and the conclusions that can be drawn from the closed-cycle MHD analysis. It is concluded that closed-cycle MHD has efficiencies comparable to that of open-cycle MHD. Its cost will possibly be slightly higher than that of the open-cycle MHD system. Also, with reasonable fuel escalation assumptions, both systems can produce lower-cost electricity than conventional steam power plants. Suggestions for further work in closed-cycle MHD components and systems are made.

  2. 40 CFR 1065.610 - Duty cycle generation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Duty cycle generation. 1065.610 Section 1065.610 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.610 Duty cycle...

  3. 40 CFR 1065.610 - Duty cycle generation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Duty cycle generation. 1065.610 Section 1065.610 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.610 Duty cycle...

  4. 40 CFR 1065.610 - Duty cycle generation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Duty cycle generation. 1065.610 Section 1065.610 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.610 Duty cycle...

  5. 40 CFR 1065.610 - Duty cycle generation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Duty cycle generation. 1065.610 Section 1065.610 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.610 Duty cycle...

  6. 40 CFR 1065.610 - Duty cycle generation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Duty cycle generation. 1065.610 Section 1065.610 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.610 Duty cycle...

  7. Life cycle assessment of overhead and underground primary power distribution.

    PubMed

    Bumby, Sarah; Druzhinina, Ekaterina; Feraldi, Rebe; Werthmann, Danae; Geyer, Roland; Sahl, Jack

    2010-07-15

    Electrical power can be distributed in overhead or underground systems, both of which generate a variety of environmental impacts at all stages of their life cycles. While there is considerable literature discussing the trade-offs between both systems in terms of aesthetics, safety, cost, and reliability, environmental assessments are relatively rare and limited to power cable production and end-of-life management. This paper assesses environmental impacts from overhead and underground medium voltage power distribution systems as they are currently built and managed by Southern California Edison (SCE). It uses process-based life cycle assessment (LCA) according to ISO 14044 (2006) and SCE-specific primary data to the extent possible. Potential environmental impacts have been calculated using a wide range of midpoint indicators, and robustness of the results has been investigated through sensitivity analysis of the most uncertain and potentially significant parameters. The studied underground system has higher environmental impacts in all indicators and for all parameter values, mostly due to its higher material intensity. For both systems and all indicators the majority of impact occurs during cable production. Promising strategies for impact reduction are thus cable failure rate reduction for overhead and cable lifetime extension for underground systems. PMID:20553042

  8. Proceedings of the 1999 international joint power generation conference (PWR-Vol. 34). Volume 2: Power

    SciTech Connect

    Penfield, S.R. Jr.; Hayes, R.H.; McMullen, R.

    1999-07-01

    Papers are arranged under the following topical sections: Benefits of software application in plant optimization; Combined cycle power plants; Recent improvements in power generation operations; Efficiency and capacity improvements for steam turbines; Condenser and heat exchange performance and fouling; Performance testing, monitoring and evaluation; Steam turbine/generator system--maintance, life assesments and upgrades; System design evaluations; Steam generators; Turbines for combined cycle and cogeneration; Case studies on steam turbine/generator problems and solutions; Condenser and feedwater heater operation and maintenance; Risked based and reliability programs for plant applications; Improving operating flexibility of steam turbine/generators (minimizing startup time, load changing, etc.); New techniques and innovations in heat transfer systems; Case studies in reliability based maintenance; and Risk analysis applied to steam turbine/generator systems. Papers within scope have been processed separately for inclusion on the database.

  9. Photoconductive switching for high power microwave generation

    SciTech Connect

    Pocha, M.D.; Hofer, W.W.

    1990-10-01

    Photoconductive switching is a technology that is being increasingly applied to generation of high power microwaves. Two primary semiconductors used for these devices are silicon and gallium arsenide. Diamond is a promising future candidate material. This paper discusses the important material parameters and switching modes, critical issues for microwave generation, and future directions for this high power, photoconductive switching technology.

  10. Electrofishing power requirements in relation to duty cycle

    USGS Publications Warehouse

    Miranda, L.E.; Dolan, C.R.

    2004-01-01

    Under controlled laboratory conditions we measured the electrical peak power required to immobilize (i.e., narcotize or tetanize) fish of various species and sizes with duty cycles (i.e., percentage of time a field is energized) ranging from 1.5% to 100%. Electrofishing effectiveness was closely associated with duty cycle. Duty cycles of 10-50% required the least peak power to immobilize fish; peak power requirements increased gradually above 50% duty cycle and sharply below 10%. Small duty cycles can increase field strength by making possible higher instantaneous peak voltages that allow the threshold power needed to immobilize fish to radiate farther away from the electrodes. Therefore, operating within the 10-50% range of duty cycles would allow a larger radius of immobilization action than operating with higher duty cycles. This 10-50% range of duty cycles also coincided with some of the highest margins of difference between the electrical power required to narcotize and that required to tetanize fish. This observation is worthy of note because proper use of duty cycle could help reduce the mortality associated with tetany documented by some authors. Although electrofishing with intermediate duty cycles can potentially increase effectiveness of electrofishing, our results suggest that immobilization response is not fully accounted for by duty cycle because of a potential interaction between pulse frequency and duration that requires further investigation.

  11. Aircraft Photovoltaic Power-Generating System.

    NASA Astrophysics Data System (ADS)

    Doellner, Oscar Leonard

    Photovoltaic cells, appropriately cooled and operating in the combustion-created high radiant-intensity environment of gas-turbine and jet engines, may replace the conventional (gearbox-driven) electrical power generators aboard jet aircraft. This study projects significant improvements not only in aircraft electrical power-generating-system performance, but also in overall aircraft performance. Jet -engine design modifications incorporating this concept not only save weight (and thus fuel), but are--in themselves --favorable to jet-engine performance. The dissertation concentrates on operational, constructional, structural, thermal, optical, radiometrical, thin-film, and solid-state theoretical aspects of the overall project. This new electrical power-generating system offers solid-state reliability with electrical power-output capability comparable to that of existing aircraft electromechanical power-generating systems (alternators and generators). In addition to improvements in aircraft performance, significant aircraft fuel- and weight-saving advantages are projected.

  12. Probabilistic Evaluation of Wind Power Generation

    NASA Astrophysics Data System (ADS)

    Muhamad Razali, N. M.; Misbah, Muizzuddin

    2013-06-01

    The power supplied by wind turbine generators (WTG) is widely random following the stochastic nature of weather conditions. For planning and decision making purposes, understanding and evaluation of the behaviour and distribution of WTG's output power are crucial. Monte Carlo simulation enables the realization of artificial futures by generating a huge number of sample paths of outcomes to perform this analysis. The paper presents an algorithm developed for a random wind speed generator governed by the probability density function of Weibull distribution and evaluates the WTG's output by using the power curve of wind turbines. The method may facilitate assessment of suitable turbine site as well as generator selection and sizing.

  13. Liquid-metal binary cycles for stationary power

    NASA Technical Reports Server (NTRS)

    Gutstein, M.; Furman, E. R.; Kaplan, G. M.

    1975-01-01

    The use of topping cycles to increase electric power plant efficiency is discussed, with particular attention to mercury and alkali metal Rankine cycle systems that could be considered for topping cycle applications. An overview of this technology, possible system applications, the required development, and possible problem areas is presented.

  14. Experience with organic Rankine cycles in heat recovery power plants

    SciTech Connect

    Bronicki, L.Y.; Elovic, A.; Rettger, P.

    1996-11-01

    Over the last 30 years, organic Rankine cycles (ORC) have been increasingly employed to produce power from various heat sources when other alternatives were either technically not feasible or economical. These power plants have logged a total of over 100 million turbine hours of experience demonstrating the maturity and field proven technology of the ORC cycle. The cycle is well adapted to low to moderate temperature heat sources such as waste heat from industrial plants and is widely used to recover energy from geothermal resources. The above cycle technology is well established and applicable to heat recovery of medium size gas turbines and offers significant advantages over conventional steam bottoming cycles.

  15. Solar energy thermally powered electrical generating system

    NASA Technical Reports Server (NTRS)

    Owens, William R. (Inventor)

    1989-01-01

    A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

  16. NV Energy Solar Integration Study: Cycling and Movements of Conventional Generators for Balancing Services

    SciTech Connect

    Diao, Ruisheng; Lu, Shuai; Etingov, Pavel V.; Ma, Jian; Makarov, Yuri V.; Guo, Xinxin

    2011-07-01

    With an increasing penetration level of solar power in the southern Nevada system, the impact of solar on system operations needs to be carefully studied from various perspectives. Qualitatively, it is expected that the balancing requirements to compensate for solar power variability will be larger in magnitude; meanwhile, generators providing load following and regulation services will be moved up or down more frequently. One of the most important tasks is to quantitatively evaluate the cycling and movements of conventional generators with solar power at different penetration levels. This study is focused on developing effective methodologies for this goal and providing a basis for evaluating the wear and tear of the conventional generators

  17. Hybrid solar central receiver for combined cycle power plant

    DOEpatents

    Bharathan, D.; Bohn, M.S.; Williams, T.A.

    1995-05-23

    A hybrid combined cycle power plant is described including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production. 1 figure.

  18. Hybrid solar central receiver for combined cycle power plant

    DOEpatents

    Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

    1995-01-01

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  19. US/USSR cooperative program in open-cycle MHD electrical power generation: joint test report No. 4. Tests in the U-25B facility: MHD generator tests No. 6 and 7

    SciTech Connect

    Picologlou, B F; Batenin, V M

    1981-01-01

    A description of the main results obtained during Tests No. 6 and 7 at the U-25B Facility using the new channel No. 2 is presented. The purpose of these tests was to operate the MHD generator at its design parameters. Described here are new plasma diagnostic devices: a traversing dual electrical probe for determining distribution of electron concentrations, and a traversing probe that includes a pitot tube for measuring total and static pressure, and a light detector for measuring plasma luminescence. Data are presented on heat flux distribution along the channel, the first data of this type obtained for an MHD facility of such size. Results are given of experimental studies of plasma characteristics, gasdynamic, thermal, and electrical MHD channel performance, and temporal and spatial nonuniformities. Typical modes of operation are analyzed by means of local electrical analyses. Computer models are used to obtain predictions for both localized and overall generator characteristics. These theoretical predictions agree closely with the results of the local analyses, as well as with measurements of the overall gasdynamic and electrical characteristics of the generator.

  20. Rankine engine solar power generation. I - Performance and economic analysis

    NASA Technical Reports Server (NTRS)

    Gossler, A. A.; Orrock, J. E.

    1981-01-01

    Results of a computer simulation of the performance of a solar flat plate collector powered electrical generation system are presented. The simulation was configured to include locations in New Mexico, North Dakota, Tennessee, and Massachusetts, and considered a water-based heat-transfer fluid collector system with storage. The collectors also powered a Rankine-cycle boiler filled with a low temperature working fluid. The generator was considered to be run only when excess solar heat and full storage would otherwise require heat purging through the collectors. All power was directed into the utility grid. The solar powered generator unit addition was found to be dependent on site location and collector area, and reduced the effective solar cost with collector areas greater than 400-670 sq m. The sites were economically ranked, best to worst: New Mexico, North Dakota, Massachusetts, and Tennessee.

  1. Fuel cell and advanced turbine power cycle

    SciTech Connect

    White, D.J.

    1995-10-19

    Solar Turbines, Incorporated (Solar) has a vested interest in the integration of gas turbines and high temperature fuel cells and in particular, solid oxide fuel cells (SOFCs). Solar has identified a parallel path approach to the technology developments needed for future products. The primary approach is to move away from the simple cycle industrial machines of the past and develop as a first step more efficient recuperated engines. This move was prompted by the recognition that the simple cycle machines were rapidly approaching their efficiency limits. Improving the efficiency of simple cycle machines is and will become increasingly more costly. Each efficiency increment will be progressively more costly than the previous step.

  2. An Implanted, Stimulated Muscle Powered Piezoelectric Generator

    NASA Technical Reports Server (NTRS)

    Lewandowski, Beth; Gustafson, Kenneth; Kilgore, Kevin

    2007-01-01

    A totally implantable piezoelectric generator system able to harness power from electrically activated muscle could be used to augment the power systems of implanted medical devices, such as neural prostheses, by reducing the number of battery replacement surgeries or by allowing periods of untethered functionality. The features of our generator design are no moving parts and the use of a portion of the generated power for system operation and regulation. A software model of the system has been developed and simulations have been performed to predict the output power as the system parameters were varied within their constraints. Mechanical forces that mimic muscle forces have been experimentally applied to a piezoelectric generator to verify the accuracy of the simulations and to explore losses due to mechanical coupling. Depending on the selection of system parameters, software simulations predict that this generator concept can generate up to approximately 700 W of power, which is greater than the power necessary to drive the generator, conservatively estimated to be 50 W. These results suggest that this concept has the potential to be an implantable, self-replenishing power source and further investigation is underway.

  3. US/USSR cooperative program in open-cycle MHD electrical power generation. Joint test report no. 4. Tests in the U-25B facility MHD generator tests No. 6 and 7

    NASA Astrophysics Data System (ADS)

    Picologlou, B. F.; Batenin, V. M.

    1981-01-01

    The MHD generator was operated at its design parameters. New plasma diagnostic devices are described and include: a traversing dual electrical probe for determining distribution of electron concentrations, a traversing probe that includes a pitot tube for measuring total and static pressure, and a light detector for measuring plasma luminescence. Data are presented on heat flux distribution along the channel, the forest data of this type obtained for an MHD facility of such size. Results are given of experimental studies of plasma characteristics, gasdynamic, thermal, and electrical MHD channel performance, and temporal and spatial nonuniformities.

  4. Fuel Cycle Comparison for Distributed Power Technologies

    SciTech Connect

    Elgowainy, A.; Wang, M. Q.

    2008-11-15

    This report examines backup power and prime power systems and addresses the potential energy and environmental effects of substituting fuel cells for existing combustion technologies based on microturbines and internal combustion engines.

  5. Scanning beam switch experiment for intense rf power generation

    NASA Astrophysics Data System (ADS)

    Humphries, Stanley, Jr.; Babcock, Steven R.; Wilson, J. M.; Adler, Richard J.

    1991-04-01

    1407_57The SBS_1 experiment at Sandia National Laboratories is designed to demonstrate the feasibility of the Scanning Beam Switch for high-power rf generation. The primary application is to pulsed rf linacs and high-frequency induction accelerators. It is expected that the apparatus will generate rf output power exceeding 100 MW at 50 MHz over a 5 microsecond(s) pulse. The device can operate as an oscillator or high gain amplifier. To achieve the capability for long-macropulse and high-duty-cycle operation, SBS_1 uses a large dispenser cathode and vacuum triode input driver.

  6. Parametric analysis of closed cycle magnetohydrodynamic (MHD) power plants

    NASA Technical Reports Server (NTRS)

    Owens, W.; Berg, R.; Murthy, R.; Patten, J.

    1981-01-01

    A parametric analysis of closed cycle MHD power plants was performed which studied the technical feasibility, associated capital cost, and cost of electricity for the direct combustion of coal or coal derived fuel. Three reference plants, differing primarily in the method of coal conversion utilized, were defined. Reference Plant 1 used direct coal fired combustion while Reference Plants 2 and 3 employed on site integrated gasifiers. Reference Plant 2 used a pressurized gasifier while Reference Plant 3 used a ""state of the art' atmospheric gasifier. Thirty plant configurations were considered by using parametric variations from the Reference Plants. Parametric variations include the type of coal (Montana Rosebud or Illinois No. 6), clean up systems (hot or cold gas clean up), on or two stage atmospheric or pressurized direct fired coal combustors, and six different gasifier systems. Plant sizes ranged from 100 to 1000 MWe. Overall plant performance was calculated using two methodologies. In one task, the channel performance was assumed and the MHD topping cycle efficiencies were based on the assumed values. A second task involved rigorous calculations of channel performance (enthalpy extraction, isentropic efficiency and generator output) that verified the original (task one) assumptions. Closed cycle MHD capital costs were estimated for the task one plants; task two cost estimates were made for the channel and magnet only.

  7. Conceptual design and analysis of ITM oxy-combustion power cycles.

    PubMed

    Mancini, N D; Mitsos, A

    2011-12-28

    Ion transport membrane (ITM)-based oxy-combustion systems could potentially provide zero-emissions power generation with a significantly reduced thermodynamic penalty compared to conventional carbon capture applications. This article investigates ITM-based oxy-combustion power cycles using an intermediate-fidelity model that captures the complex physical coupling between the two systems and accurately accounts for operational constraints. Coupled ITM-cycle simulation reveals hidden design challenges, facilitates the development of novel cycle concepts, and enables accurate assessment of new and existing power cycles. Simulations of various ITM-based zero and partial-emissions power cycles are performed using an intermediate-fidelity ITM model coupled to power cycle models created in ASPEN Plus®. The objectives herein are to analyze the prevalent ITM-based power cycle designs, develop novel design modifications, and evaluate the implementation of reactive ITMs. An assessment of the potential for these ITM power cycles to reduce both the thermodynamic penalty and reactor size associated with ITM air separation technology is conducted. The power cycle simulation and analysis demonstrate the various challenges associated with implementing reactive ITMs; hybridization (the use of both reactive and separation-only ITMs) is necessary in order to effectively utilize the advantages of reactive ITMs. The novel hybrid cycle developed herein displays the potential to reduce the size of the ITM compared to the best separation-only concept while maintaining a comparable First Law efficiency. Next, the merit of implementing partial-emissions cycles is explored based on a proposed linear-combination metric. The results indicate that the tradeoff between the main thermodynamic performance metrics efficiency and CO(2) emissions does not appear to justify the use of partial-emissions cycles. PMID:22033659

  8. Closed Brayton cycle power conversion systems for nuclear reactors :

    SciTech Connect

    Wright, Steven A.; Lipinski, Ronald J.; Vernon, Milton E.; Sanchez, Travis

    2006-04-01

    This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

  9. Coal gasification for electric power generation.

    PubMed

    Spencer, D F; Gluckman, M J; Alpert, S B

    1982-03-26

    The electric utility industry is being severely affected by rapidly escalating gas and oil prices, restrictive environmental and licensing regulations, and an extremely tight money market. Integrated coal gasification combined cycle (IGCC) power plants have the potential to be economically competitive with present commercial coal-fired power plants while satisfying stringent emission control requirements. The current status of gasification technology is discussed and the critical importance of the 100-megawatt Cool Water IGCC demonstration program is emphasized. PMID:17788466

  10. Innovative gasification technology for future power generation

    SciTech Connect

    Mahajan, K.; Shadle, L.J.; Sadowski, R.S.

    1995-07-01

    Ever tightening environmental regulations have changed the way utility and non-utility electric generation providers currently view their fuels choices. While coal is still, by far, the major fuel utilized in power production, the general trend over the past 20 years has been to switch to low-sulfur coal and/or make costly modifications to existing coal-fired facilities to reach environmental compliance. Unfortunately, this approach has led to fragmented solutions to balance our energy and environmental needs. To date, few integrated gasification combined-cycle (IGCC) suppliers have been able to compete with the cost of other more conventional technologies or fuels. One need only look at the complexity of many IGCC approaches to understand that unless a view toward IEC is adopted, the widespread application of such otherwise potentially attractive technologies will be unlikely in our lifetime. Jacobs-Sirrine Engineers and Riley Stoker Corporation are working in partnership with the Department of Energy`s Morgantown Energy Technology Center to help demonstrate an innovative coal gasification technology called {open_quotes}PyGas{trademark},{close_quotes} for {open_quotes}pyrolysis-gasification{close_quotes}. This hybrid variation of fluidized-bed and fixed-bed gasification technologies is being developed with the goal to efficiently produce clean gas at costs competitive with more conventional systems by incorporating many of the principles of IEC within the confines of a single-gasifier vessel. Our project is currently in the detailed design stage of a 4 ton-per-hour gasification facility to be built at the Fort Martin Station of Allegheny Power Services. By locating the test facility at an existing coal-fired plant, much of the facility infrastructure can be utilized saving significant costs. Successful demonstration of this technology at this new facility is a prerequisite to its commercialization.

  11. Estimation of crank angle for cycling with a powered prosthesis.

    PubMed

    Lawson, B E; Shultz, A; Ledoux, E; Goldfarb, M

    2014-01-01

    In order for a prosthesis to restore power generation during cycling, it must supply torque in a manner that is coordinated with the motion of the bicycle crank. This paper outlines an algorithm for the real time estimation of the angular position of a bicycle crankshaft using only measurements internal to an intelligent knee and ankle prosthesis. The algorithm assumes that the rider/prosthesis/bicycle system can be modeled as a four-bar mechanism. Assuming that a prosthesis can generate two independent angular measurements of the mechanism (in this case the knee angle and the absolute orientation of the shank), Freudenstein's equation can be used to synthesize the mechanism continuously. A recursive least-squares algorithm is implemented to estimate the Freudenstein coefficients, and the resulting link lengths are used to reformulate the equation in terms of input-output relationships mapping both measured angles to the crank angle. Using two independent measurements allows the algorithm to uniquely determine the crank angle from multi-valued functions. In order to validate the algorithm, a bicycle was mounted on a trainer and configured with the prosthesis using an artificial hip joint attached to the seat post. Motion capture was used to monitor the mechanism for forward and backward pedaling and the results are compared to the output of the presented algorithm. Once the parameters have converged, the algorithm is shown to predict the crank angle within 15° of the externally measured value throughout the entire crank cycle during forward rotation. PMID:25571415

  12. Power Smoothing and MPPT for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

    NASA Astrophysics Data System (ADS)

    Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

    Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation, and variable speed control and power factor control are executed for high efficiently for wind energy capture and high quality for power system voltage. In variable speed control, a wind speed or a generator speed is used for maximum power point tracking. However, performances of a wind generation power fluctuation due to wind speed variation have not yet investigated for those controls. The authors discuss power smoothing by those controls for the DFIG inter-connected to 6.6kV distribution line. The performances are verified using power system simulation software PSCAD/EMTDC for actual wind speed data and are examined from an approximate equation of wind generation power fluctuation for wind speed variation.

  13. Impact of Altitude on Power Output during Cycling Stage Racing

    PubMed Central

    Garvican-Lewis, Laura A; Clark, Bradley; Martin, David T.; Schumacher, Yorck Olaf; McDonald, Warren; Stephens, Brian; Ma, Fuhai; Thompson, Kevin G.; Gore, Christopher J.; Menaspà, Paolo

    2015-01-01

    Purpose The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour. Methods Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000m (<1000m, 1000–2000, 2000–3000 and >3000m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. Results Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5–600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level. Conclusion A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes. PMID:26629912

  14. Test results of an organic Rankine-cycle power module for a small community solar thermal power experiment

    NASA Technical Reports Server (NTRS)

    Clark, T. B.

    1985-01-01

    The organic Rankine-cycle (ORC) power conversion assembly was tested. Qualification testing of the electrical transport subsystem was also completed. Test objectives were to verify compatibility of all system elements with emphasis on control of the power conversion assembly, to evaluate the performance and efficiency of the components, and to validate operating procedures. After 34 hours of power generation under a wide range of conditions, the net module efficiency exceeded 18% after accounting for all parasitic losses.

  15. 78 FR 32385 - Exelon Generation Company, LLC; CER Generation II, LLC; Constellation Mystic Power, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-30

    ... Energy Regulatory Commission Exelon Generation Company, LLC; CER Generation II, LLC; Constellation Mystic Power, LLC; Constellation NewEnergy, Inc.; Constellation Power Source Generation, Inc.; Criterion Power..., CER Generation II, LLC, Constellation Mystic Power, LLC, Constellation NewEnergy, Inc.,...

  16. A numerical investigation of a thermodielectric power generation system

    NASA Astrophysics Data System (ADS)

    Sklar, Akiva A.

    The performance of a novel micro-thermodielectric power generation system was investigated in order to determine if thermodielectric power generation can be practically employed and if its performance can compete with current portable power generation technologies. Thermodielectric power generation is a direct energy conversion technology that converts heat directly into high voltage direct current. It requires dielectric (i.e., capacitive) materials whose charge storing capabilities are a function of temperature. This property can be exploited by heating these materials after they are charged; as their temperature increases, their charge storage capability decreases, forcing them to eject a portion of their surface charge. This ejected charge can then be supplied to an appropriate electronic storage device. There are several advantages associated with thermodielectric energy conversion; first, it requires heat addition at relatively low conventional power generation temperatures, i.e., less than 600 °K, and second, devices that utilize it have the potential for excellent power density and device reliability. The predominant disadvantage of using this power generation technique is that the device must operate in an unsteady manner; this can lead to substantial heat transfer losses that limit the device's thermal efficiency. The studied power generation system was designed so that the power generating components of the system (i.e., the thermodielectric materials) are integrated within a micro-scale heat exchange apparatus designed specifically to provide the thermodielectric materials with the unsteady heating and cooling necessary for efficient power generation. This apparatus is designed to utilize a liquid as a working fluid in order to maximize its heat transfer capabilities, minimize the size of the heat exchanger, and maximize the power density of the power generation system. The thermodielectric materials are operated through a power generation cycle that

  17. Influence of cycling current and power profiles on the cycle life of lead/acid batteries

    NASA Astrophysics Data System (ADS)

    Papazov, G.; Pavlov, D.

    Batteries are assembled with positive plates of the novel strap grid tubular (SGTP) design described in a previous paper [1]. These batteries are subjected to four tests: (i) Peukert dependence determinations; (ii) classical galvanostatic cycling (5 h charge and 1 h discharge); (iii) EV-SFUDS, and (iv) EV-ECE-15 cycling tests. It has been established that the Peukert dependence curve of SGTP batteries is very close in profile to that for SLI batteries. This guarantees SGTP's batteries high power performance. These batteries endure over 950 cycles on galvanostatic cycling. When cycled according to the SFUDS power profile under a current load of 320 A/kg positive active mass during the 15th SFUDS step, SGTP batteries exhibit a cycle life of 350-450 cycles. If the current density during the 15th step is 190 A/kg PAM, the batteries endure over 600 charge/discharge cycles. The life of positive SGT plates is limited by power loss, but not by capacity. Similar results have also been obtained from ECE-15 cycle-life tests. On cycling SGTP batteries with a current load of 210 A/kg PAM during the 23rd ECE-15 step (the step during which maximum power output is demanded from the battery), they endure between 550 and 650 charge/discharge cycles. A summary of the test results obtained for two batches of experimental batteries indicates that there is a direct dependence between the SGTP battery cycle life and the maximum current density on discharge. Increasing the discharge current density decreases the battery life. It has also been established that the capacity on SFUDS (ECE-15) discharge declines gradually on cycling in favour of the residual galvanostatic capacity at 5 h rate of discharge (100% depth-of-discharge) which increases. This implies that two types of structures are formed in the positive plates on cycling: the first type ensuring high power output and the second type yielding low power but long cycle life. The higher the power delivered by the positive plate, the

  18. Coal-burning magnetohydrodynamic power generation

    SciTech Connect

    Kessler, R.; Hals, F. )

    1992-01-01

    In this paper, coal-burning magnetohydrodynamic (MHD) electric power generation technology is described, and its economic and environmental advantages are discussed. advanced MHD/steam plants can achieve efficiencies of 55%-60% with less environmental intrusion than form conventional coal-burning steam plants. The national program for development of MHD power generation is outlined and the development status of individual components and subsystems is presented.

  19. Power generation method including membrane separation

    DOEpatents

    Lokhandwala, Kaaeid A.

    2000-01-01

    A method for generating electric power, such as at, or close to, natural gas fields. The method includes conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas by means of a membrane separation step. This step creates a leaner, sweeter, drier gas, which is then used as combustion fuel to run a turbine, which is in turn used for power generation.

  20. Life cycle water use for electricity generation: a review and harmonization of literature estimates

    NASA Astrophysics Data System (ADS)

    Meldrum, J.; Nettles-Anderson, S.; Heath, G.; Macknick, J.

    2013-03-01

    This article provides consolidated estimates of water withdrawal and water consumption for the full life cycle of selected electricity generating technologies, which includes component manufacturing, fuel acquisition, processing, and transport, and power plant operation and decommissioning. Estimates were gathered through a broad search of publicly available sources, screened for quality and relevance, and harmonized for methodological differences. Published estimates vary substantially, due in part to differences in production pathways, in defined boundaries, and in performance parameters. Despite limitations to available data, we find that: water used for cooling of thermoelectric power plants dominates the life cycle water use in most cases; the coal, natural gas, and nuclear fuel cycles require substantial water per megawatt-hour in most cases; and, a substantial proportion of life cycle water use per megawatt-hour is required for the manufacturing and construction of concentrating solar, geothermal, photovoltaic, and wind power facilities. On the basis of the best available evidence for the evaluated technologies, total life cycle water use appears lowest for electricity generated by photovoltaics and wind, and highest for thermoelectric generation technologies. This report provides the foundation for conducting water use impact assessments of the power sector while also identifying gaps in data that could guide future research.

  1. Review of pulsed rf power generation

    SciTech Connect

    Lavine, T.L.

    1992-04-01

    I am going to talk about pulsed high-power rf generation for normal-conducting electron and positron linacs suitable for applications to high-energy physics in the Next Linear Collider, or NLC. The talk will cover some basic rf system design issues, klystrons and other microwave power sources, rf pulse-compression devices, and test facilities for system-integration studies.

  2. Generation of sonic power during welding

    NASA Technical Reports Server (NTRS)

    Mc Campbell, W. M.

    1969-01-01

    Generation of intense sonic and ultrasonic power in the weld zone, close to the puddle, reduces the porosity and refinement of the grain. The ac induction brazing power supply is modified with long cables for deliberate addition of resistance to that circuit. The concept is extensible to the molding of metals and plastics.

  3. Apparatus and method for thermal power generation

    DOEpatents

    Cohen, Paul; Redding, Arnold H.

    1978-01-01

    An improved thermal power plant and method of power generation which minimizes thermal stress and chemical impurity buildup in the vaporizing component, particularly beneficial under loss of normal feed fluid and startup conditions. The invention is particularly applicable to a liquid metal fast breeder reactor plant.

  4. Hybrid Er/Yb fibre laser system for generating few-cycle 1.6 to 2.0 {mu}m pulses optically synchronised with high-power pulses near 1 {mu}m

    SciTech Connect

    Andrianov, A V; Anashkina, E A; Murav'ev, S V; Kim, A V

    2013-03-31

    This paper presents the concept of fibre laser system design for generating optically synchronised femtosecond pulses at two, greatly differing wavelengths and reports experimental and numerical simulation studies of nonlinear conversion of femtosecond pulses at 1.5 {mu}m wavelength in a dispersion-shifted fibre, with the generation of synchronised pulses in the ranges 1.6 - 2 and 1 - 1.1 {mu}m. We describe a three-stage high-power fibre amplifier of femtosecond pulses at 1 {mu}m and a hybrid Er/Yb fibre laser system that has enabled the generation of 12 fs pulses with a centre wavelength of 1.7 {mu}m, synchronised with high-power (microjoule level) 250 fs pulses at 1.03 {mu}m. (extreme light fields and their applications)

  5. Design and operation of a geopressurized-geothermal hybrid cycle power plant

    SciTech Connect

    Campbell, R.G.; Hattar, M.M.

    1991-02-01

    Geopressured-geothermal resources can contribute significantly to the national electricity supply once technical and economic obstacles are overcome. Power plant performance under the harsh conditions of a geopressured resource was unproven, so a demonstration power plant was built and operated on the Pleasant Bayou geopressured resource in Texas. This one megawatt facility provided valuable data over a range of operating conditions. This power plant was a first-of-a-kind demonstration of the hybrid cycle concept. A hybrid cycle was used to take advantage of the fact that geopressured resources contain energy in more than one form -- hot water and natural gas. Studies have shown that hybrid cycles can yield thirty percent more power than stand-alone geothermal and fossil fuel power plants operating on the same resource. In the hybrid cycle at Pleasant Bayou, gas was burned in engines to generate electricity directly. Exhaust heat from the engines was then combined with heat from the brine to generate additional electricity in a binary cycle. Heat from the gas engine was available at high temperature, thus improving the efficiency of the binary portion of the hybrid cycle. Design power output was achieved, and 3445 MWh of power were sold to the local utility over the course of the test. Plant availability was 97.5% and the capacity factor was over 80% for the extended run at maximum power production. The hybrid cycle power plant demonstrated that there are no technical obstacles to electricity generation at Pleasant Bayou. 14 refs., 38 figs., 16 tabs.

  6. On Evaluating Cycling and Movement of Conventional Generators for Balancing Services with Large Solar Penetration

    SciTech Connect

    Diao, Ruisheng; Lu, Shuai; Ma, Jian

    2012-05-07

    Abstract— The increasing uncertainty caused by a higher penetration level of renewable energy points to the need for sufficient balancing services to ensure secure operation. It is thus of necessity to accurately quantify these services and evaluate the cycling and movement of conventional generators providing load following and regulation services for optimally planning and scheduling multiple resources. This paper first introduces a systematic approach to calculating load following and regulation requirements with a large amount of solar integration. Then, two methods to quantitatively determine the cycling of conventional generators are proposed, including (1) mileage and number of direction changes in balancing service and (2) ramp statistics (or half-cycle) analysis. The proposed methods are tested on the NV Energy power system model. Simulation results demonstrate a significant impact of increased solar capacity on balancing service and cycling of conventional generators. Busy hours are identified for different study scenarios with various solar penetration levels. This study provides a basis for evaluating the wear and tear of the conventional generators in the solar integration process in the Nevada power system. Index Terms—balancing requirement, conventional generator, cycling and movement, load following, regulation, renewable energy, solar integration

  7. Fiscalini Farms Renewable Energy Power Generation Project

    SciTech Connect

    2009-02-01

    Funded by the American Recovery and Reinvestment Act of 2009 Fiscalini Farms L.P., in collaboration with University of the Pacific, Biogas Energy, Inc., and the University of California at Berkeley will measure and analyze the efficiency and regulatory compliance of a renewable energy system for power generation. The system will utilize digester gas from an anaerobic digester located at the Fiscalini Farms dairy for power generation with a reciprocating engine. The project will provide power, efficiency, emissions, and cost/benefit analysis for the system and evaluate its compliance with federal and California emissions standards.

  8. Solar driven liquid metal MHD power generator

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Hohl, F.

    1983-06-01

    A solar energy collector focuses solar energy onto a solar oven which is attached to a mixer which in turn is attached to the channel of a MHD generator. Gas enters the oven and a liquid metal enters the mixer. The gas/liquid metal mixture is heated by the collected solar energy and moves through the MHD generator thereby generating electrical power. The mixture is then separated and recycled.

  9. Solar driven liquid metal MHD power generator

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Hohl, F. (Inventor)

    1983-01-01

    A solar energy collector focuses solar energy onto a solar oven which is attached to a mixer which in turn is attached to the channel of a MHD generator. Gas enters the oven and a liquid metal enters the mixer. The gas/liquid metal mixture is heated by the collected solar energy and moves through the MHD generator thereby generating electrical power. The mixture is then separated and recycled.

  10. A combined power and ejector refrigeration cycle for low temperature heat sources

    SciTech Connect

    Zheng, B.; Weng, Y.W.

    2010-05-15

    A combined power and ejector refrigeration cycle for low temperature heat sources is under investigation in this paper. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. The ejector is driven by the exhausts from the turbine to produce power and refrigeration simultaneously. A simulation was carried out to analyze the cycle performance using R245fa as the working fluid. A thermal efficiency of 34.1%, an effective efficiency of 18.7% and an exergy efficiency of 56.8% can be obtained at a generating temperature of 395 K, a condensing temperature of 298 K and an evaporating temperature of 280 K. Simulation results show that the proposed cycle has a big potential to produce refrigeration and most exergy losses take place in the ejector. (author)