Sample records for thermal power generated

  1. 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.

  2. Thermal energy storage considerations for solar-thermal power generation

    Microsoft Academic Search

    N. Lior; P. S. Ayyaswamy; J. Oleary; K. W. Kauffman; H. Yeh; H. G. Lorsch

    1976-01-01

    The problem of thermal energy storage for solar-thermal power generation is examined. Major conceptual systems for thermal storage are proposed and described. Storage modes through sensible heat, latent heat (phase change), and thermochemical energy are reviewed and proposed. A survey of applicable materials for thermal storage, which includes available thermophysical properties, compatibility with containing and heat transfer interfaces, and economics,

  3. Radioisotope thermal generator (RTG) power conditioner

    NASA Technical Reports Server (NTRS)

    Stacey, W. S.

    1974-01-01

    New regulator: (a) permits operation with high-impedance radioisotope thermal generators at conversion efficiencies typically above 90%; (b) does not require input filtering; (c) eliminates current spiking; and (d) is simple, efficient, and reliable. Converter-charger pair could be adapted for other power levels by changing transistor, diode, capacitor bank, and inductor.

  4. Phase Change Material Thermal Power Generator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2013-01-01

    An innovative modification has been made to a previously patented design for the Phase Change Material (PCM) Thermal Generator, which works in water where ocean temperature alternatively melts wax in canisters, or allows the wax to re-solidify, causing high-pressure oil to flow through a hydraulic generator, thus creating electricity to charge a battery that powers the vehicle. In this modification, a similar thermal PCM device has been created that is heated and cooled by the air and solar radiation instead of using ocean temperature differences to change the PCM from solid to liquid. This innovation allows the device to use thermal energy to generate electricity on land, instead of just in the ocean.

  5. Thermal energy storage for power generation

    SciTech Connect

    Drost, M.K.; Antoniak, Z.I.; Brown, D.R.; Sathyanarayana, K.

    1989-10-01

    Studies strongly indicate that the United States will face widespread electrical power constraints in the 1990s, with most regions of the country experiencing capacity shortages by the year 2000. In many cases, the demand for increased power will occur during intermediate and peak demand periods. Much of this demand is expected to be met by oil- and natural gas-fired Brayton cycle turbines and combined-cycle plants. While natural gas is currently plentiful and reasonably priced, the availability of an economical long-term coal-fired option for peak and intermediate load power generation will give electric power utilities an option in case either the availability or cost of natural gas should deteriorate. 54 refs., 5 figs., 17 tabs.

  6. Low-cost distributed solar-thermal-electric power generation

    E-print Network

    Sanders, Seth

    Low-cost distributed solar-thermal-electric power generation A. Der Minassians, K. H. Aschenbach discuss the technical and economic feasibility of a low-cost distributed solar-thermal-electric power relative cost, solar electric energy systems have yet to be exploited on a widespread basis. It is believed

  7. Device for thermal transfer and power generation

    DOEpatents

    Weaver, Stanton Earl (Northville, NY); Arik, Mehmet (Niskayuna, NY)

    2011-04-19

    A system is provided. The system includes a device that includes top and bottom thermally conductive substrates positioned opposite to one another, wherein a top surface of the bottom thermally conductive substrate is substantially atomically flat and a thermal blocking layer disposed between the top and bottom thermally conductive substrates. The device also includes top and bottom electrodes separated from one another between the top and bottom thermally conductive substrates to define a tunneling path, wherein the top electrode is disposed on the thermal blocking layer and the bottom electrode is disposed on the bottom thermally conductive substrate.

  8. Thermal investigation of a micro-gap thermionic power generator

    NASA Astrophysics Data System (ADS)

    Yacine Belbachir, Remi; An, Zhonglie; Ono, Takahito

    2014-08-01

    The demand for safe and clean energy sources has become more important than ever worldwide. Thermionic power generation is one of these energy sources, which directly converts heat into electrical energy using thermionic electrons. We developed a micro-gap thermionic power generator, which operates at relatively low temperature using SiC as an emitter. Electrons are emitted and travel from the heated SiC emitter to the collector electrode by thermionic emission. In this work, we have firstly demonstrated low temperature operation at 830?oC as a result of micro-gap between the emitter and collector electrodes. An output power density of 11.5?mW/cm2 is obtained. In addition, the heat losses from the emitter electrode are evaluated. Thermal conduction to the collector is by far the predominant thermal loss. In order to validate this result, a thermal resistance measurement device is built and the thermal resistance of the micro-gap is measured. Its value of 2.4?K/W allows for estimating in a more realistic way the heat loss by thermal conduction from the emitter to the collector via the gap. The newly estimated value still corresponds to a predominant thermal loss, hence highlighting the need for downsizing the SiO2 columns of the micro-gap in order to increase the power conversion efficiency.

  9. Stirling Engines for Low-Temperature Solar-Thermal-Electric Power Generation

    E-print Network

    Sanders, Seth

    Stirling Engines for Low-Temperature Solar-Thermal- Electric Power Generation Artin Der Minassians-Temperature Solar-Thermal-Electric Power Generation by Artin Der Minassians Karshenasi (Amirkabir University-Temperature Solar-Thermal-Electric Power Generation Copyright c 2007 by Artin Der Minassians #12;1 Abstract Stirling

  10. Commercialization of solar thermal power generation: policy issues

    SciTech Connect

    Zuckerman, J.V.

    1985-10-01

    Without the focused public attention which has been drawn to nuclear power, without the tremendous outpouring of financial assistance from the federal government which was applied to nuclear development, without even the more moderate financial support devoted to synthetic fuel production, the utilization of sun-power to generate electricity has come to technical feasibility. Not only has it been demonstrated, but it has been made operational. Solar One, described in an accompanying article, is a technical success. What is additionally needed is the dimension of economic success. This article will focus on those aspects of economic feasibility which delineate the legal, financial, and policy obstacles, and the possible means of overcoming those obstacles for solar energy technology in the field of electric power generation. Included is a brief review of incentives which have been offered over the past years by the federal government to encourage the development of energy resources, including fossil fuels, nuclear energy, synthetic fuels, and renewable resources, and a statement of the monetary value of those incentives; examination of the statements of national goals for energy in the US as they have been espoused by different presidential administrations and expressed concerning solar energy; and a recommendation for policy, legal, and financial actions to be taken to produce a climate favorable for the rapid commercialization of solar thermal power generation. 2 tables.

  11. Advanced Stirling Radioisotope Generator (ASRG) Thermal Power Model in MATLAB

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen, J.

    2012-01-01

    This paper presents a one-dimensional steady-state mathematical thermal power model of the ASRG. It aims to provide a guideline of understanding how the ASRG works and what can change its performance. The thermal dynamics and energy balance of the generator is explained using the thermal circuit of the ASRG. The Stirling convertor performance map is used to represent the convertor. How the convertor performance map is coupled in the thermal circuit is explained. The ASRG performance characteristics under i) different sink temperatures and ii) over the years of mission (YOM) are predicted using the one-dimensional model. Two Stirling converter control strategies, i) fixing the hot-end of temperature of the convertor by adjusting piston amplitude and ii) fixing the piston amplitude, were tested in the model. Numerical results show that the first control strategy can result in a higher system efficiency than the second control strategy when the ambient gets warmer or the general-purpose heat source (GPHS) fuel load decays over the YOM. The ASRG performance data presented in this paper doesn't pertain to the ASRG flight unit. Some data of the ASRG engineering unit (EU) and flight unit that are available in public domain are used in this paper for the purpose of numerical studies.

  12. Solar thermal power generation. A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Bibliographies and abstracts are cited under the following topics: (1) energy overviews; (2) solar overviews; (3) conservation; (4) economics, law; (5) thermal power; (6) thermionic, thermoelectric; (7) ocean; (8) wind power; (9) biomass and photochemical; and (10) large photovoltaics.

  13. High-density thermoelectric power generation and nanoscale thermal metrology

    E-print Network

    Mayer, Peter (Peter Matthew), 1978-

    2007-01-01

    Thermoelectric power generation has been around for over 50 years but has seen very little large scale implementation due to the inherently low efficiencies and powers available from known materials. Recent material advances ...

  14. Advanced Stirling Radioisotope Generator Thermal Power Model in Thermal Desktop SINDA/FLUINT Analyzer

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen; Fabanich, William A.; Schmitz, Paul C.

    2012-01-01

    This paper presents a three-dimensional Advanced Stirling Radioisotope Generator (ASRG) thermal power model that was built using the Thermal Desktop SINDA/FLUINT thermal analyzer. The model was correlated with ASRG engineering unit (EU) test data and ASRG flight unit predictions from Lockheed Martin's Ideas TMG thermal model. ASRG performance under (1) ASC hot-end temperatures, (2) ambient temperatures, and (3) years of mission for the general purpose heat source fuel decay was predicted using this model for the flight unit. The results were compared with those reported by Lockheed Martin and showed good agreement. In addition, the model was used to study the performance of the ASRG flight unit for operations on the ground and on the surface of Titan, and the concept of using gold film to reduce thermal loss through insulation was investigated.

  15. A thermally efficient micro-reactor for thermophotovoltaic power generation

    E-print Network

    Nielsen, Ole Mattis, 1977-

    2006-01-01

    Hydrocarbon fuels exhibit very high energy densities, and micro-generators converting the stored chemical energy into electrical power are interesting alternatives to batteries in certain applications. The increasing demands ...

  16. Commercialization of solar thermal power generation: policy issues

    Microsoft Academic Search

    Zuckerman

    1985-01-01

    Without the focused public attention which has been drawn to nuclear power, without the tremendous outpouring of financial assistance from the federal government which was applied to nuclear development, without even the more moderate financial support devoted to synthetic fuel production, the utilization of sun-power to generate electricity has come to technical feasibility. Not only has it been demonstrated, but

  17. The application of thermal energy storage systems to power generation and process industries

    Microsoft Academic Search

    M. J. Braun; O. W. Durrant

    1982-01-01

    This paper investigates the use of thermal storage for energy conservation applications. The accent falls specifically on the utilization of the high temperature thermal energy storage in conjunction with a fossil boiler for energy generation, and with a solar powered boiler for both energy generation and industrial use. For medium temperature thermal energy storage the paper describes the development of

  18. The development of a solar thermal water purification, heating, and power generation system: A case study.

    E-print Network

    Wu, Mingshen

    The development of a solar thermal water purification, heating, and power generation system: A case, none of the existing concentrated solar power systems (trough, dish, and tower) that have been the potential of an invention directed to a water purification system that also recovers power from generated

  19. Optimal thermal generating unit commitment of large power system: a novel approach

    Microsoft Academic Search

    Subir Sen; D. P. Kothari

    1998-01-01

    This paper presents a new efficient solution approach for solving the unit commitment schedule of thermal generating units of a realistic large scale power system. The approach is based on the equivalencing like concept of network reduction which reduces the number of units in the large power system to the lowest possible number according to their fuel\\/generation cost characteristics. The

  20. Stirling engines for low-temperature solar-thermal-electric power generation

    Microsoft Academic Search

    Artin der Minassians

    2007-01-01

    This dissertation discusses the design and development of a distributed solar-thermal-electric power generation system that combines solar-thermal technology with a moderate-temperature Stirling engine to generate electricity. The conceived system incorporates low-cost materials and utilizes simple manufacturing processes. This technology is expected to achieve manufacturing cost of less than $1\\/W. Since solar-thermal technology is mature, the analysis, design, and experimental assessment

  1. Low-cost distributed solar-thermal-electric power generation

    NASA Astrophysics Data System (ADS)

    Der Minassians, Artin; Aschenbach, Konrad H.; Sanders, Seth R.

    2004-01-01

    Due to their high relative cost, solar electric energy systems have yet to be exploited on a widespread basis. It is believed in the energy community that a technology similar to photovoltaic (PV), but offered at about $1/W would lead to widespread deployment at residential and commercial sites. This paper addresses the investigation and feasibility study of a low-cost solar thermal electricity generation technology, suitable for distributed deployment. Specifically, we discuss a system based on nonimaging solar concentrators, integrated with free-piston Stirling engine devices incorporating integrated electric generation. We target concentrator-collector operation at moderate temperatures, in the range of 125°C to 150°C. This temperature is consistent with use of optical concentrators with concentration ratios on the order of 1-2. These low ratio concentrators admit wide angles of radiation acceptance and are thus compatible with no diurnal tracking, and no or only a few seasonal adjustments. Thus, costs and reliability hazards associated with tracking hardware systems are avoided. Further, we note that in the intended application, there is no shortage of incident solar energy, but rather it is the capital cost of the solar-electric system that is most precious. Thus, we outline a strategy for exploiting solar resources in a cost constrained manner. The paper outlines design issues, and a specific design for an appropriately dimensioned free-piston Stirling engine. Only standard low-cost materials and manufacturing methods are required to realize such a machine.

  2. Power processing and control requirements of dispersed solar thermal electric generation systems

    NASA Technical Reports Server (NTRS)

    Das, R. L.

    1980-01-01

    Power Processing and Control requirements of Dispersed Receiver Solar Thermal Electric Generation Systems are presented. Kinematic Stirling Engines, Brayton Engines and Rankine Engines are considered as prime movers. Various types of generators are considered for ac and dc link generations. It is found that ac-ac Power Conversion is not suitable for implementation at this time. It is also found that ac-dc-ac Power Conversion with a large central inverter is more efficient than ac-dc-ac Power Conversion using small dispersed inverters. Ac-link solar thermal electric plants face potential stability and synchronization problems. Research and development efforts are needed in improving component performance characteristics and generation efficiency to make Solar Thermal Electric Generation economically attractive.

  3. Experience in connecting the power generating units of thermal power plants to automatic secondary frequency regulation within the united power system of Russia

    SciTech Connect

    Zhukov, A. V.; Komarov, A. N.; Safronov, A. N.; Barsukov, I. V. [JSC 'Sistemnyi operator EES' (Russian Federation)

    2009-05-15

    The principles of central control of the power generating units of thermal power plants by automatic secondary frequency and active power overcurrent regulation systems, and the algorithms for interactions between automatic power control systems for the power production units in thermal power plants and centralized systems for automatic frequency and power regulation, are discussed. The order of switching the power generating units of thermal power plants over to control by a centralized system for automatic frequency and power regulation and by the Central Coordinating System for automatic frequency and power regulation is presented. The results of full-scale system tests of the control of power generating units of the Kirishskaya, Stavropol, and Perm GRES (State Regional Electric Power Plants) by the Central Coordinating System for automatic frequency and power regulation at the United Power System of Russia on September 23-25, 2008, are reported.

  4. Experimental investigation on a parabolic trough solar collector for thermal power generation

    Microsoft Academic Search

    QiBin Liu; YaLong Wang; ZhiChao Gao; Jun Sui; HongGuang Jin; HePing Li

    2010-01-01

    Developing solar thermal power technology in an effective manner is a great challenge in China. In this paper an experiment\\u000a platform of a parabolic trough solar collector system (PTCS) was developed for thermal power generation, and the performance\\u000a of the PTCS was experimentally investigated with synthetic oil as the circulate heat transfer fluid (HTF). The solar collector’s\\u000a efficiency with the

  5. Novel Thermal Storage Technologies for Concentrating Solar Power Generation

    SciTech Connect

    Neti, Sudhakar; Oztekin, Alparslan; Chen, John; Tuzla, Kemal; Misiolek, Wojciech

    2013-06-20

    The technologies that are to be developed in this work will enable storage of thermal energy in 100 MWe solar energy plants for 6-24 hours at temperatures around 300oC and 850oC using encapsulated phase change materials (EPCM). Several encapsulated phase change materials have been identified, fabricated and proven with calorimetry. Two of these materials have been tested in an airflow experiment. A cost analysis for these thermal energy storage systems has also been conducted that met the targets established at the initiation of the project.

  6. Technical and economical evaluation of solar thermal power generation

    Microsoft Academic Search

    Theocharis Tsoutsos; Vasilis Gekas; Katerina Marketaki

    2003-01-01

    This article presents a feasibilty on a solar power system based on the Stirling dish (SD) technology, reviews and compares the available Stirling engines in the perspective of a solar Stirling system.The system is evaluated, as a parameter to alleviate the energy system of the Cretan island while taking care of the CO2 emissions. In the results a sensitivity analysis

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

    SciTech Connect

    Yomogida, D.E. [California Energy Commission, Sacramento, CA (United States); Thinh, Ngo Dinh [California State Univ., Sacramento, CA (United States)

    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.

  8. Thermal and chemical tests of the steam generator of unit 3 at the Kalinin nuclear power station

    NASA Astrophysics Data System (ADS)

    Davidenko, N. N.; Trunov, N. B.; Saakov, E. S.; Berezanin, A. A.; Bogomolov, I. N.; Derii, V. P.; Nemytov, D. S.; Usanov, D. A.; Shestakov, N. B.; Shchelik, S. V.

    2007-12-01

    The results obtained from combined thermal and chemical tests of the steam generator of Unit 3 at the Kalinin nuclear power station are summarized. The obtained data are compared with the results of thermal and chemical tests carried out on steam generators at other nuclear power stations equipped with VVER-1000 reactors, and recommendations on selecting the steam-generator blowdown schedule are given.

  9. A Novel Approach for Generating Dynamic Compact Models of Thermal Networks Having Large Numbers of Power Sources

    E-print Network

    Paris-Sud XI, Université de

    with the number of power sources. 1 Introduction Various techniques are reported in literature for generating. These techniques cannot be applied to generate compact models of thermal networks hav- ing large numbers of powerA Novel Approach for Generating Dynamic Compact Models of Thermal Networks Having Large Numbers

  10. Solar thermal power towers

    Microsoft Academic Search

    FRANK KREITH; RICHARD T. MEYER

    1984-01-01

    The solar thermal central receiver technology, known as solar power towers, is rapidly evolving to a state of near-term energy availability for electrical power generation and industrial process heat applications. The systems consist of field arrays of heliostat reflectors, a central receiver boiler, short term thermal storage devices, and either turbine-generators or heat exchangers. Fluid temperatures up to 550 C

  11. A Feasibility Study of Solar Thermal Power Generation as the Pumping Power Source for Pumped Storage in Indonesia

    NASA Astrophysics Data System (ADS)

    Funatsu, Tetsuya; Natsume, Hiroaki

    A pumped storage hydroelectric generation (PSHG) has been studied as alternative peak power source of the oil-fired power generation in Indonesia. However, because there is no surplus base load electricity even in the night, the economic advantage can not be found. The possibility of solar thermal power generation (STPG) is investigated to restrain the increase of fuel consumption by the existing peak power source. The optimum system simulation and the analysis of economy and environmental impact by a multiobjective optimization method provide the following results. The optimum aperture area and thermal storage capacity of STPG are found by the simulation based on the climate and the solar condition in West Java. PSHG with STPG as the power source of storage pump shows lower generation cost and CO2 emission than PSHG with existing oil fired peak power sources. Even if the fuel switch from oil to gas is supposed in future, PSHG with STPG will achieve the lower generation cost and CO2 emission than PSHG with the oil/gas fired combined cycle by sharing the peak electricity supply with the oil/gas fired combined cycle in an appropriate ratio. Furthermore, if the crude oil price hike in future is considered, PSHG with STPG may be the optimal solution for the peak electricity supply of Java-Bari grid.

  12. Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux

    DOEpatents

    Bowman, Charles D. (Los Alamos, NM)

    1992-01-01

    Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux. High thermal neutron fluxes generated from the action of a high power proton accelerator on a spallation target allows the efficient burn-up of higher actinide nuclear waste by a two-step process. Additionally, rapid burn-up of fission product waste for nuclides having small thermal neutron cross sections, and the practicality of small material inventories while achieving significant throughput derive from employment of such high fluxes. Several nuclear technology problems are addressed including 1. nuclear energy production without a waste stream requiring storage on a geological timescale, 2. the burn-up of defense and commercial nuclear waste, and 3. the production of defense nuclear material. The apparatus includes an accelerator, a target for neutron production surrounded by a blanket region for transmutation, a turbine for electric power production, and a chemical processing facility. In all applications, the accelerator power may be generated internally from fission and the waste produced thereby is transmuted internally so that waste management might not be required beyond the human lifespan.

  13. Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux

    DOEpatents

    Bowman, C.D.

    1992-11-03

    Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux. High thermal neutron fluxes generated from the action of a high power proton accelerator on a spallation target allows the efficient burn-up of higher actinide nuclear waste by a two-step process. Additionally, rapid burn-up of fission product waste for nuclides having small thermal neutron cross sections, and the practicality of small material inventories while achieving significant throughput derive from employment of such high fluxes. Several nuclear technology problems are addressed including 1. nuclear energy production without a waste stream requiring storage on a geological timescale, 2. the burn-up of defense and commercial nuclear waste, and 3. the production of defense nuclear material. The apparatus includes an accelerator, a target for neutron production surrounded by a blanket region for transmutation, a turbine for electric power production, and a chemical processing facility. In all applications, the accelerator power may be generated internally from fission and the waste produced thereby is transmuted internally so that waste management might not be required beyond the human lifespan.

  14. Thermal behavior of a high power generator exciter bridge measured by optical fiber sensors

    NASA Astrophysics Data System (ADS)

    Probst, Werner K.; Bortolotti, Fernando; de Morais Sousa, Kleiton; Kalinowski, Hypolito José; Martelli, Cicero; Cardozo da Silva, Jean Carlos

    2013-05-01

    This paper presents temperature measurements taken at a 3-phase thyristor rectifier bridge in a synchronous generator using fiber Bragg grating (FBG) sensors applied directly on the thyristors upper surface. The results show the thermal behavior of the thyristors during the generator's start-up-phase and the period of time after the synchronization, with regulating operations as reaction to different load conditions. The temperature analysis is supported by current, voltage and power values of the hydroelectric power plant monitoring system. The trend of curves describes the typical behavior of thyristors which is proven with a four term transient thermal model. The different heat effect a thyristor experiences inside the switching-cabinet are also discussed.

  15. Consideration of Thermoelectric Power Generation by Using Hot Spring Thermal Energy or Industrial Waste Heat

    NASA Astrophysics Data System (ADS)

    Sasaki, Keiichi; Horikawa, Daisuke; Goto, Koichi

    2015-01-01

    Today, we face some significant environmental and energy problems such as global warming, urban heat island, and the precarious balance of world oil supply and demand. However, we have not yet found a satisfactory solution to these problems. Waste heat recovery is considered to be one of the best solutions because it can improve energy efficiency by converting heat exhausted from plants and machinery to electric power. This technology would also prevent atmospheric temperature increases caused by waste heat, and decrease fossil fuel consumption by recovering heat energy, thus also reducing CO2 emissions. The system proposed in this research generates electric power by providing waste heat or unharnessed thermal energy to built-in thermoelectric modules that can convert heat into electric power. Waste heat can be recovered from many places, including machinery in industrial plants, piping in electric power plants, waste incineration plants, and so on. Some natural heat sources such as hot springs and solar heat can also be used for this thermoelectric generation system. The generated power is expected to be supplied to auxiliary machinery around the heat source, stored as an emergency power supply, and so on. The attributes of this system are (1) direct power generation using hot springs or waste heat; (2) 24-h stable power generation; (3) stand-alone power system with no noise and no vibration; and (4) easy maintenance attributed to its simple structure with no moving parts. In order to maximize energy use efficiency, the temperature difference between both sides of the thermoelectric (TE) modules built into the system need to be kept as large as possible. This means it is important to reduce thermal resistance between TE modules and heat source. Moreover, the system's efficiency greatly depends on the base temperature of the heat sources and the material of the system's TE modules. Therefore, in order to make this system practical and efficient, it is necessary to choose the heat source first and then design the most appropriate structure for the source by applying analytical methods. This report describes how to design a prototype of a thermoelectric power generator using the analytical approach and the results of performance evaluation tests carried out in the field.

  16. State of the art on high temperature thermal energy storage for power generation. Part 1—Concepts, materials and modellization

    Microsoft Academic Search

    Antoni Gil; Marc Medrano; Ingrid Martorell; Ana Lázaro; Pablo Dolado; Belén Zalba; Luisa F. Cabeza

    2010-01-01

    Concentrated solar thermal power generation is becoming a very attractive renewable energy production system among all the different renewable options, as it has have a better potential for dispatchability. This dispatchability is inevitably linked with an efficient and cost-effective thermal storage system. Thus, of all components, thermal storage is a key one. However, it is also one of the less

  17. Performance of a direct steam generation solar thermal power plant for electricity production as a function of the solar multiple

    Microsoft Academic Search

    M. J. Montes; A. Abánades; J. M. Martínez-Val

    2009-01-01

    This paper describes the influence of the solar multiple on the annual performance of parabolic trough solar thermal power plants with direct steam generation (DSG). The reference system selected is a 50MWe DSG power plant, with thermal storage and auxiliary natural gas-fired boiler. It is considered that both systems are necessary for an optimum coupling to the electricity grid. Although

  18. Integrating planning and design optimization for thermal power generation in developing economies: Designs for Vietnam

    NASA Astrophysics Data System (ADS)

    Pham, John Dinh Chuong

    In the twenty first century, global warming and climate change have become environmental issues worldwide. There is a need to reduce greenhouse gas emissions from thermal power plants through improved efficiency. This need is shared by both developed and developing countries. It is particularly important in rapidly developing economies (for example, Vietnam, South Korea, and China) where there is very significant need to increase generation capacity. This thesis addresses improving thermal power plant efficiency through an improved planning process that emphasizes integrated design. With the integration of planning and design considerations of key components in thermal electrical generation, along with the selection of appropriate up-to-date technologies, greater efficiency and reduction of emissions could be achieved. The major barriers to the integration of overall power plant optimization are the practice of individual island tendering packages, and the lack of coordinating efforts between major original equipment manufacturers (OEM). This thesis assesses both operational and design aspects of thermal power plants to identify opportunities for energy saving and the associated reduction of CO2 emissions. To demonstrate the potential of the integrated planning design approach, three advanced thermal power plants, using anthracite coal, oil and gas as their respective fuel, were developed as a case study. The three plant formulations and simulations were performed with the cooperation of several leading companies in the power industry including Babcock & Wilcox, Siemens KWU, Siemens-Westinghouse Power Corporation, Hitachi, Alstom Air Preheater, TLT-Covent, and ABB Flakt. The first plant is a conventional W-Flame anthracite coal-fired unit for base load operation. The second is a supercritical oil-fired plant with advanced steam condition, for two shifting and cycling operations. The third plant is a gas-fired combined cycle unit employing a modern steam-cooled gas turbine and a three-pressure heat recovery steam generator with reheat, for base load and load following operations. The oil-fired and gas-fired plants showed excellent gross thermal efficiency, 49.6 and 59.4 percent, respectively. Regarding the anthracite plant, based on a traditional subcritical pressure steam cycle, the unit gross efficiency was calculated at 42.3 percent. These efficiency values represent an increase of over 2 percent compared to the comparable plant class, operating today. This 2 percent efficiency gained translates into approximately 35,000 tonnes of greenhouse gas reduction, and a saving of 16,000 tonnes of coal, per year (based on 300MWe coal-fired plant). The positive results from the three simulations have demonstrated that by integrating planning and design optimization, significant gain of efficiency in thermal power plants is possible. This establishes the need for improved planning processes. It starts with a pre-planning process, before project tendering, to identify applicable operational issues and design features to enhance efficiency and reduce emissions. It should also include a pre-contract period to provide an opportunity for all OEM finalists to consolidate and fine-tune their designs for compatibility with those of others to achieve optimal performance. The inclusion of a period for final consolidation and integrated design enables the original goals of greater overall plant efficiency and greenhouse gas emissions reduction to be achieved beyond those available from current planning and contracting procedures.

  19. Research and development on a distributed type solar thermal power generation plant

    NASA Astrophysics Data System (ADS)

    Sumida, I.; Tsukamoto, M.; Sakamoto, T.; Taki, T.; Sato, S.

    1983-12-01

    The R&D on a solar thermal power generation system of the plane parabolic type within the framework of the Japanese Sunshine Project is described. This system realizes high concentration of solar energy with a special concentrator module which combines 100 flat plate mirror heliostats of the central tower system with 5 parabolic troughs of the distributed system. A molten salt (KCl-LiCl) type thermal storage unit is used to superheat saturated steam supplied by accumulators to 300-350 C for 90 minutes after 5 hours of heat storage. Specifications and hydrodynamic characteristics for a 1000 kWe pilot plant in Nio, Kagawa, Japan, constructed in 1980 are given.

  20. Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation

    SciTech Connect

    Reddy, Ramana G. [The University of Alabama] [The University of Alabama

    2013-10-23

    The explicit UA program objective is to develop low melting point (LMP) molten salt thermal energy storage media with high thermal energy storage density for sensible heat storage systems. The novel Low Melting Point (LMP) molten salts are targeted to have the following characteristics: 1. Lower melting point (MP) compared to current salts (<222ºC) 2. Higher energy density compared to current salts (>300 MJ/m3) 3. Lower power generation cost compared to current salt In terms of lower power costs, the program target the DOE's Solar Energy Technologies Program year 2020 goal to create systems that have the potential to reduce the cost of Thermal Energy Storage (TES) to less than $15/kWh-th and achieve round trip efficiencies greater than 93%. The project has completed the experimental investigations to determine the thermo-physical, long term thermal stability properties of the LMP molten salts and also corrosion studies of stainless steel in the candidate LMP molten salts. Heat transfer and fluid dynamics modeling have been conducted to identify heat transfer geometry and relative costs for TES systems that would utilize the primary LMP molten salt candidates. The project also proposes heat transfer geometry with relevant modifications to suit the usage of our molten salts as thermal energy storage and heat transfer fluids. The essential properties of the down-selected novel LMP molten salts to be considered for thermal storage in solar energy applications were experimentally determined, including melting point, heat capacity, thermal stability, density, viscosity, thermal conductivity, vapor pressure, and corrosion resistance of SS 316. The thermodynamic modeling was conducted to determine potential high temperature stable molten salt mixtures that have thermal stability up to 1000 °C. The thermo-physical properties of select potential high temperature stable (HMP) molten salt mixtures were also experimentally determined. All the salt mixtures align with the go/no-go goals stipulated by the DOE for this project. Energy densities of all salt mixtures were higher than that of the current solar salt. The salt mixtures costs have been estimated and TES system costs for a 2 tank, direct approach have been estimated for each of these materials. All estimated costs are significantly below the baseline system that used solar salt. These lower melt point salts offer significantly higher energy density per volume than solar salt – and therefore attractively smaller inventory and equipment costs. Moreover, a new TES system geometry has been recommended A variety of approaches were evaluated to use the low melting point molten salt. Two novel changes are recommended that 1) use the salt as a HTF through the solar trough field, and 2) use the salt to not only create steam but also to preheat the condensed feedwater for Rankine cycle. The two changes enable the powerblock to operate at 500°C, rather than the current 400°C obtainable using oil as the HTF. Secondly, the use of salt to preheat the feedwater eliminates the need to extract steam from the low pressure turbine for that purpose. Together, these changes result in a dramatic 63% reduction required for 6 hour salt inventory, a 72% reduction in storage volume, and a 24% reduction in steam flow rate in the power block. Round trip efficiency for the Case 5 - 2 tank “direct” system is estimated at >97%, with only small losses from time under storage and heat exchange, and meeting RFP goals. This attractive efficiency is available because the major heat loss experienced in a 2 tank “indirect” system - losses by transferring the thermal energy from oil HTF to the salt storage material and back to oil to run the steam generator at night - is not present for the 2 tank direct system. The higher heat capacity values for both LMP and HMP systems enable larger storage capacities for concentrating solar power.

  1. Stirling engines for low-temperature solar-thermal-electric power generation

    NASA Astrophysics Data System (ADS)

    der Minassians, Artin

    This dissertation discusses the design and development of a distributed solar-thermal-electric power generation system that combines solar-thermal technology with a moderate-temperature Stirling engine to generate electricity. The conceived system incorporates low-cost materials and utilizes simple manufacturing processes. This technology is expected to achieve manufacturing cost of less than $1/W. Since solar-thermal technology is mature, the analysis, design, and experimental assessment of moderate-temperature Stirling engines is the main focus of this thesis. The design, fabrication, and test of a single-phase free-piston Stirling engine prototype is discussed. This low-power prototype is designed and fabricated as a test rig to provide a clear understanding of the Stirling cycle operation, to identify the key components and the major causes of irreversibility, and to verify corresponding theoretical models. As a component, the design of a very low-loss resonant displacer piston subsystem is discussed. The displacer piston is part of a magnetic circuit that provides both a required stiffness and actuation forces. The stillness is provided by a magnetic spring, which incorporates an array of permanent magnets and has a very linear stiffness characteristic that facilitates the frequency tuning. In this prototype, the power piston is not mechanically linked to the displacer piston and forms a mass-spring resonating subsystem with the engine chamber gas spring and has resonant frequency matched to that of the displacer. The fabricated engine prototype is successfully tested and the experimental results are presented and discussed. Extensive experimentation on individual component subsystems confirms the theoretical models and design considerations, providing a sound basis for higher power Stirling engine designs for residential or commercial deployments. Multi-phase Stirling engine systems are also considered and analyzed. The modal analysis of these machines proves their self-starting potential. The start-up temperature, i.e., the heater temperature at which the system starts its operation, is derived based on the same modal analysis. Following the mathematical modeling, the design, fabrication, and test of a symmetric three-phase free-piston Stirling engine system are discussed. The system is designed to operate with moderate-temperature heat input that is consistent with solar-thermal collectors. Diaphragm pistons and nylon flexures are considered for this prototype to eliminate surface friction and provide appropriate seals. The experimental results are presented and compared with design calculations. Experimental assessments confirm the models for flow friction and gas spring hysteresis dissipation. It is revealed that gas spring hysteresis loss is an important dissipation phenomenon in low-power low-pressure Stirling engines, and should be carefully addressed during the design as it may hinder the engine operation. Further analysis shows that the gas hysteresis dissipation can be reduced drastically by increasing the number of phases in a system with a little compromise on the operating frequency and, hence, the output power. It is further shown that for an even number of phases, half of the pistons could be eliminated by utilizing a reverser. By introducing a reverser to the fabricated system, the system proves its self-starting capability in engine mode and validates the derived expressions for computing the start-up temperature.

  2. Summary assessment of solar thermal parabolic dish technology for electrical power generation

    NASA Technical Reports Server (NTRS)

    Penda, P. L.; Fujita, T.; Lucas, J. W.

    1985-01-01

    An assessment is provided of solar thermal parabolic dish technology for electrical power generation. The assessment is based on the development program undertaken by the Jet Propulsion Laboratory for the U.S. Department of Energy and covers the period from the initiation of the program in 1976 through mid-1984. The program was founded on developing components and subsystems that are integrated into parabolic dish power modules for test and evaluation. The status of the project is summarized in terms of results obtained through testing of modules, and the implications of these findings are assessed in terms of techno-economic projections and market potential. The techno-economic projections are based on continuation of an evolutionary technological development program and are related to the accomplishments of the program as of mid-1984. The accomplishments of the development effort are summarized for each major subsystem including concentrators, receivers, and engines. The ramifications of these accomplishments are assessed in the context of developmental objectives and strategies.

  3. Potential for ocean thermal energy conversion electric power generation in the Southeast region

    Microsoft Academic Search

    P. L. Sutherland; F. G. Arey Jr.; D. H. Guild

    1979-01-01

    Evaluation of the operating characteristics and investment costs of an OTEC electric power plant in the Southeast U.S. is presented. Conceptual design of an OTEC plant is discussed with the capital cost estimate, and conventional coal fuel plant costs. A computer analysis is made of the life cycle costs of electric power generation with conventional generating plants, and an OTEC

  4. Generation displacement, power losses and emissions reduction due to solar thermal water heaters

    Microsoft Academic Search

    J. Jimenez-Gonzalez; A. A. Irizarry-Rivera

    2005-01-01

    A big portion of the electricity generated is wasted in the form of losses. Losses occur at all levels of the power system- generation, transmission, and distribution. However, at least 75% of the total system losses occur in the distribution system. We present a study of real power losses reduction at the distribution level due to the use of solar

  5. Solar Thermal Power.

    ERIC Educational Resources Information Center

    McDaniels, David K.

    The different approaches to the generation of power from solar energy may be roughly divided into five categories: distributed collectors; central receivers; biomass; ocean thermal energy conversion; and photovoltaic devices. The first approach (distributed collectors) is the subject of this module. The material presented is designed to…

  6. Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

    Microsoft Academic Search

    Brian Norton; Phillip C Eames; Steve NG Lo

    1998-01-01

    Renewable energy generation of electricity is advocated as a means of reducing carbon dioxide emissions associated with the generation from fossil fuels. Whilst it is true that renewable sources do not generate significant carbon dioxide whilst producing electricity, as with fossil-fuelled plants they do embody significant emissions in their materials of construction. The “full-chain” environmental impacts of wind, hydro, solar-thermal

  7. Thermal effects in high-power CW second harmonic generation in Mg-doped stoichiometric lithium tantalate.

    PubMed

    Tovstonog, Sergey V; Kurimura, Sunao; Suzuki, Ikue; Takeno, Kohei; Moriwaki, Shigenori; Ohmae, Noriaki; Mio, Norikatsu; Katagai, Toshio

    2008-07-21

    We investigated thermal behaviors of single-pass second-harmonic generation of continuous wave green radiation with high efficiency by quasi-phase matching in periodically poled Mg-doped stoichiometric lithium tantalate (PPMgSLT). Heat generation turned out to be directly related to the green light absorption in the material. Strong relation between an upper limit of the second harmonic power and confocal parameter was found. Single-pass second-harmonic generation of 16.1 W green power was achieved with 17.6% efficiency in Mg:SLT at room temperature. PMID:18648448

  8. Development and Demonstration of an Innovative Thermal Energy Storage System for Baseload Power Generation

    SciTech Connect

    D. Y. Goswami

    2012-09-04

    The objective of this project is to research and develop a thermal energy storage system (operating range 3000C ���¢�������� 450 0C ) based on encapsulated phase change materials (PCM) that can meet the utility-scale base-load concentrated solar power plant requirements at much lower system costs compared to the existing thermal energy storage (TES) concepts. The major focus of this program is to develop suitable encapsulation methods for existing low-cost phase change materials that would provide a cost effective and reliable solution for thermal energy storage to be integrated in solar thermal power plants. This project proposes a TES system concept that will allow for an increase of the capacity factor of the present CSP technologies to 75% or greater and reduce the cost to less than $20/kWht.

  9. Exergy analysis and investigation for various feed water heaters of direct steam generation solar–thermal power plant

    Microsoft Academic Search

    M. K. Gupta; S. C. Kaushik

    2010-01-01

    The energy and exergy analysis has been carried out for the different components of a proposed conceptual direct steam generation (DSG) solar–thermal power plant (STPP). It has been found that the maximum energy loss is in the condenser followed by solar collector field. The maximum exergy loss is in the solar collector field while in other plant components it is

  10. Design and thermal analysis of a two stage solar concentrator for combined heat and thermoelectric power generation

    Microsoft Academic Search

    Siddig A. Omer; David G. Infield

    2000-01-01

    A design procedure and thermal performance analysis of a two stage solar energy concentrator suited to combined heat and thermoelectric power generation are presented. The concentrator is comprised of a primary one axis parabolic trough concentrator and a second stage compound parabolic concentrator mounted at the focus of the primary. The thermoelectric device is attached to the absorber plate at

  11. 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.

  12. A Life Cycle Assessment (LCA) of a Paraboloidal-Dish Solar Thermal Power Generation System

    Microsoft Academic Search

    Fausto Cavallaro; Luigi Ciraolo

    2006-01-01

    The principles regarding the conversion of solar thermal power have been known for more than a century, however its commercial exploitation and the construction of plants on an industrial scale did not occur until the mid 1980's. The first pilot plants that were built in various countries around the world tested their technological, economic and environmental performance and gave highly

  13. Solar thermal electricity generation

    NASA Astrophysics Data System (ADS)

    Gasemagha, Khairy Ramadan

    1993-01-01

    This report presents the results of modeling the thermal performance and economic feasibility of large (utility scale) and small solar thermal power plants for electricity generation. A number of solar concepts for power systems applications have been investigated. Each concept has been analyzed over a range of plant power ratings from 1 MW(sub e) to 300 MW(sub e) and over a range of capacity factors from a no-storage case (capacity factor of about 0.25 to 0.30) up to intermediate load capacity factors in the range of 0.46 to 0.60. The solar plant's economic viability is investigated by examining the effect of various parameters on the plant costs (both capital and O & M) and the levelized energy costs (LEC). The cost components are reported in six categories: collectors, energy transport, energy storage, energy conversion, balance of plant, and indirect/contingency costs. Concentrator and receiver costs are included in the collector category. Thermal and electric energy transport costs are included in the energy transport category. Costs for the thermal or electric storage are included in the energy storage category; energy conversion costs are included in the energy conversion category. The balance of plant cost category comprises the structures, land, service facilities, power conditioning, instrumentation and controls, and spare part costs. The indirect/contingency category consists of the indirect construction and the contingency costs. The concepts included in the study are (1) molten salt cavity central receiver with salt storage (PFCR/R-C-Salt); (2) molten salt external central receiver with salt storage (PFCR/R-E-Salt); (3) sodium external central receiver with sodium storage (PFCR/RE-Na); (4) sodium external central receiver with salt storage (PFCR/R-E-Na/Salt); (5) water/steam external central receiver with oil/rock storage (PFCR/R-E-W/S); (6) parabolic dish with stirling engine conversion and lead acid battery storage (PFDR/SLAB); (7) parabolic dish with stirling engine conversion and redox advanced battery storage (PFDR/S-RAB); and (8) parabolic trough with oil/rock storage (LFDR/R-HT-45). Key annual efficiency and economic results of the study are highlighted in tabular format for plant sizes and capacity factor that resulted in the lowest LEC over the analysis range.

  14. Solar Thermal Power Technologies

    NSDL National Science Digital Library

    Groenendaal, B.J.

    2002-01-01

    Published in July 2002 by the Energy Research Foundation of the Netherlands, this 50-page report describes current and future Solar Thermal Power technologies. It offers a unique perspective by looking ahead to the "global energy supply and demand until 2100." Five main technologies are described, and two are examined in depth. The first is a solar tower design that uses a large array of mirrors to reflect all sunlight to a receiver at the top of a tower, and then generates electricity from a steam-powered turbine. SNAP technology is the second focus; this kind of power plant directs artificially created wind down a large tube, turning turbines as the wind escapes. A short history of each of these methods is included, as well as an analysis of world solar power potential.

  15. Concentrating solar thermal power.

    PubMed

    Müller-Steinhagen, Hans

    2013-08-13

    In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept. PMID:23816910

  16. Solar Thermal Electricity Generating System

    NASA Astrophysics Data System (ADS)

    Mishra, Sambeet; Tripathy, Pratyasha

    2012-08-01

    A Solar Thermal Electricity generating system also known as Solar Thermal Power plant is an emerging renewable energy technology, where we generate the thermal energy by concentrating and converting the direct solar radiationat medium/high temperature (300?C ñ 800?C). The resulting thermal energy is then used in a thermodynamic cycleto produce electricity, by running a heat engine, which turns a generator to make electricity. Solar thermal power is currently paving the way for the most cost-effective solar technology on a large scale and is heading to establish a cleaner, pollution free and secured future. Photovoltaic (PV) and solar thermal technologies are two main ways of generating energy from the sun, which is considered the inexhaustible source of energy. PV converts sunlight directly into electricity whereas in Solar thermal technology, heat from the sun's rays is concentrated to heat a fluid, whose steam powers a generator that produces electricity. It is similar to the way fossil fuel-burning power plants work except that the steam is produced by the collected heat rather than from the combustion of fossil fuels. In order to generate electricity, five major varieties of solar thermal technologies used are:* Parabolic Trough Solar Electric Generating System (SEGS).* Central Receiver Power Plant.* Solar Chimney Power Plant.* Dish Sterling System.* Solar Pond Power Plant.Most parts of India,Asia experiences a clear sunny weather for about 250 to 300 days a year, because of its location in the equatorial sun belt of the earth, receiving fairly large amount of radiation as compared to many parts of the world especially Japan, Europe and the US where development and deployment of solar technologies is maximum.Whether accompanied with this benefit or not, usually we have to concentrate the solar radiation in order to compensate for the attenuation of solar radiation in its way to earthís surface, which results in from 63,2 GW/m2 at the Sun to 1 kW/m2 at Earth¥s surface. The higher the concentration, the higher the temperatures we can achieve when converting solar radiation into thermal energy

  17. Development of a phase-change thermal storage system using modified anhydrous sodium hydroxide for solar electric power generation

    NASA Technical Reports Server (NTRS)

    Cohen, B. M.; Rice, R. E.; Rowny, P. E.

    1978-01-01

    A thermal storage system for use in solar power electricity generation was investigated analytically and experimentally. The thermal storage medium is principally anhydrous NaOH with 8% NaNO3 and 0.2% MnO2. Heat is charged into storage at 584 K and discharged from storage at 582 K by Therminol-66. Physical and thermophysical properties of the storage medium were measured. A mathematical simulation and computer program describing the operation of the system were developed. A 1/10 scale model of a system capable of storing and delivering 3.1 x 10 to the 6th power kJ of heat was designed, built, and tested. Tests included steady state charging, discharging, idling, and charge-discharge conditions simulating a solar daily cycle. Experimental data and computer-predicted results are correlated. A reference design including cost estimates of the full-size system was developed.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    Situational awareness and precise targeting at day, night and severe weather conditions are key elements for mission success in asymmetric warfare. To support these capabilities for the dismounted soldier, AIM has developed a family of stand-alone thermal weapon sights based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The design driver for these sights is a long ID range <1500m for the NATO standard target to cover the operational range of a platoon with the engagement range of .50 cal rifles, 40mm AGLs or for reconnaissance tasks. The most recent sight WBZG has just entered into serial production for the IdZ enhanced system of the German army with additional capabilities like a wireless data link to the soldier backbone computer. Minimum size, weight and power (SWaP) are most critical requirements for the dismounted soldiers' equipment and sometimes push a decision towards uncooled equipment with marginal performance referring to the outstanding challenges in current asymmetric warfare, e.g. the capability to distinguish between combatants and non-combatants in adequate ranges. To provide the uncompromised e/o performance with SWaP parameters close to uncooled, AIM has developed a new thermal weapon sight based on high operating temperature (HOT) MCT MWIR FPAs together with a new low power single piston stirling cooler. In basic operation the sight is used as a clip-on in front of the rifle scope. An additional eyepiece for stand-alone targeting with e.g. AGLs or a biocular version for relaxed surveillance will be available. The paper will present details of the technologies applied for such long range cooled sights with size, weight and power close to uncooled.

  19. Solar thermal power system

    DOEpatents

    Bennett, Charles L.

    2010-06-15

    A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

  20. Thermal-powered reciprocating pump

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E.

    1972-01-01

    Waste heat from radioisotope thermal generators in spacecraft is transported to keep instruments warm by two-cylinder reciprocating pump powered by energy from warm heat exchange fluid. Each cylinder has thermally nonconductive piston, heat exchange coil, and heat sink surface.

  1. 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.

  2. Control of Tardive Thermal Power

    NASA Astrophysics Data System (ADS)

    Swartz, Mitchell

    2006-03-01

    Previously, calorimetric improvements including thermal power analysis, dual ohmic controls, noise measurement and time-integration of multi-ring calorimetric systems with waveform reconstruction has led to the development of Phusor^TM devices providing undeniable proof of excess heat in palladium heavy water (Pt/D2O/Pd; 0.5 cm^3, peak excess power ratios of 2.30 ^+/- 0.84; 1). We now report improved control of tardive thermal power (TTP) which develops long after the termination of electric input power. From an engineering perspective, this is important because the effective excess power generated is further greatly increased (up to an additional ˜410% beyond that obtained without tardive thermal power operation); and because this improved means of operation can be coupled into over-unity motors and other work-producing systems. In addition, these systems have revealed further insight into the kinetics of the desired condensed matter reactions.

  3. Investigation and analysis on the combined operation of solar thermal power and conventional thermal power

    Microsoft Academic Search

    D. Y. Liu; J. Wang; X. Q. Feng; S. Guo; C. Xu

    2009-01-01

    The main constitution and the performance characteristic of Solar Thermal Power System (STPS) were introduced, and the thermal losses law of the recycled working substance of the conventional thermal power generation unit was analyzed in this paper. The key technical choke points currently existing in high-temperature solar thermal power system were demonstrated in the aspect of technical feasibility and economical

  4. Daily Integrated Generation Scheduling for Thermal, Pumped-Storage Hydro and Cascaded Hydro Units and Purchasing Power Considering Network Constraints

    NASA Astrophysics Data System (ADS)

    Sawa, Toshiyuki; Sato, Yasuo; Tsurugai, Mitsuo; Onishi, Tsukasa

    We have developed an innovative power generation scheduling method using quadratic programming (QP). The advantage of using our method is that it simultaneously solves unit commitment and economic load dispatch. We relax the binary variables of the unit state into continuous variables to apply QP to this problem. We also add the penalty term to converge the value of those variables to 0 or 1 to the objective function; the sum of fuel costs and start-up costs. This penalty term depends on per-unit fuel cost. The possibility of its variable converging to zero increases as the cost increases. This method was applied to a test system of daily generation scheduling that consisted of 29 thermal units, two pumped-storage units, four cascaded-hydro units, and one transmission. The schedule satisfied all constraints, i.e., load-power balance, operation reserve, power flow, minimum up/down-times, and fuel consumption. This result shows that the developed method is effective.

  5. Quasi-steady state temperature distribution and numerical simulation on low Ste number latent heat storage thermal unit of solar thermal power generation

    NASA Astrophysics Data System (ADS)

    Huang, J.; Zhu, D. S.

    2010-03-01

    Solar thermal power generation systems, including direct steam generation, require isothermal energy storage systems for a saturation temperature range between 190° C and 310° C. One option to fulfill this requirement is the application of phase-change materials to absorb or release energy. In this paper, the basic concept of latent heat storage system is described, and a model of phase-change heat transfer of latent heat storage thermal unit for thermal energy storage system is built. Base on the practical thermo-physical properties of phase-change materials, Quasi-Steady State temperature distribution of phase-change heat transfer is analyzed under low Ste number. Numerical simulation (finite element method) taking account into the sensible heat is adopted and the results prove that the Quasi-Steady State temperature distribution obtained from theoretical is in good agreement with the results of numerical simulation. For a latent heat storage system with low Ste number characteristic, Quasi-Steady State solution can be used as the theoretical calculation foundation for engineering design.

  6. Innovative Application of Maintenance-Free Phase-Change Thermal Energy Storage for Dish-Engine Solar Power Generation

    SciTech Connect

    Qui, Songgang [Temple University] [Temple University; Galbraith, Ross [Infinia] [Infinia

    2013-01-23

    This final report summarizes the final results of the Phase II Innovative Application of Maintenance-Free Phase-Change Thermal Energy Storage for Dish-Engine Solar Power Generation project being performed by Infinia Corporation for the U.S. Department of Energy under contract DE-FC36-08GO18157 during the project period of September 1, 2009 - August 30, 2012. The primary objective of this project is to demonstrate the practicality of integrating thermal energy storage (TES) modules, using a suitable thermal salt phase-change material (PCM) as its medium, with a dish/Stirling engine; enabling the system to operate during cloud transients and to provide dispatchable power for 4 to 6 hours after sunset. A laboratory prototype designed to provide 3 kW-h of net electrical output was constructed and tested at Infinia's Ogden Headquarters. In the course of the testing, it was determined that the system's heat pipe network - used to transfer incoming heat from the solar receiver to both the Stirling generator heater head and to the phase change salt - did not perform to expectations. The heat pipes had limited capacity to deliver sufficient heat energy to the generator and salt mass while in a charging mode, which was highly dependent on the orientation of the device (vertical versus horizontal). In addition, the TES system was only able to extract about 30 to 40% of the expected amount of energy from the phase change salt once it was fully molten. However, the use of heat pipes to transfer heat energy to and from a thermal energy storage medium is a key technical innovation, and the project team feels that the limitations of the current device could be greatly improved with further development. A detailed study of manufacturing costs using the prototype TES module as a basis indicates that meeting DOE LCOE goals with this hardware requires significant efforts. Improvement can be made by implementing aggressive cost-down initiatives in design and materials, improving system performance by boosting efficiencies, and by refining cost estimates with vendor quotes in lieu of mass-based approaches. Although the prototype did not fully demonstrate performance and realize projected cost targets, the project team believes that these challenges can be overcome. The test data showed that the performance can be significantly improved by refining the heat pipe designs. However, the project objective for phase 3 is to design and test on sun the field ready systems, the project team feels that is necessary to further refine the prototype heat pipe design in the current prototype TES system before move on to field test units, Phase 3 continuation will not be pursued.

  7. Overview of MC Power`s MCFC power generation system

    Microsoft Academic Search

    T. G. Benjamin; R. R. Woods

    1993-01-01

    The IMHEX{reg_sign} fuel cell power generation system is a skid mounted power plant which efficiently generates electricity and useful thermal energy. The primary benefits are its high electric generation efficiency (50% or greater), modular capacities (500 kW to 3 MW per unit) and minimal environmental impacts (less than 1 ppM NOâ). A cost effective, modular capacity fuel cell power plant

  8. Potential benefits of a ceramic thermal barrier coating on large power generation gas turbine

    NASA Technical Reports Server (NTRS)

    Clark, J. S.; Nainiger, J. J.

    1977-01-01

    Thermal barrier coating design option offers benefit in terms of reduced electricity costs when used in utility gas turbines. Options considered include: increased firing temperature, increased component life, reduced cooling air requirements, and increased corrosion resistance (resulting in increased tolerance for dirty fuels). Performance and cost data were obtained. Simple, recuperated and combined cycle applications were considered, and distillate and residual fuels were assumed. The results indicate that thermal barrier coatings could produce large electricity cost savings if these coatings permit turbine operation with residual fuels at distillate-rated firing temperatures. The results also show that increased turbine inlet temperature can result in substantial savings in fuel and capital costs.

  9. Superconducting Power Generation

    E-print Network

    Mario Rabinowitz

    2003-02-20

    The superconducting ac generator has the greatest potential for large-scale commercial application of superconductivity that can benefit the public. Electric power is a vital ingredient of modern society, and generation may be considered to be the vital ingredient of a power system. This articles gives background, and an insight into the physics and engineering of superconducting power generation.

  10. 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)

  11. Impacts of Wind Power on Thermal Generation Unit Commitment and Dispatch

    Microsoft Academic Search

    Bart C. Ummels; Madeleine Gibescu; Engbert Pelgrum; Wil L. Kling; Arno J. Brand

    2007-01-01

    This paper proposes a new simulation method that can fully assess the impacts of large-scale wind power on system operations from cost, reliability, and environmental perspectives. The method uses a time series of observed and predicted 15-min average wind speeds at foreseen onshore- and offshore-wind farm locations. A Unit Commitment and Economic Dispatch (UC-ED) tool is adapted to allow for

  12. 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.

  13. Development and Performance Evaluation of High Temperature Concrete for Thermal Energy Storage for Solar Power Generation

    SciTech Connect

    R. Panneer Selvam, Micah Hale and Matt strasser

    2013-03-31

    Thermal energy can be stored by the mechanism of sensible or latent heat or heat from chemical reactions. Sensible heat is the means of storing energy by increasing the temperature of the solid or liquid. Since the concrete as media cost per kWhthermal is $1, this seems to be a very economical material to be used as a TES. This research is focused on extending the concrete TES system for higher temperatures (500 �ºC to 600 �ºC) and increasing the heat transfer performance using novel construction techniques. To store heat at high temperature special concretes are developed and tested for its performance. The storage capacity costs of the developed concrete is in the range of $0.91-$3.02/kWhthermal Two different storage methods are investigated. In the first one heat is transported using molten slat through a stainless steel tube and heat is transported into concrete block through diffusion. The cost of the system is higher than the targeted DOE goal of $15/kWhthermal The increase in cost of the system is due to stainless steel tube to transfer the heat from molten salt to the concrete blocks.The other method is a one-tank thermocline system in which both the hot and cold fluid occupy the same tank resulting in reduced storage tank volume. In this model, heated molten salt enters the top of the tank which contains a packed bed of quartzite rock and silica sand as the thermal energy storage (TES) medium. The single-tank storage system uses about half the salt that is required by the two-tank system for a required storage capacity. This amounts to a significant reduction in the cost of the storage system. The single tank alternative has also been proven to be cheaper than the option which uses large concrete modules with embedded heat exchangers. Using computer models optimum dimensions are determined to have an round trip efficiency of 84%. Additionally, the cost of the structured concrete thermocline configuration provides the TES capacity cost of $33.80$/kWhthermal compared with $30.04/kWhthermal for a packed-bed thermocline (PBTC) configuration and $46.11/kWhthermal for a two-tank liquid configuration.

  14. Economic analysis of power generation from parabolic trough solar thermal plants for the Mediterranean region—A case study for the island of Cyprus

    Microsoft Academic Search

    Andreas Poullikkas

    2009-01-01

    In this work a feasibility study is carried out in order to investigate whether the installation of a parabolic trough solar thermal technology for power generation in the Mediterranean region is economically feasible. The case study takes into account the available solar potential for Cyprus, as well as all available data concerning current renewable energy sources policy of the Cyprus

  15. Generating random thermal momenta

    E-print Network

    Molnar, Denes

    2012-01-01

    Generation of random thermal particle momenta is a basic task in many problems, such as microscopic studies of equilibrium and transport properties of systems, or the conversion of a fluid to particles. In heavy-ion physics, the (in)efficiency of the algorithm matters particularly in hybrid hydrodynamics + hadronic transport calculations. With popular software packages, such as UrQMD 3.3p1 or THERMINATOR, it can still take ten hours to generate particles for a single Pb+Pb "event" at the LHC from fluid dynamics output. Below I describe reasonably efficient simple algorithms using the MPC package, which should help speed momentum generation up by at least one order of magnitude. It is likely that this wheel has been reinvented many times instead of reuse, so there may very well exist older and/or better algorithms that I am not aware of (MPC has been around only since 2000). The main goal here is to encourage practitioners to use available efficient routines, and offer a few practical solutions.

  16. Generating random thermal momenta

    E-print Network

    Denes Molnar

    2012-12-09

    Generation of random thermal particle momenta is a basic task in many problems, such as microscopic studies of equilibrium and transport properties of systems, or the conversion of a fluid to particles. In heavy-ion physics, the (in)efficiency of the algorithm matters particularly in hybrid hydrodynamics + hadronic transport calculations. With popular software packages, such as UrQMD 3.3p1 or THERMINATOR, it can still take ten hours to generate particles for a single Pb+Pb "event" at the LHC from fluid dynamics output. Below I describe reasonably efficient simple algorithms using the MPC package, which should help speed momentum generation up by at least one order of magnitude. It is likely that this wheel has been reinvented many times instead of reuse, so there may very well exist older and/or better algorithms that I am not aware of (MPC has been around only since 2000). The main goal here is to encourage practitioners to use available efficient routines, and offer a few practical solutions.

  17. SENSITIVITY OF THERMAL POWER GENERATION TO CLIMATE G. P. Harrison*, L. C. Cradden, A. Zacheshigriva, S. Nairn, J. P. Chick

    E-print Network

    Harrison, Gareth

    causes the mass flow to fall, consequently reducing the power of the gas turbine and the amount of heat generated in the heat recovery boiler (Kehlhofer et al., 1999). Plant models Three different power stations. The hot exhaust gases from the gas turbines feed their own heat recovery boiler and produce superheated

  18. High peak power generation in thermally bonded Er3+, Yb3+:glass/Co2+: MgAl2O3 microchip laser for telemetry application

    NASA Astrophysics Data System (ADS)

    Mlynczak, Jaroslaw; Belghachem, Nabil

    2015-04-01

    The highest ever reported peak power generation of 7.68?kW in thermally bonded active medium Er3+,Yb3+:glass with saturable absorber Co2+: MgAl2O3 was achieved. The sample was a quasi-continuous wave pumped by a fiber coupled laser diode operating at 975?nm wavelength. The generation threshold was 319?mW and slope efficiency was 9.63%. A comparative analysis of the generation of different output coupler transmissions is presented.

  19. 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.

  20. 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.

  1. Thermal energy storage for power plant applications

    Microsoft Academic Search

    S. Somasundaram; M. K. Drost; Z. I. Antoniak; D. R. Brown

    1990-01-01

    This study was conducted by Pacific Northwest Laboratory (PNL) to evaluate alternative methods of using coal to generate peak and intermediate load power. The approach was to review the technical and economic feasibility of using thermal energy storage (TES) with a conventional coal-fired power plant and an integrated gasification combined cycle (IGCC) power plant. In the first case, conventional pulverized

  2. Use of biogas for cogeneration of heat and electricity for local application: performance evaluation of an engine power generator and a sludge thermal dryer.

    PubMed

    Lobato, L C S; Chernicharo, C A L; Pujatti, F J P; Martins, O M; Melo, G C B; Recio, A A R

    2013-01-01

    A small unit of cogeneration of energy and heat was tested at the Centre for Research and Training on Sanitation UFMG/COPASA - CePTS, located at the Arrudas Sewage Treatment Plant, in Belo Horizonte, Minas Gerais, Brazil. The unit consisted of an engine power generator adapted to run on biogas, a thermal dryer prototype and other peripherals (compressor, biogas storage tank, air blower, etc.). The heat from engine power generator exhaust gases was directed towards the thermal dryer prototype to dry the sludge and disinfect it. The results showed that the experimental apparatus is self-sufficient in electricity, even producing a surplus, available for other uses. The tests of drying and disinfection of sludge lasted 7 h, leading to an increase in solids content from 4 to 8% (50% reduction in sludge volume). Although the drying of sludge was not possible (only thickening was achieved), the disinfection process proved very effective, enabling the complete inactivation of helminth eggs. PMID:23128634

  3. 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.

  4. A Power And Thermal System with Thermoelectric Generators At 930 C For Solar Probe Inside 0.1 AU

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.; Powers, Edward I. (Technical Monitor)

    2001-01-01

    The Power System for Solar Probe is required to provide an electrical power of 100 W to 200 W over a wide range of radial distances from the Sun. The distance varies from 5.2 AU (i.e., Jupiter gravity assist orbit) and 4 solar radii. The solar intensity varies by nearly 5 orders of magnitude. Radioactive Thermoelectric Generator (RTG) is one way to meet the power requirement. However, the use of an RTG presents a politically expensive risk for the mission. An alternative is a totally non-nuclear and intrinsically conservative method, which uses mostly developed technologies. This paper presents an innovative concept, which uses thermoelectric generators with a high temperature cooling system to meet the power requirement inside 0. 1 AU. In this concept, Silicon Germanium (SiGe)/Gallium Phosphorus (GaP) thermoelectric generators use the infrared radiation from the spacecraft primary heat shield as an energy source, and a liquid sodium high temperature cooling system to maintain the SiGe/GaP thermoelectric generators at 1200 K. It allows a routine access by interplanetary probes to the innermost regions of the heliosphere, which is prudent to the scientific community.

  5. Thermal and dynamic analysis of the RING (Radiatively-cooled, Inertially-driven Nuclear Generator) power system radiator

    SciTech Connect

    Apley, W.J.; Babb, A.L.

    1989-01-01

    The nuclear option for a space-based power system appears most suitable for missions that require long-term, sustained operation at power levels above 100 kWe. Systems currently available operate at relatively low thermal efficiencies (6--10%). Thus, a 100 kWe system must discharge nearly 2 MWth of waste heat through the comparatively inefficient process of radiative cooling. The impact of the resultant radiator assembly size on overall power system weight is significant, and has led to proposals for radiators with potentially higher efficiencies. Examples include the: liquid droplet radiator; fabric radiator; bubble membrane radiator; rotating film radiator; and dust radiator. 14 refs., 2 figs., 2 tabs.

  6. Assessment of generic solar thermal systems for large power applications: analysis of electric power generating costs for systems larger than 10 MWe

    SciTech Connect

    Apley, W.J.; Bird, S.P.; Brown, D.R.; Drost, M.K.; Fort, J.A.; Garrett-Price, B.A.; Patton, W.P.; Williams, T.A.

    1980-11-01

    Seven generic types of collectors, together with associated subsystems for electric power generation, were considered. The collectors can be classified into three categories: (1) two-axis tracking (with compound-curvature reflecting surfaces); (2) one-axis tracking (with single-curvature reflecting surfaces); and (3) nontracking (with low-concentration reflecting surfaces). All seven collectors were analyzed in conceptual system configurations with Rankine-cycle engines. In addition, two of the collectors were analyzed with Brayton-cycle engines, and one was analyzed with a Stirling-cycle engine. With these engine options, and the consideration of both thermal and electrical storage for the Brayton-cycle central receiver, 11 systems were formulated for analysis. Conceptual designs developed for the 11 systems were based on common assumptions of available technology in the 1990 to 2000 time frame. No attempt was made to perform a detailed optimization of each conceptual design. Rather, designs best suited for a comparative evaluation of the concepts were formulated. Costs were estimated on the basis of identical assumptions, ground rules, methodologies, and unit costs of materials and labor applied uniformly to all of the concepts. The computer code SOLSTEP was used to analyze the thermodynamic performance characteristics and energy costs of the 11 concepts. Year-long simulations were performed using meteorological and insolation data for Barstow, California. Results for each concept include levelized energy costs and capacity factors for various combinations of storage capacity and collector field size.

  7. Power-Generation Characteristics After Vibration and Thermal Stresses of Thermoelectric Unicouples with CoSb3/Ti/Mo(Cu) Interfaces

    NASA Astrophysics Data System (ADS)

    Bae, Kwang Ho; Choi, Soon-Mok; Kim, Kyung-Hun; Choi, Hyoung-Seuk; Seo, Won-Seon; Kim, Il-Ho; Lee, Soonil; Hwang, Hae Jin

    2015-03-01

    Reliability tests for thermoelectric unicouples were carried out to investigate the adhesion properties of CoSb3/Ti/Mo(Cu) interfaces. The n-type In0.25 Co3.95Ni0.05Sb12 and p-type In0.25Co3FeSb12 bulks were prepared for fabricating a thermoelectric unicouple (one p-n couple) by an induction melting and a spark plasma sintering process. Mo-Cu alloy was selected as an electrode for the unicouples due to its high melting temperature and proper work function value. Many thermoelectric unicouples with the CoSb3/Ti/Mo(Cu) interfaces were fabricated with the proper brazing materials by means of a repeated firing process. Reliability of the unicouples with the interfaces was evaluated by a vibration test and a thermal cycling test. After the thermal cycling and vibration tests, the power-generation characteristics of the unicouples were compared with the unicouples before the tests. Even after the vibration test, electrical power with a power density of 0.5 W/cm2 was generated. The Ti-interlayer is considered as a possible candidate for making a reliable unicouple with high adhesion strength. With the thermal cycling test, the resistance of the unicouple increased and the electrical power from the unicouple decreased. A failure mode by the thermal cycling test was ascribed to a complex effect of micro-cracks originated from the thermal stress and oxidation problem of the thermoelectric materials; that is, a thick oxide layer more than 300 ?m was detected after a high-temperature durability test of n-type In0.25Co3.95Ni0.05Sb12 material at 773 K in air for 7 days.

  8. Peak power ratio generator

    DOEpatents

    Moyer, Robert D. (Albuquerque, NM)

    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.

  9. JV Task 46 - Development and Testing of a Thermally Integrated SOFC-Gasification System for Biomass Power Generation

    SciTech Connect

    Phillip Hutton; Nikhil Patel; Kyle Martin; Devinder Singh

    2008-02-01

    The Energy & Environmental Research Center has designed a biomass power system using a solid oxide fuel cell (SOFC) thermally integrated with a downdraft gasifier. In this system, the high-temperature effluent from the SOFC enables the operation of a substoichiometric air downdraft gasifier at an elevated temperature (1000 C). At this temperature, moisture in the biomass acts as an essential carbon-gasifying medium, reducing the equivalence ratio at which the gasifier can operate with complete carbon conversion. Calculations show gross conversion efficiencies up to 45% (higher heating value) for biomass moisture levels up to 40% (wt basis). Experimental work on a bench-scale gasifier demonstrated increased tar cracking within the gasifier and increased energy density of the resultant syngas. A series of experiments on wood chips demonstrated tar output in the range of 9.9 and 234 mg/m{sup 3}. Both button cells and a 100-watt stack was tested on syngas from the gasifier. Both achieved steady-state operation with a 22% and 15% drop in performance, respectively, relative to pure hydrogen. In addition, tar tolerance testing on button cells demonstrated an upper limit of tar tolerance of approximately 1%, well above the tar output of the gasifier. The predicted system efficiency was revised down to 33% gross and 27% net system efficiency because of the results of the gasifier and fuel cell experiments. These results demonstrate the feasibility and benefits of thermally integrating a gasifier and a high-temperature fuel cell in small distributed power systems.

  10. 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.

  11. Geothermal power generation worldwide

    Microsoft Academic Search

    T. J. Hammons

    2003-01-01

    This paper discusses the state of art in harnessing geothermal power for medium- and large-scale generation of electricity (and for space heating) worldwide. It reviews current, probable, possible and potential developments both in developed and developing countries in near future and long term. First, world energy consumption is reviewed. Then relative contribution of energy sources in the world in OECD

  12. Continuous hydrino thermal power system

    Microsoft Academic Search

    Randell L. Mills; Guibing Zhao; William Good

    2011-01-01

    The specifics of a continuous hydrino reaction system design are presented. Heat from the hydrino reactions within individual cells provide both reactor power and the heat for regeneration of the reactants. These processes occur continuously and the power from each cell is constant. The conversion of thermal power to electrical power requires the use of a heat engine exploiting a

  13. Modeling of a thermal energy storage system coupled with combined heat and power generation for the heating requirements of a University Campus

    Microsoft Academic Search

    Giorgio Pagliarini; Sara Rainieri

    2010-01-01

    The optimum efficiency in the exploitation of a given energy resource in the cogeneration of electrical power and thermal energy requires the simultaneity of the electrical and thermal demands. Moreover, when the thermal demand is strongly time-varying or even discontinuous, the use of a thermal energy storage coupled with the cogeneration engine provides an attractive solution by allowing the production

  14. 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.

  15. High power microwave generator

    DOEpatents

    Ekdahl, Carl A. (Albuquerque, NM)

    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.

  16. 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.

  17. 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.

  18. Control of Tardive Thermal Power

    Microsoft Academic Search

    Mitchell Swartz

    2006-01-01

    Previously, calorimetric improvements including thermal power analysis, dual ohmic controls, noise measurement and time-integration of multi-ring calorimetric systems with waveform reconstruction has led to the development of Phusor^TM devices providing undeniable proof of excess heat in palladium heavy water (Pt\\/D2O\\/Pd; 0.5 cm^3, peak excess power ratios of 2.30 ^+\\/- 0.84; 1). We now report improved control of tardive thermal power

  19. Microfabricated thermoelectric power-generation devices

    NASA Technical Reports Server (NTRS)

    Fleurial, Jean-Pierre (Inventor); Ryan, Margaret A. (Inventor); Borshchevsky, Alex (Inventor); Phillips, Wayne (Inventor); Kolawa, Elizabeth A. (Inventor); Snyder, G. Jeffrey (Inventor); Caillat, Thierry (Inventor); Kascich, Thorsten (Inventor); Mueller, Peter (Inventor)

    2002-01-01

    A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

  20. Microfabricated thermoelectric power-generation devices

    NASA Technical Reports Server (NTRS)

    Fleurial, Jean-Pierre (Inventor); Ryan, Margaret A. (Inventor); Borshchevsky, Alex (Inventor); Phillips, Wayne (Inventor); Kolawa, Elizabeth A. (Inventor); Snyder, G. Jeffrey (Inventor); Caillat, Thierry (Inventor); Kascich, Thorsten (Inventor); Mueller, Peter (Inventor)

    2004-01-01

    A device for generating power to run an electronic component. The device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with a high temperature region. During operation, heat flows from the high temperature region into the heat-conducting substrate, from which the heat flows into the electrical power generator. A thermoelectric material (e.g., a BiTe alloy-based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. A low temperature region is located on the side of the thermoelectric material opposite that of the high temperature region. The thermal gradient generates electrical power and drives an electrical component.

  1. Micro electret power generators

    NASA Astrophysics Data System (ADS)

    Boland, Justin

    The taming of electricity and its widespread use allows people to see in the dark, to speak to one another instantaneously across the earth, and it allows retrieval of data from instruments sent out of the solar system. It is right to expect that the uses and demand for electricity will continue to grow, and to extend the ability to generate electricity; here two new micromachined devices for converting mechanical energy into electrical energy are presented. Aided by the wealth of micromachining process technology, generators that use an oscillatory motion to modify the physical structure of a capacitor with a built-in electric field provided by a permanent electret have been designed, built, and tested. The electret creates an electric field inside the capacitor structure, which induces mirror charge at some potential. The modification of the capacitor then generates an alternating displacement current through an external circuit, which provides useful electrical power. The electret microphone is a similar well known device for converting pressure waves into electrical signals by varying the distance between two charged capacitive plates. This work explores and proves feasible the ability to use mechanical forces to change the overlapping area of a charged capacitor structure and using mechanical forces to move a liquid into the gap of a charged capacitor structure, changing its permittivity to produce electricity. This work demonstrates 2.5mW of power from a 2cm diameter rotary generator at 12kRPM and 10[micro]w for a 0.1cm3 linear shaking generator at 60Hz.

  2. Electrochemical power generation

    SciTech Connect

    Zaromb, S.

    1981-12-15

    An electrochemical power generation apparatus and methods of control thereof are described. The power source comprises one or more electrochemical cells having an anode and an oxygen or hydrogen peroxide depolarized cathode, a liquid electrolyte solution, electrolyte circulation means and an electrolyte container. The methods include varying the volumes of electrolyte in said container and in said battery cell so as to control the polarization and hence the cell output voltage of said anode and cathode. The anode is of the consumable-metal type, particularly aluminum. The method of varying the volume may be effected by expanding or collapsing a reversibly expansible pocket in said electrolyte container or by varying the rate of circulation of said electrolyte solution through said battery cell. Heat exchange apparatus may be included comprising a vacuum distillation means whereby impure ambient water or water trapped in the battery reaction product is converted into distilled water , preferably by utilizing the heat generated in said power source , said distilled water being in turn used to replenish the battery electrolyte and thereby increase the energy density of the battery.

  3. 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...

  4. Power Electronics Thermal Control (Presentation)

    SciTech Connect

    Narumanchi, S.

    2010-05-05

    Thermal management plays an important part in the cost of electric drives in terms of power electronics packaging. Very promising results have been obtained by using microporous coatings and skived surfaces in conjunction with single-phase and two-phase flows. Sintered materials and thermoplastics with embedded fibers show significant promise as thermal interface materials, or TIMs. Appropriate cooling technologies depend on the power electronics package application and reliability.

  5. 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.

  6. Power generation, operation, and control

    Microsoft Academic Search

    A. J. Wood; B. F. Wollenberg

    1984-01-01

    This book discusses the economic and engineering aspects used in the planning, operating, and controlling of power generation and transmission systems for electric utilities. It presents advanced mathematical and operations research methods used for electric power engineering problems. It covers methods currently applied in the control and operation of electric power systems. The contents are characteristics of power generation units.

  7. Hybrid electric power generating system

    Microsoft Academic Search

    Bronicki

    1978-01-01

    A hybrid power system is described which comprises a pair of energy converters operating on a closed Rankine cycle, each energy converter having a vapor generator for vaporizing a high molecular weight working fluid in response to heat furnished from a burner associated with the generator, a turbo-generator responsive to vaporized working fluid for generating electrical power, a condenser responsive

  8. Thermal Power Plant Micro Module

    NSDL National Science Digital Library

    This learning object discusses and provides animations of the basic processes and components in a thermal power plant. Cycle descriptions and animations include the Carnot cycle, the basic Rankine cycle, and advanced Rankine cycles with reheating and feedwater heating. In addition, a Rankine cycle calculator allows the user to vary several operating parameters and observe the effect on power output and cycle efficiency.

  9. Financing Solar Thermal Power Plants

    Microsoft Academic Search

    H. W. Price; R. Kistner

    1999-01-01

    The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question

  10. Hybrid electric power generating system

    Microsoft Academic Search

    Bronicki

    1986-01-01

    A hybrid power system is described which consists of: (a) a first energy converter operating on a closed Rankine cycle and including a vapor generator for vaporizing an organic working fluid in response to heat furnished from a heat source associated with the vapor generator. A turbogenerator is responsive to vaporized working fluid for generating electrical power and a condenser

  11. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This presentation describes the capabilities of three-dimensional thermal power model of advanced stirling radioisotope generator (ASRG). The performance of the ASRG is presented for different scenario, such as Venus flyby with or without the auxiliary cooling system.

  12. Automotive Power Generation and Control

    E-print Network

    Caliskan, Vahe

    This paper describes some new developments in the application of power electronics to automotive power generation and control. A new load-matching technique is introduced that uses a simple switched-mode rectifier to achieve ...

  13. Wave driven power generators

    Microsoft Academic Search

    Neville

    1975-01-01

    Two one-way clutches on a power output shaft are driven through two oppositely driven power trains driven by a lever arm oscillated by a float raised by waves and lowered by gravity. In an alternate embodiment, a plurality of floatoscillated lever arms are spaced apart a fraction of a wave length and drive pairs of one-way clutches on a power

  14. Thermal management system for high performance PowerPCTM microprocessors

    Microsoft Academic Search

    Hector Sanchez; Belli Kuttanna; Tim Olson; Mike Alexander; Gian Gerosa; Ross Philip; Jose Alvarez

    1997-01-01

    Thermal management is an important design issue in high-performance, low-power portable computers. If the computer system is designed for worst-case processor power dissipation and environmental operating conditions, it carries an area and cost penalty for the system designer. The next-generation PowerPCTM microprocessor includes a thermal assist unit (TAU) comprised of an on-chip thermal sensor and associated logic. The TAU monitors

  15. 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.

  16. High-performance flat-panel solar thermoelectric generators with high thermal concentration

    Microsoft Academic Search

    Daniel Kraemer; Bed Poudel; Hsien-Ping Feng; J. Christopher Caylor; Bo Yu; Xiao Yan; Yi Ma; Xiaowei Wang; Dezhi Wang; Andrew Muto; Kenneth McEnaney; Matteo Chiesa; Zhifeng Ren; Gang Chen

    2011-01-01

    The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on

  17. Thermal gradient-hydro generation cycle \\/TGUC

    Microsoft Academic Search

    S. A. Parker

    1978-01-01

    The described thermal gradient utilization cycle (TGUC) makes use of the vertical atmospheric temperature difference. TGUC is a closed loop system. Thermal vapor is pumped to higher elevations where condensation occurs, and power is derived by a conventional hydro-prime mover along with a conventional regenerative Rankine cycle. TGUC and ocean thermal energy conversion are contrasted; in oceans the thermal gradient

  18. Independent power generator

    NASA Technical Reports Server (NTRS)

    Young, R. N. (inventor)

    1978-01-01

    A gas turbine powered aircraft auxiliary power system is described which is capable of efficiently supplying all aircraft auxiliary services both in flight and on the ground and is further capable of operating independently of the aircraft main engines. The system employs multiple gas turbine compressor stages, thereby accomplishing cabin pressurization, ventilation and heating.

  19. Thermally matched fluid cooled power converter

    DOEpatents

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

    2005-06-21

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

  20. 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.

  1. Automotive power generation and control

    Microsoft Academic Search

    David J. Perreault; Vahe Caliskan

    2004-01-01

    This paper describes some new developments in the application of power electronics to automotive power generation and control. A new load-matching technique is introduced that uses a simple switched-mode rectifier to achieve dramatic increases in peak and average power output from a conventional Lundell alternator, along with substantial improvements in efficiency. Experimental results demonstrate these capability improvements. Additional performance and

  2. Biomass combustion for power generation

    Microsoft Academic Search

    Richard van den Broek; Ad van Wijk

    1996-01-01

    An overview is given of the state of the art of biomass combustion power generation technologies with a capacity of more than 10 MWe. Biomass combustion technologies have been compared on a qualitative basis and a selection of individual biomass combustion power plants has been compared on a quantitative basis. Collected data were modified for comparison of the various power

  3. Mesofluidic magnetohydrodynamic power generation

    E-print Network

    Fucetola, Jay J

    2012-01-01

    Much of the previous research into magnetohydrodynamics has involved large-scale systems. This thesis explores the miniaturization and use of devices to convert the power dissipated within an expanding gas flow into ...

  4. Pulsed Power Generation Techniques

    Microsoft Academic Search

    D. J. Thrimawithana; U. K. Madawala; R. C. B. Woodhead

    2006-01-01

    This paper describes the evolution of high voltage pulsed-power (HVPP) technology from its inception to the present state, particularly focusing on its applicability and effectiveness for a variety of industrial applications. HVPP techniques that have been reported are discussed, highlighting advantages and disadvantages. A detailed analysis of four modern techniques that are based on capacitive energy compression elements, is presented

  5. Hybrid electric power generating system

    SciTech Connect

    Bronicki, L.Y.

    1986-11-11

    A hybrid power system is described which consists of: (a) a first energy converter operating on a closed Rankine cycle and including a vapor generator for vaporizing an organic working fluid in response to heat furnished from a heat source associated with the vapor generator. A turbogenerator is responsive to vaporized working fluid for generating electrical power and a condenser is responsive to vapor exhausted from the turbo-generator for converting such vapor to a condensed liquid. A means is included for returning the liquid to the vapor generator; (b) a second energy converter including a thermo-electric generator having a junction, a heat source for heating the junction whereby such thermo-electric generator generates electrical power; (c) a heat pipe for conveying heat from the heat source of the second converter to the vapor generator of the first converter and to the junction; and (d) means for applying the electrical power generated by the first and second converters to an electrical load.

  6. Autonomous Underwater Vehicle Thermoelectric Power Generation

    NASA Astrophysics Data System (ADS)

    Buckle, J. R.; Knox, A.; Siviter, J.; Montecucco, A.

    2013-07-01

    Autonomous underwater vehicles (AUVs) are a vital part of the oceanographer's toolbox, allowing long-term measurements across a range of ocean depths of a number of ocean properties such as salinity, fluorescence, and temperature profile. Buoyancy-based gliding, rather than direct propulsion, dramatically reduces AUV power consumption and allows long-duration missions on the order of months rather than hours or days, allowing large distances to be analyzed or many successive analyses of a certain area without the need for retrieval. Recent versions of these gliders have seen the buoyancy variation system change from electrically powered to thermally powered using phase-change materials, however a significant battery pack is still required to power communications and sensors, with power consumption in the region of 250 mW. The authors propose a novel application of a thermoelectric generation system, utilizing the depth-related variation in oceanic temperature. A thermal energy store provides a temperature differential across which a thermoelectric device can generate from repeated dives, with the primary purpose of extending mission range. The system is modeled in Simulink to analyze the effect of variation in design parameters. The system proves capable of generating all required power for a modern AUV.

  7. 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.

  8. 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.

  9. Spin Seebeck power generators

    SciTech Connect

    Cahaya, Adam B.; Tretiakov, O. A. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Bauer, Gerrit E. W. [Institute for Materials Research and WPI-AIMR, Tohoku University, Sendai 980-8577 (Japan); Kavli Institute of NanoScience, TU Delft Lorentzweg 1, 2628 CJ Delft (Netherlands)

    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.

  10. Sensible heat storage for a solar thermal power plant

    Microsoft Academic Search

    T. F. Baldwin; S. Lynn; A. S. Foss

    1979-01-01

    One possible configuration for a solar power plant with a sensible-heat storage unit was investigated. The proposed flowsheet allows thermal energy storage between the heat collection unit and the power generation unit without a reduction in the thermodynamic availability of the energy supplied to the power turbines. Energy is stored by heating a checkerwork of magnesia bricks. A gas that

  11. Coal and Nuclear Power Generation

    Microsoft Academic Search

    Jeff W. Eerkens

    \\u000a Historically the first electric power plants delivering large quantities of electric energy were hydro-electric. In 1895,\\u000a Westinghouse built the first AC electric power generator in Niagara Falls by passing water flow from the Falls through a turbine\\u000a that induced electric currents in copper windings. General Electric built high-power grid lines that took the 1.1 MWe of electricity\\u000a to Buffalo, New

  12. Second generation PFB for advanced power generation

    SciTech Connect

    Robertson, A.; Van Hook, J.

    1995-11-01

    Research is being conducted under a United States Department of Energy (USDOE) contract to develop a new type of coal-fueled plant for electric power generation. This new type of plant-called an advanced or second-generation pressurized fluidized bed combustion (APFBC) plant-offers the promise of 45-percent efficiency (HHV), with emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. This paper summarizes the pilot plant R&D work being conducted to develop this new type of plant. Although pilot plant testing is still underway, preliminary estimates indicate the commercial plant Will perform better than originally envisioned. Efficiencies greater than 46 percent are now being predicted.

  13. Solid state pulsed power generator

    DOEpatents

    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.

  14. Portable fuel cell power generator

    NASA Astrophysics Data System (ADS)

    Voss, H.; Huff, J.

    The proliferation of electronic equipment in the market-place is driving the growth of portable power generators. The ability to store a sufficient amount of energy is the key issue for applications requiring high power levels or extended operation. The source of this energy, measured in watt-hours, can be either batteries or fuel for energy conversion systems. This paper compares energy storage methods and shows that fuel cell systems are well suited for portable power applications due to their use of high energy density storage capabilities.

  15. Use of a Nonequilibrium MHD Generator for Conversion of SNTP Nuclear Thermal Rocket Exhaust to DC Electric Power for a Multimegawatt Nuclear Electric Propulsion System

    NASA Astrophysics Data System (ADS)

    Finley, Charles J.

    1994-07-01

    This paper explores a method by which the energy of a high speed flowing gas can efficiently be converted into DC electric power by a magnetohydrodynamic (MHD) generator. A nonequilibrium state may be created in the working fluid during the ionization process using an arc discharge. This nonequilibrium state may possibly be sustained in the fluid using the waste heat byproduct of the natural operation of the generator, if certain characteristics of the fluid/MHD system are maintained. The improved efficiency of the resulting nonequilibrium MHD generator not only allows the system to deliver increased power to the load, but reduces the amount of energy to be expelled from the closed fluid cycle by a radiator.

  16. Assessment of Japan's Optimal Power Generation Mix Considering Massive Deployment of Variable Renewable Power Generation

    NASA Astrophysics Data System (ADS)

    Komiyama, Ryoichi; Fujii, Yasumasa

    This paper analyzes Japan's optimal power generation mix considering massive deployment of solar photovoltaic (PV) system and wind power generation. The extensive introduction of PV system and wind power system are expected to play an important role in addressing energy security and climate change concern in Japan. Considering this expected large-scale deployment of PV system in electric power system, it is necessary to investigate the optimal power generation mix which is technologically capable of controlling and accommodating the intermittent output-power fluctuation inherently derived from PV and wind energy system. On these backgrounds, we develop optimal power generation mix model, explicitly analyzing the impact of output fluctuation in variable renewable in detailed resolution of time interval like 10 minutes at consecutive 365 days, with the role of stationary battery technology incorporated. Simulation results reveal that considerable deployment of those variable renewables do not necessarily require the scale of battery capacity similar as that of variable renewable capacity, due to quick load following treatment by thermal power plants, pumped-storage hydro power and battery technology over renewable output fluctuation.

  17. Thermal control system for Space Station Freedom photovoltaic power module

    NASA Technical Reports Server (NTRS)

    Hacha, Thomas H.; Howard, Laura

    1994-01-01

    The electric power for Space Station Freedom (SSF) is generated by the solar arrays of the photovoltaic power modules (PVM's) and conditioned, controlled, and distributed by a power management and distribution system. The PVM's are located outboard of the alpha gimbals of SSF. A single-phase thermal control system is being developed to provide thermal control of PVM electrical equipment and energy storage batteries. This system uses ammonia as the coolant and a direct-flow deployable radiator. The description and development status of the PVM thermal control system is presented.

  18. Thermal control system for Space Station Freedom photovoltaic power module

    NASA Technical Reports Server (NTRS)

    Hacha, Thomas H.; Howard, Laura S.

    1992-01-01

    The electric power for Space Station Freedom (SSF) is generated by the solar arrays of the photovoltaic power modules (PVM's) and conditioned, controlled, and distributed by a power management and distribution system. The PVM's are located outboard of the alpha gimbals of SSF. A single-phase thermal control system is being developed to provide thermal control of PVM electrical equipment and energy storage batteries. This system uses ammonia as the coolant and a direct-flow deployable radiator. This paper presents the description and development status of the PVM thermal control system.

  19. Entropy generation method to quantify thermal comfort

    NASA Technical Reports Server (NTRS)

    Boregowda, S. C.; Tiwari, S. N.; Chaturvedi, S. K.

    2001-01-01

    The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study is needed in the future to fully establish the validity of the OTCI formula and the model. One of the practical applications of this index is that could it be integrated in thermal control systems to develop human-centered environmental control systems for potential use in aircraft, mass transit vehicles, intelligent building systems, and space vehicles.

  20. Investigations for biogas operated MHD power generators

    SciTech Connect

    Dahiya, R.P.; Chand, A.; Sharma, S.C.

    1983-12-01

    Biogas is produced from the anaerobic fermentation of the organic matter containing cellulose, such as agricultural wastes, human wastes, animal wastes, etc. It contains methane (50-70%), carbon dioxide (30-50%), and very small amounts of hydrogen and hydrogen sulphide. Adequate quantities of raw material to generate biogas are normally available in rural areas, and therefore, there is a possibility that almost all the energy requirements of the rural sector may be fulfilled by biogas. Presently in the rural sector, biogas is used mainly to provide thermal energy (for cooking, etc.), and up to a limited extent, to meet the electrical energy requirements by running electrical generators with engines powered by a mixture of oil and biogas. In this paper, the authors propose a scheme in which biogas can be used to generate electricity more efficiently by using magnetohydrodynamic (MHD) power generators. Investigations have been carried out to make feasibility studies for biogas-operated open cycle MHD power generators. Composition, temperature and electrical conductivity of the seeded (with potassium) combustion products of biogas-air/oxygen systems have been analytically investigated for different percentages of CO/sub 2/ in biogas and at various combustor pressures for a seeding ratio of 1 percent by weight. The effect of preheating and enrichment of air on temperature and electrical conductivity of the seeded combustion plasmas has also been studied.

  1. Thermoelectric power generator with intermediate loop

    Microsoft Academic Search

    Bel; Lon E; Douglas Todd Crane

    2009-01-01

    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

  2. GREENHOUSE GAS ANALYSIS OF SOLAR-THERMAL ELECTRICITY GENERATION

    Microsoft Academic Search

    M. LENZEN

    1999-01-01

    Solar-thermal electricity generation contributes to climate change because it incurs the emission of greenhouse gases during the provision of services and the production of materials needed for the construction and operation of solar power plants. These greenhouse gas costs (GGC) can be determined using either material inventories in physical units or monetary cost breakdowns. Solar-only plants employing parabolic troughs, central

  3. 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 cycle. Results of this study indicate that dual flash type plants are preferred at resources with temperatures above 400 F. Closed loop (binary type) plants are preferred at resources with temperatures below 400 F. A rotary separator turbine upstream of a dual flash plant can be beneficial at Salton Sea, the hottest resource, or at high temperature resources where there is a significant variance in wellhead pressures from well to well. Full scale demonstration is required to verify cost and performance. Hot water turbines that recover energy from the spent brine in a dual flash cycle improve that cycle's brine efficiency. Prototype field tests of this technology have established its technical feasibility. If natural gas prices remain low, a combustion turbine/binary hybrid is an economic option for the lowest temperature sites. The use of mixed fluids appear to be an attractive low risk option. The synchronous turbine option as prepared by Barber-Nichols is attractive but requires a pilot test to prove cost and performance. Dual flash binary bottoming cycles appear promising provided that scaling of the brine/working fluid exchangers is controllable. Metastable expansion, reheater, Subatmospheric flash, dual flash backpressure turbine, and hot dry rock concepts do not seem to offer any cost advantage over the baseline technologies. If implemented, the next generation geothermal power plant concept may improve brine utilization but is unlikely to reduce the cost of power generation by much more than 10%. Colder resources will benefit more from the development of a next generation geothermal power plant than will hotter resources. All values presented in this study for plant cost and for busbar cost of power are relative numbers intended to allow an objective and meaningful comparison of technologies. The goal of this study is to assess various technologies on an common basis and, secondarily, to give an approximate idea of the current costs of the technologies at actual resource sites. Absolute costs at a given site will be determined by the specifics of a given pr

  4. Solar energy power generation system

    SciTech Connect

    Nilsson, J.E.; Cochran, C.D.

    1986-05-06

    A solar energy power generation system is described which consists of: (a) means for collecting and concentrating solar energy; (b) heat storage means; (c) Stirling engine means for producing power; (d) first heat transfer means for receiving the concentrated solar energy and for transferring heat to the heat storage means; and (e) second heat transfer means for controllably transferring heat from the storage means to the Stirling engine means and including a discharge heat pipe means for transferring heat to the Stirling engine means and further including means for inserting and withdrawing the discharge heat pipe means into and out of the heat storage means.

  5. Homopolar generator power supply system

    SciTech Connect

    Weldon, W. F.; Gully, J. H.

    1985-10-01

    A high-energy, high-current homopolar generator pulsed power supply system that is compact and field portable. The power supply system includes a homopolar generator (HPG), an auxiliary supply and drive system, both mounted on a skid frame, and a control system coupled to the HPG and drive system. The homopolar generator has a split rotor with insulation between the halves and a recess in the periphery. A stator ring and field coil, for producing a magnetic field through which the rotor halves make two simultaneous voltage-generating passes, are disposed within the recess in the rotor. Air-actuated brush mechanisms inside and outside the recess contact surfaces of the rotor and collect discharge current. The auxiliary supply and drive system includes a motoring system comprising hydraulic motors for driving the HPG to speed, a bearing lubrication system, a generator for energizing the field coil, and a brush actuator air supply system, all of which are driven by a prime mover. The control system comprises a logic controller for executing a prescribed sequence of steps including turning on the prime mover, initiating motoring of the HPG, energizing the field coil, and initiating the discharge of electrical current.

  6. Reliability Evaluation of Electric Power Generation Systems with Solar Power

    E-print Network

    Samadi, Saeed

    2013-11-08

    Conventional power generators are fueled by natural gas, steam, or water flow. These generators can respond to fluctuating load by varying the fuel input that is done by a valve control. Renewable power generators such as wind or solar, however...

  7. Performance analysis of solar thermal power systems

    Microsoft Academic Search

    T. A. Williams; J. A. Dirks

    1987-01-01

    Methods of analyzing and predicting the performance of solar thermal power plants for electric applications are discussed, and insight provided into the major energy loss mechanisms for solar thermal systems. The efficiency of each component in a solar thermal plant is discussed as are the plant parasitic losses and plant availability. This is followed by a discussion of the computer

  8. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    A major constraint to the evolution of solar thermal power systems is the need to provide continuous operation during periods of solar outage. A number of high temperature thermal energy storage technologies which have the potential to meet this need are currently under development. The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  9. ROSET. Solar Thermal Electric Power Simulation

    Microsoft Academic Search

    1982-01-01

    ROSET consists of five programs to calculate the energy output of a solar thermal electric power system. The ROSET programs provide two distinct functions. The first four (WTPREAD, FIELD, POWERT, and POWERE) use hourly weather data for a year to calculate hourly electric energy output for a solar thermal system. The last program (HISTO) uses one or more electric energy

  10. Thermal power installation for a water engine

    NASA Astrophysics Data System (ADS)

    Khlestkin, D. A.; Vinogradov, A. V.

    2009-11-01

    We present the main principles for developing a water-jet thermal power installation that uses a propeller operating on jet thrust developed during the flashing of metastable water. The considerable advantages of using the proposed thermal power installation as a water jet propeller over existing marine engines constructed on the basis of screw propellers are shown.

  11. 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.

  12. Solid oxide fuel cell distributed power generation

    SciTech Connect

    Veyo, S.E.

    1997-12-31

    Fuel cells are electrochemical devices that oxidize fuel without combustion to convert directly the fuel`s chemical energy into electricity. The solid oxide fuel cell (SOFC) is distinguished from other fuel cell types by its all solid state structure and its high operating temperature (1,000 C). The Westinghouse tubular SOFC stack is process air cooled and has integrated thermally and hydraulically within its structure a natural gas reformer that requires no fuel combustion and no externally supplied water. In addition, since the SOFC stack delivers high temperature exhaust gas and can be operated at elevated pressure, it can supplant the combustor in a gas turbine generator set yielding a dry (no steam) combined cycle power system of unprecedented electrical generation efficiency (greater 70% ac/LHV). Most remarkably, analysis indicates that efficiencies of 60 percent can be achieved at power plant capacities as low as 250 kWe, and that the 70 percent efficiency level should be achievable at the two MW capacity level. This paper describes the individual SOFC, the stack, and the power generation system and its suitability for distributed generation.

  13. Local control of reactive power by distributed photovoltaic generators

    SciTech Connect

    Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Sulc, Petr [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory

    2010-01-01

    High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the real power generated by the PVs. Using one adjustable parameter per circuit, we balance the requirements on power quality and desire to minimize thermal losses. Numerical analysis of two exemplary systems, with comparable total PV generation albeit a different spatial distribution, show how to adjust the optimization parameter depending on the goal. Overall, this local scheme shows excellent performance; it's capable of guaranteeing acceptable power quality and achieving significant saving in thermal losses in various situations even when the renewable generation in excess of the circuit own load, i.e. feeding power back to the higher-level system.

  14. INTEGRATED CONTROL OF NEXT GENERATION POWER SYSTEM

    SciTech Connect

    None

    2010-02-28

    Control methodologies provide the necessary data acquisition, analysis and corrective actions needed to maintain the state of an electric power system within acceptable operating limits. These methods are primarily software-based algorithms that are nonfunctional unless properly integrated with system data and the appropriate control devices. Components of the control of power systems today include protective relays, supervisory control and data acquisition (SCADA), distribution automation (DA), feeder automation, software agents, sensors, control devices and communications. Necessary corrective actions are still accomplished using large electromechanical devices such as vacuum, oil and gas-insulated breakers, capacitor banks, regulators, transformer tap changers, reclosers, generators, and more recently FACTS (flexible AC transmission system) devices. The recent evolution of multi-agent system (MAS) technologies has been reviewed and effort made to integrate MAS into next generation power systems. A MAS can be defined as ��a loosely-coupled network of problem solvers that work together to solve problems that are beyond their individual capabilities��. These problem solvers, often called agents, are autonomous and may be heterogeneous in nature. This project has shown that a MAS has significant advantages over a single, monolithic, centralized problem solver for next generation power systems. Various communication media are being used in the electric power system today, including copper, optical fiber and power line carrier (PLC) as well as wireless technologies. These technologies have enabled the deployment of substation automation (SA) at many facilities. Recently, carrier and wireless technologies have been developed and demonstrated on a pilot basis. Hence, efforts have been made by this project to penetrate these communication technologies as an infrastructure for next generation power systems. This project has thus pursued efforts to use specific MAS methods as well as pertinent communications protocols to imbed and assess such technologies in a real electric power distribution system, specifically the Circuit of the Future (CoF) developed by Southern California Edison (SCE). By modeling the behavior and communication for the components of a MAS, the operation and control of the power distribution circuit have been enhanced. The use of MAS to model and integrate a power distribution circuit offers a significantly different approach to the design of next generation power systems. For example, ways to control a power distribution circuit that includes a micro-grid while considering the impacts of thermal constraints, and integrating voltage control and renewable energy sources on the main power system have been pursued. Both computer simulations and laboratory testbeds have been used to demonstrate such technologies in electric power distribution systems. An economic assessment of MAS in electric power systems was also performed during this project. A report on the economic feasibility of MAS for electric power systems was prepared, and particularly discusses the feasibility of incorporating MAS in transmission and distribution (T&D) systems. Also, the commercial viability of deploying MAS in T&D systems has been assessed by developing an initial case study using utility input to estimate the benefits of deploying MAS. In summary, the MAS approach, which had previously been investigated with good success by APERC for naval shipboard applications, has now been applied with promising results for enhancing an electric power distribution circuit, such as the Circuit of the Future developed by Southern California Edison. The results for next generation power systems include better ability to reconfigure circuits, improve protection and enhance reliability.

  15. Method of Electric Power Compensation for Wind Power Generation Using Biomass Gas Turbine Generator and Flywheel

    Microsoft Academic Search

    M. Hara; N. Yamamura; M. Ishida; Y. Kamada; T. Maeda; M. Wakita

    2007-01-01

    The power generation using natural energy contains electric power fluctuation. Therefore, in order to put such power generation system to practical use, compensation system power fluctuation is necessary. In this paper, we propose a power compensation method using biomass gas turbine generator and flywheel energy storage equipment. In order to realize high quality natural energy power generation system considering wind

  16. Pseudorandom sequences constructed by the power generator

    E-print Network

    Katalin, Gyarmati

    Pseudorandom sequences constructed by the power generator Katalin Gyarmati # Abstract We study the pseudorandom properties of the power generator (which includes as special cases the RSA generator and the Blum functions are used. 1 Introduction We will study the pseudorandom properties of the power generator

  17. Problem 118: Power Generation Matthew Grum

    E-print Network

    St Andrews, University of

    Problem 118: Power Generation Matthew Grum Dept. Computer Science, The University of York July 2004 This problem concerns running power generators that are plugged into a grid. There are a number of generators of several types available. Each generator type has a minimum and maximum power output, a starup cost

  18. Impact of Power Generation Uncertainty on Power System Static Performance

    E-print Network

    Liberzon, Daniel

    Impact of Power Generation Uncertainty on Power System Static Performance Yu Christine Chen, Xichen uncer- tainties on the generation side of power systems. We propose a method to assess whether static determined by the forecasted renewable power injection. In our methodology, the uncertainty in generation can

  19. Control of Pollution from the Generation of Nuclear Power

    Microsoft Academic Search

    WALLACE DE LAGUNA

    1969-01-01

    Since the early days of the Manhattan District, there has been concern over potential pollution from the manufacture of atomic weapons and the generation of nuclear power. With time it has become obvious that the nuclear power plants themselves are not important sources of radioactive wastes, although they can be responsible for thermal pollution, as are conventional fossil fuel burning

  20. 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

  1. 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.

  2. Power Generation: The Next 30 Years

    ERIC Educational Resources Information Center

    Holcomb, Robert W.

    1970-01-01

    Discusses pollution problems associated with power production. Estimates power consumption in the 1980's and the availability of fossil and nuclear fuel resources. Emphasizes needed research on air pollution, nuclear pollution, and thermal pollution. (EB)

  3. 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.

  4. Waste Heat Recovery Power Generation with WOWGen

    E-print Network

    Romero, M.

    applications of heat recovery power generation can be found in Industry (e.g. steel, glass, cement, lime, pulp and paper, refining and petrochemicals), Power Generation (CHP, biomass, biofuel, traditional fuels, gasifiers, diesel engines) and Natural Gas...

  5. Parabolic Trough Solar Thermal Electric Power Plants

    SciTech Connect

    Not Available

    2003-06-01

    Although many solar technologies have been demonstrated, parabolic trough solar thermal electric power plant technology represents one of the major renewable energy success stories of the last two decades.

  6. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  7. Seventh Power Plan: Generating Resources Advisory

    E-print Network

    6/19/2013 1 Seventh Power Plan: Generating Resources Advisory Committee Schedule and Initial Topics of natural gas for electric generation Inter-regional power system & market linkages 4 #12;6/19/2013 3 Committee June 20, 2013 Seventh Power Plan ­ Discussion of Topics The Sixth Power Plan Mid Term Assessment

  8. Dispersed solar thermal generation employing parabolic dish-electric transport with field modulated generator systems

    NASA Technical Reports Server (NTRS)

    Ramakumar, R.; Bahrami, K.

    1981-01-01

    This paper discusses the application of field modulated generator systems (FMGS) to dispersed solar-thermal-electric generation from a parabolic dish field with electric transport. Each solar generation unit is rated at 15 kWe and the power generated by an array of such units is electrically collected for insertion into an existing utility grid. Such an approach appears to be most suitable when the heat engine rotational speeds are high (greater than 6000 r/min) and, in particular, if they are operated in the variable speed mode and if utility-grade a.c. is required for direct insertion into the grid without an intermediate electric energy storage and reconversion system. Predictions of overall efficiencies based on conservative efficiency figures for the FMGS are in the range of 25 per cent and should be encouraging to those involved in the development of cost-effective dispersed solar thermal power systems.

  9. Concerns generated by islanding [electric power generation

    Microsoft Academic Search

    P. L. Villenueve

    2004-01-01

    The purpose of this article is to discuss islanding operation and to provide end-users with items to consider when determining distributed generation plant and equipment design requirements. Islanding is operating an electric generating plant without an external voltage and frequency reference. Operating in parallel is the opposite of islanding. This article attempts to describe the valid concerns that grid operators

  10. Water resource and power generation

    Microsoft Academic Search

    Claude Crampes; Michel Moreaux

    2001-01-01

    We propose a simple model of competition between a thermal station and a hydrostation for the production of energy. We show that, despite the static characteristics of the thermal cost function, the thermal output is determined by intertemporal considerations. This results from the scarcity of the water resource which is storable at zero operating cost. We analyze the combination of

  11. Thermal Analysis of the Z-Pinch Power Plant Concept

    Microsoft Academic Search

    M. A. Modesto; E. R. Lindgren; C. W. Morrow

    2005-01-01

    In this work, a preliminary thermal model for the Z-Pinch Power Plant is presented. This power plant utilizes fusion energy to generate electric energy in the GW range. The Z-Pinch Technology consists of compressing high-density plasma to produce X-rays to indirectly heat to ignition a deuterium\\/tritium fusion capsule. This ignition releases a minimum of 3 GJ every 10 seconds. The

  12. Power semiconductor device with negative thermal feedback

    NASA Technical Reports Server (NTRS)

    Borky, J. M.; Thornton, R. D.

    1970-01-01

    Composite power semiconductor avoids second breakdown and provides stable operation. It consists of an array of parallel-connected integrated circuits fabricated in a single chip. The output power device and associated low-level amplifier are closely coupled thermally, so that they have a predetermined temperature relationship.

  13. The small community solar thermal power experiment

    NASA Technical Reports Server (NTRS)

    Kiceniuk, T.

    1982-01-01

    the objectives and current status of the Small Community Solar Thermal Power Experiment are discussed. The adjustments in programs goals made in response to the changing emphasis in the area of solar energy in national policy are addressed. Planned fabrication and testing activities for the test bed concentrator, power conversion assembly, and control system are outlined.

  14. Film Capacitor Thermal Strategies Increase Power Density

    Microsoft Academic Search

    Ralph M. Kerrigan; Bob Kropiewnicki

    Polypropylene dielectric film capacitors of varying types are used in large power systems due to their low heat dissipation and inherent reliability. This paper examines the construction of these capacitors for power applications and compares their heat rise performance with respect to electrodes, terminals, form factors, and packaging. Thermal behavior is measured for the internal construction of the capacitors and

  15. Pv-Thermal Solar Power Assembly

    DOEpatents

    Ansley, Jeffrey H. (El Cerrito, CA); Botkin, Jonathan D. (El Cerrito, CA); Dinwoodie, Thomas L. (Piedmont, CA)

    2001-10-02

    A flexible solar power assembly includes a flexible photovoltaic device attached to a flexible thermal solar collector. The solar power assembly can be rolled up for transport and then unrolled for installation on a surface, such as the roof or side wall of a building or other structure, by use of adhesive and/or other types of fasteners.

  16. Solar Thermal Power Systems parabolic dish project

    NASA Technical Reports Server (NTRS)

    Truscello, V. C.

    1981-01-01

    The status of the Solar Thermal Power Systems Project for FY 1980 is summarized. Included is: a discussion of the project's goals, program structure, and progress in parabolic dish technology. Analyses and test results of concentrators, receivers, and power converters are discussed. Progress toward the objectives of technology feasibility, technology readiness, system feasibility, and system readiness are covered.

  17. Power Generation and Power Use Decisions in an Industrial Process

    E-print Network

    Gilbert, J. S.; Niess, R. C.

    POWER GENERATION AND POWER USE DECIS IONS IN AN INDUSTRIAL PROCESS Joel S. Gilbert & Richard C. Niess Dames & Moore, Bethesda, Maryland ABSTRACT This paper discusses how to decide whether to generate any or all of a plant's power, or to use... power, purchased or self-generated, to move heat .or do work. The analysis can be conducted by developing energy composite curves. Using the information derived, this paper will show how to examine the potential application of heat exchange or heat...

  18. Power generation of a thermoelectric generator with phase change materials

    NASA Astrophysics Data System (ADS)

    Jo, Sung-Eun; Kim, Myoung-Soo; Kim, Min-Ki; Kim, Yong-Jun

    2013-11-01

    In this paper, a thermoelectric generator that embeds phase change materials for wasted heat energy harvesting is proposed. The proposed thermoelectric generator embeds phase change materials in its device structure. The phase change materials store large amounts of heat energy using the latent heat of fusion. When the heat source contacts the thermoelectric generator, dissipated heat from the heat source is stored in the phase change materials. When the heat source is removed from the thermoelectric generator, the output power of the thermoelectric generator slowly decreases, while the output power of conventional thermoelectric generators decreases rapidly without the heat source. The additional air layer in the proposed thermoelectric generator disturbs the heat dissipation from the phase change materials, so the thermoelectric generator can maintain the power generation for longer without a heat source. The experimental results for the thermoelectric generator fabricated clearly show the latent heat effect of the phase change materials and the embedded air layer.

  19. Electrical power generation by mechanically modulating electrical double layers.

    PubMed

    Moon, Jong Kyun; Jeong, Jaeki; Lee, Dongyun; Pak, Hyuk Kyu

    2013-01-01

    Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future. PMID:23403587

  20. 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, if it were to burn fuel, then it would also generate exhaust, similarly to other combustion-based power sources.

  1. Equilibrium and kinetic studies of in situ generation of ammonia from urea in a batch reactor for flue gas conditioning of thermal power plants

    SciTech Connect

    Sahu, J.N.; Patwardhan, A.V.; Meikap, B.C. [Indian Institute of Technology, Kharagpur (India). Dept. of Chemical Engineering

    2009-03-15

    Ammonia has long been known to be useful in the treatment of flue/tail/stack gases from industrial furnaces, incinerators, and electric power generation industries. In this study, urea hydrolysis for production of ammonia, in different application areas that require safe use of ammonia at in situ condition, was investigated in a batch reactor. The equilibrium and kinetic study of urea hydrolysis was done in a batch reactor at reaction pressure to investigate the effect of reaction temperature, initial feed concentration, and time on ammonia production. This study reveals that conversion increases exponentially with an increase in temperature but with increases in initial feed concentration of urea the conversion decreases marginally. Further, the effect of time on conversion has also been studied; it was found that conversion increases with increase in time. Using collision theory, the temperature dependency of forward rate constant developed from which activation energy of the reaction and the frequency factor has been calculated. The activation energy and frequency factor of urea hydrolysis reaction at atmospheric pressure was found to be 73.6 kJ/mol and 2.89 x 10{sup 7} min{sup -1}, respectively.

  2. 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.

  3. Thermal design of high-power LED package and system

    Microsoft Academic Search

    Moo Whan Shin

    In this paper we present thermal analysis of three kinds of ceramic package designs for high power LEDs and thermal characterization of high power LED array system. The analysis was made by transient thermal measurement and thermal simulation using the finite volume method (FVM). For the package design, thermal behaviors, as are described in thermal resistance, of the three packaging

  4. Solar thermal power systems point-focusing thermal and electric applications projects. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Marriott, A.

    1980-01-01

    The activities of the Point-Focusing Thermal and Electric Applications (PETEA) project for the fiscal year 1979 are summarized. The main thrust of the PFTEA Project, the small community solar thermal power experiment, was completed. Concept definition studies included a small central receiver approach, a point-focusing distributed receiver system with central power generation, and a point-focusing distributed receiver concept with distributed power generation. The first experiment in the Isolated Application Series was initiated. Planning for the third engineering experiment series, which addresses the industrial market sector, was also initiated. In addition to the experiment-related activities, several contracts to industry were let and studies were conducted to explore the market potential for point-focusing distributed receiver (PFDR) systems. System analysis studies were completed that looked at PFDR technology relative to other small power system technology candidates for the utility market sector.

  5. A dish-Stirling solar-thermal power system

    NASA Technical Reports Server (NTRS)

    Pons, R. L.; Clark, T. B.

    1980-01-01

    This paper presents results of a preliminary design/economic study of a first-generation point focusing distributed receiver solar-thermal electric system optimized for application to industrial and small community power plants at power levels up to 10 MWe. Power conversion is provided by small Stirling cycle engines mounted at the focus of paraboloidal solar concentrators. The output of multiple power modules (concentrator, receiver, engine, and electric generator) is collected by means of a conventional electrical system and interfaced with a utility grid. Based on the United Stirling P-75 engine, a 1 MWe system employing mass-produced components (100,000 modules/year) could produce electricity at costs competitive with those projected for electricity generated by more conventional means, e.g. with fossil fuels.

  6. Small solar thermal electric power plants with early commercial potential

    NASA Technical Reports Server (NTRS)

    Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

    1979-01-01

    Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

  7. Improved lumped parameter thermal modelling of synchronous generators 

    E-print Network

    Mejuto, Carlos

    2010-01-01

    Within the existing available mix of numerical and analytical thermal analysis options, lumped parameter thermal modelling is selected as the operational backbone to develop an improved novel synchronous generator thermal ...

  8. Pulse power applications of flux compression generators

    SciTech Connect

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

    1981-01-01

    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.

  9. Piezoelectric micro-power generation interface circuits

    Microsoft Academic Search

    Triet T. Le; Jifeng Han; Annette von Jouanne; Kartikeya Mayaram; Terri S. Fiez

    2006-01-01

    New power conversion circuits to interface to a piezoelectric micro-power generator have been fabricated and tested. Circuit designs and measurement results are presented for a half-wave synchronous rectifier with voltage doubler, a full-wave synchronous rectifier and a passive full-wave rectifier circuit connected to the piezoelectric micro-power generator. The measured power efficiency of the synchronous rectifier and voltage doubler circuit fabricated

  10. Integration of stochastic generation in power systems

    Microsoft Academic Search

    G. Papaefthymiou; P. H. Schavemaker; L. van der Sluis; W. L. Kling; D. Kurowicka; R. M. Cooke

    2006-01-01

    Stochastic generation, i.e., electrical power production by an uncontrolled primary energy source, is expected to play an important role in future power systems. A new power system structure is created due to the large-scale implementation of this small-scale, distributed, non-dispatchable generation; the ‘horizontally-operated’ system. Modeling methodologies that can deal with the operational uncertainty introduced by these power units should be

  11. Thermoelectric power generator with intermediate loop

    DOEpatents

    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.

  12. Thermoelectric power generator with intermediate loop

    SciTech Connect

    Bel,; Lon E. (Altadena, CA); Crane, Douglas Todd (Pasadena, CA)

    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.

  13. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This paper presents recent thermal model results of the Advanced Stirling Radioisotope Generator (ASRG). The three-dimensional (3D) ASRG thermal power model was built using the Thermal Desktop(trademark) thermal analyzer. The model was correlated with ASRG engineering unit test data and ASRG flight unit predictions from Lockheed Martin's (LM's) I-deas(trademark) TMG thermal model. The auxiliary cooling system (ACS) of the ASRG is also included in the ASRG thermal model. The ACS is designed to remove waste heat from the ASRG so that it can be used to heat spacecraft components. The performance of the ACS is reported under nominal conditions and during a Venus flyby scenario. The results for the nominal case are validated with data from Lockheed Martin. Transient thermal analysis results of ASRG for a Venus flyby with a representative trajectory are also presented. In addition, model results of an ASRG mounted on a Cassini-like spacecraft with a sunshade are presented to show a way to mitigate the high temperatures of a Venus flyby. It was predicted that the sunshade can lower the temperature of the ASRG alternator by 20 C for the representative Venus flyby trajectory. The 3D model also was modified to predict generator performance after a single Advanced Stirling Convertor failure. The geometry of the Microtherm HT insulation block on the outboard side was modified to match deformation and shrinkage observed during testing of a prototypic ASRG test fixture by LM. Test conditions and test data were used to correlate the model by adjusting the thermal conductivity of the deformed insulation to match the post-heat-dump steady state temperatures. Results for these conditions showed that the performance of the still-functioning inboard ACS was unaffected.

  14. Small spacecraft power and thermal subsystems

    NASA Technical Reports Server (NTRS)

    Eakman, D.; Lambeck, R.; Mackowski, M.; Slifer, L., Jr.

    1994-01-01

    This white paper provides a general guide to the conceptual design of satellite power and thermal control subsystems with special emphasis on the unique design aspects associated with small satellites. The operating principles of these technologies are explained and performance characteristics of current and projected components are provided. A tutorial is presented on the design process for both power and thermal subsystems, with emphasis on unique issues relevant to small satellites. The ability of existing technology to meet future performance requirements is discussed. Conclusions and observations are presented that stress cost-effective, high-performance design solutions.

  15. Thermal storage requirements for parabolic dish solar power plants

    NASA Technical Reports Server (NTRS)

    Wen, L.; Steele, H.

    1980-01-01

    The cost effectiveness of a high temperature thermal storage system is investigated for a representative parabolic dish solar power plant. The plant supplies electrical power in accordance with a specific, seasonally varying demand profile. The solar power received by the plant is supplemented by power from fuel combustion. The cost of electricity generated by the solar power plant is calculated, using the cost of mass-producible subsystems (specifically, parabolic dishes, receivers, and power conversion units) now being designed for this type of solar plant. The trade-off between fuel and thermal storage is derived in terms of storage effectiveness, the cost of storage devices, and the cost of fuel. Thermal storage requirements, such as storage capacity, storage effectiveness, and storage cost are established based on the cost of fuel and the overall objective of minimizing the cost of the electricity produced by the system. As the cost of fuel increases at a rate faster than general inflation, thermal storage systems in the $40 to $70/kWthr range could become cost effective in the near future.

  16. Thermal adaptation generates a diversity of thermal limits in a rainforest ant community.

    PubMed

    Kaspari, Michael; Clay, Natalie A; Lucas, Jane; Yanoviak, Stephen P; Kay, Adam

    2015-03-01

    The Thermal Adaptation Hypothesis posits that the warmer, aseasonal tropics generates populations with higher and narrower thermal limits. It has largely been tested among populations across latitudes. However, considerable thermal heterogeneity exists within ecosystems: across 31 trees in a Panama rainforest, surfaces exposed to sun were 8 °C warmer and varied more in temperature than surfaces in the litter below. Tiny ectotherms are confined to surfaces and are variously submerged in these superheated boundary layer environments. We quantified the surface CTmin and CTmax s (surface temperatures at which individuals grew torpid and lost motor control, respectively) of 88 ant species from this forest; they ranged in average mass from 0.01 to 57 mg. Larger ants had broader thermal tolerances. Then, for 26 of these species we again tested body CTmax s using a thermal dry bath to eliminate boundary layer effects: body size correlations observed previously disappeared. In both experiments, consistent with Thermal Adaptation, CTmax s of canopy ants averaged 3.5-5 °C higher than populations that nested in the shade of the understory. We impaled thermocouples in taxidermy mounts to further quantify the factors shaping operative temperatures for four ant species representing the top third (1-30 mg) of the size distribution. Extrapolations suggest the smallest 2/3rds of species reach thermal equilibrium in <10s. Moreover, the large ants that walk above the convective superheated surface air also showed more net heating by solar radiation, with operative temperatures up to 4 °C higher than surrounding air. The thermal environments of this Panama rainforest generate a range of CTmax subsuming 74% of those previously recorded for ant populations worldwide. The Thermal Adaptation Hypothesis can be a powerful tool in predicting diversity of thermal limits within communities. Boundary layer temperatures are likely key to predicting the future of Earth's tiny terrestrial ectotherm populations. PMID:25242246

  17. 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.

  18. Static and dynamic high power, space nuclear electric generating systems

    NASA Technical Reports Server (NTRS)

    Wetch, J. R.; Begg, L. L.; Koester, J. K.

    1985-01-01

    Space nuclear electric generating systems concepts have been assessed for their potential in satisfying future spacecraft high power (several megawatt) requirements. Conceptual designs have been prepared for reactor power systems using the most promising static (thermionic) and the most promising dynamic conversion processes. Component and system layouts, along with system mass and envelope requirements have been made. Key development problems have been identified and the impact of the conversion process selection upon thermal management and upon system and vehicle configuration is addressed.

  19. PV/thermal solar power assembly

    DOEpatents

    Ansley, Jeffrey H.; Botkin, Jonathan D.; Dinwoodie, Thomas L.

    2004-01-13

    A flexible solar power assembly (2) includes a flexible photovoltaic device (16) attached to a flexible thermal solar collector (4). The solar power assembly can be rolled up for transport and then unrolled for installation on a surface, such as the roof (20, 25) or side wall of a building or other structure, by use of adhesive and/or other types of fasteners (23).

  20. Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants

    E-print Network

    Hardin, Corey Lee

    2011-01-01

    CALIFORNIA RIVERSIDE Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal PowerSolar Thermal Power Plants by Corey Lee Hardin Master of Science, Graduate Program in Mechanical Engineering University of California,

  1. solar thermal power systems advanced solar thermal technology project, advanced subsystems development

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

  2. Solar Thermal Power Plants with Parabolic-Trough Collectors

    NASA Astrophysics Data System (ADS)

    Zarza, E.; Valenzuela, L.; León, J.

    2004-12-01

    Parabolic-trough collectors (PTC) are solar concentrating devices suitable to work in the 150°C- 400°C temperature range. Power plants based on this type of solar collectors are a very efficient way to produce electricity with solar energy. At present, there are eight commercial solar plants (called SEGS-II, III,.. IX) producing electricity with parabolic-trough collectors and their total output power is 340 MW. Though all SEGS plants currently in operation use thermal oil as a heat transfer fluid between the solar field and the power block, direct steam generation (DSG) in the receiver tubes is a promising option to reduce the cost of electricity produced with parabolic- trough power plants. Most of technical uncertainties associated to the DSG technology were studied and solved in the DISS project and it is expected that this new technology will be commercially available in a short term. In Spain, the Royal Decree No. 436/204 (March 12th , 2004) has defined a premium of 0,18€/kWh for the electricity produced by solar thermal power plants, thus promoting the installation of solar thermal power plants up to a limit of 200 MW. Due to the current legal and financial framework defined in Spain, several projects to install commercial solar power plants with parabolic-trough collectors are currently underway.

  3. COST-EFFECTIVE AND RELIABLE DESIGN OF A SOLAR THERMAL POWER PLANT

    Microsoft Academic Search

    A. A. Aliabadi; S. Wallace

    A design study was conducted to evaluate the cost-effectiveness of solar thermal power generation in a 50 kWe power plant that could be used in a remote location. The system combines a solar collector-thermal storage system utilizing a heat transfer Huid and a simple Rankine cycle power generator utilizing R123 refrigerant. Evacuated tube solar collectors heat mineral oil and supply

  4. Solar thermal power storage applications lead laboratory overview

    Microsoft Academic Search

    L. G. Radosevich

    1980-01-01

    The implementation of the applications elements of the thermal energy storage for Solar Thermal Applications program is described. The program includes the accelerated development of thermal storage technologies matched to solar thermal power system requirements and scheduled milestones. The program concentrates on storage development in the FY80 to 85 time period with emphasis on the more near-term solar thermal power

  5. Closed loop hermetically sealed solar power generator

    Microsoft Academic Search

    1983-01-01

    A closed loop sealed recirculatory water conservation solar power generator is provided herein. It includes a stationary hollow globular water boiler having a water inlet, a steam outlet conduit and a refractor lens window. A parabaterol reflector directs the sun's rays towards the refractor lens window to generate heat to boil the water. A primary steam-powered turbine is connected to

  6. Harnessing microbially generated power on the seafloor

    Microsoft Academic Search

    Hilmar A. Stecher; Dawn E. Holmes; Daniel R. Bond; Daniel A. Lowy; Kanoelani Pilobello; Stephanie J. Fertig; Derek R. Lovley; Leonard M. Tender; Clare E. Reimers

    2002-01-01

    In many marine environments, a voltage gradient exists across the water–sediment interface resulting from sedimentary microbial activity. Here we show that a fuel cell consisting of an anode embedded in marine sediment and a cathode in overlying seawater can use this voltage gradient to generate electrical power in situ. Fuel cells of this design generated sustained power in a boat

  7. Nonlinear control of wind power generation systems

    Microsoft Academic Search

    Yi Guo; John N. Jiang; Choon Yik Tang

    2009-01-01

    This paper proposes a nonlinear control design technique for wind generation systems that deals with both active power and reactive power at the same time in consideration of the fact that the wind generation system is a high order nonlinear dynamical system. Unlike the existing controller designs, the proposed technique is developed based on original nonlinear models of electric machine

  8. 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.

  9. Ball screw type wave power generator

    Microsoft Academic Search

    K.-I. Ohmata; H. Shimoda

    1979-01-01

    To obtain an even flow of electric power form fluctuating wave energy, the authors devised a ball screw type wave power generator (BSTWPG) which consists of a pressure plate, ball screws and nuts, one-way clutches, flywheels and generators. The equations of motion of the BSTWPG system are shown and the digital simulation using Continuous System Simulation Language is developed on

  10. The SAS-3 power and thermal systems

    NASA Technical Reports Server (NTRS)

    Sullivan, R. M.; Hogrefe, A. F.; Brenza, P. T.

    1975-01-01

    Solar array configurations of the SAS-3 are described: a configuration with two sets of coplanar panels in the horizontal and two others in the vertical position, and two other configurations with either four horizontal or four vertical sets of panels. The nickel-cadmium battery of the power subsystem is described in detail, with emphasis on voltage limits and charge-discharge characteristics. The characteristic of 'solar-only' operation in the case of damage to the battery is discussed. The thermal subsystem of SAS-3 is considered, with discussions of thermal design criteria and the thermal environment. Temperature is controlled by using internal thermal louvers that regulate the rate at which the heat load from electronic equipment is transmitted to the outer surface for dumping to space.

  11. Power Control of New Wind Power Generation System with Induction Generator Excited by Voltage Source Converter

    NASA Astrophysics Data System (ADS)

    Morizane, Toshimitsu; Kimura, Noriyuki; Taniguchi, Katsunori

    This paper investigates advantages of new combination of the induction generator for wind power and the power electronic equipment. Induction generator is popularly used for the wind power generation. The disadvantage of it is impossible to generate power at the lower rotor speed than the synchronous speed. To compensate this disadvantage, expensive synchronous generator with the permanent magnets is sometimes used. In proposed scheme, the diode rectifier is used to convert the real power from the induction generator to the intermediate dc voltage, while only the reactive power necessary to excite the induction generator is supplied from the voltage source converter (VSC). This means that the rating of the expensive VSC is minimized and total cost of the wind power generation system is decreased compared to the system with synchronous generator. Simulation study to investigate the control strategy of proposed system is performed. The results show the reduction of the VSC rating is prospective.

  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. Power electronics as efficient interface in dispersed power generation systems

    Microsoft Academic Search

    Frede Blaabjerg; Zhe Chen; S. B. Kjaer

    2004-01-01

    The global electrical energy consumption is rising and there is a steady increase of the demand on the power capacity, efficient production, distribution and utilization of energy. The traditional power systems are changing globally, a large number of dispersed generation (DG) units, including both renewable and nonrenewable energy sources such as wind turbines, photovoltaic (PV) generators, fuel cells, small hydro,

  14. Solar thermal power systems. Summary report

    SciTech Connect

    Not Available

    1980-06-01

    The work accomplished by the Aerospace Corporation from April 1973 through November 1979 in the mission analysis of solar thermal power systems is summarized. Sponsorship of this effort was initiated by the National Science Foundation, continued by the Energy Research and Development Administration, and most recently directed by the United States Department of Energy, Division of Solar Thermal Systems. Major findings and conclusions are sumarized for large power systems, small power systems, solar total energy systems, and solar irrigation systems, as well as special studies in the areas of energy storage, industrial process heat, and solar fuels and chemicals. The various data bases and computer programs utilized in these studies are described, and tables are provided listing financial and solar cost assumptions for each study. An extensive bibliography is included to facilitate review of specific study results and methodology.

  15. Review of Microscale Magnetic Power Generation

    Microsoft Academic Search

    David P. Arnold

    2007-01-01

    This paper discusses the history, current state of the art, and ongoing challenges for compact (less than a few cubic centimeters) magnetic power generation systems in the microwatts to tens of watts power range. These systems are of great interest for powering sensor networks, robotics, wireless communication systems, and other portable electronics. The paper considers the following topics. 1) The

  16. Power generating machine actuated by ocean swells

    Microsoft Academic Search

    Parr

    1976-01-01

    A power generating machine which is actuated by the continuous swells occurring in the ocean is described. The machine is supported on a pair of spaced main floats, between which is a power float connected to a linkage which allows the power float to reciprocate vertically with the passing swells. A flywheel is driven through a one way clutch connected

  17. Proceedings of the Fifth Parabolic Dish Solar Thermal Power Program

    NASA Technical Reports Server (NTRS)

    Lucas, J. W. (editor)

    1984-01-01

    The proceedings of the Fifth Parabolic Dish Solar Thermal Power Program Annual Review are presented. The results of activities within the Parabolic Dish Technology and Module/Systems Development element of the Department of Energy's Solar Thermal Energy Systems Program were emphasized. Among the topics discussed were: overall Project and Program aspects, Stirling and Brayton module development, concentrator and engine/receiver development along with associated hardware and test results; distributed systems operating experience; international parabolic dish development activities; and non-DOE-sponsored domestic dish activities. Solar electric generation was also addressed.

  18. Heliostat field layout for solar thermal power plants

    NASA Astrophysics Data System (ADS)

    Hartung; Kindermann; Mayer, W.

    1980-06-01

    The calculation of the optimum distribution of heliostats, serving a solar tower collector for solar thermal power generation, is considered. A theoretical basis for the problem is posed, encompassing physical characteristics of the heliostats, their number, and intensity of the reflected radiation from each unit in function of their layout. Theoretical results lead to numerical procedures (program package FAUST). Various heliostat field configurations (project EURELIOS and GAST) are then discussed and evaluated in light of this model.

  19. Generator synchronization in power recovery units

    Microsoft Academic Search

    C. E. Wood; R. J. Vangelisti

    1984-01-01

    There is disclosed a method and a control system for synchronizing the frequency of electrical current produced by a generator with the frequency of electrical current in an electric power grid so that the output of the generator can be provided to the grid. The generator is driven by an expansion turbine which utilizes hot pressurized gas from a process

  20. Optimum Unit Commitment for Thermal Power Plants - A Genetic Algorithm Approach

    Microsoft Academic Search

    Prashant P. Bedekar; Sudhir R. Bhide; Vijay S. Kale

    2009-01-01

    This paper presents genetic algorithm method for unit commitment of thermal power plant. The optimum allocation of generations (for a given plant load) to different units of a plant is called unit commitment (UC). It can be easily shown that the optimal operation of the units at a thermal power station can be achieved when the incremental fuel cost (incremental

  1. Hazardous Emissions from Combustion of Fossil Fuel from Thermal Power Plants Based on Turbine Technologies

    Microsoft Academic Search

    Mahboob Ali; Makshoof Athar; Misbahul Ain Khan; Shahida Begum Niazi

    2011-01-01

    Thermal power generation is associated with the emission of hazardous gaseous and particulate pollutants, which is one of the major contributors to deteriorated local ambient air quality. A comprehensive emissions assessment was carried on three thermal power plants and one oil refinery operating on fossil fuel, mainly heavy residual oil. The background ambient air quality was also monitored for criteria

  2. The generative powers of demolition

    E-print Network

    Muskopf, Christopher Jon Dalton, 1975-

    2005-01-01

    When examining the factory within the urban fabric, especially those cases that are abandoned and considered obsolete, it may be possible to see the first generative act as one of un-building. Considering demolition as an ...

  3. New low cost IGCC designs for competitive power generation

    SciTech Connect

    Brdar, D.R.; Depuy, R.A.; Gulko, G.; Jandrisevits, M.; Paolino, J.

    1999-07-01

    Design studies of coal based 450 MW new IGCC power plants reveal their ability to compete in today's power generation market. Single train unit designs coupled with significant improvements in IGCC net output and efficiency have brought down the installed costs to the range of 850--1,000 $/kW and net thermal efficiency up to 43--47%. These improvements are shown to result from IGCC design configurations integrating new generation gas turbine combined cycles with High Pressure Texaco Gasification Technology and Elevated Pressure Air Separation Units.

  4. Trough Collector Field Arrangements for Solar-Boosted Power Generation Systems

    Microsoft Academic Search

    S. D. Odeh; G. L. Morrison; M. Behnia

    Solar trough collectors with direct steam generation have being proposed to improve the performance of solar electric generation systems. In this study different arrangements of a direct steam generation solar collector field and power house backup boiler are analysed. A comparison between different solar field - power house arrangements is carried out considering the thermal and hydraulic operation of the

  5. Production and maintenance planning for electricity generators: modeling and application to Indian power systems

    E-print Network

    Dragoti-Ã?ela, Eranda

    associated with each of them. The (thermal) generating units in a power system receive fuel from the fuel, generators, and transmission network of their constituent states. The Indian power system has grown rapidlyProduction and maintenance planning for electricity generators: modeling and application to Indian

  6. 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.

  7. Solar power generation and distribution

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The production of electricity from solar energy is discussed. The economics of the proposed generation and distribution systems are analyzed. The use of photovoltaics for converting solar energy to home heating is proposed. The problems of energy distribution are analyzed from the standpoint of equipment costs and complexity.

  8. Electrical machines technology for aerospace power generators

    NASA Astrophysics Data System (ADS)

    Vaidya, Jayant G.

    Electric power generators for aerospace and aircraft applications are now required to be more reliable. It is noted that the wound field synchronous generator has been the workhorse for producing 400-Hz AC electric power for many years. Substantial evolution has occurred over the years by replacing low-speed generators with the 24,000-rpm design. The quality of the AC waveform produced by the wound field generators is excellent, the excitation power requirement is low, and control of output power is easily accomplished under abnormal operating conditions. Other changing requirements include variety of power types, increased reliability, and higher speeds and temperatures. It is pointed out that wound field synchronous generators have limitations due to rotating windings and rotating rectifiers. Other options such as self-regulating permanent magnet generators, switched reluctance generators, reluctance generators, flux switches overcome these limitations. It is suggested that the selection from these options must be based on the specific requirements for a given application, evaluating overall system constraints such as weight, performance, and cost.

  9. Thermal buffering of receivers for parabolic dish solar thermal power plants

    NASA Technical Reports Server (NTRS)

    Manvi, R.; Fujita, T.; Gajanana, B. C.; Marcus, C. J.

    1980-01-01

    A parabolic dish solar thermal power plant comprises a field of parabolic dish power modules where each module is composed of a two-axis tracking parabolic dish concentrator which reflects sunlight (insolation) into the aperture of a cavity receiver at the focal point of the dish. The heat generated by the solar flux entering the receiver is removed by a heat transfer fluid. In the dish power module, this heat is used to drive a small heat engine/generator assembly which is directly connected to the cavity receiver at the focal point. A computer analysis is performed to assess the thermal buffering characteristics of receivers containing sensible and latent heat thermal energy storage. Parametric variations of the thermal inertia of the integrated receiver-buffer storage systems coupled with different fluid flow rate control strategies are carried out to delineate the effect of buffer storage, the transient response of the receiver-storage systems and corresponding fluid outlet temperature. It is concluded that addition of phase change buffer storage will substantially improve system operational characteristics during periods of rapidly fluctuating insolation due to cloud passage.

  10. Solar thermoelectrics for small scale power generation

    E-print Network

    Amatya, Reja

    2012-01-01

    In the past two decades, there has been a surge in the research of new thermoelectric (TE) materials, driven party by the need for clean and sustainable power generation technology. Utilizing the Seebeck effect, the ...

  11. Hybrid solar-fossil fuel power generation

    E-print Network

    Sheu, Elysia J. (Elysia Ja-Zeng)

    2012-01-01

    In this thesis, a literature review of hybrid solar-fossil fuel power generation is first given with an emphasis on system integration and evaluation. Hybrid systems are defined as those which use solar energy and fuel ...

  12. Therminator: Thermal heavy-Ion generator

    E-print Network

    Adam Kisiel; Tomasz Taluc; Wojciech Broniowski; Wojciech Florkowski

    2005-09-27

    THERMINATOR is a Monte Carlo event generator designed for studying of particle production in relativistic heavy-ion collisions performed at such experimental facilities as the SPS, RHIC, or LHC. The program implements thermal models of particle production with single freeze-out. It performs the following tasks: 1) generation of stable particles and unstable resonances at the chosen freeze-out hypersurface with the local phase-space density of particles given by the statistical distribution factors, 2) subsequent space-time evolution and decays of hadronic resonances in cascades, 3) calculation of the transverse-momentum spectra and numerous other observables related to the space-time evolution. The geometry of the freeze-out hypersurface and the collective velocity of expansion may be chosen from two successful models, the Cracow single-freeze-out model and the Blast-Wave model. All particles from the Particle Data Tables are used. Experimental cuts may be introduced in a very straightforward manner. The code is written in the object-oriented c++ language and complies to the standards of the ROOT environment.

  13. Novel Thermal Powered Technology for UUV Persistent Surveillance

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Chao, Yi

    2006-01-01

    Buoyancy Generation: Various technology attempts include melting a wax, which pushes directly against a piston (U.S. Patent 5,291,847) or against a bladder (Webb Research), using ammonia or Freon 21 (U.S. Patent 5,303,552), and using solar heat to expand an oil (www.space.com, April, 10, 2002). All these heat-activated buoyancy control designs have thus far proved impractical and have ultimately failed during repeated cycling in ocean testing. JPL has demonstrated fully reversible 10 C encapsulated wax phase change, which can be used to change buoyancy without electrical hydraulic pumps. This technique has greatly improved heat transfer and much better reversibility than previous designs. Power Generation: Ocean Thermal Energy Conversion (OTEC) systems have been designed that transfer deep, cold sea water to the surface to generate electricity using turbine cycles with ammonia or water as the working fluid. JPL has designed several UUV systems: 1) Using a propeller water turbine to generate power on a gliding submersible; 2) Employing a compact CO2 turbine cycle powered by moving through thermoclines; and 3) Using melted wax to directly produce power through a piston-geared generator.

  14. Where solar thermal meets photovoltaic for high-efficiency power conversion

    E-print Network

    Bierman, David M. (David Matthew)

    2014-01-01

    To develop disruptive techniques which generate power from the Sun, one must understand the aspects of existing technologies that limit performance. Solar thermal and solar photovoltaic schemes dominate today's solar market ...

  15. Skutterudite Thermoelectric Generator for Electrical Power Generation from Automotive Waste Heat

    NASA Astrophysics Data System (ADS)

    Meisner, Gregory

    2012-02-01

    Filled skutterudites are state-of-the- art thermoelectric (TE) materials for electrical power generation from waste heat. They have suitable intrinsic transport properties as measured by the thermoelectric figure of merit ZT = S^2?T/? (S = Seebeck coefficient, ? = electrical conductivity, T = temperature, and ? = thermal conductivity) and good mechanical strength for operation at vehicle exhaust gas temperatures of >550 C. We have demonstrated TE electrical power generation on a production test vehicle equipped with a fully functional prototype TE generator (TEG). It was assembled with TE modules fabricated from filled skutterudites synthesized at GM. Our results and analysis show that improvement in total power generated can be achieved by enhanced thermal and electrical interfaces and contacts. A substantial T decrease along the exhaust gas flow results in a large variation of voltage, current, and power output for each TE module depending on its position in the module array. Total TEG output power depends directly on the position-dependent T profile via the temperature dependence of both ZT and Carnot efficiency. Total TEG power output also depends on how the modules are connected in parallel or series combinations because mismatch in output voltage and/or internal resistance among the modules degrades the performance of the entire array. Uniform T profiles and consistent TE module internal resistances improve overall TEG performance.

  16. National program for MHD power generation

    Microsoft Academic Search

    W. D. Jackson; R. V. Shanklin; P. S. Zygielbaum

    1976-01-01

    Development of MHD power generation systems in the U.S. is reviewed, with attention given to testing of MHD channels and electrodes, the use of high-temperature corrosion\\/erosion resistant materials for MHD components, and the Engineering Test Facility to be built under ERDA sponsorship in Montana. The current emphasis of the U.S. program is on the generation of electric power through utilization

  17. Power generation method including membrane separation

    DOEpatents

    Lokhandwala, Kaaeid A. (Union City, CA)

    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.

  18. Electric energy production by particle thermionic-thermoelectric power generators

    NASA Technical Reports Server (NTRS)

    Oettinger, P. E.

    1980-01-01

    Thermionic-thermoelectric power generators, composed of a thin layer of porous, low work function material separating a heated emitter electrode and a cooler collector electrode, have extremely large Seebeck coefficients of over 2 mV/K and can provide significant output power. Preliminary experiments with 20-micron thick (Ba Sr Ca)O coatings, limited by evaporative loss to temperatures below 1400 K, have yielded short circuit current densities of 500 mA/sq cm and power densities of 60 mW/ sq cm. Substantially more output is expected with cesium-coated refractory oxide particle coatings operating at higher temperatures. Practical generators will have thermal-to-electrical efficiencies of 10 to 20%. Further increases can be gained by cascading these high-temperature devices with lower temperature conventional thermoelectric generators.

  19. Selection and Evaluation of Thermal Interface Materials for Reduction of the Thermal Contact Resistance of Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Sakamoto, Tatsuya; Iida, Tsutomu; Sekiguchi, Takeshi; Taguchi, Yutaka; Hirayama, Naomi; Nishio, Keishi; Takanashi, Yoshifumi

    2014-10-01

    A variety of thermal interface materials (TIMs) were investigated to find a suitable TIM for improving the performance of thermoelectric power generators (TEGs) operating in the medium-temperature range (600-900 K). The thermal resistance at the thermal interface between which the TIM was inserted was evaluated. The TIMs were chosen on the basis of their thermal stability when used with TEGs operating at medium temperatures, their electrical insulating properties, their thermal conductivity, and their thickness. The results suggest that the boron nitride (BN)-based ceramic coating, Whity Paint, and the polyurethane-based sheet, TSU700-H, are suitable TIMs for the heat source and heat sink sides, respectively, of the TEG. Use of these effectively enhances TEG performance because they reduce the thermal contact resistance at the thermal interface.

  20. MAximum Multicore POwer (MAMPO) -An Automatic Multithreaded Synthetic Power Virus Generation

    E-print Network

    John, Lizy Kurian

    MAximum Multicore POwer (MAMPO) - An Automatic Multithreaded Synthetic Power Virus Generation power viruses. Previous research ef- forts towards automating the power virus generation process are all Multicore POwer (MAMPO), which is the pioneer attempt towards a framework to automatically generate

  1. High power matrix converter for wind power generation applications

    Microsoft Academic Search

    Jun Kang; Noriyuki Takada; Eiji Yamamoto; Eiji Watanabe

    2011-01-01

    The matrix converter has many advantages in wind power system applications. Matrix converter is compact and highly efficient because it directly converts generated power from AC generator to AC grid without intermediate DC bus while conventional back-to-back converter systems requires many electrolytic capacitors in DC link bus which are bulky and have short life-time. Matrix converter has both motoring and

  2. Chemical energy storage system for SEGS solar thermal power plant

    NASA Astrophysics Data System (ADS)

    Brown, D. R.; Lamarche, J. L.; Spanner, G. E.

    1991-09-01

    In October 1988, a symposium was held in Helendale, California, to discuss thermal energy storage (TES) concepts applicable to medium temperature (200 to 400 C) solar thermal electric power plants, in general, and the solar electric generating system (SEGS) plants developed by Luz International, in particular. Chemical reaction energy storage based on the reversible reaction between metal oxides and metal hydroxides was identified as a leading candidate for meeting Luz International's cost and performance requirements. The principal objectives of this study were to identify the design conditions, requirements, and potential feasibility for a chemical energy storage system applied to a SEGS solar thermal power plant. The remaining sections of this report begin by providing an overview of the chemical reaction energy storage concept and a SEGS solar thermal power plant. Subsequent sections describe the initial screening of alternative evaporation energy sources and the more detailed evaluation of design alternatives considered for the preferred evaporation energy source. The final sections summarize the results, conclusions, and recommendations.

  3. 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.

  4. Power electronics and alternative energy generation

    Microsoft Academic Search

    James P Lyons; Vlatko Vlatkovic

    2004-01-01

    Growth in alterative energy generation technologies and markets will have a major impact on the development of power electronics in the future. The paper discusses some of these implications, and outlines the technological and performance challenges for power electronic systems in alternative energy applications.

  5. Look at future of power generation

    SciTech Connect

    Downes, T.

    1995-10-01

    The face of independent power generation has changed more over the last 15 years than over the previous 50. Will the industry be able to sustain this change over the next decade and a half, or have we reached a plateau? Among the most dramatic breakthroughs in power generation in the last 15 years has been a considerable increase in power output from a given engine size and a given unit of fuel. This has enabled electricity requirements to be met more efficiently and with much smaller engines. The rise of these smaller engines has created an added advantage. Operators with large power requirements, who before have used only one engine, can now operate multiple power units. This results in enhanced flexibility, the ability to match power output needs more exactly and high levels of supply security and availability. Contributing to the rapid takeoff of independent power generation over this period has been the rise of two new applications - peak shaving and cogeneration in its various forms. This paper presents a general discussion on the future of power generation.

  6. Generation mechanism of power line harmonic radiation

    Microsoft Academic Search

    Alexander Kostrov; Mikhail Gushchin; Sergei Korobkov

    2010-01-01

    The questions concerning the generation of power line harmonic radiation (PLHR) and magne-tospheric line radiation (MLR) are discussed, including the effective source of high harmonics of 50\\/60 Hz, and fine dynamic structure of the frequency spectrum of PLHR and MLR. It is shown, that thyristor-based power regulators used by large electrical power consumers produce the periodic sequences of current pulses

  7. Network integration of distributed power generation

    Microsoft Academic Search

    Peter Dondi; Deia Bayoumi; Christoph Haederli; Danny Julian; Marco Suter

    2002-01-01

    The world-wide move to deregulation of the electricity and other energy markets, concerns about the environment, and advances in renewable and high efficiency technologies has led to major emphasis being placed on the use of small power generation units in a variety of forms. The paper reviews the position of distributed generation (DG, as these small units are called in

  8. Small nuclear power generation units, and electric power system interconnection

    Microsoft Academic Search

    Sang-Seung Lee; Jong-Keun Park; Seung-Il Moon; Yong-Tae Yoon; Jong-Won Kim; Goon-Cherl Park

    2006-01-01

    In this paper, we introduced a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power generation units (SNPGU). Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use

  9. Solar driven liquid metal MHD power generator

    NASA Technical Reports Server (NTRS)

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

    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. Residential Solar Combined Heat and Power Generation using Solar Thermoelectric Generation

    NASA Astrophysics Data System (ADS)

    Ohara, B.; Wagner, M.; Kunkle, C.; Watson, P.; Williams, R.; Donohoe, R.; Ugarte, K.; Wilmoth, R.; Chong, M. Zachary; Lee, H.

    2015-03-01

    Recent reports on improved efficiencies of solar thermoelectric generation (STEG) systems have generated interest in STEGs as a competitive power generation system. In this paper, the design of a combined cooling and power utilizing concentrated solar power is discussed. Solar radiation is concentrated into a receiver connected to thermoelectric modules, which are used as a topping cycle to generate power and high grade heat necessary to run an absorption chiller. Modeling of the overall system is discussed with experimental data to validate modeling results. A numerical modeling approach is presented which considers temperature variation of the source and sink temperatures and is used to maximize combined efficiency. A system is built with a demonstrated combined efficiency of 32% in actual working conditions with power generation of 3.1 W. Modeling results fell within 3% of the experimental results verifying the approach. An optimization study is performed on the mirror concentration ration and number of modules for thermal load matching and is shown to improve power generation to 26.8 W.

  11. Solar thermal electric power information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-02-01

    The results of a series of telephone interviews with groups of users of information on solar thermal electric power are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from five solar thermal electric power groups of respondents are analyzed: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Utilities, Electric Power Engineers, and Educators. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  12. Dislocation Generation by Thermal Stresses in Si: Modeling and Experiments

    SciTech Connect

    Sopori, B.; Sheldon, P.; Rupnowski, P.; Balzar, D.

    2005-11-01

    We developed a finite-element modeling program to predict the thermally generated dislocation distribution in a wafer. This model uses measured parameters that are determined from generating dislocations under a known optical flux.

  13. High power terahertz generation using 1550?nm plasmonic photomixers

    SciTech Connect

    Berry, Christopher W. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109 (United States); Hashemi, Mohammad R.; Jarrahi, Mona [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109 (United States); Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095 (United States); Preu, Sascha [Department of Electrical Engineering and Information Technology, Technical University Darmstadt, D-64283 Darmstadt (Germany); Lu, Hong; Gossard, Arthur C. [Materials Department, University of California, Santa Barbara, California 93106 (United States)

    2014-07-07

    We present a 1550?nm plasmonic photomixer operating under pumping duty cycles below 10%, which offers significantly higher terahertz radiation power levels compared to previously demonstrated photomixers. The record-high terahertz radiation powers are enabled by enhancing the device quantum efficiency through use of plasmonic contact electrodes, and by mitigating thermal breakdown at high optical pump power levels through use of a low duty cycle optical pump. The repetition rate of the optical pump can be specifically selected at a given pump duty cycle to control the spectral linewidth of the generated terahertz radiation. At an average optical pump power of 150 mW with a pump modulation frequency of 1 MHz and pump duty cycle of 2%, we demonstrate up to 0.8 mW radiation power at 1 THz, within each continuous wave radiation cycle.

  14. High power terahertz generation using 1550 nm plasmonic photomixers

    NASA Astrophysics Data System (ADS)

    Berry, Christopher W.; Hashemi, Mohammad R.; Preu, Sascha; Lu, Hong; Gossard, Arthur C.; Jarrahi, Mona

    2014-07-01

    We present a 1550 nm plasmonic photomixer operating under pumping duty cycles below 10%, which offers significantly higher terahertz radiation power levels compared to previously demonstrated photomixers. The record-high terahertz radiation powers are enabled by enhancing the device quantum efficiency through use of plasmonic contact electrodes, and by mitigating thermal breakdown at high optical pump power levels through use of a low duty cycle optical pump. The repetition rate of the optical pump can be specifically selected at a given pump duty cycle to control the spectral linewidth of the generated terahertz radiation. At an average optical pump power of 150 mW with a pump modulation frequency of 1 MHz and pump duty cycle of 2%, we demonstrate up to 0.8 mW radiation power at 1 THz, within each continuous wave radiation cycle.

  15. New Generation Power System for Space Applications

    NASA Technical Reports Server (NTRS)

    Jones, Loren; Carr, Greg; Deligiannis, Frank; Lam, Barbara; Nelson, Ron; Pantaleon, Jose; Ruiz, Ian; Treicler, John; Wester, Gene; Sauers, Jim; Giampoli, Paul; Haskell, Russ; Mulvey, Jim; Repp, John

    2004-01-01

    The Deep Space Avionics (DSA) Project is developing a new generation of power system building blocks. Using application specific integrated circuits (ASICs) and power switching modules a scalable power system can be constructed for use on multiple deep space missions including future missions to Mars, comets, Jupiter and its moons. The key developments of the DSA power system effort are five power ASICs and a mod ule for power switching. These components enable a modular and scalab le design approach, which can result in a wide variety of power syste m architectures to meet diverse mission requirements and environments . Each component is radiation hardened to one megarad) total dose. The power switching module can be used for power distribution to regular spacecraft loads, to propulsion valves and actuation of pyrotechnic devices. The number of switching elements per load, pyrotechnic firin gs and valve drivers can be scaled depending on mission needs. Teleme try data is available from the switch module via an I2C data bus. The DSA power system components enable power management and distribution for a variety of power buses and power system architectures employing different types of energy storage and power sources. This paper will describe each power ASIC#s key performance characteristics as well a s recent prototype test results. The power switching module test results will be discussed and will demonstrate its versatility as a multip urpose switch. Finally, the combination of these components will illu strate some of the possible power system architectures achievable fro m small single string systems to large fully redundant systems.

  16. Integrated propulsion and power modeling for bimodal nuclear thermal rockets

    NASA Astrophysics Data System (ADS)

    Clough, Joshua

    Bimodal nuclear thermal rocket (BNTR) engines have been shown to reduce the weight of space vehicles to the Moon, Mars, and beyond by utilizing a common reactor for propulsion and power generation. These savings lead to reduced launch vehicle costs and/or increased mission safety and capability. Experimental work of the Rover/NERVA program demonstrated the feasibility of NTR systems for trajectories to Mars. Numerous recent studies have demonstrated the economic and performance benefits of BNTR operation. Relatively little, however, is known about the reactor-level operation of a BNTR engine. The objective of this dissertation is to develop a numerical BNTR engine model in order to study the feasibility and component-level impact of utilizing a NERVA-derived reactor as a heat source for both propulsion and power. The primary contribution is to provide the first-of-its-kind model and analysis of a NERVA-derived BNTR engine. Numerical component models have been modified and created for the NERVA reactor fuel elements and tie tubes, including 1-D coolant thermodynamics and radial thermal conduction with heat generation. A BNTR engine system model has been created in order to design and analyze an engine employing an expander-cycle nuclear rocket and Brayton cycle power generator using the same reactor. Design point results show that a 316 MWt reactor produces a thrust and specific impulse of 66.6 kN and 917 s, respectively. The same reactor can be run at 73.8 kWt to produce the necessary 16.7 kW electric power with a Brayton cycle generator. This demonstrates the feasibility of BNTR operation with a NERVA-derived reactor but also indicates that the reactor control system must be able to operate with precision across a wide power range, and that the transient analysis of reactor decay heat merits future investigation. Results also identify a significant reactor pressure-drop limitation during propulsion and power-generation operation that is caused by poor tie tube thermal conductivity. This leads to the conclusion that, while BNTR operation is possible with a NERVA-derived reactor, doing so requires careful consideration of the Brayton cycle design point and fuel element survivability.

  17. Pressure drops for direct steam generation in line-focus solar thermal systems

    E-print Network

    Early direct steam generation prototypes include two central tower projects: a solar-powered enhanced oil recovery project called STEOR in the early 1980s (Romero 2002), and a solar tower projectPressure drops for direct steam generation in line-focus solar thermal systems John Pye1 , Graham

  18. Combined Thermal and Power Energy Management Optimization

    E-print Network

    Ahner, D. J.; Priestley, R. R.

    For a power generation application, these units would be simply dispatched from the gas turbine incremental heat rate characteristics using the relations: A O h. 1 = A O h. 1 = A kW I + kW 1 = kW L where A O =flul cost ($/1~ Btu) h. I .h... gas turbine load allocations occur when the incremental gas turbine heat rates are the same and the total output satisfies the plant load. The incremental power cost at this condition is: For a cogeneration configuration, the two gas turbines...

  19. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Power generation estimates. 431.6 Section...THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates....

  20. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Power generation estimates. 431.6 Section...THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates....

  1. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Power generation estimates. 431.6 Section...THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates....

  2. ENHANCED THERMAL VACUUM TEST CAPABILITY FOR RADIOISOTOPE POWER SYSTEMS AT THE IDAHO NATIONAL LABORATORY BETTER SIMULATES ENVIRONMENTAL CONDITIONS OF SPACE

    SciTech Connect

    J. C. Giglio; A. A. Jackson

    2012-03-01

    The Idaho National Laboratory (INL) is preparing to fuel and test the Advanced Stirling Radioisotope Generator (ASRG), the next generation space power generator. The INL identified the thermal vacuum test chamber used to test past generators as inadequate. A second vacuum chamber was upgraded with a thermal shroud to process the unique needs and to test the full power capability of the new generator. The thermal vacuum test chamber is the first of its kind capable of testing a fueled power system to temperature that accurately simulate space. This paper outlines the new test and set up capabilities at the INL.

  3. Solar thermal and wind energy power source

    SciTech Connect

    Argo, W.H.

    1980-09-23

    A transparent panel enclosed tower provides a confined space for solar heating air. An upright wind turbine, mounted on the tower top, communicates with the tower enclosed space. As the solar heated air expands and becomes lighter it is displaced by cooler atmospheric air at the bottom of the tower creating a turbine driving thermal updraft in combination with wind energy driving the turbine. The turbine includes an axial drive shaft driving a gear train in turn driving an electric generator, or the like.

  4. Thermoelectric Fabrics: Toward Power Generating Clothing

    PubMed Central

    Du, Yong; Cai, Kefeng; Chen, Song; Wang, Hongxia; Shen, Shirley Z.; Donelson, Richard; Lin, Tong

    2015-01-01

    Herein, we demonstrate that a flexible, air-permeable, thermoelectric (TE) power generator can be prepared by applying a TE polymer (e.g. poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)) coated commercial fabric and subsequently by linking the coated strips with a conductive connection (e.g. using fine metal wires). The poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) coated fabric shows very stable TE properties from 300?K to 390?K. The fabric device can generate a TE voltage output (V) of 4.3?mV at a temperature difference (?T) of 75.2?K. The potential for using fabric TE devices to harvest body temperature energy has been discussed. Fabric-based TE devices may be useful for the development of new power generating clothing and self-powered wearable electronics. PMID:25804132

  5. Thermoelectric fabrics: toward power generating clothing.

    PubMed

    Du, Yong; Cai, Kefeng; Chen, Song; Wang, Hongxia; Shen, Shirley Z; Donelson, Richard; Lin, Tong

    2015-01-01

    Herein, we demonstrate that a flexible, air-permeable, thermoelectric (TE) power generator can be prepared by applying a TE polymer (e.g. poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)) coated commercial fabric and subsequently by linking the coated strips with a conductive connection (e.g. using fine metal wires). The poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) coated fabric shows very stable TE properties from 300?K to 390?K. The fabric device can generate a TE voltage output (V) of 4.3?mV at a temperature difference (?T) of 75.2?K. The potential for using fabric TE devices to harvest body temperature energy has been discussed. Fabric-based TE devices may be useful for the development of new power generating clothing and self-powered wearable electronics. PMID:25804132

  6. Chemical energy storage system for SEGS solar thermal power plant

    NASA Astrophysics Data System (ADS)

    Brown, D. R.; Lamarche, J. L.; Spanner, G. E.

    1992-04-01

    The Pacific Northwest Laboratory evaluated the potential feasibility of using chemical energy storage at the Solar Electric Generating System (SEGS) power plants developed by Luz International. Like sensible or latent heat energy storage systems, chemical energy storage can be beneficially applied to solar thermal power plants to dampen the impact of cloud transients, extend the daily operating period, and/or allow a higher fraction of power production to occur during high-valued peak demand periods. Higher energy storage densities make chemical energy storage a potentially attractive option. The results of the evaluation indicated that a system based on the reversible reaction, CaO + H2O = Ca(OH)2, could be technically and economically feasible for this application, but many technical and economic issues must be resolved.

  7. The Meteosat Second Generation (MSG) power system

    SciTech Connect

    Haines, J.E.; Levins, D.; Robben, A.; Sepers, A. [European Space Agency, Noordwijk (Netherlands). Power and Energy Conversion Div.

    1997-12-31

    Under the direction of the European Meteorological Satellite Organization (EUMETSAT) and the European Space Agency (ESA), space industries within Europe are in the process of developing a new series of larger and more performant geostationary weather satellites. The initial three spacecraft within this new series, which are known by the name of Meteosat Second Generation (MSG), are due to be progressively launched from the year 2000 onwards. The major objective of this mission is the continuation of the European weather watch and space borne atmospheric sensing services provided by the present series of Meteosat spacecraft. To satisfy this mission requirement, the payload compliment to be supported by MSG will consist of a comprehensive earth viewing instrument capable of operating in both the infra-red and visible spectrum, an earth radiation measurement system and a search and rescue facility. In furnishing the power needs for these payloads, the power generating element on the spin stabilized MSG spacecraft consists of a body mounted solar array, capable of providing 628 watts of electrical power at the end of seven years of geosynchronous orbital lifetime. The energy storage elements for the spacecraft consists of two, 29 ampere-hour batteries, while centralized power management is achieved by the Power Control Unit (PCU), which satisfies the payload and battery re-charge demands by controlling the available solar array power. Power distribution for the spacecraft electrical loads and heaters is achieved by the Power Distribution Unit (PDU) and for the pyrotechnic devices by the Pyrotechnic Release Unit.

  8. Phase Change Material Thermal Power Generator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor); Chao, Yi (Inventor); Valdez, Thomas I. (Inventor)

    2014-01-01

    An energy producing device, for example a submersible vehicle for descending or ascending to different depths within water or ocean, is disclosed. The vehicle comprises a temperature-responsive material to which a hydraulic fluid is associated. A pressurized storage compartment stores the fluid as soon as the temperature-responsive material changes density. The storage compartment is connected with a hydraulic motor, and a valve allows fluid passage from the storage compartment to the hydraulic motor. An energy storage component, e.g. a battery, is connected with the hydraulic motor and is charged by the hydraulic motor when the hydraulic fluid passes through the hydraulic motor. Upon passage in the hydraulic motor, the fluid is stored in a further storage compartment and is then sent back to the area of the temperature-responsive material.

  9. Phase change material thermal power generator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor); Chao, Yi (Inventor); Valdez, Thomas I. (Inventor)

    2011-01-01

    An energy producing device, for example a submersible vehicle for descending or ascending to different depths within water or ocean, is disclosed. The vehicle comprises a temperature-responsive material to which a hydraulic fluid is associated. A pressurized storage compartment stores the fluid as soon as the temperature-responsive material changes density. The storage compartment is connected with a hydraulic motor, and a valve allows fluid passage from the storage compartment to the hydraulic motor. An energy storage component, e.g. a battery, is connected with the hydraulic motor and is charged by the hydraulic motor when the hydraulic fluid passes through the hydraulic motor. Upon passage in the hydraulic motor, the fluid is stored in a further storage compartment and is then sent back to the area of the temperature-responsive material.

  10. Electrical power generation from insect flight

    Microsoft Academic Search

    Timothy Reissman; Robert B. Maccurdy; Ephrahim Garcia

    2011-01-01

    This article presents an implementation of a miniature energy harvester (weighing 0.292 grams) on an insect (hawkmoth Manduca sexta) in un-tethered flight. The harvester utilizes a piezoelectric transducer which converts the vibratory motion induced by the insect's flight into electrical power (generating up to 59 muWRMS). By attaching a low-power management circuit (weighing 0.200 grams) to the energy harvester and

  11. Biomass gasifier gas turbine power generating technology

    Microsoft Academic Search

    R. H. Williams; E. D. Larson

    1996-01-01

    Integrating gasifiers with gas turbines, aeroderivative gas turbines in particular, makes it possible to achieve high efficiencies and low unit capital costs in modest-scale biomass power generating facilities. Electricity produced with biomass-integrated gasifier\\/gas turbine (BIG\\/GT) power systems would be competitive with electricity produced from coal and nuclear energy under a wide range of circumstances. Biomass also offers major environmental benefits.

  12. Next Generation Integrated Power System: The backbone of the electric warship(Hybrid Electric Drive: A near term opportunity)

    Microsoft Academic Search

    Lynn J. Petersen

    2009-01-01

    Advances in materials, controls, packaging, thermal management have played a significant role in improving efficiencies, power density, availability of power, and other desirable metrics in electric power systems. The US Navy, leveraging these advances, and in cooperation with industry, is developing the necessary architectures and modular building blocks, or pieces, consisting of power generation, power conversion, energy storage, power distribution,

  13. Economical photovoltaic power generation with heat recovery

    NASA Technical Reports Server (NTRS)

    Ascher, G.

    1977-01-01

    Three designs for conversion of solar radiation to electricity and thermal energy are analyzed. The objective of these converters is to increase the electric and thermal output for each photovoltaic array so as to lower the cell cost relative to the amount of energy delivered. An analysis of the economical aspects of conversion by photovoltaic cells with heat recovery is carried out in terms of hypothetical examples. Thus, it is shown that the original cost of say $40,000 per generated kilowat can be reduced to $572.00 per kilowatt by increasing the original electric output of 1 kW to 10 kW in electricity and 60 kW in thermal energy. The newly derived specific cost is only 1.4 percent of the original one. It is expected that a cost reduction of roughly 2% of the present specific cost per kilowatt will greatly stimulate public acceptance of photovoltaic terrestrial conversion to electricity.

  14. PEOPLE - The cutting edge in power generation

    SciTech Connect

    Boswell, M.J.; Hankal, S.

    1995-12-31

    As competition for the United States power consumer increases, generating companies must seek new ways to do business. One way to keep up with the pace of change is to implement unique ideas into various areas of daily operation at the generating station. From subtle new management styles to ambitious employee education programs, changes in operating the management techniques can produce valuable results over time. An educated confident workforce is capable of vast improvement in efficiency and technical competence. We become empowered.

  15. Application of the subatmospheric engine to solar thermal power

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The development of a natural gas-fired Brayton engine is discussed. It is intended to be the prime mover for a 10-ton commercial heat pump. This engine has many attractive features that make it an ideal candidate for solar thermal-power generation applications. The unique feature of this engine is its subatmospheric mode of operation. It operates between atmospheric pressure and a partial vacuum. This means that heat is added to the cycle at atmospheric pressure; this permits the receiver to be unpressurized, greatly simplifying its design and cost.

  16. Solar thermal power storage applications lead laboratory overview

    Microsoft Academic Search

    L. G. Radosevich

    1981-01-01

    An overview of activities for the applications elements of the Thermal Energy Storage for Solar Thermal Applications (TESSTA) program is presented. The TESSTA program which was initiated in FY80 is organized through a work breakdown structure which includes the development of thermal storage technologies matched to solar thermal power system requirements for several near-term applications. The status of the technology

  17. Thermal generators for waste heat utilization

    Microsoft Academic Search

    L. I. Anatychuk; Yu. Yu. Rozver; K. Misawa; N. Suzuki

    1997-01-01

    Technical and economical analysis of thermoelectric generators using heat wastes from heat machines and industrial heat wastes utilization have been given. The generators' technical and economical data resulting from this analysis have been presented. The block concept of 100-200 W generators development has been described. Development and test results of a 500 W and 1 kW generator blocks have been

  18. Method of operating a thermal engine powered by a chemical reaction

    DOEpatents

    Ross, John (Stanford, CA); Escher, Claus (Nieder-Ronstadt, DE)

    1988-01-01

    The invention involves a novel method of increasing the efficiency of a thermal engine. Heat is generated by a non-linear chemical reaction of reactants, said heat being transferred to a thermal engine such as Rankine cycle power plant. The novel method includes externally perturbing one or more of the thermodynamic variables of said non-linear chemical reaction.

  19. Method of operating a thermal engine powered by a chemical reaction

    DOEpatents

    Ross, J.; Escher, C.

    1988-06-07

    The invention involves a novel method of increasing the efficiency of a thermal engine. Heat is generated by a non-linear chemical reaction of reactants, said heat being transferred to a thermal engine such as Rankine cycle power plant. The novel method includes externally perturbing one or more of the thermodynamic variables of said non-linear chemical reaction. 7 figs.

  20. Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management

    NASA Technical Reports Server (NTRS)

    Pantano, David R.; Dottore, Frank; Geng, Steven M.; Schrieber, Jeffrey G.; Tobery, E. Wayne; Palko, Joseph L.

    2005-01-01

    One of the advantages of using a Radioisotope Power System (RPS) for deep space or planetary surface missions is the readily available waste heat, which can be used to maintain electronic components within a controlled temperature range, to warm propulsion tanks and mobility actuators, and to gasify liquid propellants. Previous missions using Radioisotope Thermoelectric Generators (RTGs) dissipated a very large quantity of waste heat due to the relatively low efficiency of the thermoelectric conversion technology. The next generation RPSs, such as the 110-watt Stirling Radioisotope Generator (SRG110) will have much higher conversion efficiencies than their predecessors and therefore may require alternate approaches to transferring waste heat to the spacecraft. RTGs, with efficiencies of approx. 6 to 7% and 200 C housing surface temperatures, would need to use large and heavy radiator heat exchangers to transfer the waste heat to the internal spacecraft components. At the same time, sensitive spacecraft instruments must be shielded from the thermal radiation by using the heat exchangers or additional shields. The SRG110, with an efficiency around 22% and 50 C nominal housing surface temperature, can use the available waste heat more efficiently by more direct heat transfer methods such as heat pipes, thermal straps, or fluid loops. The lower temperatures allow the SRG110 much more flexibility to the spacecraft designers in configuring the generator without concern of overheating nearby scientific instruments, thereby eliminating the need for thermal shields. This paper will investigate using a high efficiency SRG110 for spacecraft thermal management and outline potential methods in several conceptual missions (Lunar Rover, Mars Rover, and Titan Lander) to illustrate the advantages with regard to ease of assembly, less complex interfaces, and overall mass savings.

  1. Advanced Soldier Thermoelectric Power System for Power Generation from Battlefield Heat Sources

    SciTech Connect

    Hendricks, Terry J.; Hogan, Tim; Case, Eldon D.; Cauchy, Charles J.

    2010-09-01

    The U.S. military uses large amounts of fuel during deployments and battlefield operations. This project sought to develop a lightweight, small form-factor, soldier-portable advanced thermoelectric (TE) system prototype to recover and convert waste heat from various deployed military equipment (i.e., diesel generators/engines, incinerators, vehicles, and potentially mobile kitchens), with the ultimate purpose of producing power for soldier battery charging, advanced capacitor charging, and other battlefield power applications. The technical approach employed microchannel technology, a unique “power panel” approach to heat exchange/TE system integration, and newly-characterized LAST (lead-antimony-silver-telluride) and LASTT (lead-antimony-silver-tin-telluride) TE materials segmented with bismuth telluride TE materials in designing a segmented-element TE power module and system. This project researched never-before-addressed system integration challenges (thermal expansion, thermal diffusion, electrical interconnection, thermal and electrical interfaces) of designing thin “power panels” consisting of alternating layers of thin, microchannel heat exchangers (hot and cold) sandwiching thin, segmented-element TE power generators. The TE properties, structurally properties, and thermal fatigue behavior of LAST and LASTT materials were developed and characterized such that the first segmented-element TE modules using LAST / LASTT materials were fabricated and tested at hot-side temperatures = 400 °C and cold-side temperatures = 40 °C. LAST / LASTT materials were successfully segmented with bismuth telluride and electrically interconnected with diffusion barrier materials and copper strapping within the module electrical circuit. A TE system design was developed to produce 1.5-1.6 kW of electrical energy using these new TE modules from the exhaust waste heat of 60-kW Tactical Quiet Generators as demonstration vehicles.

  2. Spin-on-doping for output power improvement of silicon nanowire array based thermoelectric power generators

    SciTech Connect

    Xu, B., E-mail: bin.xu09@imperial.ac.uk; Fobelets, K. [Department of Electrical and Electronic Engineering, Imperial College London, Exhibition Road, SW7 2BT London (United Kingdom)

    2014-06-07

    The output power of a silicon nanowire array (NWA)-bulk thermoelectric power generator (TEG) with Cu contacts is improved by spin-on-doping (SOD). The Si NWAs used in this work are fabricated via metal assisted chemical etching (MACE) of 0.01–0.02 ? cm resistivity n- and p-type bulk, converting ?4% of the bulk thickness into NWs. The MACE process is adapted to ensure crystalline NWs. Current-voltage and Seebeck voltage-temperature measurements show that while SOD mainly influences the contact resistance in bulk, it influences both contact resistance and power factor in NWA-bulk based TEGs. According to our experiments, using Si NWAs in combination with SOD increases the output power by an order of 3 under the same heating power due to an increased power factor, decreased thermal conductivity of the NWA and reduced Si-Cu contact resistance.

  3. Optimisation of Concentrating Solar Thermal Power Plants with Neural Networks

    E-print Network

    Ábrahám, Erika

    Optimisation of Concentrating Solar Thermal Power Plants with Neural Networks Pascal Richter1 of solar power for energy supply is of in- creasing importance. While technical development mainly takes introduce our tool for the optimisation of parameterised solar thermal power plants, and report

  4. A fuzzy logic controller application for thermal power plants

    Microsoft Academic Search

    ?lhan Kocaarslan; Ertu?rul Çam; Hasan Tiryaki

    2006-01-01

    This study presents a fuzzy logic based control technique to regulate the power and enthalpy outputs in a boiler of a 765MW coal fired thermal power plant. An approximate mathematical model of the thermal power plant was developed by using real time data on Computer Aided Design and Control (CADACS) software. Conventional proportional, integral and derivative (PID), fuzzy logic (FL)

  5. Low thermal resistance power module assembly

    DOEpatents

    Hassani, Vahab (Denver, CO); Vlahinos, Andreas (Castle Rock, CO); Bharathan, Desikan (Arvada, CO)

    2010-12-28

    A power module assembly (400) with low thermal resistance and enhanced heat dissipation to a cooling medium. The assembly includes a heat sink or spreader plate (410) with passageways or openings (414) for coolant that extend through the plate from a lower surface (411) to an upper surface (412). A circuit substrate (420) is provided and positioned on the spreader plate (410) to cover the coolant passageways. The circuit substrate (420) includes a bonding layer (422) configured to extend about the periphery of each of the coolant passageways and is made up of a substantially nonporous material. The bonding layer (422) may be solder material which bonds to the upper surface (412) of the plate to provide a continuous seal around the upper edge of each opening (414) in the plate. The assembly includes power modules (430) mounted on the circuit substrate (420) on a surface opposite the bonding layer (422). The power modules (430) are positioned over or proximal to the coolant passageways.

  6. A Thermoelectric Generator Using Porous Si Thermal Isolation

    PubMed Central

    Hourdakis, Emmanouel; Nassiopoulou, Androula G.

    2013-01-01

    In this paper we report on a thermoelectric generator (TEG) using thermal isolation provided by a thick porous Si layer locally formed on the Si wafer and thermocouples composed of p-doped polycrystalline Si/Al. The “hot” contacts of the thermocouples lie on the porous Si layer, while the “cold” contacts lie on bulk crystalline Si. A housing was also designed and fabricated in order to transfer any external temperature change on the “hot” contacts of the thermocouples, the “cold” contacts being isolated from the “hot” contacts by a thick resist layer. The fabrication of the sensing element (Si die) is fully compatible with batch Si processing. The output power of the thermoelectric generator depends on the porous Si isolation layer thickness, porosity, structure and morphology. For a mesoporous Si layer of 60% porosity and a macroscopic temperature differential of 10 K, an output power of 0.39 ?W/cm2 was measured for a 50 ?m thick porous Si layer. PMID:24152923

  7. Global Climate Change - The Power Generation Challenge

    EPA Science Inventory

    The planet continues to warm; O.5 C from the 1970’s to the 2000’s. Also, worldwide CO2 emissions have increased at a 3% annual growth rate from 2000 to 2010. Such emissions are driven by fossil fuel combustion, especially in the power generation sector, & especial...

  8. Environmental effects of tidal power generating schemes

    Microsoft Academic Search

    C. Mettam

    1978-01-01

    The Severn Estuary has been proposed as a site for a tidal power generating barrage. The character of the existing environment would be changed but, if the risks of accumulating pollutants and eutrophication can be avoided, the reduction in turbidity and tidal scour could increase species diversity and productivity. The interests of wading birds and wildfowl could be accommodated by

  9. Black tungsten for solar power generation

    NASA Astrophysics Data System (ADS)

    Ungaro, Craig; Gray, Stephen K.; Gupta, Mool C.

    2013-08-01

    The viability of micro/nano textured tungsten as an efficient solar absorber is explored via computational electrodynamics simulations. Pseudo-random structures are investigated, along with the effects of protective oxide coatings. These structures show extremely high absorption across the solar spectrum along with relaxed requirements for manufacturing, allowing them to be applied for power generation.

  10. Solar power generator and water purifier

    Microsoft Academic Search

    1981-01-01

    A combined solar power generator and water purifier is provided herein. It includes a hollow globular boiler floating on and anchored atop a body of water to be purified. The globular boiler includes water inlet means disposed adjacent an upper portion of the globular boiler, an upwardly directed steam outlet conduit originating from an upper portion of the globular boiler,

  11. Plasma plume MHD power generator and method

    DOEpatents

    Hammer, J.H.

    1993-08-10

    A method is described of generating power at a situs exposed to the solar wind which comprises creating at separate sources at the situs discrete plasma plumes extending in opposed directions, providing electrical communication between the plumes at their source and interposing a desired electrical load in the said electrical communication between the plumes.

  12. Cascading Closed Loop Cycle Power Generation

    E-print Network

    Romero, M.

    2008-01-01

    WOW Energies was issued Patent 6,857,268 B2 on Feb 22, 2005 titled “CASCADING CLOSED LOOP CYCLE (CCLC) and Patent 7,096,665 B2 on August 29, 2006 titled “CASCADING CLOSED LOOP CYCLE POWER GENERATION”. These patented technologies are collectively...

  13. Value of Concentrating Solar Power and Thermal Energy Storage

    SciTech Connect

    Sioshansi, R.; Denholm, P.

    2010-02-01

    This paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in four regions in the southwestern United States. Our analysis shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant?s solar field to be used, by allowing a CSP plant to accommodate a larger solar field, and by allowing CSP generation to be shifted to hours with higher energy prices. We analyze the sensitivity of CSP value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, capacity value and dry cooling of the CSP plant. We also discuss the value of CSP plants and TES net of capital costs.

  14. 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

    ...EL13-64-000] Exelon Generation Company, LLC; CER Generation II, LLC; Constellation Mystic Power, LLC; Constellation NewEnergy, Inc.; Constellation Power Source Generation, Inc.; Criterion Power Partners, LLC; Notice of...

  15. Research and Development for Novel Thermal Energy Storage Systems (TES) for Concentrating Solar Power (CSP)

    SciTech Connect

    Faghri, Amir; Bergman, Theodore L; Pitchumani, Ranga

    2013-09-26

    The overall objective was to develop innovative heat transfer devices and methodologies for novel thermal energy storage systems for concentrating solar power generation involving phase change materials (PCMs). Specific objectives included embedding thermosyphons and/or heat pipes (TS/HPs) within appropriate phase change materials to significantly reduce thermal resistances within the thermal energy storage system of a large-scale concentrating solar power plant and, in turn, improve performance of the plant. Experimental, system level and detailed comprehensive modeling approaches were taken to investigate the effect of adding TS/HPs on the performance of latent heat thermal energy storage (LHTES) systems.

  16. New Generation Perovskite Thermal Barrier Coating Materials

    NASA Astrophysics Data System (ADS)

    Ma, W.; Jarligo, M. O.; Mack, D. E.; Pitzer, D.; Malzbender, J.; Vaßen, R.; Stöver, D.

    2008-12-01

    Advanced ceramic materials of perovskite structure have been developed for potential application in thermal barrier coating systems, in an effort to improve the properties of the pre-existing ones like yttria-stabilized zirconia. Yb2O3 and Gd2O3 doped strontium zirconate (SrZrO3) and barium magnesium tantalate (Ba(Mg1/3Ta2/3)O3) of the ABO3 and complex A(B'1/3B''2/3)O3 systems, respectively, have been synthesized using ball milling prior to solid state sintering. Thermal and mechanical investigations show desirable properties for high-temperature coating applications. On atmospheric plasma spraying, the newly developed thermal barrier coatings reveal promising thermal cycle lifetime up to 1350 °C.

  17. Recent advances in RF power generation

    SciTech Connect

    Tallerico, P.J.

    1990-01-01

    This paper is a review of the progress and methods used in RF generation for particle accelerators. The frequencies of interest are from a few megahertz to 100 GHz, and the powers are for super linear collider applications, but in this case the pulses are short, generally below 1 {mu}s. The very high-power, short-pulse generators are only lightly reviewed here, and for more details the reader should follow the specialized references. Different RF generators excel over various parts of the frequency spectrum. Below 100 MHz solid-state devices and gridded tubes prevail, while the region between 400 MHz and 3 GHz, the cyclotron-resonant devices predominate, and above 250 GHz, Free-Electron Lasers and ubitrons are the most powerful generators. The emphasis for this review is on microwave generation at frequencies below 20 GHz, so the cyclotron-resonant devices are only partially reviewed, while the progress on free-electron laser and ubitrons is not reviewed in this paper. 39 refs., 4 figs.

  18. Apollo experience report: Power generation system

    NASA Technical Reports Server (NTRS)

    Bell, D., III; Plauche, F. M.

    1973-01-01

    A comprehensive review of the design philosophy and experience of the Apollo electrical power generation system is presented. The review of the system covers a period of 8 years, from conception through the Apollo 12 lunar-landing mission. The program progressed from the definition phase to hardware design, system development and qualification, and, ultimately, to the flight phase. Several problems were encountered; however, a technology evolved that enabled resolution of the problems and resulted in a fully manrated power generation system. These problems are defined and examined, and the corrective action taken is discussed. Several recommendations are made to preclude similar occurrences and to provide a more reliable fuel-cell power system.

  19. Photovoltaic Power Generation in the Stellar Environments

    E-print Network

    T. E. Girish; S. Aranya

    2010-12-03

    In this paper we have studied the problem of photovoltaic power generation near selected stars in the solar neighborhood. The nature of the optical radiation from a star will depend on its luminosity,HR classification and spectral characteristics. The solar celloperation in the habitable zones of the stars is similar to AM1.0 operation near earth.Thecurrent space solar cell technology can be adopted for power generation near G,K and Mtype stars. Silicon solar cells with good near IR response are particularly suitable in theenvironments of M type stars which are most abundant in the universe. . Photovoltaicpower generation near binary stars like Sirius and Alpha Centauri is also discussed.

  20. Efficient, monochromatic, high-power microwave generator

    SciTech Connect

    Kwan, T.J.T.; Snell, C.M.

    1986-01-01

    Microwave generation by electron beams in virtual cathode configurations can achieve significant power levels. However, most designs inherently have two competing mechanisms generating microwaves; namely the oscillating virtual cathode and the reflexing electrons. These two mechanisms tend to interfere destructively with each other. Specifically, the reflexing electrons subject the electron beam to two-stream instability, causing considerable heating of the electron beam. In addition, the space-charge of the reflexing electrons can cause the diode independence to fluctuate, resulting in oscillations of the electron beam energy. We have investigated a novel idea to remove these undesirable effects and we found that high-power, narrow-band, and monochromatic microwaves could be generated with efficiency of 10 to 20%. 16 refs., 7 figs.

  1. Autonomous quantum thermal machine for generating steady-state entanglement

    E-print Network

    Jonatan Bohr Brask; Nicolas Brunner; Géraldine Haack; Marcus Huber

    2015-04-15

    We discuss a simple quantum thermal machine for the generation of steady-state entanglement between two interacting qubits. The machine is autonomous in the sense that it uses only incoherent interactions with thermal baths, but no source of coherence or external control. By weakly coupling the qubits to thermal baths at different temperatures, inducing a heat current through the system, steady-state entanglement is generated far from thermal equilibrium. Finally, we discuss two possible implementations, using superconducting flux qubits or a semiconductor double quantum dot. Experimental prospects for steady-state entanglement are promising in both systems.

  2. Thermal Powered Reciprocating-Force Motor

    NASA Technical Reports Server (NTRS)

    Tatum, III, Paul F. (Inventor); McDow Elliott, Amelia (Inventor)

    2015-01-01

    A thermal-powered reciprocating-force motor includes a shutter switchable between a first position that passes solar energy and a second position that blocks solar energy. A shape memory alloy (SMA) actuator is coupled to the shutter to control switching thereof between the shutter's first and second position. The actuator is positioned with respect to the shutter such that (1) solar energy impinges on the SMA when the shutter is in its first position so that the SMA experiences contraction in length until the shutter is switched to its second position, and (2) solar energy is impeded from impingement on the SMA when the shutter is in its second position so that the SMA experiences extension in length. Elastic members coupled to the actuator apply a force to the SMA that aids in its extension in length until the shutter is switched to its first position.

  3. Validation of Dynamic Thermal Simulations of Power Assemblies Using a Thermal Test Chip

    Microsoft Academic Search

    X. Jorda; M. Vellvehi; X. Perpinya; J. L. Galvez; P. Godignon

    2007-01-01

    Thermal simulation is the main thermal design tool used to predict temperature distributions of complex power electronics assemblies. Nevertheless, the validation of the simulation results remains a complex problem, mainly in dynamic operation, due to the difficulty in measuring semiconductor device temperatures. This paper proposes a methodology for the accurate validation of CFD 3-D thermal simulations of power modules. A

  4. On Distinguishing between Internet Power Law Topology Generators

    E-print Network

    Massachusetts at Amherst, University of

    On Distinguishing between Internet Power Law Topology Generators Tian Bu and Don Towsley Department exhibit power laws. Since then several algorithms have been proposed to generate such power law graphs developed power law topology generators, [5] [6] [10] [20] for generating repre­ sentative Internet

  5. On Distinguishing between Internet Power Law Topology Generators

    E-print Network

    Massachusetts at Amherst, University of

    On Distinguishing between Internet Power Law Topology Generators Tian Bu and Don Towsley Department power laws. Since then several algorithms have been proposed to generate such power law graphs developed power law topology generators, [5] [6] [10] [20] for generating repre- sentative Internet

  6. Energy storage and thermal control system design status. [for space station power supplies

    NASA Technical Reports Server (NTRS)

    Simons, Stephen N.; Willhoite, Bryan C.; Van Ommering, Gert

    1989-01-01

    The Space Station Freedom electric power system (EPS) will initially rely on photovoltaics for power generation and Ni/H2 batteries for electrical energy storage. The current design for the development status of two major subsystems in the PV Power Module is discussed. The energy storage subsystem comprised of high capacity Ni/H2 batteries and the single-phase thermal control system that rejects the excess heat generated by the batteries and other components associated with power generation andstorage is described.

  7. An electromagnetic micro power generator for wideband environmental vibrations

    Microsoft Academic Search

    Ibrahim Sari; Tuna Balkan; Haluk Kulah

    2008-01-01

    This paper presents a wideband electromagnetic vibration-to-electrical micro power generator. The micro generator is capable of generating steady power over a predetermined frequency range. Power is generated by means of the relative motion between a magnet and coils fabricated over resonating cantilevers through electromagnetic induction. The reported generator covers a wide band of external vibration frequency by implementing a number

  8. Thermophotovoltaic and thermoelectric portable power generators

    NASA Astrophysics Data System (ADS)

    Chan, Walker R.; Waits, Christopher M.; Joannopoulos, John D.; Celanovic, Ivan

    2014-06-01

    The quest for developing clean, quiet, and portable high energy density, and ultra-compact power sources continues. Although batteries offer a well known solution, limits on the chemistry developed to date constrain the energy density to 0.2 kWh/kg, whereas many hydrocarbon fuels have energy densities closer to 13 kWh/kg. The fundamental challenge remains: how efficiently and robustly can these widely available chemical fuels be converted into electricity in a millimeter to centimeter scale systems? Here we explore two promising technologies for high energy density power generators: thermophotovoltaics (TPV) and thermoelectrics (TE). These heat to electricity conversion processes are appealing because they are fully static leading to quiet and robust operation, allow for multifuel operation due to the ease of generating heat, and offer high power densities. We will present some previous work done in the TPV and TE fields. In addition we will outline the common technological barriers facing both approaches, as well as outline the main differences. Performance for state of the art research generators will be compared as well as projections for future practically achievable systems. A viable TPV or TE power source for a ten watt for one week mission can be built from a <10% efficient device which is achievable with current state of the art technology such as photonic crystals or advanced TE materials.

  9. Isotope powered Stirling generator for terrestrial applications

    SciTech Connect

    Tingey, G.L.; Sorensen, G.C. [Pacific Northwest Lab., Richland, WA (United States); Ross, B.A. [Stirling Technology Co., Richland, WA (United States)

    1995-01-01

    An electric power supply, small enough to be man-portable, is being developed for remote, terrestrial applications. This system is designed for an operating lifetime of five years without maintenance or refueling. A small Radioisotope Stirling Generator (RSG) has been developed. The energy source of the generator is a 60 watt plutonium-238 fuel clad used in the General Purpose Heat Sources (GPHS) developed for space applications. A free piston Stirling Engine drives a linear alternator to convert the heat to power. The system weighs about 7.5 kg and produces 11 watts AC power with a conversion efficiency of 18.5%. Two engine models have been designed, fabricated, and tested to date: (a) a developmental model instrumented to confirm and test parameters, and (b) an electrically heated model with an electrical heater equipped power input leads. Critical components have been tested for 10,000 to 20,000 hours. One complete generator has been operating for over 11,000 hours. Radioisotope heated prototypes are expected to be fabricated and tested in late 1995.

  10. Isotope powered stirling generator for terrestrial applications

    NASA Astrophysics Data System (ADS)

    Tingey, Garth L.; Sorensen, Gerald C.; Ross, Brad A.

    1995-01-01

    An electric power supply, small enough to be man-portable, is being developed for remote, terrestrial applications. This system is designed for an operating lifetime of five years without maintenance or refueling. A small Radioisotope Stirling Generator (RSG) has been developed. The energy source of the generator is a 60 watt plutonium-238 fuel clad used in the General Purpose Heat Sources (GPHS) developed for space applications. A free piston Stirling ENgine drives a linear alternator to convert the heat to power. The system weighs about 7.5 kg and produces 11 watts AC power with a conversion efficiency of 18.5%. Two engine models have been designed, fabricated, and tested to data: (a) a development model instrumented to confirm and test parameters, and (b) an electrically heated model with an electrical heater equipped power input leads. Critical components have been tested for 10,000 to 20,000 hours. One complete generator has been operating for over 11,000 hours. Radioisotope heated prototypes are expected to be fabricated and tested in late 1995.

  11. Standard Guide for Specifying Thermal Performance of Geothermal Power Systems

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide covers power plant performance terms and criteria for use in evaluation and comparison of geothermal energy conversion and power generation systems. The special nature of these geothermal systems makes performance criteria commonly used to evaluate conventional fossil fuel-fired systems of limited value. This guide identifies the limitations of the less useful criteria and defines an equitable basis for measuring the quality of differing thermal cycles and plant equipment for geothermal resources. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Fresnel Concentrators for Space Solar Power and Solar Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Bradford, Rodney; Parks, Robert W.; Craig, Harry B. (Technical Monitor)

    2001-01-01

    Large deployable Fresnel concentrators are applicable to solar thermal propulsion and multiple space solar power generation concepts. These concentrators can be used with thermophotovoltaic, solar thermionic, and solar dynamic conversion systems. Thin polyimide Fresnel lenses and reflectors can provide tailored flux distribution and concentration ratios matched to receiver requirements. Thin, preformed polyimide film structure components assembled into support structures for Fresnel concentrators provide the capability to produce large inflation-deployed concentrator assemblies. The polyimide film is resistant to the space environment and allows large lightweight assemblies to be fabricated that can be compactly stowed for launch. This work addressed design and fabrication of lightweight polyimide film Fresnel concentrators, alternate materials evaluation, and data management functions for space solar power concepts, architectures, and supporting technology development.

  13. 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.

  14. Modeling of solar thermal selective surfaces and thermoelectric generators

    E-print Network

    McEnaney, Kenneth

    2010-01-01

    A thermoelectric generator is a solid-state device that converts a heat flux into electrical power via the Seebeck effect. When a thermoelectric generator is inserted between a solar-absorbing surface and a heat sink, a ...

  15. Transient Non-linear Thermal FEM Simulation of Smart Power Switches and Verification by Measurements

    E-print Network

    V. Kosel; R. Sleik; M. Glavanovics

    2008-01-07

    Thermal FEM (Finite Element Method) simulations can be used to predict the thermal behavior of power semiconductors in application. Most power semiconductors are made of silicon. Silicon thermal material properties are significantly temperature dependent. In this paper, validity of a common non-linear silicon material model is verified by transient non-linear thermal FEM simulations of Smart Power Switches and measurements. For verification, over-temperature protection behavior of Smart Power Switches is employed. This protection turns off the switch at a pre-defined temperature which is used as a temperature reference in the investigation. Power dissipation generated during a thermal overload event of two Smart Power devices is measured and used as an input stimulus to transient thermal FEM simulations. The duration time of the event together with the temperature reference is confronted with simulation results and thus the validity of the silicon model is proved. In addition, the impact of non-linear thermal properties of silicon on the thermal impedance of power semiconductors is shown.

  16. Output power analyses for the thermodynamic cycles of thermal power plants

    NASA Astrophysics Data System (ADS)

    Sun, Chen; Cheng, Xue-Tao; Liang, Xin-Gang

    2014-05-01

    Thermal power plant is one of the important thermodynamic devices, which is very common in all kinds of power generation systems. In this paper, we use a new concept, entransy loss, as well as exergy destruction, to analyze the single reheating Rankine cycle unit and the single stage steam extraction regenerative Rankine cycle unit in power plants. This is the first time that the concept of entransy loss is applied to the analysis of the power plant Rankine cycles with reheating and steam extraction regeneration. In order to obtain the maximum output power, the operating conditions under variant vapor mass flow rates are optimized numerically, as well as the combustion temperatures and the off-design flow rates of the flue gas. The relationship between the output power and the exergy destruction rate and that between the output power and the entransy loss rate are discussed. It is found that both the minimum exergy destruction rate and the maximum entransy loss rate lead to the maximum output power when the combustion temperature and heat capacity flow rate of the flue gas are prescribed. Unlike the minimum exergy destruction rate, the maximum entransy loss rate is related to the maximum output power when the highest temperature and heat capacity flow rate of the flue gas are not prescribed.

  17. Turbine sizing of a solar thermal power plant

    NASA Technical Reports Server (NTRS)

    Manvi, R.; Fujita, T.

    1979-01-01

    Since the insolation is intermittent, thermal energy storage is necessary to extend the time of power generation with solar heat past sunset. There are two approaches to specifying the size of turbine-generator units depending on the system operation. In the first approach, the turbine operates at its full capacity when operating on direct solar heat, and at reduced capacity when operating on collected heat out of energy storage. In the second approach, the turbine will always operate at a uniform level either on derated energy from the receiver or from energy storage. Both of these approaches have certain advantages and disadvantages. In this paper, a simple analysis is outlined and exercised to compare the performance and economics of these two approaches.

  18. Thermal power systems small power systems application project: Siting issues for solar thermal power plants with small community applications

    NASA Technical Reports Server (NTRS)

    Holbeck, H. J.; Ireland, S. J.

    1979-01-01

    The siting issues associated with small, dispersed solar thermal power plants for utility/small community applications of less than 10 MWe are reported. Some specific requirements are refered to the first engineering experiment for the Small Power Systems Applications (SPSA) Project. The background for the subsequent issue discussions is provided. The SPSA Project and the requirements for the first engineering experiment are described, and the objectives and scope for the report as a whole. A overview of solar thermal technologies and some technology options are discussed.

  19. Coupled Monte Carlo neutronics and thermal hydraulics for power reactors

    SciTech Connect

    Bernnat, W.; Buck, M.; Mattes, M. [Institut fuer Kernenergetik und Energiesysteme IKE, Universitaet Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); Zwermann, W.; Pasichnyk, I.; Velkov, K. [Gesellschaft fuer Anlagen- und Reaktorsicherheit GRS MbH, Forschungszentrum, Boltzmannstrase 14, 85748 Garching (Germany)

    2012-07-01

    The availability of high performance computing resources enables more and more the use of detailed Monte Carlo models even for full core power reactors. The detailed structure of the core can be described by lattices, modeled by so-called repeated structures e.g. in Monte Carlo codes such as MCNP5 or MCNPX. For cores with mainly uniform material compositions, fuel and moderator temperatures, there is no problem in constructing core models. However, when the material composition and the temperatures vary strongly a huge number of different material cells must be described which complicate the input and in many cases exceed code or memory limits. The second problem arises with the preparation of corresponding temperature dependent cross sections and thermal scattering laws. Only if these problems can be solved, a realistic coupling of Monte Carlo neutronics with an appropriate thermal-hydraulics model is possible. In this paper a method for the treatment of detailed material and temperature distributions in MCNP5 is described based on user-specified internal functions which assign distinct elements of the core cells to material specifications (e.g. water density) and temperatures from a thermal-hydraulics code. The core grid itself can be described with a uniform material specification. The temperature dependency of cross sections and thermal neutron scattering laws is taken into account by interpolation, requiring only a limited number of data sets generated for different temperatures. Applications will be shown for the stationary part of the Purdue PWR benchmark using ATHLET for thermal- hydraulics and for a generic Modular High Temperature reactor using THERMIX for thermal- hydraulics. (authors)

  20. Analysis of Wind Power Generation of Texas

    E-print Network

    Liu, Z.; Haberl, J.; Subbarao, K.; Baltazar, J. C.

    1 ? Energy Systems Laboratory, Texas A&M University Page 1 ANALYSIS OF WIND POWER GENERATION OF TEXAS April 2007 Zi ?Betty? Liu, Ph.D., Jeff Haberl, Ph.D., P.E., Kris Subbarao, Ph.D., P.E., Juan-Carlos Baltazar, Ph.D. Energy Systems Laboratory... OUTLINE Application of Method 1 ? Prediction of Power Production in Base Year Using Daily Regression Model for Each Wind Farm (22 subsites). Method 1 Improvement ? Daily Regression Model Based on Synthesized On-site Wind Using Artificial Neural Nets...

  1. Electrokinetic Power Generation from Liquid Water Microjets

    SciTech Connect

    Duffin, Andrew M.; Saykally, Richard J.

    2008-02-15

    Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.

  2. The New Generation of Thermal Mapping

    ERIC Educational Resources Information Center

    Patterson, Valerie B.

    2012-01-01

    Thermal imaging was used 60+ years ago to enable the targeting of heat-seeking missiles and seeing opposing forces at night. Today thermograpy is employed for myriad uses, from turning on faucets, to tracking and attacking enemies from aerial spy drones, to identifying the scope of moisture infiltration in building envelopes. Thermography for…

  3. Human body thermal images generated by conduction or radiation heat

    Microsoft Academic Search

    Gheorghe Gavriloaia; Emil Sofron; Radu Fumarel

    2009-01-01

    Humans and animals in general, are usually in a thermal steady state with respect to their surroundings. The tissues heat, generated at normal or diseases states, is lost to environment though several mechanisms: radiation, conduction, convection, evaporation, etc. Skin temperature is not the same on the entire body and a thermal body signature can be got. The temperature at skin

  4. Optimal Trajectory Generation for Manipulator Robots under Thermal Constraints

    E-print Network

    Paris-Sud XI, Université de

    the stabilized temperature, reason why we need a thermal model to predict it. Since most robotic applicationsOptimal Trajectory Generation for Manipulator Robots under Thermal Constraints Matthieu Guilbert St¨aubli Robotics Faverges, France 74210 Email: matthieu.guilbert@inrialpes.fr Pierre-Brice Wieber INRIA Rh

  5. Complementary power output characteristics of electromagnetic generators and triboelectric generators

    NASA Astrophysics Data System (ADS)

    Fan, Feng-Ru; Tang, Wei; Yao, Yan; Luo, Jianjun; Zhang, Chi; Wang, Zhong Lin

    2014-04-01

    Recently, a triboelectric generator (TEG) has been invented to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction. Compared to the traditional electromagnetic generator (EMG) that produces a high output current but low voltage, the TEG has different output characteristics of low output current but high output voltage. In this paper, we present a comparative study regarding the fundamentals of TEGs and EMGs. The power output performances of the EMG and the TEG have a special complementary relationship, with the EMG being a voltage source and the TEG a current source. Utilizing a power transformed and managed (PTM) system, the current output of a TEG can reach as high as ˜3 mA, which can be coupled with the output signal of an EMG to enhance the output power. We also demonstrate a design to integrate a TEG and an EMG into a single device for simultaneously harvesting mechanical energy. In addition, the integrated NGs can independently output a high voltage and a high current to meet special needs.

  6. Wave and tide powered generation apparatus

    SciTech Connect

    Suggs, L. F.

    1985-09-03

    A wave and tide powered generation apparatus includes a frame which is fixed relative to the varying level of the body of water, and includes a float operably associated with the frame for movement in response to the varying level of the body of water. A rotatable drum is attached to the float and has a drive line with a middle portion wrapped around the rotatable drum. Upper and lower ends of the drive line are attached to upper and lower portions of the frame. Movement of the float upward or downward relative to the frame causes the rotatable drum to be rotated due to its engagement with the drive line. A power transfer apparatus transmits the rotary motion of the drum to a generator.

  7. Solar Power Satellite Thermal Control Approach

    NASA Astrophysics Data System (ADS)

    Sacchi, E.; Cassisa, G.; Gottero, M.

    2004-12-01

    The concept of generating solar power in space and transmitting it to earth or any other desired destination such as a planet, moon, or to charge a space vehicle via microwaves, stems from a wide variety of human needs and necessities. It is now a well-known fact that world population increases at a very rapid rate, nearly 80 millions or more per year, and the world-wide energy demand seems to double in the course of the present century. If technology has to advance at the present rate, in phase with high living standards, energy growth must not lag behind. These estimates are based on the population growth rate in the developing countries and the simultaneous increase in per capita energy consumption in these countries, coupled with economical boost. In most of the underdeveloped countries energy needs are of small scales, faraway from the power distribution line and can be very easily satisfied by harnessing solar energy. Furthermore, the Earth temperature has increased by 0.5° to 1° F during the past century. This rise in temperature is believed to have been caused by the use of oil, coal, and natural gas (fossil fuels) for transportation and energy production. Actually, fossil fuel combustion-based power plants are the dominant sources for energy demands. Therefore, increased power production will accelerate the production of greenhouse gases (predominantly CO2). To cope with their energy needs, countries could be engaged in the use of nuclear energy, which could accelerate the diffusion of nuclear arms as a bye- product.

  8. Utility interconnection issues for wind power generation

    NASA Technical Reports Server (NTRS)

    Herrera, J. I.; Lawler, J. S.; Reddoch, T. W.; Sullivan, R. L.

    1986-01-01

    This document organizes the total range of utility related issues, reviews wind turbine control and dynamic characteristics, identifies the interaction of wind turbines to electric utility systems, and identifies areas for future research. The material is organized at three levels: the wind turbine, its controls and characteristics; connection strategies as dispersed or WPSs; and the composite issue of planning and operating the electric power system with wind generated electricity.

  9. Transient thermal behavior of high power diode laser arrays

    Microsoft Academic Search

    Roland Puchert; Artur Bärwolff; M. Voss; U. Menzel; J. W. Tomm; J. Luft

    2000-01-01

    Reliability and lifetime of high power laser arrays are governed by their thermal properties. Thus the understanding of the thermal behavior such as thermal transients as well as the optimization of laser chips and mounting are key features for obtaining improved devices. We present numerical simulations of the active layer temperature employing the finite element method (FEM). Both continuous wave

  10. High voltage power condition systems powered by flux compression generators

    Microsoft Academic Search

    R. E. Reinovsky; I. R. Lindemuth; J. E. Vorthman

    1989-01-01

    Compact, high-gain magnetic flux compressors (FCGs) are convenient sources of substantial energy for plasma-physics and electron-beam-physics experiments, but the need for highvoltage, fast-rising pulses is difficult to meet directly with conventional generators. While a variety of novel concepts employing simultaneous, axially-detonated explosive systems are under development, power-conditioning systems based on fuse opening switches and high-voltage transformers constitute an approach that

  11. High voltage power condition systems powered by flux compression generators

    Microsoft Academic Search

    R. E. Reinovsky; I. R. Lindemuth; J. E. Vorthman

    1989-01-01

    Compact, high-gain magnetic flux compressors (FCGs) are convenient sources of substantial energy for plasma-physics and electron-beam-physics experiments, but the need for high-voltage, fast-rising pulses is difficult to meet directly with conventional generators. While a variety of novel concepts employing simultaneous, axially-detonated explosive systems are under development, power-conditioning systems based on fuse opening switches and high-voltage transformers constitute another approach that

  12. Model for Increasing the Power Obtained from a Thermoelectric Generator Module

    NASA Astrophysics Data System (ADS)

    Huang, Gia-Yeh; Hsu, Cheng-Ting; Yao, Da-Jeng

    2014-06-01

    We have developed a model for finding the most efficient way of increasing the power obtained from a thermoelectric generator (TEG) module with a variety of operating conditions and limitations. The model is based on both thermoelectric principles and thermal resistance circuits, because a TEG converts heat into electricity consistent with these two theories. It is essential to take into account thermal contact resistance when estimating power generation. Thermal contact resistance causes overestimation of the measured temperature difference between the hot and cold sides of a TEG in calculation of the theoretical power generated, i.e. the theoretical power is larger than the experimental power. The ratio of the experimental open-loop voltage to the measured temperature difference, the effective Seebeck coefficient, can be used to estimate the thermal contact resistance in the model. The ratio of the effective Seebeck coefficient to the theoretical Seebeck coefficient, the Seebeck coefficient ratio, represents the contact conditions. From this ratio, a relationship between performance and different variables can be developed. The measured power generated by a TEG module (TMH400302055; Wise Life Technology, Taiwan) is consistent with the result obtained by use of the model; the relative deviation is 10%. Use of this model to evaluate the most efficient means of increasing the generated power reveals that the TEG module generates 0.14 W when the temperature difference is 25°C and the Seebeck coefficient ratio is 0.4. Several methods can be used triple the amount of power generated. For example, increasing the temperature difference to 43°C generates 0.41 W power; improving the Seebeck coefficient ratio to 0.65 increases the power to 0.39 W; simultaneously increasing the temperature difference to 34°C and improving the Seebeck coefficient ratio to 0.5 increases the power to 0.41 W. Choice of the appropriate method depends on the limitations of system, the cost, and the environment.

  13. High thermal power density heat transfer. [thermionic converters

    NASA Technical Reports Server (NTRS)

    Morris, J. F. (inventor)

    1980-01-01

    Heat from a high temperature heat pipe is transferred through a vacuum or a gap filled with electrically nonconducting gas to a cooler heat pipe. The heat pipe is used to cool the nuclear reactor while the heat pipe is connected thermally and electrically to a thermionic converter. If the receiver requires greater thermal power density, geometries are used with larger heat pipe areas for transmitting and receiving energy than the area for conducting the heat to the thermionic converter. In this way the heat pipe capability for increasing thermal power densities compensates for the comparatively low thermal power densities through the electrically non-conducting gap between the two heat pipes.

  14. Fast thermal cycling-enhanced electromigration in power metallization

    Microsoft Academic Search

    H. V. Nguyen; Cora Salm; B. H. Krabbenborg; J. Bisschop; A. J. Ton Mouthaan; Fred G. Kuper

    2004-01-01

    Multilevel interconnects used in power ICs are susceptible to short circuit failure due to a combination of fast thermal cycling and electromigration stresses. In this paper, we present a study of electromigration-induced extrusion short-circuit failure in a standard two level metallization currently used in power ICs and in particular the effect of fast thermal cycling on the subsequent electromigration lifetime.

  15. Exergetic analysis of a solar thermal power system

    Microsoft Academic Search

    Narendra Singh; S. C. Kaushik; R. D. Misra

    2000-01-01

    This communication presents a second law analysis based on an exergy concept for a solar thermal power system. Basic energy and exergy analysis for the system components (viz. parabolic trough collector\\/receiver and Rankine heat engine, etc.) are carried out for evaluating the respective losses as well as exergetic efficiency for typical solar thermal power systems under given operating conditions. It

  16. Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management

    NASA Technical Reports Server (NTRS)

    Pantano, David R.; Dottore, Frank; Tobery, E. Wayne; Geng, Steven M.; Schreiber, Jeffrey G.; Palko, Joseph L.

    2005-01-01

    An advantage of using a Radioisotope Power System (RPS) for deep space or planetary surface missions is the readily available waste heat, which can be used for a number of beneficial purposes including: maintaining electronic components within a controlled temperature range, warming propulsion tanks and mobility actuators, and maintaining liquid propellants above their freezing temperature. Previous missions using Radioisotope Thermoelectric Generators (RTGs) dissipated large quantities of waste heat due to the low efficiency of the thermoelectric conversion technology. The next generation RPSs, such as the 110-Watt Stirling Radioisotope Generator (SRG110) will have higher conversion efficiencies, thereby rejecting less waste heat at a lower temperature and may require alternate approaches to transferring waste heat to the spacecraft. RTGs, with efficiencies of 6 to 7 percent, reject their waste heat at the relatively high heat rejection temperature of 200 C. This is an advantage when rejecting heat to space; however, transferring heat to the internal spacecraft components requires a large and heavy radiator heat exchanger. At the same time, sensitive spacecraft instruments must be shielded from the thermal radiation of the RTG. The SRG110, with an efficiency around 22 percent and 50 C nominal housing surface temperature, can readily transfer the available waste heat directly via heat pipes, thermal straps, or fluid loops. The lower temperatures associated with the SRG110 avoid the chances of overheating other scientific components, eliminating the need for thermal shields. This provides the spacecraft designers more flexibility when locating the generator for a specific mission. A common misconception with high-efficiency systems is that there is not enough waste heat for spacecraft thermal management. This paper will dispel this misconception and investigate the use of a high-efficiency SRG110 for spacecraft thermal management and outline potential methods of waste heat utilization in several conceptual missions (Lunar Rover, Mars Rover, and Titan Lander). The advantages associated with the SRG110 as they relate to ease of assembly, less complex interfaces, and overall mass savings for a spacecraft will be highlighted.

  17. CONVERTING ENERGY FROM RECLAIMED HEAT: THERMAL ELECTRIC GENERATOR

    EPA Science Inventory

    The use of solar energy acquiring devices has been slow to gain acceptance due to their overall low power generation versus high cost of a solar system. The goal of this project is to construct a model which increases the overall power generation of a solar building system by...

  18. Accurate Online Power Estimation and Automatic Battery Behavior Based Power Model Generation for Smartphones

    E-print Network

    Tomkins, Andrew

    Accurate Online Power Estimation and Automatic Battery Behavior Based Power Model Generation the model generated by PowerBooter for online power esti- mation. PowerBooter is intended to make it quick and easy for application developers and end users to generate power models for new smartphone variants

  19. Utility scale hybrid wind–solar thermal electrical generation: A case study for Minnesota

    Microsoft Academic Search

    J. P. Reichling; F. A. Kulacki

    2008-01-01

    The performance of a hybrid wind–solar power plant in southwestern Minnesota is modeled for a 2-yr period using hourly wind and solar insolation data. The wind portion of the plant consists of four interconnected wind farms within a radius of 90km. The solar component of the plant is a parabolic trough solar thermal electric generating system using a heat transfer

  20. Modeling Generator Power Plant Portfolios and Pollution Taxes

    E-print Network

    Nagurney, Anna

    Modeling Generator Power Plant Portfolios and Pollution Taxes in Electric Power Supply Chain of the Electrical Power Network with the Transportation Network #12;A Numerical Example #12;· Generating cost functions · Transaction cost between power generators and the suppliers The Cost Functions #12;The Cost

  1. OPTIMAL DISTRIBUTED POWER GENERATION UNDER NETWORK LOAD CONSTRAINTS,

    E-print Network

    Frank, Jason

    OPTIMAL DISTRIBUTED POWER GENERATION UNDER NETWORK LOAD CONSTRAINTS, MARJAN VAN DEN AKKER, GABRI of novel components for decentral power generation (solar panels, small wind turbines and heat pumps the power consumption and decentral power generation are considered as stochastic variables, which

  2. Designing nanosecond high voltage pulse generators using power MOSFETs

    E-print Network

    Baker, R. Jacob

    Designing nanosecond high voltage pulse generators using power MOSFETs R.J. Baker and S.T. Ward Inde."'Cing terms: Power transistors, MOSFETs, Pulse generators, High-voltage engineering, High-voltage techniques, Power electronics Power MOSFETs in series are used for generating high voltage, >lkV, pulses

  3. BATTERY STORAGE CONTROL FOR STEADYING RENEWABLE POWER GENERATION

    E-print Network

    BATTERY STORAGE CONTROL FOR STEADYING RENEWABLE POWER GENERATION By Shengyuan (Mike) Chen, Emilie-626-7370 URL: http://www.ima.umn.edu #12;Battery Storage Control for Steadying Renewable Power Generation generation. Excess en- ergy must be stored during times of excess power generation, and then released when

  4. Maximum power throughput in the multiphase BLDC generator

    Microsoft Academic Search

    H.-W. Lee; T. Kim; M. Ehsani

    2004-01-01

    This paper presents an advanced control technique for maximum power throughput of the multiphase Brushless DC (BLDC) generator of given design. In a generator of given rating, the weight and size of the system affect the fuel consumption directly. Therefore, maximum power density is one of the most important issues in a stand-alone generator. BLDC generator has high power density

  5. Solar salt pond potential site survey for electrical power generation

    NASA Technical Reports Server (NTRS)

    Hurick, M. G.

    1982-01-01

    A solar salt gradient pond acts as a passive heat sink or thermal battery in which energy can be recovered through the conversion of thermal energy into electrical energy. Here, a condensation of a larger report that focused on the identification of potential salt gradient pond sites in the United States using in-situ resources is presented. It is shown that there are at least 24 states that lie in a primary or secondary potential site category. Fourteen states are assigned as primary states and ten are assigned as secondary. The division is subjectively based on the severity of winter weather. The most promising states are those that lie in the southern half of the country. When the primary and secondary category states are combined with the other states that may be able to support a pond, a total of 38 states exhibit the possibility of supporting power generation sites of various size.

  6. New Generation Perovskite Thermal Barrier Coating Materials

    Microsoft Academic Search

    W. Ma; M. O. Jarligo; D. E. Mack; D. Pitzer; J. Malzbender; R. Vaßen; D. Stöver

    2008-01-01

    Advanced ceramic materials of perovskite structure have been developed for potential application in thermal barrier coating\\u000a systems, in an effort to improve the properties of the pre-existing ones like yttria-stabilized zirconia. Yb2O3 and Gd2O3 doped strontium zirconate (SrZrO3) and barium magnesium tantalate (Ba(Mg1\\/3Ta2\\/3)O3) of the ABO3 and complex A(B?1\\/3B??2\\/3)O3 systems, respectively, have been synthesized using ball milling prior to solid

  7. Applicability of advanced automotive heat engines to solar thermal power

    NASA Technical Reports Server (NTRS)

    Beremand, D. G.; Evans, D. G.; Alger, D. L.

    1981-01-01

    The requirements of a solar thermal power system are reviewed and compared with the predicted characteristics of automobile engines under development. A good match is found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65-100 kW (87 to 133 hp) are operated to the nominal 20-40 kW electric output requirement of the solar thermal application. At these reduced power levels it appears that the automotive gas turbine and Stirling engines have the potential to deliver the 40+ percent efficiency goal of the solar thermal program.

  8. INDUCTION HEATING OF CARBON-FIBER COMPOSITES: THERMAL GENERATION MODEL

    EPA Science Inventory

    A theory of local and global mechanisms of heat generation and distribution in carbon-fiber-based composites subjected to an alternating magnetic field has been proposed. A model that predicts the strength and distribution of thermal generation through the thickness of carbon-fib...

  9. Solar power generating systems as sources of non-polluting energy (power generation in space and power generation on the ground)

    Microsoft Academic Search

    T. Tani; T. Horigome

    1974-01-01

    Various systems of solar power generation in space and on the ground which have been made public thus far are considered. In connection with the proposed American system for building solar power stations in space, the composition of the solar power stations and the microwave power transmission system, the efficiency of the microwave power transmission system, the method of delivering

  10. Thermoacoustic power effect on the refrigeration performance of thermal separators

    NASA Astrophysics Data System (ADS)

    Liang, S. B.; Li, X. L.; Ma, H. B.

    2003-09-01

    An experimental investigation on the refrigeration processes occurring in a receiving tube of a thermal separator was conducted in order to determine the primary factors affecting the refrigeration performance of this new type of refrigerator. In the current investigation, the gas in the system is divided into the oscillating gas and driving gas. While the compression/expansion of the oscillating gas caused by the driving gas determines the refrigeration process occurring in the receiving tube of the thermal separator, the temperature gradient on the receiving tube significantly affects the acoustic power generation and refrigeration performance. Experimental results demonstrate that when the tube-wall temperature difference near the open end of the receiving tube increases, the refrigeration coefficient increases. Using the information presented in the paper, a new cryogenic refrigeration system was developed, and the experimental data shows that the temperature of the cryogenic air flow in the system could reach -130 °C within 50 min. It suggests that the thermal separator investigated in the paper can be employed in the field of cryogenic engineering.

  11. Power Generator with Thermo-Differential Modules

    NASA Technical Reports Server (NTRS)

    Saiz, John R.; Nguyen, James

    2010-01-01

    A thermoelectric power generator consists of an oven box and a solar cooker/solar reflector unit. The solar reflector concentrates sunlight into heat and transfers the heat into the oven box via a heat pipe. The oven box unit is surrounded by five thermoelectric modules and is located at the bottom end of the solar reflector. When the heat is pumped into one side of the thermoelectric module and ejected from the opposite side at ambient temperatures, an electrical current is produced. Typical temperature accumulation in the solar reflector is approximately 200 C (392 F). The heat pipe then transfers heat into the oven box with a loss of about 40 percent. At the ambient temperature of about 20 C (68 F), the temperature differential is about 100 C (180 F) apart. Each thermoelectric module, generates about 6 watts of power. One oven box with five thermoelectric modules produces about 30 watts. The system provides power for unattended instruments in remote areas, such as space colonies and space vehicles, and in polar and other remote regions on Earth.

  12. Numerical simulations of thermally generated currents in laser plasmas

    Microsoft Academic Search

    J. Buff; C. Muller; R. Peterkin

    1996-01-01

    Summary form only given. The generation of large currents and intense magnetic fields in laser-generated plasmas has attracted a great deal of attention especially at high intensities necessary for laser fusion (~1014 W\\/cm2). The fields are generated by conversion of the thermal energy in the plasma to magnetic energy in regions where the temperature and density gradients are not parallel:

  13. Spindle position regulation for wind power generators

    NASA Astrophysics Data System (ADS)

    Tsai, Nan-Chyuan; Chiang, Chao-Wen

    2010-04-01

    The three-time-scale plant model of a wind power generator, including a wind turbine, a flexible vertical shaft, a variable inertia flywheel (VIF) module, an active magnetic bearing (AMB) unit and the applied wind sequence, is constructed. In order to make the wind power generator be still able to operate as the spindle speed exceeds its rated speed, the VIF is equipped so that the spindle speed can be appropriately slowed down once any stronger wind field is exerted. Currently, most of wind energy input is, as a matter of fact, a waste since the commercially available wind power generators only operate for fairly mild or low-speed wind field. To prevent any potential damage due to collision by shaft against conventional bearings, the AMB unit is proposed to replace the traditional bearings and regulate the shaft position deviation. By singular perturbation order-reduction technique, a lower-order plant model can be established for the synthesis of feedback controller. It is found that two major system parameter uncertainties, an additive uncertainty and a multiplicative uncertainty, are constituted by the wind turbine and the VIF, respectively. The upper bounds of system parameters variation can be therefore estimated and the frequency shaping sliding mode control (FSSMC) loop is proposed to account for these uncertainties and suppress the unmodeled higher-order plant dynamics. At last, the efficacy of the FSSMC is verified by intensive computer and experimental simulations for regulation on position deviation of the shaft and counter-balance of unpredictable wind disturbance.

  14. High-performance flat-panel solar thermoelectric generators with high thermal concentration.

    PubMed

    Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

    2011-07-01

    The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity. PMID:21532584

  15. Thermoelectric power enhancement by way of flow impedance for fixed thermal input conditions

    NASA Astrophysics Data System (ADS)

    Amaral, Calil; Brandão, Caio; Sempels, Éric V.; Lesage, Frédéric J.

    2014-12-01

    Liquid-to-liquid thermoelectric generators are now being considered for the purpose of converting low cost heat to electricity for local energy uses. The importance in investigating their system efficiency lies in the fact that the generator's purpose is to maintain a heat source and a heat sink for its embedded thermoelectric modules. Of particular importance is the generator's ability to maintain an asymmetric thermal field across its embedded modules since this mechanism partially dictates the devices' thermal to electric conversion efficiency. Indeed, since the modules' semiconductor materials' ability to generate an electromotive force is dependent on the quality of the thermal dipole across the material, gains in thermoelectric generator energy conversion efficiency are made possible with thermal system management. In an effort to improve the system conversion efficiency of a liquid-to-liquid thermoelectric generator (TEG), the present work builds upon recent advancements in TEG inner pipe flow optimisation by investigating the thermoelectric power enhancement brought upon by flow impeding panel inserts in a thermoelectric generator's flow channels for fixed thermal input conditions and with respect to varying insert panel densities. The pumping penalty associated with the flow impedance is measured in order to present and to discuss the net thermoelectric power enhancement.

  16. Application of field-modulated generator systems to dispersed solar thermal electric generation

    NASA Technical Reports Server (NTRS)

    Ramakumar, R.

    1979-01-01

    The state-of-the-art of field modulated generation system (FMGS) is presented, and the application of FMGS to dispersed solar thermal electric generation is discussed. The control and monitoring requirements for solar generation system are defined. A comparison is presented between the FMGS approach and other options and the technological development needs are discussed.

  17. Modeling Generator Power Plant Portfolios and Pollution Taxes Electric Power Supply Chain Networks

    E-print Network

    Nagurney, Anna

    Modeling Generator Power Plant Portfolios and Pollution Taxes in Electric Power Supply Chain at the electric power industry with taxes applied according to the type of fuel used by the power generators generators faced with a portfolio of power plant options and subject to pollution taxes. We then demonstrate

  18. Review Article Solar-Thermal Powered Desalination: Its Significant

    E-print Network

    Reif, John H.

    1 Review Article Solar-Thermal Powered Desalination: Its Significant Challenges and Potential John@kau.edu.sa Abstract Solar-desalination systems are desalination systems that are powered by solar energy-recovery. Existing demonstrations of solar-powered desalination systems have generally been indirect solar

  19. Power Modeling and Thermal Management Techniques for Manycores

    E-print Network

    Simunic, Tajana

    Power Modeling and Thermal Management Techniques for Manycores Rajib Nath Computer Science number of cores in manycore archi- tectures, along with technology scaling, results in high power in such processors, we need an accurate online estimate of the power consumption. In this paper, we present the first

  20. Effect of Heat Generation of Ultrasound Transducer on Ultrasonic Power Measured by Calorimetric Method

    NASA Astrophysics Data System (ADS)

    Uchida, Takeyoshi; Kikuchi, Tsuneo

    2013-07-01

    Ultrasonic power is one of the key quantities closely related to the safety of medical ultrasonic equipment. An ultrasonic power standard is required for establishment of safety. Generally, an ultrasonic power standard below approximately 20 W is established by the radiation force balance (RFB) method as the most accurate measurement method. However, RFB is not suitable for high ultrasonic power because of thermal damage to the absorbing target. Consequently, an alternative method to RFB is required. We have been developing a measurement technique for high ultrasonic power by the calorimetric method. In this study, we examined the effect of heat generation of an ultrasound transducer on ultrasonic power measured by the calorimetric method. As a result, an excessively high ultrasonic power was measured owing to the effect of heat generation from internal loss in the transducer. A reference ultrasound transducer with low heat generation is required for a high ultrasonic power standard established by the calorimetric method.

  1. Entropy generation in the Blasius flow under thermal radiation

    NASA Astrophysics Data System (ADS)

    Saeed Butt, Adnan; Munawar, Sufian; Ali, Asif; Mehmood, Ahmer

    2012-03-01

    In this work, we examine the effects of thermal radiation and viscous dissipation on entropy generation in the Blasius flow. The governing boundary layer equations for the velocity and temperature fields are transformed into ordinary differential equations with the help of suitable similarity transformation and then solved numerically with the help of the shooting method. The expressions for the volumetric entropy generation rate and the Bejan number are calculated for thermal radiation. The effects of various physical parameters on the entropy production number, average entropy and the Bejan number are studied through graphs using velocity and temperature profiles. It is noticed that by increasing the thermal radiation parameter the entropy production in a thermal system can be reduced and viscous dissipation increases the entropy production.

  2. Dynamic modeling and control strategies for a micro-CSP plant with thermal storage powered by the Organic Rankine cycle

    E-print Network

    Ireland, Melissa Kara

    2014-01-01

    Organic Rankine cycle (ORC) systems are gaining ground as a means of effectively providing sustainable energy. Coupling small-scale ORCs powered by scroll expander- generators with solar thermal collectors and storage can ...

  3. Reassessment of irrigation potential for micro Hydro Power Generation

    Microsoft Academic Search

    S. P. Adhau; R. M. Moharil; P. G. Adhau

    2010-01-01

    Hydro Power Generation projects are generally viewed as constructing large dams and reservoirs but available new research and engineering techniques have helped Hydro Power generation without large dams and without large reservoirs. In India, we have several water installations, irrigation dams, canals, streams or running rivers not tapped to generate power. In these cases the existing system and facilities can

  4. Commitment of Electric Power Generators under Stochastic Market Prices

    E-print Network

    Mazumdar, Mainak

    Commitment of Electric Power Generators under Stochastic Market Prices Jorge Valenzuela 1 November 2001 1 Corresponding author. #12;1 Commitment of Electric Power Generators under Stochastic Market Prices Abstract A formulation for the commitment of electric power generators under a deregulated

  5. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...service and propulsion power do not need additional ship's service generators provided that with...such as a shaft generator) which is capable...providing electrical power continuously, regardless...continuous electrical power may be utilized as a supplemental generator provided that...

  6. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...service and propulsion power do not need additional ship's service generators provided that with...such as a shaft generator) which is capable...providing electrical power continuously, regardless...continuous electrical power may be utilized as a supplemental generator provided that...

  7. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...service and propulsion power do not need additional ship's service generators provided that with...such as a shaft generator) which is capable...providing electrical power continuously, regardless...continuous electrical power may be utilized as a supplemental generator provided that...

  8. Electromagnetic Generators for Portable Power Applications Matthew Kurt Senesky

    E-print Network

    Sanders, Seth

    Electromagnetic Generators for Portable Power Applications by Matthew Kurt Senesky B.A. (Dartmouth Generators for Portable Power Applications Copyright 2005 by Matthew Kurt Senesky #12;1 Abstract Electromagnetic Generators for Portable Power Applications by Matthew Kurt Senesky Doctor of Philosophy

  9. Optimal distributed power generation under network load constraints

    E-print Network

    Utrecht, Universiteit

    Optimal distributed power generation under network load constraints Marjan van den Akker Gabri.089 3508 TB Utrecht The Netherlands #12;OPTIMAL DISTRIBUTED POWER GENERATION UNDER NETWORK LOAD CONSTRAINTS, mainly because of the development of novel components for decentral power generation (solar panels, small

  10. Design of a Power Saving Methodology for Next Generation

    E-print Network

    Jantsch, Axel

    Design of a Power Saving Methodology for Next Generation Wireless System-on-Chip Design S A E E D K-39 Design of a Power Saving Methodology for Next Generation Wireless SoC Master of Science in System on Chip;Design of a Power Saving Methodology for Next Generation Wireless SoC © KASHIF SAEED, 2006 Master Thesis

  11. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Using water for power generation. 418.16 Section 418...Operations and Management § 418.16 Using water for power generation. All use of Project water for power generation must be incidental to...

  12. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Using water for power generation. 418.16 Section 418...Operations and Management § 418.16 Using water for power generation. All use of Project water for power generation must be incidental to...

  13. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2011-10-01 true Using water for power generation. 418.16 Section 418...Operations and Management § 418.16 Using water for power generation. All use of Project water for power generation must be incidental to...

  14. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Using water for power generation. 418.16 Section 418...Operations and Management § 418.16 Using water for power generation. All use of Project water for power generation must be incidental to...

  15. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Using water for power generation. 418.16 Section 418...Operations and Management § 418.16 Using water for power generation. All use of Project water for power generation must be incidental to...

  16. Wind Generation and Power System Interaction Analysis using Probabilistic Techniques

    Microsoft Academic Search

    Marco Ortiz; Juan Ríos; Manuel Acosta

    Energy power from renewable sources, especially wind turbine generators, are being considered as an important generation alternative in the electrical power systems around the world due to their non contaminant nature and low environmental effects. In particular, the power supplied by wind generators is widely random following the random nature of weather conditions; therefore a probabilistic approach during planning seems

  17. 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.

  18. 18 CFR 801.12 - Electric power generation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    18 Conservation of Power and Water Resources 2 2013-04-01...12 Conservation of Power and Water Resources SUSQUEHANNA...presently being made of the waters of the basin for the generation of electric power at hydro, pumped...

  19. 18 CFR 801.12 - Electric power generation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    18 Conservation of Power and Water Resources 2 2011-04-01...12 Conservation of Power and Water Resources SUSQUEHANNA...presently being made of the waters of the basin for the generation of electric power at hydro, pumped...

  20. 18 CFR 801.12 - Electric power generation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    18 Conservation of Power and Water Resources 2 2012-04-01...12 Conservation of Power and Water Resources SUSQUEHANNA...presently being made of the waters of the basin for the generation of electric power at hydro, pumped...

  1. 18 CFR 801.12 - Electric power generation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    18 Conservation of Power and Water Resources 2 2014-04-01...12 Conservation of Power and Water Resources SUSQUEHANNA...presently being made of the waters of the basin for the generation of electric power at hydro, pumped...

  2. 18 CFR 801.12 - Electric power generation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    18 Conservation of Power and Water Resources 2 2010-04-01...12 Conservation of Power and Water Resources SUSQUEHANNA...presently being made of the waters of the basin for the generation of electric power at hydro, pumped...

  3. Stochastic Security for Operations Planning With Significant Wind Power Generation

    Microsoft Academic Search

    FranÇois Bouffard; Francisco D. Galiana

    2008-01-01

    In their attempt to cut down on greenhouse gas emissions from electricity generation, several countries are committed to install wind power generation up to and beyond the 10%-20% penetration mark. However, the large-scale integration of wind power represents a challenge for power system operations planning because wind power 1) cannot be dispatched in the classical sense; and 2) its output

  4. Coupled generator and combustor performance calculations for potential early commercial MHD power plants

    NASA Technical Reports Server (NTRS)

    Dellinger, T. C.; Hnat, J. G.; Marston, C. H.

    1979-01-01

    A parametric study of the performance of the MHD generator and combustor components of potential early commercial open-cycle MHD/steam power plants is presented. Consideration is given to the effects of air heater system concept, MHD combustor type, coal type, thermal input power, oxygen enrichment of the combustion, subsonic and supersonic generator flow and magnetic field strength on coupled generator and combustor performance. The best performance is found to be attained with a 3000 F, indirectly fired air heater, no oxygen enrichment, Illinois no. 6 coal, a two-stage cyclone combustor with 85% slag rejection, a subsonic generator, and a magnetic field configuration yielding a constant transverse electric field of 4 kV/m. Results indicate that optimum net MHD generator power is generally compressor-power-limited rather than electric-stress-limited, with optimum net power a relatively weak function of operating pressure.

  5. Enhancement of power system quality using distributed generation

    Microsoft Academic Search

    H. D. Mathur

    2010-01-01

    The global demand for energy is increasing at a breathtaking pace. This sharp increase in world energy demand will require significant investment in new power generating capacity and grid infrastructure. Considering the present energy scenario and the degrading environmental conditions, distributed generation seems to be a promising option. Distributed Generation generally refers to small-scale electric power generators that produce electricity

  6. SENSIBLE HEAT STORAGE FOR A SOLAR THERMAL POWER PLANT

    E-print Network

    Baldwin, Thomas F.

    2011-01-01

    Design. Propofied Solar Cooling Tower Type Wet-Cooled Powerdry-cooling tower was used in the proposed solar power plantTower • Power-Generation Subsystem Summary An Overall Summary of the Proposed Solar

  7. Prospectives for China's solar thermal power technology development

    Microsoft Academic Search

    Zhifeng Wang

    2010-01-01

    China's total installed electrical power capacity reached 700GW by the end of 2007 and is predicted to surpass 900GW in 2010. The rapid increase in energy demand and increasing global warming have both pushed China to change its current electrical power structure where coal power accounts for nearly 75% of the total electric power generation. China has already become the

  8. Solar thermal powered desalination: membrane versus distillation technologies

    Microsoft Academic Search

    G. Burgess; K. Lovegrove

    Multiple Effect Distillation (MED) is generally considered to be the desalination technology most suited to integration with concentrating solar thermal collectors on a medium to large scale. However the cost and energy requirement of Reverse Osmosis (RO) have fallen significantly in recent years, so that solar thermal powered RO deserves consideration. We compare commercial desalination processes on the basis of

  9. Assessment of generic solar thermal systems for large power applications

    Microsoft Academic Search

    W. J. Apley; S. P. Bird

    1984-01-01

    A comparative analysis of generic solar thermal conversion configurations was performed to evaluate and rank the principal concepts under consideration in the DOE Solar Thermal Power Program. Year-long performance simulations were conducted for the 50- to 200-MWe systems using Barstow, California meteorological and insolation data. Multi-attributable utility methodology was used to rank the eleven concepts.

  10. Solar thermal powered desalination: membrane versus distillation technologies

    E-print Network

    Solar thermal powered desalination: membrane versus distillation technologies G. Burgess and K Canberra ACT 0200 AUSTRALIA E-mail: greg.burgess@anu.edu.au Multiple Effect Distillation (MED) is generally assisted) desalination has been conducted. Solar thermal driven Multiple Effect Distillation (MED) has been

  11. Recurrent Neural Approaches for Power Transformers Thermal Modeling

    Microsoft Academic Search

    Michel Hell; Luiz Secco; Pyramo Costa Jr.; Fernando A. C. Gomide

    2005-01-01

    \\u000a This paper introduces approaches for power transformer thermal modeling based on two conceptually different recurrent neural\\u000a networks. The first is the Elman recurrent neural network model whereas the second is a recurrent neural fuzzy network constructed\\u000a with fuzzy neurons based on triangular norms. These two models are used to model the thermal behavior of power transformers\\u000a using data reported in

  12. Performance evaluation of solar thermal electric generation systems

    Microsoft Academic Search

    S. D Odeh; M Behnia; G. L Morrison

    2003-01-01

    A unified model of a solar electric generation system (SEGS) is developed using a thermo–hydrodynamic model of a direct steam collector combined with a model of a traditional steam power house. The model is used to study the performance of different collector field and power house arrangements under Australian conditions. To find the effect of collector inclination on the SEGS

  13. New power politics will determine generation's path

    SciTech Connect

    Maize, K.; Neville, A.; Peltier, R.

    2009-01-15

    The US power industry's story in 2009 will be all about change, to borrow a now-familiar theme. Though the new administration's policy specifics had not been revealed as this report was prepared, it appears that flat load growth in 2009 will give the new Obama administration a unique opportunity to formulate new energy policy without risking that the lights will go out. New coal projects are now facing increasing difficulties. It looks as though the electricity supply industry will continue to muddle through. It may see an advancement in infrastructure investment, significant new generation or new technology development. It also faces the possibility that policies necessary to achieving those goals will not materialize, for political and economic reasons. 4 figs.

  14. Thermal Energy Corporation Combined Heat and Power Project

    SciTech Connect

    E. Bruce Turner; Tim Brown; Ed Mardiat

    2011-12-31

    To meet the planned heating and cooling load growth at the Texas Medical Center (TMC), Thermal Energy Corporation (TECO) implemented Phase 1 of a Master Plan to install an additional 32,000 tons of chilled water capacity, a 75,000 ton-hour (8.8 million gallon) Thermal Energy Storage (TES) tank, and a 48 MW Combined Heat and Power (CHP) system. The Department of Energy selected TMC for a $10 million grant award as part of the Financial Assistance Funding Opportunity Announcement, U.S. Department of Energy National Energy Technology, Recovery Act: Deployment of Combined Heat and Power (CHP) Systems, District Energy Systems, Waste Energy Recovery Systems, and Efficiency Industrial Equipment Funding Opportunity Number: DE-FOA-0000044 to support the installation of a new 48 MW CHP system at the TMC located just outside downtown Houston. As the largest medical center in the world, TMC is home to many of the nationâ??s best hospitals, physicians, researchers, educational institutions, and health care providers. TMC provides care to approximately six million patients each year, and medical instruction to over 71,000 students. A medical center the size of TMC has enormous electricity and thermal energy demands to help it carry out its mission. Reliable, high-quality steam and chilled water are of utmost importance to the operations of its many facilities. For example, advanced medical equipment, laboratories, laundry facilities, space heating and cooling all rely on the generation of heat and power. As result of this project TECO provides this mission critical heating and cooling to TMC utilizing a system that is both energy-efficient and reliable since it provides the capability to run on power independent of the already strained regional electric grid. This allows the medical center to focus on its primary mission â?? providing top quality medical care and instruction â?? without worrying about excessive energy costs or the loss of heating and cooling due to the risk of power outages. TECOâ??s operation is the largest Chilled Water District Energy System in the United States. The company used DOEâ??s funding to help install a new high efficiency CHP system consisting of a Combustion Turbine and a Heat Recovery Steam Generator. This CHP installation was just part of a larger project undertaken by TECO to ensure that it can continue to meet TMCâ??s growing needs. The complete efficiency overhaul that TECO undertook supported more than 1,000 direct and indirect jobs in manufacturing, engineering, and construction, with approximately 400 of those being jobs directly associated with construction of the combined heat and power plant. This showcase industrial scale CHP project, serving a critical component of the nationâ??s healthcare infrastructure, directly and immediately supported the energy efficiency and job creation goals established by ARRA and DOE. It also provided an unsurpassed model of a district energy CHP application that can be replicated within other energy intensive applications in the industrial, institutional and commercial sectors.

  15. Thermal expansion of slag and fly ash from coal gasification in IGCC power plant

    Microsoft Academic Search

    M. Aineto; A. Acosta; J. Ma. Rincón; M. Romero

    2006-01-01

    Integrated gasification in combined cycle (IGCC) is an electrical power generation system which is characterized to be a clean coal technology different than conventional process in combustible treatment. IGCC process gives rise to inorganic solid wastes in the form of vitreous slag and fly ashes with singular thermal properties. The gasification of the fuel takes place at high temperature and

  16. Flue gas conditioning for reducing suspended particulate matter from thermal power stations

    Microsoft Academic Search

    S. Shanthakumar; D. N. Singh; R. C. Phadke

    2008-01-01

    Increased population and industrial development demands sustainable electricity, the majority of which is produced by thermal power stations, which utilize coal as a fuel all over the world. Coal burning results in generation of large quantities of coal residues, which contains very fine particles that tend to become air-borne and which contribute to the formation of suspended particulate matter (SPM).

  17. High voltage power condition systems powered by flux compression generators

    NASA Astrophysics Data System (ADS)

    Reinovsky, R. E.; Lindemuth, I. R.; Vorthman, J. E.

    Compact, high-gain magnetic flux compressors (FCGs) are convenient sources of substantial energy for plasma-physics and electron-beam-physics experiments, but the need for high-voltage, fast-rising pulses is difficult to meet directly with conventional generators. While a variety of novel concepts employing simultaneous, axially-detonated explosive systems are under development, power-conditioning systems based on fuse opening switches and high-voltage transformers constitute another approach that complements the fundamental size, weight, and configuration of the small helical flux compressor. In this paper, we consider first a basic inductive store/opening switch circuit and the implications associated with, specifically, a fuse opening switch and an FCG energy source. We develop a general solution to a transformer/opening switch circuit---which also includes (as a special case) the direct inductive store/opening switch circuit (without transformer) and we report results of one elementary experiment demonstrating the feasibility of the approach.

  18. Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m

    ScienceCinema

    None

    2013-05-28

    Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

  19. Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m

    SciTech Connect

    None

    2010-01-01

    Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

  20. Alternative method for steam generation for thermal oxidation of silicon

    Microsoft Academic Search

    Jeffrey J. Spiegelman

    2010-01-01

    Thermal oxidation of silicon is an important process step in MEMS device fabrication. Thicker oxide layers are often used as structural components and can take days or weeks to grow, causing high gas costs, maintenance issues, and a process bottleneck. Pyrolytic steam, which is generated from hydrogen and oxygen combustion, was the default process, but has serious drawbacks: cost, safety,

  1. Power generation from nuclear reactors in aerospace applications

    SciTech Connect

    English, R.E.

    1982-01-01

    Power generation in nuclear powerplants in space is addressed. In particular, the states of technology of the principal competitive concepts for power generation are assessed. The possible impact of power conditioning on power generation is also discussed. For aircraft nuclear propulsion, the suitability of various technologies is cursorily assessed for flight in the Earth's atmosphere. A program path is suggested to ease the conditions of first use of aircraft nuclear propulsion.

  2. Power Generation from Nuclear Reactors in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    English, Robert E.

    1982-01-01

    Power generation in nuclear powerplants in space is addressed. In particular, the states of technology of the principal competitive concepts for power generation are assessed. The possible impact of power conditioning on power generation is also discussed. For aircraft nuclear propulsion, the suitability of various technologies is cursorily assessed for flight in the Earth's atmosphere; a program path is suggested to ease the conditions of first use of aircraft nuclear propulsion.

  3. Nanostructured thermal batteries with high power density

    NASA Astrophysics Data System (ADS)

    Au, Ming

    Nanostructured FeS 2 has been synthesized and used as the cathode material in LiSi/FeS 2 thermal batteries. With the same weight, the nanostructured cathode pellets are 23% thinner than conventional counterparts resulting in 31% increase of pellet density. Therefore, the volume of batteries can be reduced significantly. With the nanostructure, the electrode materials of the thermal batteries react more rapidly and completely during discharge resulting with a remarkable increase of energy output. The discharge tests show that the energy density of the nanostructured thermal batteries is two times higher (109 J/g) than the conventional counterpart (58 J/g). The nanostructured pellets are more robust mechanically than the conventional counterparts that could increase productivity and lower manufacturing cost.

  4. Utilizing the heat content of gas-to-liquids by-product streams for commercial power generation

    E-print Network

    Adegoke, Adesola Ayodeji

    2006-10-30

    plant thermal efficiency. A detailed economic analysis on the LNG, stand-alone GTL, and Integrated GTL Power-Generation plants indicates that the integrated system is more profitable than the other options considered. Justifying...

  5. Prediction-data-based maximum-power-point-tracking method for photovoltaic power generation systems

    Microsoft Academic Search

    Nobuyoshi Mutoh; Takatoshi Matuo; Kazuhito Okada; Masahiro Sakai

    2002-01-01

    A new maximum-power-point-tracking (MPPT) method for a photovoltaic (PV) power generation system was studied which can efficiently generate PV power even under changing weather conditions. In order to research a method suitable for the actual photovoltaic power system, PV characteristics of the maximum power point were measured for more than six months using a PV curve tracer. The actual maximum

  6. Self-powered signal processing using vibration-based power generation

    Microsoft Academic Search

    Rajeevan Amirtharajah; Anantha P. Chandrakasan

    1998-01-01

    Low power design trends raise the possibility of using ambient energy to power future digital systems. A chip has been designed and tested to demonstrate the feasibility of operating a digital system from power generated by vibrations in its environment. A moving coil electromagnetic transducer was used as a power generator. Calculations show that power on the order of 400

  7. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    NASA Astrophysics Data System (ADS)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-12-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  8. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    NASA Technical Reports Server (NTRS)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-01-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  9. An immune-tabu hybrid algorithm for thermal unit commitment of electric power systems

    Microsoft Academic Search

    Wei Li; Hao-yu Peng; Wei-hang Zhu; De-ren Sheng; Jian-hong Chen

    2009-01-01

    This paper presents a new method based on an immune-tabu hybrid algorithm to solve the thermal unit commitment (TUC) problem\\u000a in power plant optimization. The mathematical model of the TUC problem is established by analyzing the generating units in\\u000a modern power plants. A novel immune-tabu hybrid algorithm is proposed to solve this complex problem. In the algorithm, the\\u000a objective function

  10. Calculation of guaranteed mean power from wind turbine generators

    NASA Technical Reports Server (NTRS)

    Spera, D. A.

    1981-01-01

    A method for calculating the 'guaranteed mean' power output of a wind turbine generator is proposed. The term 'mean power' refers to the average power generated at specified wind speeds during short-term tests. Correlation of anemometers, the method of bins for analyzing non-steady data, the PROP Code for predicting turbine power, and statistical analysis of deviations in test data from theory are discussed. Guaranteed mean power density for the Clayton Mod-OA system was found to be 8 watts per square meter less than theoretical power density at all power levels, with a confidence level of 0.999. This amounts to 4 percent of rated power.

  11. Rankine-Brayton engine powered solar thermal aircraft

    DOEpatents

    Bennett, Charles L. (Livermore, CA)

    2009-12-29

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  12. Rankline-Brayton engine powered solar thermal aircraft

    DOEpatents

    Bennett, Charles L. (Livermore, CA)

    2012-03-13

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  13. Design of Commercial Solar Updraft Tower Systems—Utilization of Solar Induced Convective Flows for Power Generation

    Microsoft Academic Search

    Jo?rg Schlaich; Rudolf Bergermann; Wolfgang Schiel; Gerhard Weinrebe

    2005-01-01

    A solar updraft tower power plant - sometimes also called 'solar chimney' or just 'solar tower' - is a solar thermal power plant utilizing a combination of solar air collector and central updraft tube to generate a solar induced convective flow which drives pressure staged turbines to generate electricity. The paper presents theory, practical experience, and economy of solar updraft

  14. A simulation model for solar thermal electric power systems

    Microsoft Academic Search

    G. R. Johnson; N. El Gabalawi

    1975-01-01

    The paper discusses SIMSTEPS, a generalized computer simulation model for the dynamic performance analysis of solar thermal electric power systems. The current subsystem models contained in the program are briefly described, including those for the Fresnel reflectors, the absorber, the steam accumulator, and the steam turbine. The simulation of a 12-MW distributed power plant is outlined, and results are presented

  15. On Solar Thermal Electric Power Capacity Sizing

    NASA Technical Reports Server (NTRS)

    Clark, J. S.

    1984-01-01

    The commercialization of parabolic dish/generator modules are investigated. Design analysis indicates that a 10 sq m/ three kilowatt generator configuration is simple and easy to maintain, manufacturing is easily adaptable, the demand is already established, the unit is cost effective and the hardware is readily available.

  16. PSS Controller for Wind Power Generation Systems

    NASA Astrophysics Data System (ADS)

    Domínguez-García, J. L.; Gomis-Bellmunt, O.; Bianchi, F.; Sumper, A.

    2012-10-01

    Small signal stability analysis for power systems with wind farm interaction is presented. Power systems oscillation modes can be excited by disturbance or fault in the grid. Variable speed wind turbines can be regulated to reduce these oscillations, stabilising the power system. A power system stabiliser (PSS) control loop for wind power is designed in order to increase the damping of the oscillation modes. The proposed power system stabiliser controller is evaluated by small signal analysis.

  17. A New Smooth Scheme for Power Fluctuations using Inverter of Wind Power Generation with Doubly Fed Induction Generator

    NASA Astrophysics Data System (ADS)

    Kai, Takaaki; Tanaka, Akio

    The power fluctuations of the wind power generation due to the wind speed variation cause a considerable frequency deviation to the power system in Tohoku and Hokkaido, etc. The frequency deviation has hardly an allowance. It is necessary to smooth the power fluctuations to interconnect a new wind power generation to the power system in those areas. Thus, the power storage system such as the battery system must be installed together with wind power generation. It needs the inverter system because there is DC power supply in the battery system. However, the system is expensive. A recent wind power generation has inverter system. The smoothing performance for wind power fluctuations can be given to the wind power generation by using the inverter system. The paper proposes a new wind power generation for which the smoothing performance is provided by such a scheme. The smoothing performance is examined in using simulation software PSCAD/EMTDC. The simulation result shows that a new wind power generation has an excellent smoothing performance for wind power fluctuations.

  18. Sustainable Power Generation in Microbial Fuel Cells Using

    E-print Network

    Tullos, Desiree

    Sustainable Power Generation in Microbial Fuel Cells Using Bicarbonate Buffer and Proton Transfer and renewable energy generation (1, 2). Amplifying the power density is one of the greatest challenges with cloth electrode assemblies (CEA) were evaluated using bicarbonate buffer solutions. A maximum power

  19. A Novel MultiLevel High Voltage Pulsed Power Generator

    Microsoft Academic Search

    D. J. Thrimawithana; U. K. Madawala

    2007-01-01

    This paper presents a novel solid-state and high power pulse generation technique that is suitable for a wide range of pulsed power applications. The technique, termed as multi-level pulsed power converter, can be considered as a hybrid of the direct discharge type and the Marx generator but with considerably less complexity in both control and circuitry. It has the ability

  20. Challenges and Opportunities for Fuel Cells in Stationary Power Generation

    Microsoft Academic Search

    Suresh Sriramulu; Jason Targoff; Stephen Lasher; Eric Carlson; Robert Zogg

    2005-01-01

    Fuel cell power systems are considered attractive for a wide range of stationary power generation applications including residential, commercial, and industrial distributed generation, as well as large utility power plants. The current interest in fuel cell systems stems from their potential for high efficiency (lower heating value (LHV) efficiencies of 35–70 percent, depending on technology and system capacity). In addition,

  1. An Evolutionary Path for Concentrating Thermal Solar Power Technologies: A New Approach for Modeling CSP Power Costs and Potential

    SciTech Connect

    Zhang, Yabei; Smith, Steven J.

    2008-05-08

    Concentrating thermal solar power (CSP) technology is a potentially competitive power generation option, particularly in arid regions where direct sunlight is abundant. We examine the potential role of CSP power plants and their contribution to carbon emissions reduction. The answers to these questions depend on the cost of electricity generated by CSP plants. Although a few studies have projected future CSP costs based on assumptions for technology advancement and the effect of economies of scale and learning curves, few studies have considered the combined effects of intermittency, solar irradiance changes by season, and diurnal and seasonal system load changes. Because the generation of a solar plant varies over a day and by season, the interactions between CSP generators and other generators in the electric system can play an important role in determining costs. In effect, CSP electricity generation cost will depend on the CSP market penetration. This paper examines this relationship and explores possible evolutionary paths for CSP technologies with and without thermal storage.

  2. Thermocline Thermal Storage Test for Large-Scale Solar Thermal Power Plants

    Microsoft Academic Search

    S. T. LAURENT; STEVEN J

    2000-01-01

    Solar thermal-to-electric power plants have been tested and investigated at Sandia National Laboratories (SNL) since the late 1970s, and thermal storage has always been an area of key study because it affords an economical method of delivering solar-electricity during non-daylight hours. This paper describes the design considerations of a new, single-tank, thermal storage system and details the benefits of employing

  3. The application of simulation modeling to the cost and performance ranking of solar thermal power plants

    NASA Technical Reports Server (NTRS)

    Rosenberg, L. S.; Revere, W. R.; Selcuk, M. K.

    1981-01-01

    Small solar thermal power systems (up to 10 MWe in size) were tested. The solar thermal power plant ranking study was performed to aid in experiment activity and support decisions for the selection of the most appropriate technological approach. The cost and performance were determined for insolation conditions by utilizing the Solar Energy Simulation computer code (SESII). This model optimizes the size of the collector field and energy storage subsystem for given engine generator and energy transport characteristics. The development of the simulation tool, its operation, and the results achieved from the analysis are discussed.

  4. Combined power generation with wind and ocean waves

    Microsoft Academic Search

    V. N. M. R. Lakkoju

    1996-01-01

    It is often advantageous to generate power with combinations of wind and ocean waves. In fact ocean waves, their generation, propagation, dissipation are directly related to wind velocity and its duration oven the sea. In this paper an attempt has been made to demonstrate statistically to present some advantages with combined wind and ocean wave power generation. Even though many

  5. Coal and Coal/Biomass-Based Power Generation

    EPA Science Inventory

    For Frank Princiotta's book, Global Climate Change--The Technology Challenge Coal is a key, growing component in power generation globally. It generates 50% of U.S. electricity, and criteria emissions from coal-based power generation are being reduced. However, CO2 emissions m...

  6. Analysis of waste-heat thermoelectric power generators

    Microsoft Academic Search

    Chih Wu

    1996-01-01

    A real thermoelectric power generator utilizing waste heat is proposed. The generator is treated as an external and internal irreversible heat engine. The specific power output of the generator is analyzed and compared with that of the Carnot, endoreversible and external reversible thermoelectric heat engines.

  7. Turbine Drive Gas Generator for Zero Emission Power Plants

    Microsoft Academic Search

    Stephen E. Doyle; Roger E. Anderson

    2001-01-01

    The Vision 21 Program seeks technology development that can reduce energy costs, reduce or eliminate atmospheric pollutants from power plants, provide choices of alternative fuels, and increase the efficiency of generating systems. Clean Energy Systems is developing a gas generator to replace the traditional boiler in steam driven power systems. The gas generator offers the prospects of lower electrical costs,

  8. 13. INTERIOR OF POWER PLANT LOOKING EASTNORTHEAST. 1925 GE GENERATOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. INTERIOR OF POWER PLANT LOOKING EAST-NORTHEAST. 1925 GE GENERATOR IN FOREGROUND, WITH C. 1910 GENERATOR COVER IN BACKGROUND. STEEL FRAME SUPPORTS HOISTING MECHANISM USED TO MOVE, REPAIR, OR REPLACE GENERATORS. - Potomac Power Plant, On West Virginia Shore of Potomac River, about 1 mile upriver from confluence with Shenandoah River, Harpers Ferry, Jefferson County, WV

  9. On Distinguishing between Internet Power Law Topology Generators

    Microsoft Academic Search

    Tian Bu; Donald F. Towsley

    2002-01-01

    Recent work has shown that the node degree in the WWW induced graph and the AS-level Internet topology exhibit power laws. Since then several algorithms have been proposed to generate such power law graphs. In this paper we evaluate the effectiveness of these generators to generate representative AS-level topologies. Our conclusions are mixed. Although they (mostly) do a reasonable job

  10. A simplified wind power generation model for reliability evaluation

    Microsoft Academic Search

    Rajesh Karki; Po Hu; R. Billinton

    2006-01-01

    Renewable energy sources, especially wind turbine generators, are considered as important generation alternatives in electric power systems due to their nonexhausted nature and benign environmental effects. The fact that wind power penetration continues to increase has motivated a need to develop more widely applicable methodologies for evaluating the actual benefits of adding wind turbines to conventional generating systems. Reliability evaluation

  11. Installation Schemes of Superconducting Generators in Power Systems

    Microsoft Academic Search

    Worawut Sae-Kok; Akihiko Yokoyama

    2007-01-01

    Superconducting generator (SCG) with superconducting field winding has many advantages such as small size, light weight, high generation efficiency. In particular, the property of low synchronous reactances, which is not realized in conventional generators, is able to improve power system stability. Installation scheme of SCGs in multi-machine power system becomes one of the topics that should be considered. It concerns

  12. Impacts of energy storage in distributed Power Generation: A review

    Microsoft Academic Search

    G. Coppez; S. Chowdhury

    2010-01-01

    Distributed Generation (DG) in the form of Renewable Power Generation systems are currently preferred for clean power generation. However due to their intermittent and unpredictable nature, energy storage needs to be used to ensure that the load is met at all times. There are many possible options for energy storage and the most popular and technologically matured option, batteries, is

  13. Worker health and safety in solar thermal power systems. III. Thermal energy storage subsystems

    Microsoft Academic Search

    A. Z. Ullman; B. B. Sokolow; J. Daniels; P. Hurt

    1979-01-01

    The effects of the use of thermal energy storage (TES) subsystems in solar thermal power systems (STPS) on operating failures and on worker health and safety are examined. Revelant near- and medium-term designs for TES subsystems are reviewed. Generic failure events are considered by an event tree methodology. Three generic categories of initiating events are identified which can lead to

  14. Worker health and safety in solar thermal power systems. III. Thermal energy storage subsystems

    Microsoft Academic Search

    A. Z. Ullman; B. B. Sokolow; J. Daniels; P. Hurt

    1979-01-01

    The effects of the use of thermal energy storage (TES) subsystems in solar thermal power systems (STPS) on operating failures and on worker health and safety are examined. Relevant near- and medium-term designs for TES subsystems are reviewed. Generic failure events are considered by an event tree methodology. Three generic categories of initiating events are identified which can lead to

  15. Energy management in solar thermal power plants with double thermal storage system and subdivided solar field

    Microsoft Academic Search

    Antonio Rovira; Manuel Valdes; José María Martínez-Val

    2011-01-01

    In the paper, two systems for solar thermal power plants (STPPs) are devised for improving the overall performance of the plant. Each one attempts to reduce losses coming from two respective sources. The systems are simulated and compared to a reference STPP.They consists on: (a) a double thermal energy storage (DTS) with different functionalities for each storage and (b) the

  16. Integrated engine-generator concept for aircraft electric secondary power

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.; Macosko, R. P.; Repas, D. S.

    1972-01-01

    The integrated engine-generator concept of locating an electric generator inside an aircraft turbojet or turbofan engine concentric with, and driven by, one of the main engine shafts is discussed. When properly rated, the generator can serve as an engine starter as well as a generator of electric power. The electric power conversion equipment and generator controls are conveniently located in the aircraft. Preliminary layouts of generators in a large engine together with their physical sizes and weights indicate that this concept is a technically feasible approach to aircraft secondary power.

  17. Effects of Thermal Cycling on Control and Irradiated EPC 2nd Generation GaN FETs

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Scheick, Leif; Lauenstein, Jean-Marie; Casey, Megan; Hammoud, Ahmad

    2013-01-01

    The power systems for use in NASA space missions must work reliably under harsh conditions including radiation, thermal cycling, and exposure to extreme temperatures. Gallium nitride semiconductors show great promise, but information pertaining to their performance is scarce. Gallium nitride N-channel enhancement-mode field effect transistors made by EPC Corporation in a 2nd generation of manufacturing were exposed to radiation followed by long-term thermal cycling in order to address their reliability for use in space missions. Results of the experimental work are presented and discussed.

  18. Direct charge radioisotope activation and power generation

    DOEpatents

    Lal, Amit (Madison, WI); Li, Hui (Madison, WI); Blanchard, James P. (Madison, WI); Henderson, Douglass L. (Madison, WI)

    2002-01-01

    An activator has a base on which is mounted an elastically deformable micromechanical element that has a section that is free to be displaced toward the base. An absorber of radioactively emitted particles is formed on the base or the displaceable section of the deformable element and a source is formed on the other of the displaceable section or the base facing the absorber across a small gap. The radioactive source emits charged particles such as electrons, resulting in a buildup of charge on the absorber, drawing the absorber and source together and storing mechanical energy as the deformable element is bent. When the force between the absorber and the source is sufficient to bring the absorber into effective electrical contact with the source, discharge of the charge between the source and absorber allows the deformable element to spring back, releasing the mechanical energy stored in the element. An electrical generator such as a piezoelectric transducer may be secured to the deformable element to convert the released mechanical energy to electrical energy that can be used to provide power to electronic circuits.

  19. Advanced gasification-based biomass power generation

    SciTech Connect

    Williams, R.H.; Larson, E.D. [Princeton Univ., NJ (United States)

    1993-12-31

    A promising strategy for modernizing bioenergy is the production of electricity or the cogeneration of electricity and heat using gasified biomass with advanced conversion technologies. Major advances that have been made in coal gasification technology, to marry the gas turbine to coal, are readily adaptable to biomass applications. Integrating biomass gasifiers with aeroderivative gas turbines in particular makes it possible to achieve high efficiencies and low unit capital costs at the modest scales required for bioenergy systems. Electricity produced with biomass-integrated gasifier/gas turbine (BIG/GT) power systems not only offers major environmental benefits but also would be competitive with electricity produced from fossil fuels and nuclear energy under a wide range of circumstances. Initial applications will be with biomass residues generated in the sugarcane, pulp and paper, and other agro- and forest-product industries. Eventually, biomass grown for energy purposes on dedicated energy farms will also be used to fuel these gas turbine systems. Continuing improvements in jet engine and biomass gasification technologies will lead to further gains in the performance of BIG/GT systems over the next couple of decades. Fuel cells operated on gasified biomass offer the promise of even higher performance levels in the period beyond the turn of the century. 79 refs., 21 figs., 11 tabs.

  20. Thermal management of next-generation contact-cooled synchrotron x-ray mirrors

    SciTech Connect

    Khounsary, A.

    1999-10-29

    In the past decade, several third-generation synchrotrons x-ray sources have been constructed and commissioned around the world. Many of the major problems in the development and design of the optical components capable of handling the extremely high heat loads of the generated x-ray beams have been resolved. It is expected, however, that in the next few years even more powerful x-ray beams will be produced at these facilities, for example, by increasing the particle beam current. In this paper, the design of a next generation of synchrotron x-ray mirrors is discussed. The author shows that the design of contact-cooled mirrors capable of handing x-ray beam heat fluxes in excess of 500 W/mm{sup 2} - or more than three times the present level - is well within reach, and the limiting factor is the thermal stress rather then thermally induced slope error.

  1. Maximum power and thermal efficiency of an irreversible power cycle

    NASA Astrophysics Data System (ADS)

    Ait-Ali, Mohand A.

    1995-10-01

    A simple Carnot-like irreversible power cycle is modeled with two isothermal and two adiabatic, irreversible processes. The generic source of internal irreversibility, deduced from the Clausius inequality, produces entropy at a rate proportional to the external heat conductance and the engine temperature ratio. This cycle is optimized for maximum power and maximum efficiency, and its performances compared to those of the endoreversible cycle, based on typical heat source and heat sink temperatures. Both cycles produce maximum power at the same engine temperature ratio, but the irreversible cycle prediction of maximum efficiency and heat conductance allocation between steam boiler and condenser, appear to be not only more realistic, but also more relevant to actual design considerations of power plants.

  2. High voltage power condition systems powered by flux compression generators

    SciTech Connect

    Reinovsky, R.E.; Lindemuth, I.R.; Vorthman, J.E.

    1989-01-01

    Compact, high-gain magnetic flux compressors (FCGs) are convenient sources of substantial energy for plasma-physics and electron-beam-physics experiments, but the need for high-voltage, fast-rising pulses is difficult to meet directly with conventional generators. While a variety of novel concepts employing simultaneous, axially- detonated explosive systems are under development, power-conditioning systems based on fuse opening switches and high-voltage transformers constitute another approach that complements the fundamental size, weight, and configuration of the small helical flux compressor. In this paper, we consider first a basic inductive store/opening switch circuit and the implications associated with, specifically, a fuse opening switch and an FCG energy source. We develop a general solution to a transformer/opening switch circuit---which also includes (as a special case) the direct inductive store/opening switch circuit (without transformer) and we report results of one elementary experiment demonstrating the feasibility of the approach. 9 figs.

  3. Generating Functions for the Powers of Fibonacci Sequences

    ERIC Educational Resources Information Center

    Terrana, D.; Chen, H.

    2007-01-01

    In this note, based on the Binet formulas and the power-reducing techniques, closed forms of generating functions for the powers of Fibonacci sequences are presented. The corresponding results are extended to some other famous sequences as well.

  4. Fuel cells-the clean and efficient power generators

    Microsoft Academic Search

    M. Farooque; H. C. Maru

    2001-01-01

    Fuel cell generators ranging from subkilowatt portable power units to multimegawatt stationary power plants are emerging to deliver clean and efficient power using a large variety of gaseous and liquid fuels. This new technology is suitable for producing heat and power for residential, commercial, and industrial customers. The fuel cells produce electricity without combustion and use very few moving parts,

  5. A new generation of high voltage pulsed power converters

    Microsoft Academic Search

    Sasan Zabihi; Firuz Zare; Gerard Ledwich; A. Ghosh; H. Akiyama

    2010-01-01

    Improving efficiency and flexibility in pulsed power supply technologies are the most substantial concerns of pulsed power systems specifically for plasma generation. Recently, the improvement of pulsed power supply becomes of greater concern due to extension of pulsed power applications to environmental and industrial areas. A current source based topology is proposed in this paper which gives the possibility of

  6. Thermal evaluation method for Klystron RF power

    NASA Technical Reports Server (NTRS)

    Conroy, B. L.; Schleier, H.; Tesarek, T.

    1987-01-01

    The feasibility of adding instrumentation to the cooling system of a microwave transmitter for use as a calorimetric power measurement calibration is examined. It considers the accuracy of the basic measurements as well as heat sources and losses not measured. Experimental results are presented in support of the theory.

  7. Thermal Analysis and Testing of Fastrac Gas Generator Design

    NASA Technical Reports Server (NTRS)

    Nguyen, H.

    1998-01-01

    The Fastrac Engine is being developed by the Marshall Space Flight Center (MSFC) to help meet the goal of substantially reducing the cost of access to space. This engine relies on a simple gas-generator cycle, which burns a small amount of RP-1 and oxygen to provide gas to drive the turbine and then exhausts the spent fuel. The Fastrac program envisions a combination of analysis, design and hot-fire evaluation testing. This paper provides the supporting thermal analysis of the gas generator design. In order to ensure that the design objectives were met, the evaluation tests have started on a component level and a total of 15 tests of different durations were completed to date at MSFC. The correlated thermal model results will also be compared against hot-fire thermocouple data gathered.

  8. Neuro-Fuzzy Computational Technique to Control Load Frequency in Hydro-Thermal Interconnected Power System

    NASA Astrophysics Data System (ADS)

    Prakash, S.; Sinha, S. K.

    2014-08-01

    In this research work, two areas hydro-thermal power system connected through tie-lines is considered. The perturbation of frequencies at the areas and resulting tie line power flows arise due to unpredictable load variations that cause mismatch between the generated and demanded powers. Due to rising and falling power demand, the real and reactive power balance is harmed; hence frequency and voltage get deviated from nominal value. This necessitates designing of an accurate and fast controller to maintain the system parameters at nominal value. The main purpose of system generation control is to balance the system generation against the load and losses so that the desired frequency and power interchange between neighboring systems are maintained. The intelligent controllers like fuzzy logic, artificial neural network (ANN) and hybrid fuzzy neural network approaches are used for automatic generation control for the two area interconnected power systems. Area 1 consists of thermal reheat power plant whereas area 2 consists of hydro power plant with electric governor. Performance evaluation is carried out by using intelligent (ANFIS, ANN and fuzzy) control and conventional PI and PID control approaches. To enhance the performance of controller sliding surface i.e. variable structure control is included. The model of interconnected power system has been developed with all five types of said controllers and simulated using MATLAB/SIMULINK package. The performance of the intelligent controllers has been compared with the conventional PI and PID controllers for the interconnected power system. A comparison of ANFIS, ANN, Fuzzy and PI, PID based approaches shows the superiority of proposed ANFIS over ANN, fuzzy and PI, PID. Thus the hybrid fuzzy neural network controller has better dynamic response i.e., quick in operation, reduced error magnitude and minimized frequency transients.

  9. Ames Lab 101: Next Generation Power Lines

    ScienceCinema

    Russell, Alan

    2012-08-29

    Ames Laboratory scientist Alan Russell discusses the need to develop new power lines that are stronger and more conductive as a way to address the problem of the nation's aging and inadequate power grid.

  10. Investigation of thermal storage and steam generator issues

    SciTech Connect

    Not Available

    1993-08-01

    A review and evaluation of steam generator and thermal storage tank designs for commercial nitrate salt technology showed that the potential exists to procure both on a competitive basis from a number of qualified vendors. The report outlines the criteria for review and the results of the review, which was intended only to assess the feasibility of each design, not to make a comparison or select the best concept.

  11. Two DOF controller for parallel operation of fuel cell power generator with power grid

    Microsoft Academic Search

    Junggi Lee; Jaihong Kim; Jungmin Kwon; Kwanghee Nam

    2005-01-01

    Parallel operation of a fuel cell power generator is considered in connection with the power grid. For a smooth power flow control between the local fuel cell generator system and the power grid, we propose a connection topology along with a two degree of freedom (DOF) controller. The two DOF controller inherently contains the inverse dynamics of the plant in

  12. The impact of large scale wind power generation on power system oscillations

    Microsoft Academic Search

    J. G. Slootweg; W. L. Kling

    2003-01-01

    Increasing amounts of wind turbines are connected to electrical power systems. This affects many aspects of their operation and behaviour. In this paper, the impact of large scale wind power generation on power system oscillations is treated. The three main types of power system oscillations, namely oscillations of a group of generators against a strong system and intra- and inter-area

  13. Optimal reactive power flow with distributed generating plants in electric power distribution systems

    Microsoft Academic Search

    U. Leeton; T. Ratniyomchai; T. Kulworawanichpong

    2010-01-01

    This paper presents the solution of reactive power flow optimization for electric power distribution systems integrating with distributed generating (Distributed Generator: DG) plants which can support daily load demand. To reduce the total energy losses of the entire system, transformer tap and reactive power injection from available reactive power source are required. The setting of variables based on a particular

  14. Investigation of thermally-induced phase mismatching in continuous-wave second harmonic generation: a theoretical model.

    PubMed

    Sabaeian, Mohammad; Mousave, Laleh; Nadgaran, Hamid

    2010-08-30

    A fraction of the fundamental beam energy deposited into nonlinear crystals to generate second harmonic waves (SHW) causes a temperature gradient within the crystal. This temperature inhomogeneity can alter the refractive index of the medium leading to a well-known effect called thermal dispersion. Therefore, the generated SHW suffers from thermal lensing and a longitudinal thermal phase mismatching. In this work by coupling the heat equation with second harmonic generation (SHG) formalism applied to type-II configuration along with walk-off effect, we investigate the continuous wave (CW) SHW beam profile and conversion efficiency when a non-linear KTP crystal is under induced thermal load. We have demonstrated for average and high powers, the thermal de-phasing lead to considerable reduction in SHG compared to an ideal case in which induced heat is neglected. PMID:20940766

  15. Power Electronics Thermal Management R&D (Presentation)

    SciTech Connect

    Waye, S.

    2014-11-01

    This project will investigate and develop thermal-management strategies for wide bandgap (WBG)-based power electronics systems. Research will be carried out to deal with thermal aspects at the module- and system-level. Module-level research will focus on die- and substrate-integrated cooling strategies and heat-transfer enhancement technologies. System-level research will focus on thermal-management strategies for the entire power electronics system to enable smart packaging solutions. One challenge with WBG device-based power electronics is that although losses in the form of heat may be lower, the footprint of the components is also likely to be reduced to reduce cost, weight, and volume. Combined with higher operational temperatures, this creates higher heat fluxes which much be removed from a smaller footprint, requiring advanced cooling strategies.

  16. Study of Low Voltage Ride Through Performance for Wind Power Generation with Doubly Fed Induction Generator

    NASA Astrophysics Data System (ADS)

    Hirawata, Ryoya; Kai, Takaaki

    Recently, the introduction of wind power generation is increasing rapidly. The ratio of wind power generation to the capacity of a total generation is getting higher and higher. When the phase-to-phase fault occurs in the power system, the frequency of power system is lower due to disconnecting of the wind power generation with doubly fed induction generator (DFIG). Therefore, the power system might become unstable. This paper describes the LVRT (low voltage ride through) performance improvement scheme of the wind power generation with DFIG. The wind power generation is disconnected from the grid in case of the power system fault. It is independently in operation from the grid by controlling of the inverter equipped in the generation. After clearance of the power system fault, the wind power generation is immediately re-connected to the grid. As a result, instability in the power system disappears. The performance of LVRT is confirmed by using simulation software PSCAD/EMTDC. The simulation result shows an excellent result to the three-phase short-circuit fault of the voltage dip 100%.

  17. Generation of Multitemporal Thermal Orthophotos from Uav Data

    NASA Astrophysics Data System (ADS)

    Pech, K.; Stelling, N.; Karrasch, P.; Maas, H.-G.

    2013-08-01

    The paper deals with using a TIR camera on an UAV for acquiring multitemporal thermal images of a building block against the background of detecting, monitoring and analysing urban heat islands. It is motivated by a research project called EO2HEAVEN (Earth Observation and Environmental Modelling for the Mitigation of Health Risks) which analyses the influence of environmental effects to human health. Therefore, the aim is the generation of thermal orthophotos from UAV data which can be used for further thematic analysis. The paper describes the data acquisition on the one hand and the processing of the obtained data on the other hand. The data acquisition comprises three image flights at different times of day from which only the first two missions could be processed until now. The low image contrasts, the radiometric differences between images as well as the poor initial positioning and orientation values limit the suitability of available software for automatic tie point measurement so that this step was outsourced and implemented in C++. The following aerial triangulation and orthophoto generation was realised in TerraPhoto (Terrasolid). However, two orthophotos could be generated with a geometric resolution of 15 cm. Furthermore, the radiation temperatures from the thermal images were compared to ground measurements to check the correctness of the camera measurements.

  18. Alternative power generation concepts for space

    SciTech Connect

    Brandhorst, H.W. Jr.; Juhasz, A.J.; Jones, B.I. [Lewis Research Center, Cleveland, OH (United States)

    1994-09-01

    With the advent of the NASA Space Station, there has emerged a general realization that large quantities of power in space are necessary and, in fact, enabling. This realization has led to the examination of alternative options to the ubiquitous solar array/battery power system. Several factors led to the consideration of solar dynamic and nuclear power systems. These include better scaling to high power levels, higher efficiency conversion and storage subsystems, and lower system specific mass. The objective of this paper is to present the results of trade and optimization studies that high-light the potential of solar and nuclear dynamic systems relative to photovoltaic power systems.

  19. Solar thermal power systems. Annual technical progress report, FY 1979

    SciTech Connect

    Braun, Gerald W.

    1980-06-01

    The Solar Thermal Power Systems Program is the key element in the national effort to establish solar thermal conversion technologies within the major sectors of the national energy market. It provides for the development of concentrating mirror/lens heat collection and conversion technologies for both central and dispersed receiver applications to produce electricity, provide heat at its point of use in industrial processes, provide heat and electricity in combination for industrial, commercial, and residential needs, and ultimately, drive processes for production of liquid and gaseous fuels. This report is the second Annual Technical Progress Report for the Solar Thermal Power Systems Program and is structured according to the organization of the Solar Thermal Power Systems Program on September 30, 1979. Emphasis is on the technical progress of the projects rather than on activities and individual contractor efforts. Each project description indicates its place in the Solar Thermal Power Systems Program, a brief history, the significant achievements and real progress during FY 1979, also future project activities as well as anticipated significant achievements are forecast. (WHK)

  20. Science 101: How do windmills generate power?

    NSDL National Science Digital Library

    William C. Robertson, Ph.D.

    2009-07-01

    This is a timely question given that you can now buy your own windmill (or more correctly, wind turbine ) for residential use. More on that later. Using windmills to generate electricity makes sense once you understand how we generate electricity.

  1. Experimental and numerical investigation of hydro power generator ventilation

    NASA Astrophysics Data System (ADS)

    Jamshidi, H.; Nilsson, H.; Chernoray, V.

    2014-12-01

    Improvements in ventilation and cooling offer means to run hydro power generators at higher power output and at varying operating conditions. The electromagnetic, frictional and windage losses generate heat. The heat is removed by an air flow that is driven by fans and/or the rotor itself. The air flow goes through ventilation channels in the stator, to limit the electrical insulation temperatures. The temperature should be kept limited and uniform in both time and space, avoiding thermal stresses and hot-spots. For that purpose it is important that the flow of cooling air is distributed uniformly, and that flow separation and recirculation are minimized. Improvements of the air flow properties also lead to an improvement of the overall efficiency of the machine. A significant part of the windage losses occurs at the entrance of the stator ventilation channels, where the air flow turns abruptly from tangential to radial. The present work focuses exclusively on the air flow inside a generator model, and in particular on the flow inside the stator channels. The generator model design of the present work is based on a real generator that was previously studied. The model is manufactured taking into consideration the needs of both the experimental and numerical methodologies. Computational Fluid Dynamics (CFD) results have been used in the process of designing the experimental setup. The rotor and stator are manufactured using rapid-prototyping and plexi-glass, yielding a high geometrical accuracy, and optical experimental access. A special inlet section is designed for accurate air flow rate and inlet velocity profile measurements. The experimental measurements include Particle Image Velocimetry (PIV) and total pressure measurements inside the generator. The CFD simulations are performed based on the OpenFOAM CFD toolbox, and the steady-state frozen rotor approach. Specific studies are performed, on the effect of adding "pick-up" to spacers, and the effects of the inlet fan blades on the flow rate through the model. The CFD results capture the experimental flow details to a reasonable level of accuracy.

  2. Modular Analysis of Automobile Exhaust Thermoelectric Power Generation System

    NASA Astrophysics Data System (ADS)

    Deng, Y. D.; Zhang, Y.; Su, C. Q.

    2014-10-01

    In this paper, an automobile exhaust thermoelectric power generation system is packaged into a model with its own operating principles. The inputs are the engine speed and power, and the output is the power generated by the system. The model is divided into two submodels. One is the inlet temperature submodel, and the other is the power generation submodel. An experimental data modeling method is adopted to construct the inlet temperature submodel, and a theoretical modeling method is adopted to construct the power generation submodel. After modeling, simulation is conducted under various engine operating conditions to determine the variation of the power generated by the system. Finally, the model is embedded into a Honda Insight vehicle model to explore the energy-saving effect of the system on the vehicle under Economic Commission for Europe and cyc-constant_60 driving cycles.

  3. Monolithic fuel cell based power source for burst power generation

    SciTech Connect

    Fee, D.C.; Blackburn, P.E.; Busch, D.E.; Dees, D.W.; Dusek, J.; Easler, T.E.; Ellingson, W.A.; Flandermeyer, B.K.; Fousek, R.J.; Heiberger, J.J.; Majumdar, S.; McPheeters, C.C.; Mrazek, F.C.; Picciolo, J.J.; Singh, J.P.; Poeppel, R.B.

    1988-01-01

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The requisite high power, long-duration bursts appear achievable with appropriate development of the concept. A monolithic fuel cell/nuclear reactor system clearly possesses several advantages. Fabrication methods, performance advantages, and applications are discussed in this report.

  4. Investigation and study on compressed air storage power generation system, part 2

    NASA Astrophysics Data System (ADS)

    1989-03-01

    Compressed air storage power generation system (CAES) was studied. As a system for response to peak loads, both output and efficiency were better than those of the previous year due to the study on the temperature of the turbine's inlet. As a system for response to peak and middle loads, steam power generation, which makes use of exhaust heat from the aftercooler and the low pressure turbine's outlet, was integrated into the system, and its heat efficiency was better than that of the usual thermal power generation. However, it is inferior to the latest LNG combined cycle power generation and it does not appeal much as a middle load power source. Deformation strength characteristics of the underground cavity rocks were clarified, and a multi-structure lining method was suggested. Its location area is restricted by the layer distribution. Construction cost per kW is 220,000 yen, and the power generation prime cost is a little higher than that of pumped storage power generation. As a pumped storage power station has difficulty in finding suitable location and is higher in costs, CAES can be put into existence as a system for response to peak loads in view of economy in the future.

  5. Load Frequency Control in Power System with Distributed Generation

    NASA Astrophysics Data System (ADS)

    Yukita, Kazuto; Ota, Takuya; Fujimoto, Koji; Goto, Yasuyuki; Ichiyanagi, Katuhiro

    This paper proposes a method to improve the load frequency control in a power system with distributed generation (DG). DG is assumed to include photovoltaic generation, wind power generation, fuel cells and etc. In this paper, a simulation is performed using a microgrid model or island model that is composed of a storage system with either wind power generation or photovoltaic generation system as the DG. The effectiveness of load frequency control (LFC) using a storage system is examined using a power transmission simulator. The model for the experiment has been composed of inverter, battery, synchronous generator and load. Using this model, the comparison examination was done in respect of output setting control and the case in which the PI control was used. As a result, when the output set-point control using power demand estimation method is executed, the control characteristic is very excellent.

  6. Thermal management system options for high power space platforms

    NASA Technical Reports Server (NTRS)

    Sadunas, J. A.; Lehtinen, A.; Parish, R.

    1985-01-01

    Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

  7. Underwater vehicle propulsion and power generation

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    An underwater vehicle includes a shaft with a propeller disposed thereon; a generator/motor having a stator and a rotor, the rotor being operable to rotate with the propeller; at least one energy storage device connected to the generator/motor; and a controller for setting the generator/motor in a charge mode, a propulsion mode and an idle mode.

  8. Fault Current Issues for Market Driven Power Systems with Distributed Generation

    E-print Network

    1 Fault Current Issues for Market Driven Power Systems with Distributed Generation Natthaphob of installing distributed generation (DG) to electric power systems. The proliferation of new generators creates Terms--Distributed / dispersed generation, power distri- bution, power system protection, fault

  9. A Vector Control 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 due to high efficiently for wind energy capture. An inverter system is required to control wind turbine speed and power factor in those generators. The inverter rating of the synchronous generator equals to generator rating. However, DFIG has the advantage that the inverter rating is about 25% to the generator rating. The paper describes a vector control of DFIG inter-connected to power line. The performance of proposed vector control is examined using power system simulation software PSCAD/EMTDC for the DFIG inter-connected to 6.6kv distribution line. The results show good dynamic responses and high accuracy to the stator active power control and the stator reactive power control.

  10. Technical and economical system comparison of photovoltaic and concentrating solar thermal power systems depending on annual global irradiation

    Microsoft Academic Search

    Volker Quaschning

    2004-01-01

    Concentrating solar thermal power and photovoltaics are two major technologies for converting sunlight to electricity. Variations of the annual solar irradiation depending on the site influence their annual efficiency, specific output and electricity generation cost. Detailed technical and economical analyses performed with computer simulations point out differences of solar thermal parabolic trough power plants, non-tracked and two-axis-tracked PV systems. Therefore,

  11. Determination of the maximum power generation of renewable energy generating units in an islanded microgrid

    Microsoft Academic Search

    Wen-Chih Yang; Wei-Tzer Huang

    2011-01-01

    Renewable energy generating units (REGNs) are widely used in microgrids (MGs). REGNs can reduce the operating cost of a MG; they also affect the operating states of the connected grids, especially the voltages. The larger the power generation of REGNs, the greater the impact on voltage of MGs. Therefore, the power generation of a REGN in a MG should be

  12. Terrestrial Solar Thermal Power Plants: On the Verge of Commercialization

    NASA Astrophysics Data System (ADS)

    Romero, M.; Martinez, D.; Zarza, E.

    2004-12-01

    Solar Thermal Power Plants (STPP) with optical concentration technologies are important candidates for providing the bulk solar electricity needed within the next few decades, even though they still suffer from lack of dissemination and confidence among citizens, scientists and decision makers. Concentrating solar power is represented nowadays at pilot-scale and demonstration-scale by four technologies, parabolic troughs, linear Fresnel reflector systems, power towers or central receiver systems, and dish/engine systems, which are ready to start up in early commercial/demonstration plants. Even though, at present those technologies are still three times more expensive than intermediate-load fossil thermal power plants, in ten years from now, STPP may already have reduced production costs to ranges competitive. An important portion of this reduction (up to 42%) will be obtained by R&D and technology advances in materials and components, efficient integration schemes with thermodynamic cycles, highly automated control and low-cost heat storage systems.

  13. Power enhancement of heat engines via correlated thermalization in multilevel systems

    E-print Network

    David Gelbwaser-Klimovsky; Wolfgang Niedenzu; Paul Brumer; Gershon Kurizki

    2014-11-05

    We analyze a heat machine based on a periodically-driven quantum system permanently coupled to hot and cold baths. It is shown that the maximal power output of a degenerate $V$-type three-level heat engine is that generated by two independent two-level systems. For $N$ levels, this maximal enhancement is $(N-1)$-fold. Hence, level degeneracy is a thermodynamic resource that may effectively boost the power output. The efficiency, however, is not affected. We find that coherence is not an essential asset in multilevel-based heat machines. The existence of multiple thermalization pathways sharing a common ground state suffices for power enhancement.

  14. Integrated power clock generators for low energy logic

    Microsoft Academic Search

    D. Maksimovic; V. G. Oklobdzija

    1995-01-01

    Low-energy (adiabatic) logic families have been proposed to reduce energy consumption of VLSI logic devices. Instead of the conventional DC power supply, these logic families require AC power supplies (power clocks) that allow energy recovery and also serve as timing clocks for the logic. In this paper, high-frequency resonant DC\\/AC inverters are proposed as power clock generators where all power

  15. Efficiency at maximum power of thermally coupled heat engines.

    PubMed

    Apertet, Y; Ouerdane, H; Goupil, C; Lecoeur, Ph

    2012-04-01

    We study the efficiency at maximum power of two coupled heat engines, using thermoelectric generators (TEGs) as engines. Assuming that the heat and electric charge fluxes in the TEGs are strongly coupled, we simulate numerically the dependence of the behavior of the global system on the electrical load resistance of each generator in order to obtain the working condition that permits maximization of the output power. It turns out that this condition is not unique. We derive a simple analytic expression giving the relation between the electrical load resistance of each generator permitting output power maximization. We then focus on the efficiency at maximum power (EMP) of the whole system to demonstrate that the Curzon-Ahlborn efficiency may not always be recovered: The EMP varies with the specific working conditions of each generator but remains in the range predicted by irreversible thermodynamics theory. We discuss our results in light of nonideal Carnot engine behavior. PMID:22680454

  16. Generating Power Leveling of Renewable Energy for Small Power System in Isolated Island

    NASA Astrophysics Data System (ADS)

    Senjyu, Tomonobu; Hayashi, Daisuke; Sakamoto, Ryosei; Urasaki, Naomitu; Funabashi, Toshihisa

    Wind turbine generators and PV system generate fluctuating power condition. Therefore, the fluctuating power causes frequency and voltage fluctuations. To solve this problem, we propose a new power supply system with using renewable energy in isolated island. The feature of this system is to use an aqua electrolyzer and fuel cell. The operation of suggested system absorbs fluctuating power of renewable energy. Furthermore, the proposed system is able to generate reactive power and active power with using three-phase inverter. The effectiveness of the proposed power supply system is shown through simulation results in this paper.

  17. The thermal circuit of a nuclear power station's unit built around a supercritical-pressure water-cooled reactor

    NASA Astrophysics Data System (ADS)

    Silin, V. A.; Zorin, V. M.; Tagirov, A. M.; Tregubova, O. I.; Belov, I. V.; Povarov, P. V.

    2010-12-01

    Main results obtained from calculations of the steam generator and thermal circuit of the steam turbine unit for a nuclear power unit with supercritical-pressure water coolant and integral layout are presented. The obtained characteristics point to the advisability of carrying out further developments of this promising nuclear power technology.

  18. Effect of gas thermal lens in laser resonator on beam mode of high-power CO2 laser

    Microsoft Academic Search

    Zhiyong Wang; Jiming Chen; Yong Bao; Tao Chen; Tiechuan Zuo

    2002-01-01

    For gas laser, working gases in resonator have two interaction with laser. One is to generate excited radiation, the other is to affect the propagation of the laser beam. For the latter, gas thermal lens has great effect on laser beam in the resonator for high-power CO2 laser because of long resonator and high laser power in resonator. In this

  19. Two dimensional thermal and charge mapping of power thyristors

    NASA Technical Reports Server (NTRS)

    Hu, S. P.; Rabinovici, B. M.

    1975-01-01

    The two dimensional static and dynamic current density distributions within the junction of semiconductor power switching devices and in particular the thyristors were obtained. A method for mapping the thermal profile of the device junctions with fine resolution using an infrared beam and measuring the attenuation through the device as a function of temperature were developed. The results obtained are useful in the design and quality control of high power semiconductor switching devices.

  20. Spin current generated by thermally driven ultrafast demagnetization

    NASA Astrophysics Data System (ADS)

    Choi, Gyung-Min; Min, Byoung-Chul; Lee, Kyung-Jin; Cahill, David G.

    2014-07-01

    Spin current is the key element for nanoscale spintronic devices. For ultrafast operation of such nano-devices, generation of spin current in picoseconds, a timescale that is difficult to achieve using electrical circuits, is highly desired. Here we show thermally driven ultrafast demagnetization of a perpendicular ferromagnet leads to spin accumulation in a normal metal and spin transfer torque in an in-plane ferromagnet. The data are well described by models of spin generation and transport based on differences and gradients of thermodynamic parameters. The temperature difference between electrons and magnons is the driving force for spin current generation by ultrafast demagnetization. On longer timescales, a few picoseconds following laser excitation, we also observe a small contribution to spin current by a temperature gradient and the spin-dependent Seebeck effect.

  1. Direct plasmadynamic conversion of plasma thermal power to electricity

    Microsoft Academic Search

    Robert M. Mayo; Randell L. Mills

    2002-01-01

    The generation of electrical energy using direct plasmadynamic conversion (PDC) is studied experimentally for small-scale, chemically-assisted plasmas (CA-plasma) for the first time. Glow discharge and microwave-generated plasma sources are operated at power levels on the order of a few to 50 W in the discharge case and up to 12.83 W\\/cm3 in the microwave case. Extracted power approaching 1\\/4 W

  2. Neural-net based real-time economic dispatch for thermal power plants

    SciTech Connect

    Djukanovic, M.; Milosevic, B. [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems] [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems; Calovic, M. [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering] [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering; Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)] [Electric Power Research Inst., Palo Alto, CA (United States)

    1996-12-01

    This paper proposes the application of artificial neural networks to real-time optimal generation dispatch of thermal units. The approach can take into account the operational requirements and network losses. The proposed economic dispatch uses an artificial neural network (ANN) for generation of penalty factors, depending on the input generator powers and identified system load change. Then, a few additional iterations are performed within an iterative computation procedure for the solution of coordination equations, by using reference-bus penalty-factors derived from the Newton-Raphson load flow. A coordination technique for environmental and economic dispatch of pure thermal systems, based on the neural-net theory for simplified solution algorithms and improved man-machine interface is introduced. Numerical results on two test examples show that the proposed algorithm can efficiently and accurately develop optimal and feasible generator output trajectories, by applying neural-net forecasts of system load patterns.

  3. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

    SciTech Connect

    Paul Tubel

    2004-02-01

    The development work during this quarter was focused in the assembly of the downhole power generator hardware and its electronics module. The quarter was also spent in the development of the surface system electronics and software to extract the acoustic data transmitted from downhole to the surface from the noise generated by hydrocarbon flow in wells and to amplify very small acoustic signals to increase the distance between the downhole tool and the surface receiver. The tasks accomplished during this report period were: (1) Assembly of the downhole power generator mandrel for generation of electrical power due to flow in the wellbore. (2) Test the piezoelectric wafers to assure that they are performing properly prior to integrating them to the mechanical power generator mandrel. (3) Coat the power generator wafers to prevent water from shorting the power generator wafers. (4) Test of the power generator using a water tower and an electric pump to create a water flow loop. (5) Test the power harvesting electronics module. (6) Upgrade the signal condition and amplification from downhole into the surface system. (7) Upgrade the surface processing system capability to process data faster. (8) Create a new filtering technique to extract the signal from noise after the data from downhole is received at the surface system.

  4. NATURE'S STRATEGY FOR OPTIMIZING POWER GENERATION IN INSECT FLIGHT MUSCLE

    Microsoft Academic Search

    David Maughan; Jim Vigoreaux

    The most important mechanical function of the actomyosin motor in striated muscles is to generate power, particularly in systems that operate in an oscillatory manner. Since all striated muscles have the same basic motor protein (myosin II), the question arises as to what structural modifications of the sarcomere have evolved to allow oscillatory work and power generated by the motor

  5. ENERGY PAYBACK OPTIMIZATION OF THERMOELECTRIC POWER GENERATOR SYSTEMS

    E-print Network

    in distributed power generation and waste heat recovery. Thermoelectrics, due to their moderate energy conversion and the heat sink. Thermoelectric element aspect ratio and fill factor are found to be key parameters a fractional area of ~1%. The role of the substrate heat spreading for thermoelectric power generation

  6. INTEGRATED POWER GENERATION SYSTEMS FOR COAL MINE WASTE METHANE UTILIZATION

    Microsoft Academic Search

    Peet M. Soot; Dale R. Jesse; Michael E. Smith

    2005-01-01

    An integrated system to utilize the waste coal mine methane (CMM) at the Federal No. 2 Coal Mine in West Virginia was designed and built. The system includes power generation, using internal combustion engines, along with gas processing equipment to upgrade sub-quality waste methane to pipeline quality standards. The power generation has a nominal capacity of 1,200 kw and the

  7. Optimal pricing of non-utility generated electric power

    Microsoft Academic Search

    Shams N. Siddiqi; Martin L. Baughman

    1994-01-01

    The importance of an optimal pricing policy for pricing nonutility generated power is pointed out in this paper. An optimal pricing policy leads to benefits for all concerned: the utility, industry, and the utility's other customers. In this paper, it is shown that reliability differentiated real-time pricing provides an optimal nonutility generated power pricing policy, from a societal welfare point

  8. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    Microsoft Academic Search

    LC BROWN; GE BESENBRUCH; KR SCHULTZ; JF FUNK; PS PICKARD; AC MARSHALL; SK SHOWALTER

    2003-01-01

    OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of

  9. Frequency optimization for direct drive synchronous current power generator

    Microsoft Academic Search

    Erik Segergren; Karin Nilsson; Mats Leijon

    2005-01-01

    The objective of this paper is to theoretically demonstrate how the operational frequency affects the efficiency of a low-speed generator. Due to the varying nature of underwater currents, the voltage from a current power converter has to be rectified first and then digitally reconverted into a stable alternating current. When designing a direct drive generator for water current power conversion,

  10. Study of Thermal Control Systems for orbiting power systems

    NASA Technical Reports Server (NTRS)

    Howell, H. R.

    1981-01-01

    Thermal control system designs were evaluated for the 25 kW power system. Factors considered include long operating life, high reliability, and meteoroid hazards to the space radiator. Based on a cost advantage, the bumpered pumped fluid radiator is recommended for the initial 25 kW power system and intermediate versions up to 50 kW. For advanced power systems with heat rejection rates above 50 kW the lower weight of the advanced heat pipe radiator offsets the higher cost and this design is recommended. The power system payloads heat rejection allocations studies show that a centralized heat rejection system is the most weight and cost effective approach. The thermal interface between the power system and the payloads was addressed and a concept for a contact heat exchanger that eliminates fluid transfer between the power system and the payloads was developed. Finally, a preliminary design of the thermal control system, with emphasis on the radiator and radiator deployment mechanism, is presented.

  11. Thermal behavior of BAW filters at high RF power levels.

    PubMed

    Wunnicke, Olaf; van der Wel, Paul J; Strijbos, Remco C; de Bruijn, Frank

    2009-12-01

    The temperature increase of bulk acoustic wave filters at high RF power levels has been investigated. Self-heating due to power dissipation in the filter leads to a nonuniform frequency shift of the insertion loss. At the right filter skirt, self-heating is amplified by the negative temperature coefficient of frequency. We demonstrate that at high RF power levels, this can cause thermal instabilities resulting in an abrupt step in the insertion loss. A novel frequency transformation is introduced to describe the nonuniform frequency shift of the insertion loss as well as the thermal instabilities. A condition for the occurrence of thermal instabilities is derived. It is argued that because of this nonuniform frequency shift at high power levels, accelerated lifetime tests can overestimate the lifetime, if the stress frequency is not compensated for self-heating. Here, the frequency transformation is used to determine the stress frequencies at high RF power levels from low-power S-parameter measurements. PMID:20040405

  12. Future Photovoltaic Power Generation for Space-Based Power Utilities

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Landis, Geoffrey; Hepp, Aloysius; Raffaelle, Ryne

    2002-01-01

    This paper discusses requirements for large earth orbiting power stations that can serve as central utilities for other orbiting spacecraft, or for beaming power to the earth itself. The current state of the art of space solar cells, and a variety of both evolving thin film cells as well as new technologies that may impact the future choice of space solar cells for high power mission applications are addressed.

  13. Analysis of a combined refrigerator-generator space power system

    NASA Technical Reports Server (NTRS)

    Klann, J. L.

    1973-01-01

    Compatibility of the Brayton power and refrigeration cycles is considered. Performance of the power- and cryo-loop is plotted against compressor pressure ratio. The power- and cryo-loop performance is determined by dividing the compressor work between the two loops in proportion to mass flow rate. Cycle efficiency is defined as the ratio of shaft power available in the power loop to the net thermal input from the heat source. The available shaft power is the excess of the power turbine work over the compressor work needed in the power loop. The best power loop efficiency occurred at a compressor pressure ratio of 1.8, and the best cryo-loop performance was at a compressor pressure ratio of 2.1. Good individual cycle performance occurred over a fairly large range in compressor pressure ratio.

  14. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    SciTech Connect

    BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

    2003-06-01

    OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil fuels has trace contaminants (primarily carbon monoxide) that are detrimental to precious metal catalyzed fuel cells, as is now recognized by many of the world's largest automobile companies. Thermochemical hydrogen will not contain carbon monoxide as an impurity at any level. Electrolysis, the alternative process for producing hydrogen using nuclear energy, suffers from thermodynamic inefficiencies in both the production of electricity and in electrolytic parts of the process. The efficiency of electrolysis (electricity to hydrogen) is currently about 80%. Electric power generation efficiency would have to exceed 65% (thermal to electrical) for the combined efficiency to exceed the 52% (thermal to hydrogen) calculated for one thermochemical cycle. Thermochemical water-splitting cycles have been studied, at various levels of effort, for the past 35 years. They were extensively studied in the late 70s and early 80s but have received little attention in the past 10 years, particularly in the U.S. While there is no question about the technical feasibility and the potential for high efficiency, cycles with proven low cost and high efficiency have yet to be developed commercially. Over 100 cycles have been proposed, but substantial research has been executed on only a few. This report describes work accomplished during a three-year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.'' The emphasis of the first phase was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen from water in which the primary energy input is high temperature heat from an advanced nuclear reactor and to select one (or, at most three) for further detailed consideration. During Phase 1, an exhaustive literature search was performed to locate all cycles previously proposed. The cycles located were screened using objective criteria to determine which could benefit, in terms of efficien

  15. Nuclear power generation and fuel cycle report 1997

    SciTech Connect

    NONE

    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.

  16. IR scene image generation from visual image based on thermal database

    NASA Astrophysics Data System (ADS)

    Liao, Binbin; Wang, Zhangye; Ke, Xiaodi; Xia, Yibin; Peng, Qunsheng

    2007-11-01

    In this paper, we propose a new method to generate complex IR scene image directly from the corresponding visual scene image based on material thermal database. For the input visual scene image, we realize an interactive tool based on the combined method of global magic wand and intelligent scissors to segment the object areas in the scene. And the thermal attributes are assigned to each object area from the thermal database of materials. By adopting the scene infrared signature model based on infrared Physics and Heat Transfer, the surface temperature distribution of the scene are calculated and the corresponding grayscale of each area in IR image is determined by our transformation rule. We also propose a pixel-based RGB spacial similarity model to determine the mixture grayscales of residual area in the scene image. To realistically simulate the IR scene, we develop an IR imager blur model considering the effect of different resolving power of visual and thermal imagers, IR atmospheric noise and the modulation transfer function of thermal imager. Finally, IR scene images at different intervals under different weather conditions are generated. Compared with real IR scene images, our simulated results are quite satisfactory and effective.

  17. Assessment of the potential of solar thermal small power systems in small utilities

    NASA Technical Reports Server (NTRS)

    Steitz, P.; Mayo, L. G.; Perkins, S. P., Jr.

    1978-01-01

    The potential economic benefit of small solar thermal electric power systems to small municipal and rural electric utilities is assessed. Five different solar thermal small power system configurations were considered in three different solar thermal technologies. The configurations included: (1) 1 MW, 2 MW, and 10 MW parabolic dish concentrators with a 15 kW heat engine mounted at the focal point of each dish, these systems utilized advanced battery energy storage; (2) a 10 MW system with variable slat concentrators and central steam Rankine energy conversion, this system utilized sensible thermal energy storage; and (3) a 50 MW central receiver system consisting of a field of heliostats concentrating energy on a tower-mounted receiver and a central steam Rankine conversion system, this system also utilized sensible thermal storage. The results are summarized in terms of break-even capital costs. The break-even capital cost was defined as the solar thermal plant capital cost which would have to be achieved in order for the solar thermal plants to penetrate 10 percent of the reference small utility generation mix by the year 2000. The calculated break-even capital costs are presented.

  18. Parabolic Dish Solar Thermal Power Annual Program Review Proceedings

    NASA Technical Reports Server (NTRS)

    Lucas, J. W.

    1982-01-01

    The results of activities of the parabolic dish technology and applications development element of DOE's Solar Thermal Energy System Program are presented. Topics include the development and testing of concentrators, receivers, and power conversion units; system design and development for engineering experiments; economic analysis and marketing assessment; and advanced development activities. A panel discussion concerning industrial support sector requirements is also documented.

  19. Cost and performance evaluation of terrestrial solar thermal power systems

    Microsoft Academic Search

    El Gabalawi

    1982-01-01

    A thorough evaluation of cost and performance of solar thermal power systems is required in order to assess the viability of such systems for commercial applications, particularly before the commitment of large investments to the manufacture of particular systems. Optimization and simulation models can be effectively used for the evaluation and analysis of several varieties of these systems. A cost

  20. Cost and performance evaluation of terrestrial solar thermal power systems

    Microsoft Academic Search

    N. Elgabalawi

    1982-01-01

    A cost optimization model was developed based on relating systems costs to performance and minimizing the system electric energy production costs. The model was applied to systems representing major categories of solar thermal power systems such as the central receiver, the parabolic dish, the line-focusing and the fixed orientation focusing collectors. Several types of engines and energy storage systems were