Science.gov

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. MultiUse solar thermal power generators

    NASA Astrophysics Data System (ADS)

    Abbott, Russell

    2001-02-01

    This paper describes Ontario Engineering International, Inc. (OEI) approach to a solar thermal power generation system using a number of thermal power generation technologies for possible applications to Mars exploration, material processing and for power generation on Earth. The latest power stage and generator design presented here were the culmination of studies covering a wide variety of generator configurations and operating parameters. The many steps and rationale leading to OEI's design evolution and materials selection will not be repeated here except for a description of OEI's latest design, including a heat source support scheme and power stage configuration. OEI's performance predictions were based on its techniques for the thermal analyses of thermal power generators. The analytical results indicate that the OEI power system design, operating within the stipulated solar input and temperature limits and well within its mass goals, can yield power outputs and system efficiencies that substantially exceed existing solar power generation technologies. The calculated efficiency for a cascaded power generation system is estimated to be 42% for a DC output or 37% for an AC power output. With the addition of a thermal storage medium power can be provided on a continuous basis during any shadow period. Recent advances in thermal power generation technologies have now progressed to the point where a solar thermal power generation system can be fabricated. This system can provide terrestrial power generation capacity in remote areas and provide a means for load leveling in the commercial power grid. This system is also adaptable for material processing and/or life-support on Mars. .

  3. Thermoelectric power generator for variable thermal power source

    SciTech Connect

    Bell, Lon E; Crane, Douglas Todd

    2015-04-14

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

  4. Apparatus and method for thermal power generation

    DOEpatents

    Cohen, Paul; Redding, Arnold H.

    1978-01-01

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

  5. Method and apparatus for thermal power generation

    DOEpatents

    Mangus, James D.

    1979-01-01

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

  6. 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.

  7. 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.

  8. Thermal energy storage for power generation applications

    NASA Astrophysics Data System (ADS)

    Drost, M. K.; Antoniak, Zen I.; Brown, D. R.

    1990-03-01

    Studies strongly indicate that the United States will face widespread electrical power constraints in the 1990s. In many cases, the demand for increased power will occur during peak and intermediate demand periods. While natural gas is currently plentiful and economically attractive for meeting peak and intermediate loads, the development of a coal-fired peaking option would give utilities insurance against unexpected supply shortages or cost increases. This paper discusses a conceptual evaluation of using thermal energy storage (TES) to improve the economics of coal-fired peak and intermediate load power generation. The use of TES can substantially improve the economic attractiveness of meeting peak and intermediate loads with coal-fired power generation. In this case, conventional pulverized coal combustion equipment is continuously operated to heat molten nitrate salt, which is then stored. During peak demand periods, hot salt is withdrawn from storage and used to generate steam for a Rankine steam power cycle. This allows the coal-fired salt heater to be approximately one-third the size of a coal-fired boiler in a conventional cycling plant. The general impact is to decouple the generation of thermal energy from its conversion to electricity. The present study compares a conventional cycling pulverized coal-fired power plant to a pulverized coal-fired plant using nitrate salt TES. The study demonstrates that a coal-fired salt heater is technically feasible and should be less expensive than a similar coal-fired boiler. The results show the use of nitrate salt TES reduced the levelized cost of power by between 5 and 24 percent, depending on the operating schedule.

  9. 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.

  10. Device for thermal transfer and power generation

    DOEpatents

    Weaver, Stanton Earl; Arik, Mehmet

    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.

  11. Thermal analysis of thermoelectric power generator; Including thermal stresses

    NASA Astrophysics Data System (ADS)

    Al-Merbati, Abdulrahman Salman

    In recent years, the energy demand is increasing leads to use and utilization of clean energy becomes target of countries all over the world. Thermoelectric generator is one type of clean energy generators which is a solid-state device that converts heat energy into electrical energy through the Seebeck effect. With availability of, heat from different sources such as solar energy and waste energy from systems, thermoelectric research becomes important research topic and researchers investigates efficient means of generating electricity from thermoelectric generators. One of the important problems with a thermoelectric is development of high thermal stresses due to formation of temperature gradient across the thermoelectric generator. High thermal stress causes device failure through cracks or fractures and these short comings may reduce the efficiency or totally fail the device. In this thesis work, thermodynamic efficiency and thermal stresses developed in thermoelectric generator are analyzed numerically. The bismuth telluride (Bi2Te3) properties are used in simulation. Stress levels in thermoelectric device pins are computed for various pin geometric configurations. MASTER.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Analytical investigation of thermal barrier coatings on advanced power generation gas turbines

    NASA Technical Reports Server (NTRS)

    Amos, D. J.

    1977-01-01

    An analytical investigation of present and advanced gas turbine power generation cycles incorporating thermal barrier turbine component coatings was performed. Approximately 50 parametric points considering simple, recuperated, and combined cycles (including gasification) with gas turbine inlet temperatures from current levels through 1644K (2500 F) were evaluated. The results indicated that thermal barriers would be an attractive means to improve performance and reduce cost of electricity for these cycles. A recommended thermal barrier development program has been defined.

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

    EPA Science Inventory

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

  20. Power generation by thermally assisted electroluminescence: like optical cooling, but different

    NASA Astrophysics Data System (ADS)

    Buckner, Benjamin D.; Heeg, Bauke

    2008-02-01

    Thermally assisted electro-luminescence may provide a means to convert heat into electricity. In this process, radiation from a hot light-emitting diode (LED) is converted to electricity by a photovoltaic (PV) cell, which is termed thermophotonics. Novel analytical solutions to the equations governing such a system show that this system combines physical characteristics of thermophotovoltaics (TPV) and the inverse process of laser cooling. The flexibility of having both adjustable bias and load parameters may allow an optimized power generation system based on this concept to exceed the power throughput and efficiency of TPV systems. Such devices could function as efficient solar thermal, waste heat, and fuel-based generators.

  1. Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines

    NASA Technical Reports Server (NTRS)

    Amos, D. J.

    1977-01-01

    An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

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

    SciTech Connect

    Yomogida, D.E.; Thinh, Ngo Dinh

    1995-09-01

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

  3. Construction of power-generating gas turbine units with the use of efficient thermal schemes

    NASA Astrophysics Data System (ADS)

    Ermolenko, D. I.; Gusev, A. A.; Zhuravlev, Yu. I.; Lesnichenko, A. Ya.; Tsai, S. S.

    2008-08-01

    The design features of GTE-30 and GTE-50 power-generating gas turbines, the basic thermal circuit of a PGU-90 (150) combined-cycle plant, and a layout solution for a cogeneration station built around a gas-turbine unit are considered.

  4. Industry sector analysis, Ecuador: Thermal power generating equipment. Export trade information

    SciTech Connect

    Not Available

    1993-04-01

    The article is derived from a report titled: The Thermal Power Generation Equipment Market in Ecuador, dated April 1993, prepared by P. Zaldumbide, A. Moreno, and N. Ordonez, American Embassy - Quito. The article consists of 10 pages and contains the following subtopics: Overview; Statistical Data; Market Assessment; Best Sales Prospects; Competitive Situation; Market Access; and Trade Promotion Opportunities.

  5. 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.

  6. Quantity, Quality, and Availability of Waste Heat from United States Thermal Power Generation.

    PubMed

    Gingerich, Daniel B; Mauter, Meagan S

    2015-07-21

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJ(th) of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 °C. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040. PMID:26061407

  7. Automated determinations of selenium in thermal power plant wastewater by sequential hydride generation and chemiluminescence detection.

    PubMed

    Ezoe, Kentaro; Ohyama, Seiichi; Hashem, Md Abul; Ohira, Shin-Ichi; Toda, Kei

    2016-02-01

    After the Fukushima disaster, power generation from nuclear power plants in Japan was completely stopped and old coal-based power plants were re-commissioned to compensate for the decrease in power generation capacity. Although coal is a relatively inexpensive fuel for power generation, it contains high levels (mgkg(-1)) of selenium, which could contaminate the wastewater from thermal power plants. In this work, an automated selenium monitoring system was developed based on sequential hydride generation and chemiluminescence detection. This method could be applied to control of wastewater contamination. In this method, selenium is vaporized as H2Se, which reacts with ozone to produce chemiluminescence. However, interference from arsenic is of concern because the ozone-induced chemiluminescence intensity of H2Se is much lower than that of AsH3. This problem was successfully addressed by vaporizing arsenic and selenium individually in a sequential procedure using a syringe pump equipped with an eight-port selection valve and hot and cold reactors. Oxidative decomposition of organoselenium compounds and pre-reduction of the selenium were performed in the hot reactor, and vapor generation of arsenic and selenium were performed separately in the cold reactor. Sample transfers between the reactors were carried out by a pneumatic air operation by switching with three-way solenoid valves. The detection limit for selenium was 0.008 mg L(-1) and calibration curve was linear up to 1.0 mg L(-1), which provided suitable performance for controlling selenium in wastewater to around the allowable limit (0.1 mg L(-1)). This system consumes few chemicals and is stable for more than a month without any maintenance. Wastewater samples from thermal power plants were collected, and data obtained by the proposed method were compared with those from batchwise water treatment followed by hydride generation-atomic fluorescence spectrometry. PMID:26653491

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

    DOEpatents

    Bowman, Charles D.

    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.

  9. 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.

  10. Thermal Analysis of Step 2 GPHS for Next Generation Radioisotope Power Source Missions

    NASA Astrophysics Data System (ADS)

    Pantano, David R.; Hill, Dennis H.

    2005-02-01

    The Step 2 General Purpose Heat Source (GPHS) is a slightly larger and more robust version of the heritage GPHS modules flown on previous Radioisotope Thermoelectric Generator (RTG) missions like Galileo, Ulysses, and Cassini. The Step 2 GPHS is to be used in future small radioisotope power sources, such as the Stirling Radioisotope Generator (SRG110) and the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). New features include an additional central web of Fine Weave Pierced Fabric (FWPF) graphite in the aeroshell between the two Graphite Impact Shells (GIS) to improve accidental reentry and impact survivability and an additional 0.1-inch of thickness to the aeroshell broad faces to improve ablation protection. This paper details the creation of the thermal model using Thermal Desktop and AutoCAD interfaces and provides comparisons of the model to results of previous thermal analysis models of the heritage GPHS. The results of the analysis show an anticipated decrease in total thermal gradient from the aeroshell to the iridium clads compared to the heritage results. In addition, the Step 2 thermal model is investigated under typical SRG110 boundary conditions, with cover gas and gravity environments included where applicable, to provide preliminary guidance for design of the generator. Results show that the temperatures of the components inside the GPHS remain within accepted design limits during all envisioned mission phases.

  11. 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.

  12. The challenges of fuel options for the new generation of Indian thermal power plants

    SciTech Connect

    Roy, C.; Sanyal, A.

    1999-07-01

    The selection of fuel supply is probably the most important challenge a potential power project developer for a new Indian thermal power plant has to face when considering the overall project economics. The paper reviews the essential issues and the effect of fuel selection on project costs of the new generation of thermal power plants of India. Coal, lignite and natural gas are India's indigenous fossil fuel resources for power generation. The country has a modest reserve of petroleum crude. India is the world's third largest coal producer and has 205 billion metric tons of assessed and 73 billion tons of proven reserves. The indigenous supply of petroleum is unlikely to improve much in the near future. Liquid fuel based generation is therefore marginal in the country. Although coal will continue to be the mainstay fuel, there is a short term need to examine the possibility of using alternative fuels due to two basic reasons: (a) A 70 million tons of shortfall is forecast for the power sector during the 1997--2002 period. The deficit has to be met by either import of coal or other fuels. Development of new mines is a long gestation activity. (b) There is an uneven geographical location of Indian coal reserves. For the load centers, which are distant from the indigenous coal sources, use of alternative fuel could also prove to be economical in the long term. Moving coal will become harder in view of the high demands being placed on the railways by many other sectors.

  13. Power generation costs and ultimate thermal hydraulic power limits in hypothetical advanced designs with natural circulation

    SciTech Connect

    Duffey, R.B.; Rohatgi, U.S.

    1996-12-31

    Maximum power limits for hypothetical designs of natural circulation plants can be described analytically. The thermal hydraulic design parameters are those which limit the flow, being the elevations, flow areas, and loss coefficients. WE have found some simple ``design`` equations for natural circulation flow to power ratio, and for the stability limit. The analysis of historical and available data for maximum capacity factor estimation shows 80% to be reasonable and achievable. The least cost is obtained by optimizing both hypothetical plant performance for a given output,a nd the plant layout and design. There is also scope to increase output and reduce cost by considering design variations of primary and secondary pressure, and by optimizing component elevations and loss coefficients. The design limits for each are set by stability and maximum flow considerations, which deserve close and careful evaluation.

  14. 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.

  15. 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.

  16. Solar thermal power generation: a bibliography with abstracts. Quarterly update, October-December 1979

    SciTech Connect

    Not Available

    1980-04-01

    This annotated bibliography contains the following subjects: energy overviews, solar overviews, energy conservation, economics and law, solar thermal power, thermionic and thermoelectric, ocean thermal energy conversion, biomass and photochemical energy, and large-scale photovoltaics. (MHR)

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

    SciTech Connect

    Reddy, Ramana G.

    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.

  18. Metal Hydride Thermal Storage: Reversible Metal Hydride Thermal Storage for High-Temperature Power Generation Systems

    SciTech Connect

    2011-12-05

    HEATS Project: PNNL is developing a thermal energy storage system based on a Reversible Metal Hydride Thermochemical (RMHT) system, which uses metal hydride as a heat storage material. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. PNNL’s metal hydride material can reversibly store heat as hydrogen cycles in and out of the material. In a RHMT system, metal hydrides remain stable in high temperatures (600- 800°C). A high-temperature tank in PNNL’s storage system releases heat as hydrogen is absorbed, and a low-temperature tank stores the heat until it is needed. The low-cost material and simplicity of PNNL’s thermal energy storage system is expected to keep costs down. The system has the potential to significantly increase energy density.

  19. Thermally cascaded thermoelectric generator

    NASA Technical Reports Server (NTRS)

    Flaherty, R.

    1970-01-01

    High efficiency thermoelectric generator utilizes a high-temperature thermoelectric material in thermal series with a low-temperature material. A thermally cascaded generator increases system efficiency.

  20. 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.

  1. Empirical analysis of production and technology using heterogeneous capital: thermal-electric power generation

    SciTech Connect

    Bushe, D.M.

    1981-01-01

    A putty-clay model is developed for thermal-electric power generation where the heterogeneous characteristics of the capital equipment are explicitly represented. Engineering-design specifications and thermodynamics principles are employed to link increases in process efficiency to embodied technical change. This information is used to elect a set of design characteristics which define classes, or cells, of technologically homogeneous generating units. The model is used to examine changes in the production function across different technologies. Technical change is found to influence the parameter values of the ex post input requirements functions rather than to simply displace these functions in a neutral fashion. Within each cell, the savings in fuel (the dominant input) which result from increases in capacity decline as the size of a generating unit approaches maximum capacity within the cell. This suggests that changes in technology were required before further increases in capacity could be economically justified. There is also evidence that the scale of certain units was expanded beyond the level warranted by the associated savings in fuel and labor.

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

    SciTech Connect

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

    1985-09-15

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

    NASA Astrophysics Data System (ADS)

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

    1985-09-01

    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.

  4. 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.

  5. Analysis and optimization of a solar thermal power generation and desalination system using a novel approach

    NASA Astrophysics Data System (ADS)

    Torres, Leovigildo

    Using a novel approach for a Photovoltaic-Thermal (PV-T) panel system, analytical and optimization analyses were performed for electricity generation as well as desalinated water production. The PV-T panel was design with a channel under it where seawater would be housed at a constant pressure of 2.89 psia and ambient temperature of 520°R. The surface of the PV panel was modeled by a high absorption black chrome surface. Irradiation flux on the surface and the heat addition on the saltwater were calculated hourly between 9:00am and 6:00pm. At steady state conditions, the saturation temperature of 600°R was limited at PV tank-channel outlet and the evaporation rate was measured to be 2.53 lbm/hr-ft2. The desorbed air then passed through a turbine, where it generated electrical power at 0.84 Btu/hr, condensing into desalinated water at the outlet. Optimization was performed for max capacity yield based on available temperature distribution of 600°R to 1050°R at PV tank-channel outlet. This gave an energy generation range for the turbine of 0.84 Btu/hr to 3.84 Btu/hr, while the desalinated water production range was 2.53 lbm/hr-ft2 to 10.65 lbm/hr-ft2. System efficiency was found to be between 7.5% to 24.3%. Water production efficiency was found to be 40% to 43%.

  6. 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.

  7. 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…

  8. 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

  9. Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators.

    PubMed

    Bernardi, Michael P; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

    2015-01-01

    The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses. PMID:26112658

  10. Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators

    NASA Astrophysics Data System (ADS)

    Bernardi, Michael P.; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

    2015-06-01

    The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses.

  11. Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators

    PubMed Central

    Bernardi, Michael P.; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

    2015-01-01

    The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses. PMID:26112658

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

    PubMed

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

    2015-08-19

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

  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. An improved absorption generator for solar-thermal powered heat pumps. Part 1: Feasibility

    SciTech Connect

    Fineblum, S.

    1997-12-31

    Solar heated absorption chiller installations have been, typically, very expensive for their rating. The need to keep the liquid flowing within the collectors as cool as possible to enhance collector thermal efficiency, conflicts with the need to operate the absorption chiller at a higher temperature. The compromise usually results in poor collector efficiency as well as a relatively poor specific chiller effect. The proposed vortex generator permits a heat pump to operate efficiently with relatively low temperature solar heated fluid (70--80 C). As a result, the collectors are cooler and much more efficient. In addition, the specific heat pumping capacity is about 27% greater than conventional systems operating at the same reduced generator temperatures and, therefore, a smaller chiller is required. The economic consequences of these benefits will be presented in Part 2.

  15. An improved absorption generator for solar-thermal powered heat pumps. Part 2: Energy and economics

    SciTech Connect

    Fineblum, S.

    1997-12-31

    Solar heated absorption chiller installations have been very expensive for their rating. To enhance collector thermal efficiency the liquid flowing within the collectors must be kept as cool as possible. However, there is also a need to operate the absorption reported earlier. The compromise usually results in poor collector efficiency as well as a relatively poor specific chiller effect. The proposed vortex generator permits a heat pump to operate efficiently with relatively low temperature solar heated fluid (70--80 C). As a result, the collectors are cooler and more efficient. As noted in Part 1, the specific heat pumping capacity is about 27% greater than conventional systems operating at the same reduced generator temperatures. Therefore, a smaller, less expensive chiller is required. The reduced investment in solar arrays and absorption chillers is estimated along with a range of paybacks.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  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. 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

  19. 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

  20. Development of a Thermal Buffering Device to Cope with Temperature Fluctuations for a Thermoelectric Power Generator

    NASA Astrophysics Data System (ADS)

    Mizuno, Kuniaki; Sawada, Kazunori; Nemoto, Takashi; Iida, Tsutomu

    2012-06-01

    To stabilize the heat input to a thermoelectric generator (TEG) and protect it from large temperature fluctuations, a thermal buffering device (TBD) was fabricated and examined using a typical Bi-Te TEG module and a brand-new Mg2Si TEG module. The TBD comprises two adjoining heat storage containers, each containing different alloys, which can be optimized for the temperature range of the TEG. The combination of two alloys in series diminishes the thermal fluctuations, stabilizing the heat input to the TEG module. This is achieved by having two metallic materials with large enthalpies of fusion that can be placed between the heat source and the TEG. The combination of the two alloys can be optimized for the temperature ranges of Bi-Te, Pb-Te, or Co-Sb. For the Bi-Te TEG, 15Al-85Zn and 30Sn-70Zn alloys were used for the heat source side and the TEG side, respectively. The corresponding alloys for the Mg2Si TEG were 20Ni-80Al and 7Si-93Al. With the use of a TBD, the Bi-Te TEG exhibited no notable damage even in the rather high temperature range beyond ˜573 K. For the Mg2Si TEG, no operational damage of the Mg2Si TEG module was observed even with a temperature of 1020 K.

  1. 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.

  2. 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.

  3. 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.

  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. Geothermal Power Generation

    SciTech Connect

    2007-11-15

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

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

    SciTech Connect

    Qui, Songgang; Galbraith, Ross

    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. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. Wind power generating system

    SciTech Connect

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

    1985-03-12

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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. High-power and high-quality, green-beam generation by employing a thermally near-unstable resonator design.

    PubMed

    Bo, Yong; Geng, Aicong; Bi, Yong; Sun, Zhipei; Yang, Xiaodong; Peng, Qinjun; Li, Huiqing; Li, Ruining; Cui, Dafu; Xu, Zuyan

    2006-04-10

    We have obtained green-beam quality of M2 = 6.2 at an average output power of 120 W by intracavity frequency doubling of a diode-side-pumped, Q-switched Nd:YAG rod laser with a repetition rate of 10 kHz and an optical-to-optical conversion efficiency of 15.2%. To achieve high-beam quality at high average power, the laser employs a thermally near-unstable resonator design with two-rod birefringence compensation in an L-shaped flat-flat cavity. The output power fluctuation of the green laser remains less than 0.9% in 4 h. PMID:16623247

  18. 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.

  19. Recovering heat when generating power

    SciTech Connect

    Ganapathy, V.

    1993-02-01

    Intelligent use of heat-recovery stream generators (HRSGs) is vital for the efficient operation of cogeneration plants, which furnish both thermal energy (usually in the form of steam) and electric energy. HRSGs are similarly important in combined-cycle power plants, in which the thermal energy rejected from the primary electric-power-generation step is harnessed (as discussed below) to produce additional electrical energy. In these facilities, the HRSG is typically heated by gas-turbine exhaust. Natural gas is the fuel most widely used for gas turbines in the U.S., whereas fuel oil is the main fuel in other countries. Depending on the amount of steam to be produced, HRSGs for gas-turbine-exhaust applications may be unfired, supplementary-fired or furnace fired. The paper describes these three options; the pressure drop encountered in all three systems; the Cheng cycle; catalytic reduction of nitrogen oxides and CO; and performance testing.

  20. 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

  1. 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.

  2. Ocean thermal gradient hydraulic power plant.

    PubMed

    Beck, E J

    1975-07-25

    Solar energy stored in the oceans may be used to generate power by exploiting ploiting thermal gradients. A proposed open-cycle system uses low-pressure steam to elevate vate water, which is then run through a hydraulic turbine to generate power. The device is analogous to an air lift pump. PMID:17813707

  3. Magma energy for power generation

    SciTech Connect

    Dunn, J.C.

    1987-01-01

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

  4. Generating a representative signal of coal ash content to anticipate combustion control in a thermal power station.

    PubMed

    Prieto-Fernández, Ismael; Santurio-Díaz, José M; Folgueras-Díaz, Belén; López-Bobo, M Rosario; Fernández-Viar, Pedro

    2004-05-01

    This paper describes the possibilities of continuously measuring coal ash in the boiler feeding circuit of a thermal power station so that the measurement can be used as a signal for the boiler combustion control system. An installation was designed, at semi-industrial scale, that could faithfully reproduce the operation of a belt feeder. In order to measure the ash content, a natural radioactivity meter was installed and a large number of coal samples with different ranks and grain sizes were tested, eventually showing the possibility of achieving the objective. PMID:15082052

  5. Peak power ratio generator

    DOEpatents

    Moyer, Robert D.

    1985-01-01

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

  6. Peak power ratio generator

    DOEpatents

    Moyer, R.D.

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

  7. 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.

  8. Oscillating fluid power generator

    SciTech Connect

    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.

  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. 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

    2015-06-01

    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 μm was detected after a high-temperature durability test of n-type In0.25Co3.95Ni0.05Sb12 material at 773 K in air for 7 days.

  11. Thermal batteries for aircraft emergency power

    NASA Astrophysics Data System (ADS)

    Ryan, David M.

    1993-02-01

    Thermal batteries are being proposed for the Emergency Power System for aircraft. Thermal batteries are a reserve type battery which is essentially inert until activated. Thermal batteries can generate full power in several seconds and nominally produce 20 WHr/Ib and operate over a temperature range of -65 deg to 165 deg. Thermal batteries have a proven field storage life exceeding 25 years. They contain no liquids, can be maintained at any attitude, operate at any altitude, and do not leak any toxic or noxious materials. Expended thermal batteries contain no lead or cadmium and do not represent a significant disposal or environmental problem. Thermal batteries have a thirty year history of excellent performance providing on-board power for missiles and other weapons and have a proven safety record with no field injuries ever. Thermal batteries have a relatively low cost of initial ownership and require no maintenance.

  12. Thermal batteries for aircraft emergency power

    SciTech Connect

    Ryan, D.M.

    1993-01-01

    Thermal batteries are being proposed for the Emergency Power System for aircraft. Thermal batteries are a reserve type battery which is essentially inert until activated. Thermal batteries can generate full power in several seconds and nominally produce 20 WHr/Ib and operate over a temperature range of -65 deg to 165 deg. Thermal batteries have a proven field storage life exceeding 25 years. They contain no liquids, can be maintained at any attitude, operate at any altitude, and do not leak any toxic or noxious materials. Expended thermal batteries contain no lead or cadmium and do not represent a significant disposal or environmental problem. Thermal batteries have a thirty year history of excellent performance providing on-board power for missiles and other weapons and have a proven safety record with no field injuries ever. Thermal batteries have a relatively low cost of initial ownership and require no maintenance.

  13. 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.

  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, 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.

  16. High power microwave generator

    DOEpatents

    Ekdahl, Carl A.

    1986-01-01

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

  17. Numerical Simulation on Measurement of Optical and Thermal Properties for Warm Dense Matter Generated by Isochoric Heating with Pulsed Power Discharge Device

    NASA Astrophysics Data System (ADS)

    KIKUCHI, Takashi; HAYASHI, Ryota; TAKAHASHI, Takuya; TAMURA, Fumihiro; TAKAHASHI, Kazumasa; SASAKI, Toru; ASO, Tsukasa; HARADA, Nob.

    2016-03-01

    Property data in warm dense matter (WDM) are important to optimize implosion dynamics in a fuel pellet of inertial confinement fusion (ICF). A table-top pulsed power discharge device with isochoric heating using a sapphire hollow capillary was proposed, and was used to generate the extreme state of matter with a well-defined condition. We investigated numerically to generate the WDM by using the pulsed power discharge device. The numerical model was developed by time-dependent one-dimensional thermal diffusion with radiative transfer of multi-group approximation, and the numerical simulation was carried out according with the experimental condition. The achieved temperature of the numerical simulation result was confirmed by the previous experimental result. Also, the radiation energy density was shown at each group of the wavelength of emission.

  18. 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.

  19. Waterwheel power generator

    SciTech Connect

    Smith, J.

    1982-08-17

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

  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)

    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.

  1. 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.

  2. 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.

  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. Generation of electrical power

    DOEpatents

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

    1976-01-01

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

  5. Wave powered buoy generator

    SciTech Connect

    Rowe, R.A.

    1985-01-08

    The wave powered buoy generator includes a hollow buoy which has inner and outer surfaces. The buoy is preferably spherical in shape. One or more windings are mounted to the buoy parallel to its surfaces with each winding having a pair of ends. A magnetized device which, is preferably a ball, is located within the buoy for rolling back and forth therein. A device is connected to the ends of the windings for rectifying current flow therefrom. With this arrangement the buoy can be moored in a body of water, and, when there is water motion, the flux lines of the magnetized roller device cut the one or more windings so as to cause electrical current flow to be provided through the rectifying device.

  6. Wave powered buoy generator

    SciTech Connect

    Rowe, R.A.

    1982-12-02

    The wave powered buoy generator includes a hollow buoy which has inner and outer surfaces. The buoy is preferably spherical in shape. One or more windings are mounted to the buoy parallel to its surfaces with each winding havng a pair of ends. A magnetized device which, is preferably a ball, is located within the buoy for rolling back and forth therein. A device is connected to the ends of the windings for rectifying current flow therefrom. With this arrangement the buoy can be moored in a body of water, and, when there is water motion, the flux lines of the magnetized roller device cut the one or more windings so as to cause electrical current flow to be provided through the rectifying device.

  7. 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.

  8. Dynamic power systems for power generation

    SciTech Connect

    English, R.E.

    1984-04-01

    The characteristics of dynamic power systems have considerable potential value, especially for the space station. The base of technology that makes these dynamic power systems practical is reviewed. The following types of power-generating systems are examined herein: organic Rankine cycle, potassium Rankine cycle, Brayton cycle, and Stirling cycle.

  9. 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.

  10. Selecting the thermal circuit and profile of a Russian large new-generation power-generating gas turbine unit and a combined-cycle plant built around it

    NASA Astrophysics Data System (ADS)

    Favorskii, O. N.; Polishchuk, V. L.

    2010-02-01

    Proposals on the most advisable lines in which the Russian industry can develop advanced new-generation gas-turbine units and combined-cycle plants competitive in the first half of the 21st century are formulated.

  11. 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.

  12. Levelized Power Generation Cost Codes

    Energy Science and Technology Software Center (ESTSC)

    1996-04-30

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

  13. High power microwave generator

    DOEpatents

    Minich, Roger W.

    1988-01-01

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

  14. 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.

  15. 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.

  16. Wind Power Charged Aerosol Generator

    SciTech Connect

    Marks, A.M.

    1980-07-01

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

  17. Tide operated power generating apparatus

    SciTech Connect

    Kertzman, H. Z.

    1981-02-03

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

  18. 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.

  19. Financing Solar Thermal Power Plants

    SciTech Connect

    Price, H. W.; Kistner, R.

    1999-11-01

    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 must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised i n debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies.

  20. Infrared power generation in an insulated environment

    NASA Astrophysics Data System (ADS)

    Schwab, Yosyp; Mann, Harkirat; Lang, Brian; Lancaster, Jarrett; Parise, Ronald; Vincent-Johnson, Anita; Scarel, Giovanna

    2014-03-01

    Alternative energy sources are an increasingly popular field of research, in particular energy harvesting through solar radiation, focusing on infrared (IR) radiation. Exploitation of readily available thermal energy is particularly interesting due to possible widespread applications. This work examines the behavior of thermoelectric devices exposed to infrared radiation in a controlled environment. Thermoelectric power generators work according to the Seebeck effect, where the temperature difference ΔV induced between the two junctions is linearly proportional to the voltage difference ΔT across the two contacts. Our experimental results show that heat and radiation do not activate the same mechanisms in the thermoelectric power generator. Analysis and simulation further support the distinction between the IR and heat power generation. In particular, ΔT and ΔV have a linear and exponential behavior versus time with heat and IR, respectively. Our work is of significant importance for designing IR sensors, detectors, and radiation harvesting devices.

  1. An Isotope-Powered Thermal Storage unit for space applications

    NASA Astrophysics Data System (ADS)

    Lisano, Michael E.; Rose, M. F.

    An Isotope-Powered Thermal Storage Unit (ITSU), that would store and utilize heat energy in a 'pulsed' fashion in space operations, is described. Properties of various radioisotopes are considered in conjunction with characteristics of thermal energy storage materials, to evaluate possible implementation of such a device. The utility of the unit is discussed in light of various space applications, including rocket propulsion, power generation, and spacecraft thermal management.

  2. Small community solar thermal power experiment

    SciTech Connect

    Marriott, A.T.; Kiceniuk, T.

    1980-01-01

    The first solar thermal power plant specifically designed as an alternate source of electric energy for small communities in this country is now in its second phase of development. As a result of Phase I concept definition studies, a decision was made to pursue a parabolic dish system using distributed generation. Both the design approach and the site selection status are described. The concentrator is a parabolic dish developed by the General Electric Company under the Low Cost Concentrator activity within the Module Development element of the JPL Solar Thermal Power Systems Project. It is a first generation concentrator using a reflective film bonded to a reinforced plastic substrate. The receiver is designed to heat an intermediary heat transfer fluid and is a new approach being developed by Ford. The power conversion subsystem will employ a Rankine engine. The Phase II effort will include design, development, and verification testing. This is a two-year activity that will provide a system design including the plant control system and other balance of plant considerations. The verification testing will be at the JPL Edwards AFB Parabolic Dish Test Site. Testing will be conducted at the module level; that is, a complete concentrator, receiver, and engine assembly test is planned. Phase II will follow with fabrication, installation, and operation of the power plant in the selected community to occur in 1983.

  3. Taming power: Generative historical consciousness.

    PubMed

    Winter, David G

    2016-04-01

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

  4. Solid state pulsed power generator

    SciTech Connect

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

    2014-02-11

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

  5. 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.

  6. Kinetics of thermal donor generation in silicon

    NASA Technical Reports Server (NTRS)

    Mao, B.-Y.; Lagowski, J.; Gatos, H. C.

    1984-01-01

    The generation kinetics of thermal donors at 450 C in Czochralski-grown silicon was found to be altered by high-temperature preannealing (e.g., 1100 C for 30 min). Thus, when compared with as-grown Si, high-temperature preannealed material exhibits a smaller concentration of generated thermal donors and a faster thermal donor saturation. A unified mechanism of nucleation and oxygen diffusion-controlled growth (based on solid-state plate transformation theory) is proposed to account for generation kinetics of thermal donors at 450 C, in as-grown and high-temperature preannealed Czochralski silicon crystals. This mechanism is consistent with the main features of the models which have been proposed to explain the formation of oxygen thermal donors in silicon.

  7. 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.

  8. D Surface Generation from Aerial Thermal Imagery

    NASA Astrophysics Data System (ADS)

    Khodaei, B.; Samadzadegan, F.; Dadras Javan, F.; Hasani, H.

    2015-12-01

    Aerial thermal imagery has been recently applied to quantitative analysis of several scenes. For the mapping purpose based on aerial thermal imagery, high accuracy photogrammetric process is necessary. However, due to low geometric resolution and low contrast of thermal imaging sensors, there are some challenges in precise 3D measurement of objects. In this paper the potential of thermal video in 3D surface generation is evaluated. In the pre-processing step, thermal camera is geometrically calibrated using a calibration grid based on emissivity differences between the background and the targets. Then, Digital Surface Model (DSM) generation from thermal video imagery is performed in four steps. Initially, frames are extracted from video, then tie points are generated by Scale-Invariant Feature Transform (SIFT) algorithm. Bundle adjustment is then applied and the camera position and orientation parameters are determined. Finally, multi-resolution dense image matching algorithm is used to create 3D point cloud of the scene. Potential of the proposed method is evaluated based on thermal imaging cover an industrial area. The thermal camera has 640×480 Uncooled Focal Plane Array (UFPA) sensor, equipped with a 25 mm lens which mounted in the Unmanned Aerial Vehicle (UAV). The obtained results show the comparable accuracy of 3D model generated based on thermal images with respect to DSM generated from visible images, however thermal based DSM is somehow smoother with lower level of texture. Comparing the generated DSM with the 9 measured GCPs in the area shows the Root Mean Square Error (RMSE) value is smaller than 5 decimetres in both X and Y directions and 1.6 meters for the Z direction.

  9. 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 project.

  10. 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.

  11. 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.

  12. Investigation of thermal plasma generator of technological function

    NASA Astrophysics Data System (ADS)

    Anshakov, A. S.; Urbakh, E. K.; Cherednichenko, V. S.; Kuzmin, M. G.; Urbakh, A. E.

    2015-11-01

    Experimental results on energy characteristics of electric-arc plasma generator for heating technical nitrogen with the power of up to 500 kW are presented. The features of arc discharge glow, thermal efficiency, and service life of the electrodes were determined under the regime of melting the metallurgical raw material in the test plasma electric furnace.

  13. 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.

  14. Windmill having thermal and electric power output

    SciTech Connect

    Kenney, C.E.

    1980-11-25

    A windmill is described which has thermal and electric power output and includes windmill blades rotatably mounted and connected to a speed increaser mechanism of gears and shafts and a centrifugal compressor connected to the windmill thru the speed increaser to be driven by virtue of the wind applied to the blades of the windmill itself. A directional control is connected to the windmill head to have the windmill blades face into the wind, as desired. The compressor is connected to an insulated heat storage tank which contains storage material, such as brick, and the compressor discharge velocity and pressure difference are converted to heat, and the compressor fluid is returned to the compressor thru a screen which protects the compressor, and there is a flow control which automatically compensates for changes in density of the circulated air or compressor fluid. Also, a gas turbine generator can be connected with the compressor to be driven thereby, and electric elements could be connected with the generator for producing electricity. Two other embodiments show an impeller type of air brake and a valve and a heat-sensitive control, for generating heat or power.

  15. 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.

  16. Wind wheel electric power generator

    NASA Astrophysics Data System (ADS)

    Kaufman, J. W.

    1980-03-01

    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.

  17. 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

  18. Local control of reactive power by distributed photovoltaic generators

    SciTech Connect

    Chertkov, Michael; Turitsyn, Konstantin; Sulc, Petr; Backhaus, Scott

    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.

  19. Advanced piggyback water power generator

    SciTech Connect

    Wiggs, B.R.

    1988-02-16

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

  20. 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)

  1. Thermal Design of a Thermoelectric Micro-Generator

    NASA Astrophysics Data System (ADS)

    Hama, S.; Yabuki, T.; Tranchant, L.; Miyazaki, K.

    2015-12-01

    In this study, we fabricated micro thermoelectric power generator using freestanding film substrate, and we evaluated the performance of the generator from the standpoint of thermoelectric performance and thermal design. We fabricated a SiNx free-standing film substrate about 5 μm thick on Si wafer, using MEMS processes. Then, we prepared for both p and n type of bismuth telluride thermoelectric thin films by using a coaxial type vacuum arc evaporation method, and annealed for one hour at 573 K. As an electrode, Cu was deposited using a vacuum deposition method. We fabricated the thermoelectric power generator of 5 mm × 5 mm using a shadow mask for the patterning. The fabricated generator can create temperature difference of 22.3 K due to its high thermal resistance of the structure when the heat source temperature is 373 K. The exergy of the thermoelectric device is up to 7%. Therefore, the generator can convert about 0.4% of thermal energy into electric energy, even though the material performance is low with ZT = 0.28. The conversion efficiency is much higher than that of the conventional Π type thermoelectric module. It was possible to get higher performance by the thermal design, which is a more simple way than an improvement of ZT.

  2. Electronic load for testing power generating devices

    NASA Technical Reports Server (NTRS)

    Friedman, E. B.; Stepfer, G.

    1968-01-01

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

  3. Wind power generator and velocimeter

    SciTech Connect

    Chang, D.B.

    1993-06-29

    An electrical power generating apparatus is described comprising: a conduit receptive of fluid flow for channeling the fluid flow along a predetermined path wherein the conduit has a fluid flow input section and a flow region constructed to maintain laminar fluid flow; baffle means disposed in the conduit in the path of the laminar fluid flow and shaped to form vortices in the fluid flow; and a plurality of piezoelectric transducers disposed axially within the flow region in the path of the laminar fluid flow for producing an electrical signal in response to stress created in the transducers by the vortices, wherein a portion of the baffle means is cylindrically shaped, the portion having a predetermined diameter and a longitudinal axis disposed perpendicular to the predetermined path, and wherein the predetermined diameter is selected such that the Reynold's number representative of fluid flow at the baffle is in the range from 40 to 300.

  4. Solar thermal organic rankine cycle for micro-generation

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  5. Scanning thermal plumes. [from power plant condensers

    NASA Technical Reports Server (NTRS)

    Scarpace, F. L.; Madding, R. P.; Green, T., III

    1974-01-01

    In order to study the behavior and effects of thermal plumes associated with the condenser cooling of power plants, thermal line scans are periodically made from aircraft over all power plants along the Wisconsin shore of Lake Michigan. Simultaneous ground truth is also gathered with a radiometer. Some sequential imagery has been obtained for periods up to two hours to study short term variations in the surface temperature of the plume. The article concentrates on the techniques used to analyze thermal scanner data for a single power plant which was studied intensively. The calibration methods, temperature dependence of the thermal scanner, and calculation of the modulation transfer function for the scanner are treated. It is concluded that obtaining quantitative surface-temperature data from thermal scanning is a nontrivial task. Accuracies up to plus or minus 0.1 C are attainable.

  6. Low cost space power generation

    NASA Technical Reports Server (NTRS)

    Olsen, Randall B.

    1991-01-01

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

  7. Wave activated power generation system

    SciTech Connect

    Ono, Y.

    1983-08-09

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

  8. 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.

  9. 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.

  10. Power plant with pressurized-gas generator

    SciTech Connect

    Pfenninger, H.

    1980-04-29

    A power plant essentially comprises a thermal prime mover, a pressurized-gas generator for generating hot producer gas from coal, the producer gas following separation out of dust and sulphur content being utilized as fuel for the power plant. Included is a pressure-charging group consisting of coupled compressor and gas turbine units, the compressor serving to compress air and deliver it to the pressurized gas generator, and the gas turbine being driven by the hot pressurized and unburned producer gas. Two dry-state dust separators for dust entrained in the producer gas are arranged in series in the flow path of the producer gas after leaving the pressurized-gas generator. The first dust separator is a cyclone type which functions to remove coarser particles of the dust and the second separator which is structurally integrated into the gas turbine to remove any dust particles still remaining in the producer gas is constituted by a volute casing located at the inlet end of the turbine which serves as a replacement for the normally used row of guide vanes and which functions to centrifuge out the dust into an annular duct through an entrance gap thereto formed in the outer wall of the turbine ahead of the first row of rotor blading thus to avoid any erosive action on the latter. A second similar annular duct for receiving centrifuged out dust particles can also be provided in the gas flow path immediately after the first row of rotor blading. The hot producer gas following expansion in passing through the turbine accompanied by a drop in temperature but without further cooling is then passed through a dry state porous mass which chemically binds and removes the sulphur content prior to delivery to a combustion chamber component wherein the prime mover is a further gas turbine driving a load such as electrical generator or to a boiler wherein the prime mover is a steam turbine.

  11. 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.

  12. Pv-Thermal Solar Power Assembly

    DOEpatents

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

    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.

  13. 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.

  14. High efficiency power generating system

    SciTech Connect

    Cook, A.; Rice, J.N.; Hitt, D.H.

    1990-10-16

    This patent describes a power generating system. It comprises: a converter for producing an AC output including a fundamental and at least one harmonic of the fundamental in response to applied control signals; a frequency analyzer, having at least one input coupled to the AC output, for providing an analysis of a frequency spectrum of the AC output; a processor, coupled to the frequency analyzer, for calculating a least one switching frequency, each switching frequency being used for transforming a different harmonic within the AC output of the fundamental; a controller, responsive to the at least one calculated switching frequency, for producing control signals at the at least one calculated switching frequency for transforming the at least one harmonic back to the fundamental and control signals for the converter for producing the AC output; a separating filter, coupled to the AC output, for separating the AC output into the fundamental and the at least one harmonic; at least one additional converter, coupled to the at least one harmonic from the converter and to the controller, each converter being switched by control signals from the controller which have a calculated switching frequency for transforming one of the at least one harmonics to the fundamental; and outputs from the at least one converter being combined with the fundamental from the separating filter.

  15. Modeling The Potential For Thermal Concentrating Solar Power Technologies

    SciTech Connect

    Zhang, Yabei; Smith, Steven J.; Kyle, G. Page; Stackhouse, Jr., Paul W.

    2010-10-25

    In this paper we explore the tradeoffs between thermal storage capacity, cost, and other system parameters in order to examine possible evolutionary pathways for thermal Concen-trating Solar Power (CSP) technologies. A representation of CSP performance that is suit-able for incorporation into economic modeling tools is developed. We find that, as the fraction of electricity supplied by CSP technologies grows, the application of thermal CSP technologies might progress from current hybrid plants, to plants with a modest amount of thermal storage, and potentially even to plants with sufficient thermal storage to provide base load generation capacity. The representation of CSP cost and performance developed here was implemented in the ObjECTS MiniCAM long-term integrated assessment model. Datasets for global solar resource characteristics as applied to CSP technology were also developed. The regional and global potential of thermal CSP technologies is examined.

  16. 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.

  17. Alternative biomass sources for thermal energy generation

    NASA Astrophysics Data System (ADS)

    Steensen, Torge; Müller, Sönke; Dresen, Boris; Büscher, Olaf

    2015-04-01

    Traditionally, renewable biomass energy sources comprise forests, agriculture and other large vegetation units. With the increasing demand on those landscape elements, including conflicts of interest to nature conservation and food production, the research focus should also incorporate smaller vegetation entities. In this study, we highlight the availability of small-scale features like roadside vegetation or hedges, which are rarely featured in maps. Roadside vegetation, however, is well known and regularly trimmed to allow the passing of traffic but the cut material is rarely harvested. Here, we combine a remote-sensing-based approach to quantify the seasonal biomass harvests with a GIS-based method to outline optimal transportation routes to, and the location of, storage units and power plants. Our main data source will be ESA's upcoming Sentinel-2 optical satellite. Spatial resolution of 10 meters in the visible and near infrared requires the use of spectral unmixing to derive end member spectra of the targeted biomass objects. Additional stereo-matching and LIDAR measurements allow the accompanying height estimate to derive the biomass volume and its changes over time. GIS data bases from the target areas allow the discrimination between traditional, large features (e.g. forests and agriculture) as well as previously unaccounted for, smaller vegetation units. With the mapped biomass occurrence and additional, GIS-based infrastructure information, we can outline transport routes that take into account local restrictions like nature reserve areas, height or weight limitations as well as transport costs in relation to potential gains. This information can then be processed to outline optimal places for power plants. To simulate the upcoming Sentinel-2 data sets, we use airborne data from the AISA Eagle, spatially and spectrally down-sampled to match Sentinel 2's resolution. Our test scenario is an area in western Germany, the Kirchheller Heide, close to the city of Bottrop-Kirchhellen in the state of North Rhine-Westphalia. This region consists of nature reserves, forests, farmland and a few villages. To present a qualitative comparison between simulated and true biomass volume, we conducted field work by mapping the spatial extent of the desired biomass occurrences in the area. First results indicate a qualitative match of about 75%. Our research highlights the small-scale biomass features that have not been incorporated in previous biomass estimates. With the regular trimming and the accompanied raw material that becomes available, a new sector of thermal energy generation can be outlined. An automated quantification using satellite and GIS data will allow a regular monitoring of the vegetation growth and an assessment of the transport routes and costs as well as the location of the prospective power plants. In the endeavour of creating a sustainable energy supply, these biomass units should not be neglected, especially since the usage of the traditional units is limited due to competing interests in food production and nature conservation.

  18. Environment Friendly Coal Based Power Generation in Pakistan

    NASA Astrophysics Data System (ADS)

    Qureshi, S. A.; Javed, M. Adnan

    2010-06-01

    The main emphasis of this paper is on the engineering economics and design developments in the field of thermal power generation in Pakistan. Pakistan is rich with coal fields but is making no use of this available natural resource to fulfil its energy demands. The shortage of power is getting worst day by day and to align with the power requirements, Pakistan needs to add 2000 MW each year to national grid. With the increasing prices of natural gas and oil, Pakistan should consider coal, the abundantly available natural resource, as an alternate fuel for its new power plants to overcome the power crises.

  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. Identifying and bounding uncertainties in nuclear reactor thermal power calculations

    SciTech Connect

    Phillips, J.; Hauser, E.; Estrada, H.

    2012-07-01

    Determination of the thermal power generated in the reactor core of a nuclear power plant is a critical element in the safe and economic operation of the plant. Direct measurement of the reactor core thermal power is made using neutron flux instrumentation; however, this instrumentation requires frequent calibration due to changes in the measured flux caused by fuel burn-up, flux pattern changes, and instrumentation drift. To calibrate the nuclear instruments, steam plant calorimetry, a process of performing a heat balance around the nuclear steam supply system, is used. There are four basic elements involved in the calculation of thermal power based on steam plant calorimetry: The mass flow of the feedwater from the power conversion system, the specific enthalpy of that feedwater, the specific enthalpy of the steam delivered to the power conversion system, and other cycle gains and losses. Of these elements, the accuracy of the feedwater mass flow and the feedwater enthalpy, as determined from its temperature and pressure, are typically the largest contributors to the calorimetric calculation uncertainty. Historically, plants have been required to include a margin of 2% in the calculation of the reactor thermal power for the licensed maximum plant output to account for instrumentation uncertainty. The margin is intended to ensure a cushion between operating power and the power for which safety analyses are performed. Use of approved chordal ultrasonic transit-time technology to make the feedwater flow and temperature measurements (in place of traditional differential-pressure- based instruments and resistance temperature detectors [RTDs]) allows for nuclear plant thermal power calculations accurate to 0.3%-0.4% of plant rated power. This improvement in measurement accuracy has allowed many plant operators in the U.S. and around the world to increase plant power output through Measurement Uncertainty Recapture (MUR) up-rates of up to 1.7% of rated power, while also decreasing the probability of significant over-power events. This paper will examine the basic elements involved in calculation of thermal power using ultrasonic transit-time technology and will discuss the criteria for bounding uncertainties associated with each element in order to achieve reactor thermal power calculations to within 0.3% to 0.4%. (authors)

  1. Synergi: a new-generation thermal imaging system

    NASA Astrophysics Data System (ADS)

    Marche, Pierre M.; Packard, Paul D.; Kaiser, Winfried M.

    1995-09-01

    SYNERGI is a set of modules developed in collaboration between Thomson TTD Optronique, Pilkington Optronics, and Carl Zeiss. This module set is dedicated to new generation multipurpose high performance thermal cameras based on the SOFRADIR 288 by 4 element IRCCD detector. The manufactured products, as well as the various camera configurations designed, exhibit the key features of SYNERGI: cost effectiveness, compactness, flexibility, reduced power consumption. Special care has been taken in the technical design to minimize noise sources (early video digitization, power supplies synchronization), to maximize boresight stability (specific scan sensor), to enhance image characteristics (zoom modes, digital outputs, external synchronization), to make easy maintenance (dedicated serial link, BITE).

  2. Space Station Freedom solar dynamic power generation

    NASA Astrophysics Data System (ADS)

    Springer, T.; Friefeld, Jerry M.

    Viewgraphs on Space Station Freedom solar dynamic power generation are presented. Topics covered include: prime contract activity; key solar dynamic power module requirements; solar dynamic heat receiver technology; and solar concentrator advanced development.

  3. Space Station Freedom solar dynamic power generation

    NASA Technical Reports Server (NTRS)

    Springer, T.; Friefeld, Jerry M.

    1990-01-01

    Viewgraphs on Space Station Freedom solar dynamic power generation are presented. Topics covered include: prime contract activity; key solar dynamic power module requirements; solar dynamic heat receiver technology; and solar concentrator advanced development.

  4. Thermoelectric power generator with intermediate loop

    DOEpatents

    Bel,; Lon E.; Crane, Douglas Todd

    2009-10-27

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

  5. 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.

  6. 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.

  7. Fast onset medications through thermally generated aerosols.

    PubMed

    Rabinowitz, Joshua D; Wensley, Martin; Lloyd, Peter; Myers, Daniel; Shen, William; Lu, Amy; Hodges, Craig; Hale, Ron; Mufson, Daniel; Zaffaroni, Alejandro

    2004-05-01

    Smoking involves heating a drug to form a mixture of drug vapor and gaseous degradation products. These gases subsequently cool and condense into aerosol particles that are inhaled. Here, we demonstrate rapid and reliable systemic delivery of pure pharmaceutical compounds without degradation products through a related process that also involves inhalation of thermally generated aerosol. Drug is coated as a thin film on a metallic substrate and vaporized by heating the metal. The thin nature of the drug coating minimizes the length of time during which the drug is exposed to elevated temperatures, thereby preventing its thermal decomposition. The vaporized, gas-phase drug rapidly condenses and coagulates into micrometer-sized aerosol particles. For the commonly prescribed antimigraine drug rizatriptan, inhalation of these particles results in nearly instantaneous systemic drug action. PMID:14752061

  8. Comparison of advanced thermal and electrical storage for parabolic dish solar thermal power systems

    SciTech Connect

    Fujita, T.; Awaya, H.I.; Birur, G.C.; Bowyer, J.M.; Schredder, J.M.

    1982-08-01

    Optional arrangements for generating electrical power from solar thermal parabolic dish systems are compared. An option which employs a cluster of two-axis tracking parabolic dish collectors to supply solar-derived heat to a ground-based thermal storage/power conversion unit is assessed. Each multi-dish cluster is a power module, and a large power system can be composed of a multiplicity of such modules. The use of advanced Stirling and Brayton engines is investigated. An important finding is that promising multi-dish clusters employing advanced sensible and latent heat thermal storage attain energy costs comparable to those of dishbattery systems over a wide range of dish cluster sizes. This has major implementation advantages in allowing the selection of cluster sizes and associated engines that are tailored to application system requirements and, in particular, permitting the use of a wide range of engines that are being developed for other applications.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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).

  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. 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.

  18. Pneumatic tire-based piezoelectric power generation

    NASA Astrophysics Data System (ADS)

    Makki, Noaman; Pop-Iliev, Remon

    2011-03-01

    Plug-in Hybrid Electric Vehicles (PHEVs) and Extended Range Electric Vehicles (EREVs) currently mainly rely on Internal Combustion Engines (ICE) utilizing conventional fuels to recharge batteries in order to extend their range. Even though Piezo-based power generation devices have surfaced in recent years harvesting vibration energy, their output has only been sufficient to power up sensors and other such smaller devices. The permanent need for a cleaner power generation technique still remains. This paper investigates the possibility of using piezoceramics for power generation within the vehicle's wheel assembly by exploiting the rotational motion of the wheel and the continuously variable contact point between the pneumatic tire and the road.

  19. 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.

  20. 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.

  1. 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.

  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. Economic dispatch control for large scale thermal power systems

    SciTech Connect

    Not Available

    1986-01-01

    A realistic model for economic dispatch control (EDC) which is valid for large scale thermal power system is described. This model properly accounts for the nonlinearities of the generation cost-curves introduced by the operation constraints of thermal units. The methodology of this model computes the optimal readjustments of generation schedules such that their total generation output meets the system demand, including the Area Control Error (ACE). The objective function to be minimized is the instantaneous operating cost of a power system subjected to several equality and inequality constraints, which represent the performance characteristics and operation limitations of the various units in the system as well as the active power loss in the transmission network. The generation cost curves and the active losses are represented using one of two models. The first model includes the exact piecewise linear curve formulation and the well known loss formula, while the second one considers a second order polynomial approximation of the generation cost curves and assumes that the active network losses are independent on the generation configuration and have constant percentage value from the total system demand. Each of these models has its merits to EDC strategies. 10 references, 7 figures, 3 tables.

  4. 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.

  5. An Implanted, Stimulated Muscle Powered Piezoelectric Generator

    NASA Technical Reports Server (NTRS)

    Lewandowski, Beth; Gustafson, Kenneth; Kilgore, Kevin

    2007-01-01

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

  6. Compliance strategy in national thermal power corporation, India

    SciTech Connect

    Basu, B.; Rao, M.H.

    1998-07-01

    Established in the mid-seventies the National Thermal Power Corporation (NTPC) is now the largest power producing company in India with an installed capacity of more than 16,000 MW. The environmental impacts associated with thermal power generation are inviting greater attention in the country. Power generation, a vital input for industrial development has to grow but at the same time emphasis on mitigation of environmental impact associated with thermal power generation can not be undermined. The Regulatory Agencies in the country are also enacting several environmental laws progressively to ensure that the industrial development is sustainable. The growing concern of Regulatory Agencies is evident from the Environmental Clearance accorded by them for power plants. As against simple conditions stipulated in clearances for projects in the late seventies the current regulatory clearances address specific protective actions in almost all areas of environment like air, water, noise, ecology etc. Compliance by utilities to environmental laws and requirements of the Regulatory Agencies is a major step toward sustainable development. At the NTPC Stations apart from compliance there is emphasis on data generation through scientific studies on different aspects of ecosystem where information are scanty or ground truth is to be established, adoption of eco-friendly measures like re-use and recycling where feasible for optimization of requirement of plant, schemes for treatments of effluents etc. to ensure enhanced performance and adoption of comprehensive environmental management program with a view to identify critical parameters and take timely corrective action. The paper underscores the concern of NTPC toward environmental protection. Compliance strategies vis a vis the environmental laws and requirements of Regulatory Agencies have been discussed.

  7. 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.

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

    SciTech Connect

    Lucas, J.W.

    1984-03-01

    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. For individual titles, see N84-28225 through N84-28258.

  9. 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.

  10. 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.

  11. Solar powered navigation buoy generator

    SciTech Connect

    Meyers, R.D.

    1991-11-19

    This patent describes a solar generating system designed to convert existing navigation buoys using conventional throw-away batteries to more economical rechargeable batteries lasting several years. It comprises a flat rectangular stainless steel mounting platform with two solar panels and two flexible antennas mounted on the platform and a hole punched in the center of the platform in the space between the two solar panels and sized to fit over the existing caisson of the buoy and adapted to be secured in place on the existing buoy caisson by means of the existing lens locking nut and security bolt of the caisson, a wiring harness connected to the solar panels mounted on the flat rectangular stainless steel platform adapted to extend through the wall of the buoy caisson and to connect with the rechargeable battery, further including a series connected blocking diode to prevent the battery from discharging during peak periods.

  12. Power generation method including membrane separation

    DOEpatents

    Lokhandwala, Kaaeid A.

    2000-01-01

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

  13. Concepts for central solar electric power generation

    NASA Technical Reports Server (NTRS)

    Kintigh, J. K.

    1974-01-01

    The investigation reported was conducted to select the best conceptual design of a power plant for the dynamic conversion of solar heat to electricity. Conversion of thermal energy to electricity was to be an accomplished with conventional turbomachinery. Questions of site selection are discussed along with solar energy collection systems, aspects of candidate system definition, and reference systems.

  14. 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.

  15. Review of pulsed rf power generation

    SciTech Connect

    Lavine, T.L.

    1992-04-01

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

  16. Control of thermal therapies with moving power deposition field

    NASA Astrophysics Data System (ADS)

    Arora, Dhiraj; Minor, Mark A.; Skliar, Mikhail; Roemer, Robert B.

    2006-03-01

    A thermal therapy feedback control approach to control thermal dose using a moving power deposition field is developed and evaluated using simulations. A normal tissue safety objective is incorporated in the controller design by imposing constraints on temperature elevations at selected normal tissue locations. The proposed control technique consists of two stages. The first stage uses a model-based sliding mode controller that dynamically generates an 'ideal' power deposition profile which is generally unrealizable with available heating modalities. Subsequently, in order to approximately realize this spatially distributed idealized power deposition, a constrained quadratic optimizer is implemented to compute intensities and dwell times for a set of pre-selected power deposition fields created by a scanned focused transducer. The dwell times for various power deposition profiles are dynamically generated online as opposed to the commonly employed a priori-decided heating strategies. Dynamic intensity and trajectory generation safeguards the treatment outcome against modelling uncertainties and unknown disturbances. The controller is designed to enforce simultaneous activation of multiple normal tissue temperature constraints by rapidly switching between various power deposition profiles. The hypothesis behind the controller design is that the simultaneous activation of multiple constraints substantially reduces treatment time without compromising normal tissue safety. The controller performance and robustness with respect to parameter uncertainties is evaluated using simulations. The results demonstrate that the proposed controller can successfully deliver the desired thermal dose to the target while maintaining the temperatures at the user-specified normal tissue locations at or below the maximum allowable values. Although demonstrated for the case of a scanned focused ultrasound transducer, the developed approach can be extended to other heating modalities with moving deposition fields, such as external and interstitial ultrasound phased arrays, multiple radiofrequency needle applicators and microwave antennae.

  17. Grumman evaluates Space Station thermal control and power systems

    SciTech Connect

    Kandebo, S.W.

    1985-09-01

    Attention is given to the definition of requirements for the NASA Space Station's electrical power and thermal control systems, which must be highly dependable to minimize the need for external support and will embody a highly flexible modular design concept. Module maintenance will be performed by in-orbit replacement of failed modules, and energy storage system growth will be accomplished by the incorporation of additional modules. Both photovoltaic and solar heat-driven electrical generator concepts are under consideration as the basis of the power system.

  18. Fiscalini Farms Renewable Energy Power Generation Project

    SciTech Connect

    2009-02-01

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

  19. Evaluation of thermoelectric modules for power generation

    NASA Astrophysics Data System (ADS)

    Rowe, D. M.; Min, Gao

    A procedure is developed to assess the potential of thermoelectric modules when used for electrical power generation. The generating performance of a thermoelectric module is evaluated in terms of its power output, conversion efficiency and reliability, while the potential for improving its performance is investigated based upon the power-per-area, cost-per-watt and manufacture quality factor. The methods employed in determining these parameters are described and used to evaluate several commercially available modules. The results show that a thermoelectric module is a promising device for low temperature waste heat recovery.

  20. Solar driven liquid metal MHD power generator

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  1. Solar driven liquid metal MHD power generator

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Hohl, F.

    1983-06-01

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

  2. Low thermal resistance power module assembly

    DOEpatents

    Hassani, Vahab; Vlahinos, Andreas; Bharathan, Desikan

    2007-03-13

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

  3. 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^2σT/κ (S = Seebeck coefficient, σ = electrical conductivity, T = temperature, and κ = 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.

  4. Radio-frequency power-assisted performance improvement of a magnetohydrodynamic power generator

    SciTech Connect

    Murakami, Tomoyuki; Okuno, Yoshihiro; Yamasaki, Hiroyuki

    2005-12-01

    We describe a radio-frequency (rf) electromagnetic-field-assisted magnetohydrodynamic power generation experiment, where an inductively coupled rf field (13.56 MHz, 5.2 kW) is continuously supplied to the disk generator. The rf power assists the precise plasma ignition, by which the otherwise irregular plasma behavior was stabilized. The rf heating suppresses the ionization instability in the plasma behavior and homogenizes the nonuniformity of the plasma structures. The power-generating performance is significantly improved with the aid of the rf power under wide seeding conditions: insufficient, optimum, and excessive seed fractions. The increment of the enthalpy extraction ratio of around 2% is significantly greater than the fraction of the net rf power, that is, 0.16%, to the thermal input.

  5. Radio-frequency power-assisted performance improvement of a magnetohydrodynamic power generator

    NASA Astrophysics Data System (ADS)

    Murakami, Tomoyuki; Okuno, Yoshihiro; Yamasaki, Hiroyuki

    2005-12-01

    We describe a radio-frequency (rf) electromagnetic-field-assisted magnetohydrodynamic power generation experiment, where an inductively coupled rf field (13.56MHz, 5.2kW) is continuously supplied to the disk generator. The rf power assists the precise plasma ignition, by which the otherwise irregular plasma behavior was stabilized. The rf heating suppresses the ionization instability in the plasma behavior and homogenizes the nonuniformity of the plasma structures. The power-generating performance is significantly improved with the aid of the rf power under wide seeding conditions: insufficient, optimum, and excessive seed fractions. The increment of the enthalpy extraction ratio of around 2% is significantly greater than the fraction of the net rf power, that is, 0.16%, to the thermal input.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Geothermal power generation - An aggressive utility program

    NASA Astrophysics Data System (ADS)

    Crane, G. K.

    1981-05-01

    In the last ten years, utilities and resource production companies have made major commitments to the development of geothermal resources, located in the Imperial Valley. The program considered includes the construction of three flash steam power plants with varying objectives and designs which will assist in the assessment of the feasibility of hot water geothermal as a base load generation option. Attention is given to the geothermal potential, a 10 MW power plant project, a cooling water system, a 45 MW power plant project, an evaluation of steam condition and turbine, a Salton Sea 9 MW power plant project, resource exploration, a technology assessment, and the expected results.

  11. A Thermoelectric Generation System and Its Power Electronics Stage

    NASA Astrophysics Data System (ADS)

    Gao, Junling; Sun, Kai; Ni, Longxian; Chen, Min; Kang, Zhengdong; Zhang, Li; Xing, Yan; Zhang, Jianzhong

    2012-06-01

    The electricity produced by a thermoelectric generator (TEG) must satisfy the requirements of specific loads given the signal level, stability, and power performance. In the design of such systems, one major challenge involves the interactions between the thermoelectric power source and the power stage and signal-conditioning circuits of the load, including DC-DC conversion, the maximum power point tracking (MPPT) controller, and other power management controllers. In this paper, a survey of existing power electronics designs for TEG systems is presented first. Second, a flat, wall-like TEG system consisting of 32 modules is experimentally optimized, and the improved power parameters are tested. Power-conditioning circuitry based on an interleaved boost DC-DC converter is then developed for the TEG system in terms of the tested power specification. The power electronics design features a combined control scheme with an MPPT and a constant output voltage as well as the low-voltage and high-current output characteristics of the TEG system. The experimental results of the TEG system with the power electronics stage and with purely resistive loads are compared. The comparisons verify the feasibility and effectiveness of the proposed design. Finally, the thermal-electric coupling effects caused by current-related heat source terms, such as the Peltier effect etc., are reported and discussed, and the potential influence on the power electronics design due to such coupling is analyzed.

  12. 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.

  13. 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.

    2015-06-01

    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.

  14. 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.

  15. 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.

  16. Flywheel-powered X-ray generator

    NASA Astrophysics Data System (ADS)

    Siedband, M. P.

    1984-11-01

    The use of a small flywheel appears to be a practical alternative to other power sources for mobile X-ray system applications. A 5 kg flywheel has been constructed which runs at 10 krpm and stores 30 KJ while requiring less than 500 W to bring the system up to speed. The wheel is coupled to an aircraft alternator and can yield pulsed power levels over 50 KWp. The aircraft alternator has the advantage of high frequency output which has also permitted the design of smaller high voltage transformers. A series of optical sensors detecting shaft position function as an electronic commutator so that the alternator may operate as a motor to bring the wheel up to operating speed. The system permits the generation of extremely powerful X-rays from a variety of low power sources such as household power outlets, automobile batteries or sources of poorly regulated electrical power such as those found in third world countries.

  17. 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.

  18. 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 (ΔT) 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

  19. 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 (ΔT) 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

  20. The Meteosat Second Generation (MSG) power system

    SciTech Connect

    Haines, J.E.; Levins, D.; Robben, A.; Sepers, A.

    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.

  1. 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.

  2. Advanced Coal-Based Power Generations

    NASA Technical Reports Server (NTRS)

    Robson, F. L.

    1982-01-01

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

  3. 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.

  4. Microelectromechanical power generator and vibration sensor

    DOEpatents

    Roesler, Alexander W.; Christenson, Todd R.

    2006-11-28

    A microelectromechanical (MEM) apparatus is disclosed which can be used to generate electrical power in response to an external source of vibrations, or to sense the vibrations and generate an electrical output voltage in response thereto. The MEM apparatus utilizes a meandering electrical pickup located near a shuttle which holds a plurality of permanent magnets. Upon movement of the shuttle in response to vibrations coupled thereto, the permanent magnets move in a direction substantially parallel to the meandering electrical pickup, and this generates a voltage across the meandering electrical pickup. The MEM apparatus can be fabricated by LIGA or micromachining.

  5. 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.

  6. Efficient hybrid electric and thermal energy generation

    NASA Astrophysics Data System (ADS)

    Xia, X. Winston; Parfenov, Alexander V.; Aye, Tin M.; Shih, Min-Yi

    2011-10-01

    We demonstrate a novel hybrid solar photovoltaic electrical and thermal energy cogeneration system with high efficiency, at potentially reduced overall weight and size compared with current solar energy systems. The new system is based on highly efficient photovoltaic solar cells and tubular water thermal receivers, incorporating holographic spectral beam light guide concentrators resulting in a more cost-effective solution. Details of fabrication and preliminary experimental testing results are presented.

  7. Electrical Power Generation by Mechanically Modulating Electrical Double Layers

    NASA Astrophysics Data System (ADS)

    Pak, Hyuk Kyu; Moon, Jong Kyun

    2014-11-01

    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 and for understanding the interfacial charge distribution in solid-liquid interfaces in the near future. This work was supported by Center for Soft and Living Matter through IBS prgram in Korea.

  8. Global Climate Change - The Power Generation Challenge

    EPA Science Inventory

    The planet continues to warm; O.5 C from the 1970s to the 2000s. 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...

  9. 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.

  10. 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...

  11. Thermoelectric unicouple used for power generation

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry (Inventor); Zoltan, Andrew (Inventor); Zoltan, Leslie (Inventor); Snyder, Jeffrey (Inventor)

    2004-01-01

    A high-efficiency thermoelectric unicouple is used for power generation. The unicouple is formed with a plurality of legs, each leg formed of a plurality of segments. The legs are formed in a way that equalizes certain aspects of the different segments. Different materials are also described.

  12. 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.

  13. Wind power generation and dispatch in competitive power markets

    NASA Astrophysics Data System (ADS)

    Abreu, Lisias

    Wind energy is currently the fastest growing type of renewable energy. The main motivation is led by more strict emission constraints and higher fuel prices. In addition, recent developments in wind turbine technology and financial incentives have made wind energy technically and economically viable almost anywhere. In restructured power systems, reliable and economical operation of power systems are the two main objectives for the ISO. The ability to control the output of wind turbines is limited and the capacity of a wind farm changes according to wind speeds. Since this type of generation has no production costs, all production is taken by the system. Although, insufficient operational planning of power systems considering wind generation could result in higher system operation costs and off-peak transmission congestions. In addition, a GENCO can participate in short-term power markets in restructured power systems. The goal of a GENCO is to sell energy in such a way that would maximize its profitability. However, due to market price fluctuations and wind forecasting errors, it is essential for the wind GENCO to keep its financial risk at an acceptable level when constituting market bidding strategies. This dissertation discusses assumptions, functions, and methodologies that optimize short-term operations of power systems considering wind energy, and that optimize bidding strategies for wind producers in short-term markets. This dissertation also discusses uncertainties associated with electricity market environment and wind power forecasting that can expose market participants to a significant risk level when managing the tradeoff between profitability and risk.

  14. Optical generation of radio-frequency power

    SciTech Connect

    Hietala, V.M.; Vawter, G.A.; Brennan, T.M.; Hammons, B.E.; Meyer, W.J.

    1994-11-01

    An optical technique for high-power radio-frequency (RF) signal generation is described. The technique uses a unique photodetector based on a traveling-wave design driven by an appropriately modulated light source. The traveling-wave photodetector (TWPD) exhibits simultaneously a theoretical quantum efficiency approaching 100 % and a very large electrical bandwidth. Additionally, it is capable of dissipating the high-power levels required for the RF generation technique. The modulated light source is formed by either the beating together of two lasers or by the direct modulation of a light source. A system example is given which predicts RF power levels of 100`s of mW`s at millimeter wave frequencies with a theoretical ``wall-plug`` efficiency approaching 34%.

  15. Thermoelectric power generation system optimization studies

    NASA Astrophysics Data System (ADS)

    Karri, Madhav A.

    A significant amount of energy we consume each year is rejected as waste heat to the ambient. Conservative estimates place the quantity of energy wasted at about 70%. Converting the waste heat into electrical power would be convenient and effective for a number of primary and secondary applications. A viable solution for converting waste heat into electrical energy is to use thermoelectric power conversion. Thermoelectric power generation is based on solid state technology with no moving parts and works on the principle of Seebeck effect. In this work a thermoelectric generator (TEG) system simulator was developed to perform various parametric and system optimization studies. Optimization studies were performed to determine the effect of system size, exhaust and coolant ow conditions, and thermoelectric material on the net gains produced by the TEG system and on the optimum TEG system design. A sports utility vehicle was used as a case study for the application of TEG in mobile systems.

  16. 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.

  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. Economic analysis of ocean thermal and wind power plants and power generation. 1972-1981 (Citations from the International Aerospace Abstracts Data Base). Report for Jan 72-Dec 81

    SciTech Connect

    Not Available

    1981-12-01

    This bibliography covers economic analyses and evaluations of techniques and technology for ocean thermal energy and small and large wind energy conversion systems and apparatus. Government policies and economic incentives to commercialization world-wide are cited, along with considerations of economic prospects and feasibility. (This updated bibliography contains 219 citations, 154 of which are new entries to the previous edition.)

  19. Low thermal resistance power module assembly

    SciTech Connect

    Hassani, Vahab; Vlahinos, Andreas; Bharathan, Desikan

    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.

  20. Thermoelectric power generation for hybrid-electric vehicle auxiliary power

    NASA Astrophysics Data System (ADS)

    Headings, Leon M.; Washington, Gregory N.; Midlam-Mohler, Shawn; Heremans, Joseph P.

    2009-03-01

    The plug-in hybrid-electric vehicle (PHEV) concept allows for a moderate driving range in electric mode but uses an onboard range extender to capitalize on the high energy density of fuels using a combustion-based generator, typically using an internal combustion engine. An alternative being developed here is a combustion-based thermoelectric generator in order to develop systems technologies which capitalize on the high power density and inherent benefits of solid-state thermoelectric power generation. This thermoelectric power unit may find application in many military, industrial, and consumer applications including range extension for PHEVs. In this research, a baseline prototype was constructed using a novel multi-fuel atomizer with diesel fuel, a conventional thermoelectric heat exchange configuration, and a commercially available bismuth telluride module (maximum 225°C). This prototype successfully demonstrated the viability of diesel fuel for thermoelectric power generation, provided a baseline performance for evaluating future improvements, provided the mechanism to develop simulation and analysis tools and methods, and highlighted areas requiring development. The improvements in heat transfer efficiency using catalytic combustion were evaluated, the system was redesigned to operate at temperatures around 500 °C, and the performance of advanced high temperature thermoelectric modules was examined.

  1. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS

    SciTech Connect

    Paul Tubel

    2003-04-24

    The second quarter of the project was dedicated to convert the conceptual designs for the wireless tool and power generator into mechanical and electrical drawings as well as software code to create the new system. The tasks accomplished during this report period were: (1) Basic mechanical design for the wireless communications system was created and the detailed drawings were started. (2) Basic design for the power generator system was created and the detailed machining drawings were started. The generator design was modified to provide a direct action between the wellbore fluid flow and the piezoelectric stack to generate energy. The new design eliminates the inefficiencies related to picking up outside the tubing wall the pressure fluctuations occurring inside the tubing walls. (3) The new piezoelectric acoustic generator design was created and ordered from the manufacturer. The system will be composed of 40 ceramic wafers electrically connected in parallel and compressed into a single generator assembly. (4) The acoustic two-way communications requirements were also defined and the software and hardware development were started. (5) The electrical hardware development required to transmit information to the surface and to receive commands from the surface was started.

  2. Thermoelectric power generation for battery charging

    SciTech Connect

    Rahman, M.; Shuttleworth, R.

    1995-12-31

    Thermoelectric generators use the Seebeck effect to produce electrical power from a temperature difference caused by heat energy flow. In this paper the principle of using thermoelectrically converted heat energy for powering portable electronic equipment or charging its battery has been investigated for a lap-top computer. The thermoelectric battery charger developed, consists of a thermoelectric battery charger developed, consists of a thermoelectric converter system, powered from butane gas, and a dc-to-dc boost up converter. Both the sub-assemblies are designed using computer models and constructed. The unit produces an output power of 5 watts which doubles the life of the lap-top computer`s internal batteries.

  3. 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.

  4. 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

  5. A thermoelectric generator using porous Si thermal isolation.

    PubMed

    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 μW/cm2 was measured for a 50 μm thick porous Si layer. PMID:24152923

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

    NASA Astrophysics Data System (ADS)

    Xu, B.; Fobelets, K.

    2014-06-01

    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.

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

    SciTech Connect

    Xu, B. Fobelets, K.

    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 Ω 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.

  8. 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.

  9. Isotope powered Stirling generator for terrestrial applications

    SciTech Connect

    Tingey, G.L.; Sorensen, G.C.; Ross, B.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 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. Thermal analyses of power subsystem components

    NASA Technical Reports Server (NTRS)

    Morehouse, Jeffrey H.

    1990-01-01

    The hiatus in the Space Shuttle (Orbiter) program provided time for an in-depth examination of all the subsystems and their past performance. Specifically, problems with reliability and/or operating limits were and continue to be of major engineering concern. The Orbiter Auxiliary Power Unit (APU) currently operates with electric resistance line heaters which are controlled with thermostats. A design option simplification of this heater subsystem is being considered which would use self-regulating heaters. A determination of the properties and thermal operating characteristics of these self-regulating heaters was needed. The Orbiter fuel cells are cooled with a freon loop. During a loss of external heat exchanger coolant flow, the single pump circulating the freon is to be left running. It was unknown what temperature and flow rate transient conditions of the freon would provide the required fuel cell cooling and for how long. The overall objective was the development of the thermal characterization and subsequent analysis of both the proposed self-regulating APU heater and the fuel cell coolant loop subsystem. The specific objective of the APU subsystem effort was to determine the feasibility of replacing the current heater and thermostat arrangement with a self-regulating heater. The specific objective of the fuel cell coolant subsystem work was to determine the tranient coolant temperature and associated flow rates during a loss-of-external heat exchanger flow.

  11. 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.

  12. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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.

  14. Coal Gasification for Power Generation, 3. edition

    SciTech Connect

    2007-11-15

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

  15. 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…

  16. 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.

  17. 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%.

  18. Power enhancement of piezoelectric transformers by adding thermal pad

    NASA Astrophysics Data System (ADS)

    Su, Y. H.; Liu, Y. P.; Vasic, D.; Costa, F.

    2012-04-01

    It is well known that power density of piezoelectric transformers is limited by mechanical stress. The power density of piezoelectric transformers calculated by the stress boundary can reach 330 W/cm3. However, no piezoelectric transformer has ever reached such a high power density in practice. The power density of the piezoelectric transformer is limited to 33 W/cm3 typically. This fact implies that there is another physical limitation in piezoelectric transformer. In fact, it is also known that piezoelectric material is constrained by vibration velocity. Once the vibration velocity is too large, the piezoelectric transformer generates heat until it cracks. To explain the instability of piezoelectric transformer, we will first model the relationship between vibration velocity and resulting heat by a physical feedback loop. It will be shown that the vibration velocity as well as the heat generation determines the loop gain. A large vibration velocity and heat may cause the feedback loop to enter into an unstable state. Therefore, to enhance the power capacity of piezoelectric transformer, the heat needs to be dissipated. In this paper, we used commercial thermal pads on the surface of the piezoelectric transformer to dissipate the heat. The mechanical current of piezoelectric transformers can move from 0.382A/2W to 0.972A/9W at a temperature of 55°C experimentally. It implies that the power capacity possibly increases 3 times in the piezoelectric material. Moreover, piezoelectric transformers that are well suited in applications of high voltage/low current becomes also well suited for low voltage/high current power supplies that are widely spread. This technique not only increases the power capacity of the piezoelectric transformer but also allows it to be used in enlarged practical applications. In this paper, the theoretical modeling will be detailed and verified by experiments.

  19. 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.

  20. 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.

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

    PubMed

    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. PMID:24595200

  2. 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.

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

    DOEpatents

    Ross, John; Escher, Claus

    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.

  4. A market focus. [The changing power generation equipment market

    SciTech Connect

    Burr, M.T.

    1991-10-01

    This article is a compilation of the views of the changing power generation equipment market by executives of ASEA-Brown Boveri, General Electric Power Generation, Siemans Power Generation Group, and Westinghouse Electric Corporation Power Generation unit. The topics of the article include a changing market, the home market, the turnkey supplier, and back to baseload.

  5. Heat Management in Thermoelectric Power Generators

    NASA Astrophysics Data System (ADS)

    Zebarjadi, M.

    2016-04-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one.

  6. ADVANCED CO2 CYCLE POWER GENERATION

    SciTech Connect

    A. Nehrozoglu

    2003-10-01

    Research is being conducted under United States Department of Energy (DOE) Contract DE-FC26-02NT41621 to develop a conceptual design and determine the performance characteristics of a new IGCC plant configuration that facilitates CO{sub 2} removal for sequestration. This new configuration will be designed to achieve CO{sub 2} sequestration without the need for water gas shifting and CO{sub 2} separation, and may eliminate the need for a separate sequestration compressor. This research introduces a novel concept of using CO{sub 2} as a working fluid for an advanced coal gasification based power generation system, where it generates power with high system efficiency while concentrating CO{sub 2} for sequestration. This project supports the DOE research objective of development of concepts for the capture and storage of CO{sub 2}.

  7. Heat Management in Thermoelectric Power Generators

    PubMed Central

    Zebarjadi, M.

    2016-01-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one. PMID:27033717

  8. 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.

  9. Heat Management in Thermoelectric Power Generators.

    PubMed

    Zebarjadi, M

    2016-01-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one. PMID:27033717

  10. ICAN: High power neutral beam generation

    NASA Astrophysics Data System (ADS)

    Moustaizis, S. D.; Lalousis, P.; Perrakis, K.; Auvray, P.; Larour, J.; Ducret, J. E.; Balcou, P.

    2015-10-01

    During the last few years there is an increasing interest on the development of alternative high power new negative ion source for Tokamak applications. The proposed new neutral beam device presents a number of advantages with respect to: the density current, the acceleration voltage, the relative compact dimension of the negative ion source, and the coupling of a high power laser beam for photo-neutralization of the negative ion beam. Here we numerically investigate, using a multi-fluid 1-D code, the acceleration and the extraction of high power ion beam from a Magnetically Insulated Diode (MID). The diode configuration will be coupled to a high power device capable of extracting a current up to few kA with an accelerating voltage up to MeV. An efficiency of up to 92% of the coupling of the laser beam, is required in order to obtain a high power, up to GW, neutral beam. The new high energy, high average power, high efficiency (up to 30%) ICAN fiber laser is proposed for both the plasma generation and the photo-neutralizer configuration [1].

  11. 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.

  12. Power generation with synthetic liquid fuels

    SciTech Connect

    Lebowitz, H.E.

    1984-06-01

    The authors report combustion tests in full-scale utility power generation equipment using Exxon Donor Solvent coal liquids and H-Coal liquids. Details of the tests are given and results are presented. It was shown that the coal liquids could be used as turbine fuels with 1800 F or higher firing temperatures. Additional industrial hygiene precautions were taken to ensure minimum crew contact with the synfuel.

  13. Electrostrictions in high-power soliton generator

    SciTech Connect

    Ikezi, H.; Lin-Liu, Y.R.; Ohkawa, T.; deGrassie, J.S.

    1988-11-01

    Electrostriction effects are considered in a high power dielectric loaded transmission line designed to generate solitons. The Cerenkov emission of elastic waves from the metal-dielectric interface produces the largest strain among the strain producing mechanisms. The expression for strain as a function of electric field strength is found. The signal loss due to the emission of elastic waves is shown to be insignificant.

  14. Weight driven rotary power generating apparatus

    SciTech Connect

    Jones, S.W.

    1982-06-08

    The present invention entails a weight driven rotary power generating apparatus that is designed to efficiently provide energy that can be harnessed and effectively utilized. Forming the weight driven rotary power generating apparatus of the present invention is a heavy flywheel rotatively mounted within a frame structure and including a plurality of radially extending and circumferentially spaced projectors or drive panels that extends from the flywheel. Peripherally disposed about said flywheel is a closed, off-axis weight track that includes a plurality of weights movable therein. Because of the off-axis orientation with respect to the flywheel, the track is oriented such that as the weights fall due to gravity through a falling run of said track, they engage said projectors projecting from said flywheel and act to drive said flywheel. Once past the falling run, the power generating apparatus is provided with a chain weight transfer assembly that engages the weights as they enter a return run of said track and act to transfer said weights to an elevated position where they may be held and selectively released in accordance with the rpm of said flywheel. Once released, the respective weights again move through the falling run and act to drive the flywheel as just described.

  15. Combined body and power generating system

    SciTech Connect

    Paleologos, G.E.

    1982-12-14

    A system is disclosed for converting a standard buoy design into an electrical power producing apparatus. The vertical arms slide in sleeves attached to the buoy body and terminate in feet in the form of flat discs. As the buoy bobs and pivots in the water, the resistance of the feet to motion cause the arms to reciprocate, operating pneumatic piston pumps within the buoy. These piston pumps power pneumatic turbines which activate generators for producing electrical power. The moving parts of the linkages connecting the arms to the pumps are protected by a plastic casing which keeps out sea water. The casing includes facets which act as sails. Annular wipers are provided between the arms and sleeves within which the arms reciprocate, so as to prevent sea water from seeping therebetween.

  16. Cummins Power Generation SECA Phase 1

    SciTech Connect

    Charles Vesely

    2007-08-17

    The following report documents the progress of the Cummins Power Generation (CPG) SECA Phase 1 SOFC development and final testing under the U.S. Department of Energy Solid State Energy Conversion Alliance (SECA) contract DE-FC26-01NT41244. This report overviews and summarizes CPG and partner research development leading to successful demonstration of the SECA Phase 1 objectives and significant progress towards SOFC commercialization. Significant Phase 1 Milestones: (1) Demonstrated: (a) Operation meeting Phase 1 requirements on commercial natural gas. (b) LPG and Natural Gas CPOX fuel reformers. (c) SOFC systems on dry CPOX reformate. (c) Steam reformed Natural Gas operation. (d) Successful start-up and shut-down of SOFC system without inert gas purge. (e) Utility of stack simulators as a tool for developing balance of plant systems. (2) Developed: (a) Low cost balance of plant concepts and compatible systems designs. (b) Identified low cost, high volume components for balance of plant systems. (c) Demonstrated high efficiency SOFC output power conditioning. (d) Demonstrated SOFC control strategies and tuning methods. The Phase 1 performance test was carried out at the Cummins Power Generation facility in Minneapolis, Minnesota starting on October 2, 2006. Performance testing was successfully completed on January 4, 2007 including the necessary steady-state, transient, efficiency, and peak power operation tests.

  17. Nonlinear Generation of Electromagnetic Waves Through Scattering by Thermal Electrons

    NASA Astrophysics Data System (ADS)

    Tejero, E. M.; Crabtree, C. E.; Blackwell, D. D.; Amatucci, B.; Mithaiwala, M.; Rudakov, L.; Ganguli, G.

    2014-12-01

    Nonlinear interactions involving whistler wave turbulence are important contributors to radiation belt dynamics, including the acceleration and loss of trapped electrons. Given sufficient whistler energy density, nonlinear scattering from thermal electrons can substantially change the wave normal angle, while inducing a small frequency shift [Ganguli et al., 2010]. This nonlinear process is being studied in the NRL Space Physics Simulation Chamber (SPSC) in scaled magnetospheric conditions. The plasma response as a function of transmitted lower hybrid wave amplitude is monitored with magnetic loop antennas. Measurements of the magnetic field vectors for the pump and daughter waves allow for the determination of wave distribution functions, which indicate the power distribution as a function of wave-normal angle and azimuthal angle. The wave distribution functions measured in the experiment demonstrate a dramatic change in propagation direction when the launched wave amplitude exceeds a small threshold (δB / B ~ 4 × 10-7). The experimental results support the theory of electromagnetic whistler wave generation through nonlinear scattering of electrostatic lower hybrid waves by thermal electrons in the Earth's magnetosphere [Crabtree et al, 2012].

  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. Using thermoelectric nuclear power generators in spacecraft power-generation propulsion complexes

    SciTech Connect

    Andreev, P.V.; Galkin, A.Ya.; Gryaznov, G.M.

    1994-04-01

    Power-generation and propulsion complexes for spacecraft, universal space platforms (US) which combine a power unit and high- and low-thrust propulsion unions, make it possible to efficiently solve problems involved in creating satellite communication systems, environmental monitoring systems, industrial technology platforms, interorbital shuttles, etc. Electrical power consumed by prospective spacecraft designed for communication or environmental monitoring may be as high as 20-30 kW. Manufacturing of semiconductors and biological materials in space may require electrical power of 30-l00 kW in the coming decades. The power required to transport loads between orbits using ion-plasma jet engines will amount to tens to hundreds of kilowatts. For all these missions, nuclear power units have important advantages over solar photoelectric power units in their mass, size, cost, and performance characteristics. There is a good reason to consider the use of thermoelectric Nuclear Power Generators (NPG) for USPs due to their small bulk, their capacity for generating greatly increased power in the high-power mode during 15-20% of the total length of the mission, and minimal disturbance of the motion of the spacecraft.

  20. 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.

  1. Exergetic analysis of parabolic trough solar thermal power plants

    NASA Astrophysics Data System (ADS)

    Petrakopoulou, F.; Ruperez, B.; San Miguel, G.

    2014-12-01

    A very important component to achieve sustainable development in the energy sector is the improvement of energy efficiency of widely applied thermodynamic processes. Evaluation and optimization methods of energy processes play a crucial role in fulfilling this goal. A suitable method for the evaluation and optimization of energy conversion systems has been proven to be the exergetic analysis. In this work, two parabolic trough solar thermal power plants are simulated in detail using commercial software, and they are further analysed and compared using an exergetic analysis. The first plant uses a thermal fluid to produce the steam required in a steam generator, while the second one produces the steam directly in the solar field. The analysis involves the evaluation of the individual components of the power plants, as well as the performance evaluation of the overall structures. The main goal is to detect thermodynamic inefficiencies of the two different configurations and propose measures to minimize those. We find that the two examined plants have similar main sources of exergy destruction: the solar field (parabolic trough solar collectors), followed by the steam generator. This reveals the importance of an optimal design of these particular components, which could reduce inefficiencies present in the system. The differences in the exergy destruction and exergetic efficiencies of individual components of the two plants are analyzed in detail based on comparable operational conditions.

  2. 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.

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

    SciTech Connect

    Bernnat, W.; Buck, M.; Mattes, M.; Zwermann, W.; Pasichnyk, I.; Velkov, K.

    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)

  4. 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.

  5. Future Photovoltaic Power Generation for Space-Based Power Utilities

    NASA Astrophysics Data System (ADS)

    Bailey, S.; Landis, G.; Raffaelle, R.; Hepp, A.

    2002-01-01

    A recent NASA program, Space Solar Power Exploratory Research and Technology (SERT), investigated the technologies needed to provide cost-competitive ground baseload electrical power from space based solar energy conversion. This goal mandated low cost, light weight gigawatt (GW) power generation. Investment in solar power generation technologies would also benefit high power military, commercial and science missions. These missions are generally those involving solar electric propulsion, surface power systems to sustain an outpost or a permanent colony on the surface of the moon or mars, space based lasers or radar, or as large earth orbiting power stations which can serve as central utilities for other orbiting spacecraft, or as in the SERT program, potentially beaming power to the earth itself. This paper will discuss requirements for the two latter options, the current state of the art of space solar cells, and a variety of both evolving thin film cells as well as new technologies which may impact the future choice of space solar cells for a high power mission application. The space world has primarily transitioned to commercially available III-V (GaInP/GaAs/Ge) cells with 24-26% air mass zero (AMO) efficiencies. Research in the III-V multi-junction solar cells has focused on fabricating either lattice-mismatched materials with optimum stacking bandgaps or new lattice matched materials with optimum bandgaps. In the near term this will yield a 30% commercially available space cell and in the far term possibly a 40% cell. Cost reduction would be achieved if these cells could be grown on a silicon rather than a germanium substrate since the substrate is ~65% of the cell cost or, better yet, on a polyimide or possibly a ceramic substrate. An overview of multi-junction cell characteristics will be presented here. Thin film cells require substantially less material and have promised the advantage of large area, low cost manufacturing. However, space cell requirements dictate a more complicated trade space. Until recently the focus in space cells has been on efficiency rather than cost. In a several billion-dollar spacecraft the cell cost is relatively small at even a thousand dollars per watt, which is approximately the current array cost. This has primarily been true for spacecraft with power needs from a few hundred watts to tens of kilowatts. However, deployment of a large earth orbiting space power system will require major advances in the photovoltaic array weight, stability in the space environment, efficiency, and ultimately the cost of production and deployment of such arrays. The development of large space power systems, and a host of other proposed space missions, will require the development of viable thin film arrays. The specific power required is almost 40 times what is presently available in commercial arrays. While high efficiency ultra lightweight arrays are not likely to become commercially available anytime soon, advances in thin film photovoltaics may still impact other space technologies (i.e., thin film integrated power supplies) and thus support a broad range of missions in the next decade. Mission examples include micro- air vehicles, ultra-long duration balloons (e.g. Olympus), deep space solar electric propulsion (SEP) "Tug" Array, Mars SEP Array, and Mars surface power outpost. A discussion of the state of the art of thin film cells and their characteristics will be included, particularly focused on their applicability to the space environment. This survey of thin film cells will also include a discussion of inorganic/organic solar cells and their adaptability to the space environment. Enhancements to the efficiency of thin film cells, such as intermediate band quantum dots will be discussed and results presented for current cell configurations.

  6. Turbostar: an ICF reactor using both direct and thermal power conversion. Revision 1

    SciTech Connect

    Pitts, J.H.

    1986-07-31

    Combining direct and thermal power conversion results in a 52% gross plant efficiency with DT fuel and 68% with advanced DD fuel. We maximize the fraction of fusion-yield energy converted to kinetic energy in a liquid-lithium blanket, and use this energy directly with turbine generators to produce electricity. We use the remainder of the energy to produce electricity in a standard Rankine thermal power conversion cycle.

  7. 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.

  8. 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.

  9. Manure digester and power generating system

    SciTech Connect

    Santina, P.F.; Chatterjee, A.K.

    1988-06-14

    A manure digester and power generating system is described comprising: a mixing tank for receiving manure, and for mixing water with the manure to produce a manure slurry of desired consistency; a closed anaerobic digester tank of fixed volume; the mixing tank being separate from and spaced from the digester tank; pumping and conduit means for transferring the contents of the mixing tank to the digester tank; automatic control means, associated with the pumping means, for monitoring and controlling temperature and volume of the contents of the mixing tank before transfer to the digester tank; means for discharging effluent by-products out the outflow end of the digester tank; a gas-fueled engine and a generator coupled to the engine, for generating electrical power; heater means; means for drawing off biogas from the digester tank and for conducting it to the engine as fuel, and wherein the manure slurry is heated sufficiently, prior to introduction into the digester tank and separately from the digester tank, to prevent temperature shock of already digesting slurry in the digester tank when the slurry is introduced into the digester tank.

  10. Evaluation Of Different Power Conditioning Options For Stirling Generators

    NASA Astrophysics Data System (ADS)

    Garrigos, A.; Blanes, J. M.; Carrasco, J. A.; Maset, E.; Montalban, G.; Ejea, J.; Ferreres, A.; Sanchis, E.

    2011-10-01

    Free-piston Stirling engines are an interesting alternative for electrical power systems, especially in deep space missions where photovoltaic systems are not feasible. This kind of power generators contains two main parts, the Stirling machine and the linear alternator that converts the mechanical energy from the piston movement to electrical energy. Since the generated power is in AC form, several aspects should be assessed to use such kind of generators in a spacecraft power system: AC/DC topologies, power factor correction, power regulation techniques, integration into the power system, etc. This paper details power generator operation and explores different power conversion approaches.

  11. A thermal signal generator probe for the study of neural thermal transduction.

    PubMed

    Maluf, N I; McNutt, E L; Monroe, S; Tanelian, D L; Kovacs, G T

    1994-07-01

    The study of thermal transduction in neural tissues has been impeded by the lack of instrumentation able to generate complex, focal temperature variations. Specifically, we are interested in the study of neural thermal transduction within the cornea, with its homogeneous thermal conductivity and avascularity. We present a thermal signal generator probe that is capable of producing arbitrarily shaped bipolar (heating or cooling) thermal swings in a small volume of corneal tissue with which it is in contact. Heating and cooling of the probe tip are achieved by means of a Peltier effect thermoelectric device. The probe temperature, measured directly at the tip, is controlled using closed-loop control circuitry and waveform generation software on a host computer. Response characteristics of thermally sensitive C-fibers were investigated in an in vitro preparation of the rabbit cornea. PMID:7927385

  12. 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...

  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. Improvement of water treatment at thermal power plants

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Bushuev, E. N.; Larin, A. B.; Karpychev, E. A.; Zhadan, A. V.

    2015-04-01

    Prospective and existing technologies for water treatment at thermal power plants, including pretreatment, ion exchange, and membrane method are considered. The results obtained from laboratory investigations and industrial tests of the proposed technologies carried out at different thermal power plants are presented. The possibilities of improving the process and environmental indicators of water treatment plants are shown.

  15. Thermal Regime of High-power Laser Diodes

    NASA Astrophysics Data System (ADS)

    Bezotosnyi, V. V.; Krokhin, O. N.; Oleshchenko, V. A.; Pevtsov, V. F.; Popov, Yu. M.; Cheshev, E. A.

    We discuss the design and application perspectives of different crystal, ceramic and composite-type submounts with thermo-compensating properties as well as submounts from materials with high thermal conductivity for overcoming thermal problem in high-power laser diodes (LD) and improving thermal management of other high-power optoelectronic and electronic semiconductor devices. Thermal fields in high-power laser diodes were calculated in 3 D thermal model at CW operation for some heatsink designs taking into account the experimental dependence of laser total efficiency against pumping current in order to extend the range of reliable operation up to thermal loads 20-30 W and corresponding output optical power up to 15-20 W for 100 μm stripe laser diodes.

  16. 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.

  17. Integrated control of next generation power system

    SciTech Connect

    None, None

    2010-02-28

    The multi-agent system (MAS) approach has been applied with promising results for enhancing an electric power distribution circuit, such as the Circuit of the Future as developed by Southern California Edison. These next generation power system results include better ability to reconfigure the circuit as well as the increased capability to improve the protection and enhance the reliability of the circuit. There were four main tasks in this project. The specific results for each of these four tasks and their related topics are presented in main sections of this report. Also, there were seven deliverables for this project. The main conclusions for these deliverables are summarized in the identified subtask section of this report. The specific details for each of these deliverables are included in the “Project Deliverables” section at the end of this Final Report.

  18. Neutrino Generation in Powerful Solar Flares

    NASA Astrophysics Data System (ADS)

    Bazilevskaya, G. A.; Nikolsky, S. I.; Stozhkov, Y. I.; Charakhchyan, T. N.

    The combined analysis of data from the solar neutrino Cl-Ar detector and those on powerful solar cosmic ray and solar γ-bursts showed that: (1) The powerful solar cosmic ray bursts with a 24-hr averaged solar proton intensity I(≥150 MeV) ≥ 3 cm-2s-1sr-1 are the source of neutrino fluxes sufficient for a significant contribution to the 37Ar production in the Cl-Ar experiment. (2) The increased neutrino generation is observed in the solar flares in which high-energy γ-quanta were observed. (3). The flares on the back side of the sun do not contribute to the production rate of 37Ar in the neutrino experiment although they can produce a significant flux of high-energy solar particles at the Earth.

  19. 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.

  20. Neutron generator power supply modeling in EMMA

    SciTech Connect

    Robinson, A.C.; Farnsworth, A.V.; Montgomery, S.T.; Peery, J.S; Merewether, K.O.

    1996-12-01

    Sandia National Laboratories has prime responsibility for neutron generator design and manufacturing, and is committed to developing predictive tools for modeling neutron generator performance. An important aspect of understanding component performance is explosively driven ferroelectric power supply modeling. EMMA (ElectroMechanical Modeling in ALEGRA) is a three dimensional compile time version of Sandia`s ALEGRA code. The code is built on top of the general ALEGRA framework for parallel shock-physics computations but also includes additional capability for modeling the electric potential field in dielectrics. The overall package includes shock propagation due to explosive detonation, depoling of ferroelectric ceramics, electric field calculation and coupling with a general lumped element circuit equation system. The AZTEC parallel iterative solver is used to solve for the electric potential. The DASPK differential algebraic equation package is used to solve the circuit equation system. Sample calculations are described.

  1. 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...

  2. 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.

  3. 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.

  4. Self Excitation and Harmonics in Wind Power Generation: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Romanowitz, H.; Yinger, R.

    2004-11-01

    Traditional wind turbines are equipped with induction generators. Induction generators are preferred because they are inexpensive, rugged, and require very little maintenance. Unfortunately, induction generators require reactive power from the grid to operate. Because reactive power varies with the output power, the terminal voltage at the generator may become too low to compensate the induction generator. The interactions among the wind turbine, the power network, and the capacitor compensation, are important aspects of wind generation. In this paper, we will show the interactions among the induction generator, capacitor compensation, power system network, and magnetic saturations and examine the cause of resonance conditions and self-excitation.

  5. Piezoelectric power generation for civil infrastructure systems

    NASA Astrophysics Data System (ADS)

    Erturk, A.; Inman, D. J.

    2011-04-01

    Civil infrastructure systems (CIS) employ various small electronic components ranging from temperature and humidity sensors used in buildings to acoustics emission sensors used for damage detection in bridges. Other than solar energy that has already found several applications in CIS; moving loads, surface strain fluctuations, and wind energy available in the vicinity of CIS constitute important sources of energy that can be converted into electricity. This paper focuses on low power generation from these energy sources using piezoelectric transduction. Moving loads caused by travelling vehicles can be used for exciting piezoceramics located on the road. Structural vibrations resulting from various sources such as support motions and interaction of CIS with the surrounding fluid may yield local surface strain fluctuations. Wind energy is available not only due to regular atmospheric flow but also due to the motion of vehicles travelling at relatively high speeds. This paper investigates and formulates (1) the electromechanical moving load problem for slender bridges with a piezoelectric cantilever and with embedded piezoceramics, (2) the problem of piezoelectric power generation from surface strain fluctuations using a piezoceramic patch, and (3) piezoelectric energy harvesting from wind excitation through aeroelastic flutter.

  6. Generation mechanism of power line harmonic radiation

    NASA Astrophysics Data System (ADS)

    Kostrov, Alexander; Gushchin, Mikhail; Korobkov, Sergei

    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 with duration of about 10 microseconds in a power line. The repetition rate of these pulses is typically 100/120 Hz; the bandwidth is as broad as 100 kHz. For high harmonics of 50/60 Hz, the power line represents an effective traveling-wave (or Beverage) antenna, especially in a frequency range of several kHz corresponding to VLF whistler band in Earth ionosphere and magnetosphere. For the fixed length of the power line, which acts as antenna, radiation directivity diagram in relation to horizon depends of frequency. Hence the spatial separation of whistlers emitted at various frequencies (1-10 kHz in a consid-ered case) is possible, with subsequent propagation of whistlers with different frequencies along different L-shells. Estimations show that the efficiency of power line as travelling-wave antenna can be changed by variations of its load, but not more than twice ("weekend effect"). Since the PLHR can represent the sequence of short electromagnetic bursts, then careful se-lection of frequency-time resolution of the data acquisition equipment is needed. Typically, the time constant of the data recording and processing is too large, and the spectra of PLHR or MLR are characterized by a well-known line structure. At the same time, original bursty structure of PLHR can not be defined. Fine structure of MLR is also discussed. Frequency drift of MLR can be explained by the perturbations of the magnetospheric plasma by intense ULF waves and particle flows affecting the propagation of PLHR. Hence the physical nature of PLHR and MLR is the same, excepting the propagation conditions: MLR is a product of PLHR after passage through the perturbed magnetospheric regions. The work is supported by OFN-15 RAS program, RFBR grants Nos. 09-02-97058-r, 09-02-91052-NCNI-a.

  7. 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.

  8. 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.

  9. Embedded Thermal Control for Subsystems for Next Generation Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Didion, Jeffrey R.

    2015-01-01

    Thermal Fluids and Analysis Workshop, Silver Spring MD NCTS 21070-15. NASA, the Defense Department and commercial interests are actively engaged in developing miniaturized spacecraft systems and scientific instruments to leverage smaller cheaper spacecraft form factors such as CubeSats. This paper outlines research and development efforts among Goddard Space Flight Center personnel and its several partners to develop innovative embedded thermal control subsystems. Embedded thermal control subsystems is a cross cutting enabling technology integrating advanced manufacturing techniques to develop multifunctional intelligent structures to reduce Size, Weight and Power (SWaP) consumption of both the thermal control subsystem and overall spacecraft. Embedded thermal control subsystems permit heat acquisition and rejection at higher temperatures than state of the art systems by employing both advanced heat transfer equipment (integrated heat exchangers) and high heat transfer phenomena. The Goddard Space Flight Center Thermal Engineering Branch has active investigations seeking to characterize advanced thermal control systems for near term spacecraft missions. The embedded thermal control subsystem development effort consists of fundamental research as well as development of breadboard and prototype hardware and spaceflight validation efforts. This paper will outline relevant fundamental investigations of micro-scale heat transfer and electrically driven liquid film boiling. The hardware development efforts focus upon silicon based high heat flux applications (electronic chips, power electronics etc.) and multifunctional structures. Flight validation efforts include variable gravity campaigns and a proposed CubeSat based flight demonstration of a breadboard embedded thermal control system. The CubeSat investigation is technology demonstration will characterize in long-term low earth orbit a breadboard embedded thermal subsystem and its individual components to develop optimized operational schema.

  10. Diagnosis of thermal flaws in the magnetic circuits of hydroelectric generators

    SciTech Connect

    Naslyan, T.A.; Akopyan, R.E.; Gushchin, E.V.; Nemeni, T.M.

    1986-09-01

    By means of mathematical simulation certain types of thermal flaws have been evaluated for the magnetic circuits of stators in hydroelectric generators of the Krasnoyarsk power plant. The temperature field of a stator with thermal flaws was calculated in order to examine the possibility of timely detection for local hot spots in it as well as for the total or partial ventilation failures in radial channels by using diagnostic equipment that provides a thermal check on the inner surface of the bore. A determination was made of the maximal temperatures reached in the area of local hot spots and on the end surface of a tooth in order to estimate the risks there.

  11. Development of an HTS hydroelectric power generator for the hirschaid power station

    NASA Astrophysics Data System (ADS)

    Fair, Ruben; Lewis, Clive; Eugene, Joseph; Ingles, Martin

    2010-06-01

    This paper describes the development and manufacture of a 1.7MW, 5.25kV, 28pole, 214rpm hydroelectric power generator consisting of superconducting HTS field coils and a conventional stator. The generator is to be installed at a hydro power station in Hirschaid, Germany and is intended to be a technology demonstrator for the practical application of superconducting technology for sustainable and renewable power generation. The generator is intended to replace and uprate an existing conventional generator and will be connected directly to the German grid. The HTS field winding uses Bi-2223 tape conductor cooled to about 30K using high pressure helium gas which is transferred from static cryocoolers to the rotor via a bespoke rotating coupling. The coils are insulated with multi-layer insulation and positioned over laminated iron rotor poles which are at room temperature. The rotor is enclosed within a vacuum chamber and the complete assembly rotates at 214rpm. The challenges have been significant but have allowed Converteam to develop key technology building blocks which can be applied to future HTS related projects. The design challenges, electromagnetic, mechanical and thermal tests and results are presented and discussed together with applied solutions.

  12. Comparison of advanced engines for parabolic dish solar thermal power plants

    NASA Technical Reports Server (NTRS)

    Fujita, T.; Bowyer, J. M.; Gajanana, B. C.

    1980-01-01

    A paraboloidal dish solar thermal power plant produces electrical energy by a two-step conversion process. The collector subsystem is composed of a two-axis tracking paraboloidal concentrator and a cavity receiver. The concentrator focuses intercepted sunlight (direct, normal insolation) into a cavity receiver whose aperture encircles the focal point of the concentrator. At the internal wall of the receiver the electromagnetic radiation is converted to thermal energy. A heat engine/generator assembly then converts the thermal energy captured by the receiver to electricity. Developmental activity has been concentrated on small power modules which employ 11- to 12-meter diameter dishes to generate nominal power levels of approximately 20 kWe. A comparison of advanced heat engines for the dish power module is presented in terms of the performance potential of each engine with its requirements for advanced technology development. Three advanced engine possibilities are the Brayton (gas turbine), Brayton/Rankine combined cycle, and Stirling engines.

  13. 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

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

    NASA Astrophysics Data System (ADS)

    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.

  15. 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.

  16. 43 CFR 431.4 - Power generation responsibilities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Power generation responsibilities. 431.4..., DEPARTMENT OF THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

  17. 43 CFR 431.4 - Power generation responsibilities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Power generation responsibilities. 431.4..., DEPARTMENT OF THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

  18. 43 CFR 431.4 - Power generation responsibilities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Power generation responsibilities. 431.4..., DEPARTMENT OF THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

  19. 43 CFR 431.4 - Power generation responsibilities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Power generation responsibilities. 431.4..., DEPARTMENT OF THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

  20. 43 CFR 431.4 - Power generation responsibilities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Power generation responsibilities. 431.4..., DEPARTMENT OF THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

  1. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Power generation estimates. 431.6 Section... THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates. Reclamation shall...

  2. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Power generation estimates. 431.6 Section... THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates. Reclamation shall...

  3. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Power generation estimates. 431.6 Section... THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates. Reclamation shall...

  4. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Power generation estimates. 431.6 Section... THE INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE, AND REPLACEMENT AT THE BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates. Reclamation shall...

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... is not capable of providing continuous electrical power may be utilized as a supplemental generator... driven by a main propulsion unit (such as a shaft generator) which is capable of providing electrical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... is not capable of providing continuous electrical power may be utilized as a supplemental generator... driven by a main propulsion unit (such as a shaft generator) which is capable of providing electrical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... is not capable of providing continuous electrical power may be utilized as a supplemental generator... driven by a main propulsion unit (such as a shaft generator) which is capable of providing electrical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

  8. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... is not capable of providing continuous electrical power may be utilized as a supplemental generator... driven by a main propulsion unit (such as a shaft generator) which is capable of providing electrical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

  9. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... is not capable of providing continuous electrical power may be utilized as a supplemental generator... driven by a main propulsion unit (such as a shaft generator) which is capable of providing electrical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

  10. A Thermal and Electrical Analysis of Power Semiconductor Devices

    NASA Technical Reports Server (NTRS)

    Vafai, Kambiz

    1997-01-01

    The state-of-art power semiconductor devices require a thorough understanding of the thermal behavior for these devices. Traditional thermal analysis have (1) failed to account for the thermo-electrical interaction which is significant for power semiconductor devices operating at high temperature, and (2) failed to account for the thermal interactions among all the levels involved in, from the entire device to the gate micro-structure. Furthermore there is a lack of quantitative studies of the thermal breakdown phenomenon which is one of the major failure mechanisms for power electronics. This research work is directed towards addressing. Using a coupled thermal and electrical simulation, in which the drift-diffusion equations for the semiconductor and the energy equation for temperature are solved simultaneously, the thermo-electrical interactions at the micron scale of various junction structures are thoroughly investigated. The optimization of gate structure designs and doping designs is then addressed. An iterative numerical procedure which incorporates the thermal analysis at the device, chip and junction levels of the power device is proposed for the first time and utilized in a BJT power semiconductor device. In this procedure, interactions of different levels are fully considered. The thermal stability issue is studied both analytically and numerically in this research work in order to understand the mechanism for thermal breakdown.

  11. AC power generation from microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Lobo, Fernanda Leite; Wang, Heming; Forrestal, Casey; Ren, Zhiyong Jason

    2015-11-01

    Microbial fuel cells (MFCs) directly convert biodegradable substrates to electricity and carry good potential for energy-positive wastewater treatment. However, the low and direct current (DC) output from MFC is not usable for general electronics except small sensors, yet commercial DC-AC converters or inverters used in solar systems cannot be directly applied to MFCs. This study presents a new DC-AC converter system for MFCs that can generate alternating voltage in any desired frequency. Results show that AC power can be easily achieved in three different frequencies tested (1, 10, 60 Hz), and no energy storage layer such as capacitors was needed. The DC-AC converter efficiency was higher than 95% when powered by either individual MFCs or simple MFC stacks. Total harmonic distortion (THD) was used to investigate the quality of the energy, and it showed that the energy could be directly usable for linear electronic loads. This study shows that through electrical conversion MFCs can be potentially used in household electronics for decentralized off-grid communities.

  12. 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 2014-04-01 false Electric power... COMMISSION GENERAL POLICIES § 801.12 Electric power generation. (a) Significant uses are presently being made of the waters of the basin for the generation of electric power at hydro, pumped storage,...

  13. 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 2011-04-01 false Electric power... COMMISSION GENERAL POLICIES § 801.12 Electric power generation. (a) Significant uses are presently being made of the waters of the basin for the generation of electric power at hydro, pumped storage,...

  14. 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 2010-04-01 false Electric power... COMMISSION GENERAL POLICIES § 801.12 Electric power generation. (a) Significant uses are presently being made of the waters of the basin for the generation of electric power at hydro, pumped storage,...

  15. 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 2012-04-01 false Electric power... COMMISSION GENERAL POLICIES § 801.12 Electric power generation. (a) Significant uses are presently being made of the waters of the basin for the generation of electric power at hydro, pumped storage,...

  16. 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 2012-04-01 true Electric power... COMMISSION GENERAL POLICIES § 801.12 Electric power generation. (a) Significant uses are presently being made of the waters of the basin for the generation of electric power at hydro, pumped storage,...

  17. Investigation of Maximum Power Point Tracking for Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Phillip, Navneesh; Maganga, Othman; Burnham, Keith J.; Ellis, Mark A.; Robinson, Simon; Dunn, Julian; Rouaud, Cedric

    2013-07-01

    In this paper, a thermoelectric generator (TEG) model is developed as a tool for investigating optimized maximum power point tracking (MPPT) algorithms for TEG systems within automotive exhaust heat energy recovery applications. The model comprises three main subsystems that make up the TEG system: the heat exchanger, thermoelectric material, and power conditioning unit (PCU). In this study, two MPPT algorithms known as the perturb and observe (P&O) algorithm and extremum seeking control (ESC) are investigated. A synchronous buck-boost converter is implemented as the preferred DC-DC converter topology, and together with the MPPT algorithm completes the PCU architecture. The process of developing the subsystems is discussed, and the advantage of using the MPPT controller is demonstrated. The simulation results demonstrate that the ESC algorithm implemented in combination with a synchronous buck-boost converter achieves favorable power outputs for TEG systems. The appropriateness is by virtue of greater responsiveness to changes in the system's thermal conditions and hence the electrical potential difference generated in comparison with the P&O algorithm. The MATLAB/Simulink environment is used for simulation of the TEG system and comparison of the investigated control strategies.

  18. Diagnostics on the COBRA pulsed power generator

    SciTech Connect

    Shelkovenko, T. A.; Chalenski, D. A.; Chandler, K. M.; Douglass, J. D.; Greenly, J. B.; Hammer, D. A.; Kusse, B. R.; McBride, R. D.; Pikuz, S. A.

    2006-10-15

    The COBRA pulsed power generator has a variable current pulse wave form and amplitude (95-180 ns rise time, up to 1 MA peak current). It was designed to study wire array Z pinches and X pinches, including plasma formation, pinch implosion dynamics, and pinch plasma parameters as a function of current rise time. These loads have been studied using an extensive set of diagnostics with spatial and/or temporal resolution. The set of electrical diagnostics on the COBRA generator includes Rogowski coils to monitor the total load current and the current through individual return current posts, and there is also an inductive voltage monitor. A set of extreme ultraviolet and x-ray detectors is used to study the load radiation. Wire array and X pinch plasma formation and dynamics are studied using two-frame, point projection X-pinch x-ray imaging as well as with multiframe laser probing. Flat potassium acid phtalate crystal (KAP), convex, extreme luminosity imaging conical spectrograph, and focusing spectrograph with spatial resolution with mica crystal, pinhole cameras, and a camera with a slit and a step filter set (slip step-wedge camera) can be used in each pulse to monitor the x-ray emission from the X pinch(es) and arrays in several spectral bands.

  19. 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.

  20. Analysis on Possible Introduction of PV System Considering Output Power Fluctuation and Battery Technology Employing Optimal Power Generation Mix Model

    NASA Astrophysics Data System (ADS)

    Komiyama, Ryoichi; Shibata, Saeko; Nakamura, Yosuke; Fujii, Yasumasa

    This paper presents the evaluation on the impact of an extensive introduction of photovoltaic (PV) system and stationary battery technology into optimal power generation mix in Kanto and Kinki region. The introduction of solar PV system is expected to be extensively deployed in Japanese household sector and utility company in order to address the concerns of energy security and climate change. 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 system. On these backgrounds, we develop both solar photovoltaic power generation model and optimal power generation mix model, including stationary battery technology, which are able to explicitly analyze the impact of PV output fluctuation in detailed resolution of time interval like 10 minutes at consecutive 365 days. Simulation results reveal that PV introduction does not necessarily increase battery technology due to the cost competitiveness of thermal power plants in load following requirement caused by PV system. Additionally, on the basis of sensitivity analysis on PV system cost, dramatic cost reduction proves to be indispensable enough for PV to supply a bulk of electricity similarly as thermal and nuclear power plant.

  1. 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.

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

    SciTech Connect

    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.

  3. Metal Hydrides for High-Temperature Power Generation

    DOE PAGESBeta

    Ronnebro, Ewa; Whyatt, Greg A.; Powell, Michael R.; Westman, Matthew P.; Zheng, Feng; Fang, Zhigang Zak

    2015-08-10

    Metal hydrides can be utilized for hydrogen storage and for thermal energy storage (TES) applications. By using TES with solar technologies, heat can be stored from sun energy to be used later which enables continuous power generation. We are developing a TES technology based on a dual-bed metal hydride system, which has a high-temperature (HT) metal hydride operating reversibly at 600-800°C to generate heat as well as a low-temperature (LT) hydride near room temperature that is used for hydrogen storage during sun hours until there is a need to produce electricity, such as during night time, a cloudy day, ormore » during peak hours. We proceeded from selecting a high-energy density, low-cost HT-hydride based on performance characterization on gram size samples, to scale-up to kilogram quantities and design, fabrication and testing of a 1.5kWh, 200kWh/m3 bench-scale TES prototype based on a HT-bed of titanium hydride and a hydrogen gas storage instead of a LT-hydride. COMSOL Multiphysics was used to make performance predictions for cylindrical hydride beds with varying diameters and thermal conductivities. Based on experimental and modeling results, a bench-scale prototype was designed and fabricated and we successfully showed feasibility to meet or exceed all performance targets.« less

  4. Metal Hydrides for High-Temperature Power Generation

    SciTech Connect

    Ronnebro, Ewa; Whyatt, Greg A.; Powell, Michael R.; Westman, Matthew P.; Zheng, Feng; Fang, Zhigang Zak

    2015-08-10

    Metal hydrides can be utilized for hydrogen storage and for thermal energy storage (TES) applications. By using TES with solar technologies, heat can be stored from sun energy to be used later which enables continuous power generation. We are developing a TES technology based on a dual-bed metal hydride system, which has a high-temperature (HT) metal hydride operating reversibly at 600-800°C to generate heat as well as a low-temperature (LT) hydride near room temperature that is used for hydrogen storage during sun hours until there is a need to produce electricity, such as during night time, a cloudy day, or during peak hours. We proceeded from selecting a high-energy density, low-cost HT-hydride based on performance characterization on gram size samples, to scale-up to kilogram quantities and design, fabrication and testing of a 1.5kWh, 200kWh/m3 bench-scale TES prototype based on a HT-bed of titanium hydride and a hydrogen gas storage instead of a LT-hydride. COMSOL Multiphysics was used to make performance predictions for cylindrical hydride beds with varying diameters and thermal conductivities. Based on experimental and modeling results, a bench-scale prototype was designed and fabricated and we successfully showed feasibility to meet or exceed all performance targets.

  5. Innovative gasification technology for future power generation

    SciTech Connect

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

    1995-07-01

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

  6. 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.

  7. 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.

  8. 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.

  9. Thermal Energy Corporation Combined Heat and Power Project

    SciTech Connect

    Turner, E. Bruce; Brown, Tim; Mardiat, Ed

    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 nation'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 providing top quality medical care and instruction without worrying about excessive energy costs or the loss of heating and cooling due to the risk of power outages. TECO's operation is the largest Chilled Water District Energy System in the United States. The company used DOE'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 TMC'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 nation'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.

  10. Microwave power heterojunction bipolar transistors fabricated with thermal shunt bathtub

    SciTech Connect

    Bozada, C.A.; Barlage, D.W.; Barrette, J.P.

    1995-12-31

    Heterojunction bipolar transistor devices and circuits were fabricated using thermal shunt and bathtub thermal management techniques. Broadband cascode MMICs exhibited 10 - 14 dB gain at an output power of 2.5 - 3.0 Watts across 7 - 11 GHz. A 200 {mu}m{sup 2} common-emitter unit cell achieved 7 - 8 dB linear power gain and 40% power-added efficiency at a noise power ratio (NPR) of 18 dBc at 12 GHz. Under single tone measurements at 12 GHz, the unit cell achieved 52% power-added efficiency, with 9.5 dB linear gain, 8 dB power gain and 240 mW output power at 5 V bias.

  11. Upconversion-induced heat generation and thermal lensing in Nd:YLF and Nd:YAG

    NASA Astrophysics Data System (ADS)

    Pollnau, M.; Hardman, P. J.; Kern, M. A.; Clarkson, W. A.; Hanna, D. C.

    1998-12-01

    We investigate the influence of interionic upconversion between neighboring ions in the upper laser level of Nd:YLF and Nd:YAG on population dynamics, heat generation, and thermal lensing under lasing and nonlasing conditions. It is shown that cascaded multiphonon relaxations following each upconversion process generate significant extra heat dissipation in the crystal under nonlasing compared to lasing conditions. Owing to the unfavorable temperature dependence of thermal and thermo-optical parameters, this leads, first, to a significant temperature increase in the rod, second, to strong thermal lensing with pronounced spherical aberrations and, ultimately, to rod fracture in a high-power end-pumped system. In a three-dimensional finite-element calculation, excitation densities, upconversion rates, heat generation, temperature profiles, and thermal lensing are calculated. Differences in thermal lens power between nonlasing and lasing conditions up to a factor of 6 in Nd:YLF and up to a factor of 2 in Nd:YAG are experimentally observed and explained by the calculation. This results in a strong deterioration in performance when operating these systems in a Q-switched regime, as an amplifier, or on a low-gain transition. Methods to decrease the influence of interionic upconversion are discussed. It is shown that tuning of the pump wavelength can significantly alter the rod temperature.

  12. Generator powered electrically heated diesel particulate filter

    DOEpatents

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

    2014-03-18

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

  13. Exploiting metastability and thermal noise to build a reconfigurable hardware random number generator

    NASA Astrophysics Data System (ADS)

    Lim, Daihyun; Ranasinghe, Damith C.; Devadas, Srinivas; Jamali, Behnam; Abbott, Derek; Cole, Peter H.

    2005-05-01

    While pseudo random number generators based on computational complexity are widely used for most of cryptographic applications and probabilistic simulations, the generation of true random numbers based on physical randomness is required to guarantee the advanced security of cryptographic systems. In this paper we present a method to exploit manufacturing variations, metastablity, and thermal noise in integrated circuits to generate random numbers. This metastability based physical random number generator provides a compact and low-power solution which can be fabricated using standard IC manufacturing processes. Test-chips were fabricated in TSMC 0.18um process and experimental results show that the generated random bits pass standard randomness tests successfully. The operation of the proposed scheme is robust against environmental changes since it can be re-calibrated to new environmental conditions such as temperature and power supply voltage.

  14. Thermal performance monitoring and assessment in Dukovany nuclear power plant

    SciTech Connect

    Madron, F.; Papuga, J.; Pliska, J.

    2006-07-01

    Competition in the European electricity market forces generators to achieve - in compliance with safety and environmental standards - efficiency of production as high as possible. This efficiency or heat rate is an important indicator of both the condition of the plant equipment and the quality of plant operation. Similar thermal performance indicators can also be calculated for components of the plant equipment such as heat exchangers. However, it is not easy to quantify these indicators with sufficient precision so that the results can be used for conduct of plant operation in near-real time and for predictive maintenance. This paper describes a present state of the system monitoring and evaluating thermal performance of the reactor units in Dukovany Nuclear Power Plant. The system provides information on actual and desirable (should-be) values of thermal performance indicators for control room operators, performance engineers and maintenance planners. The system is designed to monitor steady states and has two main functions: data validation and process simulation. Data validation is based on data reconciliation methodology and carried out with Recon software by Chemplant Technology. A detailed model of the secondary side for mass and heat balancing has been made up by means of the Recon's graphical editor; now it contains roughly 300 flows and employs data of about 200 measurements. Main advantages of the data reconciliation are: - reconciled data are consistent with the model, - reconciled data are more precise than data directly measured with consequence that the thermal power of steam generators is determined with substantially lower uncertainty than before - data reconciliation represents a solid basis for detection and identification of data corrupted by gross errors. Simulation is performed with a different analytical model of plant components configured into secondary side. The model has been developed by I and C Energo. Main purposes of simulation are: - the calculation of performance indicators and output capacity for a desirable state of the plant equipment and mode of operation. Boundary conditions for the calculation are taken from the preceding data reconciliation procedure. Control room operators (in near-real time) and performance engineers then can compare an actual and ideal state of the performance indicators. - 'what-if' analysis and efficiency optimization based on varying user selected parameters of the plant components and flow-sheet structure changes. The system is integrated into an overall nuclear power plant process information system and data warehouse. The solution is based on the Industrial SQL server database and the InTouch human machine interface by Invensys' Wonderware. The system nowadays works with hourly averages of process data and monitors secondary side of the Dukovany units No. 1 and 3 from steam generators to alternators. A detailed description of the system and some obtained results are presented. (authors)

  15. Advanced gasification-based biomass power generation

    SciTech Connect

    Williams, R.H.; Larson, E.D.

    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.

  16. Direct charge radioisotope activation and power generation

    DOEpatents

    Lal, Amit; Li, Hui; Blanchard, James P.; Henderson, Douglass L.

    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.

  17. 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.

  18. Technological renovation of thermal power plants as a long-term check factor of electricity price growth

    NASA Astrophysics Data System (ADS)

    Veselov, F. V.; Novikova, T. V.; Khorshev, A. A.

    2015-12-01

    The paper focuses on economic aspects of the Russian thermal generation sector's renovation in a competitive market environment. Capabilities of the existing competitive electricity and capacity pricing mechanisms, created during the wholesale market reform, to ensure the wide-scale modernization of thermal power plants (TPPs) are estimated. Some additional stimulating measures to focus the investment process on the renovation of the thermal generation sector are formulated, and supplementing and supporting costs are assessed. Finally, the systemic effect of decelerating wholesale electricity prices caused by efficiency improvements at thermal power plants is analyzed depending on the scales of renovation and fuel prices.

  19. Power MOSFET Thermal Instability Operation Characterization Support

    NASA Technical Reports Server (NTRS)

    Shue, John L.; Leidecker, Henning

    2010-01-01

    Metal-oxide semiconductor field-effect transistors (MOSFETs) are used extensively in flight hardware and ground support equipment. In the quest for faster switching times and lower "on resistance," the MOSFETs designed from 1998 to the present have achieved most of their intended goals. In the quest for lower on resistance and higher switching speeds, the designs now being produced allow the charge-carrier dominated region (once small and outside of the area of concern) to become important and inside the safe operating area (SOA). The charge-carrier dominated region allows more current to flow as the temperature increases. The higher temperatures produce more current resulting in the beginning of thermal runaway. Thermal runaway is a problem affecting a wide range of modern MOSFETs from more than one manufacturer. This report contains information on MOSFET failures, their causes and test results and information dissemination.

  20. Rankline-Brayton engine powered solar thermal aircraft

    DOEpatents

    Bennett, Charles L.

    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.

  1. Rankine-Brayton engine powered solar thermal aircraft

    SciTech Connect

    Bennett, Charles L.

    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.

  2. GE power generation technology challenges for advanced gas turbines

    SciTech Connect

    Cook, C.S.; Nourse, J.G.

    1993-11-01

    The GE Utility ATS is a large gas turbine, derived from proven GEPG designs and integrated GEAE technology, that utilizes a new turbine cooling system and incorporates advanced materials. This system has the potential to achieve ATS objectives for a utility sized machine. Combined with use of advanced Thermal Barrier Coatings (TBC`s), the new cooling system will allow higher firing temperatures and improved cycle efficiency that represents a significant improvement over currently available machines. Developing advances in gas turbine efficiency and emissions is an ongoing process at GEPG. The third generation, ``F`` class, of utility gas turbines offers net combined cycle efficiencies in the 55% range, with NO{sub x} programs in place to reduce emissions to less than 10 ppM. The gas turbines have firing temperatures of 2350{degree}F, and pressure ratios of 15 to 1. The turbine components are cooled by air extracted from the cycle at various stages of the compressor. The heat recovery cycle is a three pressure steam system, with reheat. Throttle conditions are nominally 1400 psi and 1000{degree}F reheat. As part of GEPG`s ongoing advanced power generation system development program, it is expected that a gas fired advanced turbine system providing 300 MW power output greater than 58% net efficiency and < 10 ppM NO{sub x} will be defined. The new turbine cooling system developed with technology support from the ATS program will achieve system net efficiency levels in excess of 60%.

  3. ERDA's central receiver solar thermal power system studies

    NASA Technical Reports Server (NTRS)

    Lippy, L. J.; Heaton, T. R.

    1977-01-01

    The utilization of solar energy for electrical power production was studied. Efforts underway on the central receiver solar thermal power system are presented. Preliminary designs are included of pilot plant utilizing large numbers of heliostats in a collector field. Safety hazards are also discussed, as well as the most beneficial location of such a plant within the United States.

  4. 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.

  5. 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

    ... Power, LLC; Constellation NewEnergy, Inc.; Constellation Power Source Generation, Inc.; Criterion Power..., CER Generation II, LLC, Constellation Mystic Power, LLC, Constellation NewEnergy, Inc., Constellation... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY...

  6. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Using water for power generation. 418.16... Operations and Management § 418.16 Using water for power generation. All use of Project water for power..., incentive water (§ 418.35), or spills....

  7. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Using water for power generation. 418.16... Operations and Management § 418.16 Using water for power generation. All use of Project water for power..., incentive water (§ 418.35 ), or spills....

  8. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Using water for power generation. 418.16... Operations and Management § 418.16 Using water for power generation. All use of Project water for power..., incentive water (§ 418.35 ), or spills....

  9. 43 CFR 418.16 - Using water for power generation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Using water for power generation. 418.16... Operations and Management § 418.16 Using water for power generation. All use of Project water for power..., incentive water (§ 418.35 ), or spills....

  10. 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.

  11. Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

    NASA Technical Reports Server (NTRS)

    Choi, Michael K.

    2015-01-01

    The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

  12. 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...

  13. 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

  14. Thermal modeling of power gallium arsenide microwave integrated circuits

    SciTech Connect

    Webb, P.W. )

    1993-05-01

    Low-power Gallium Arsenide-based microwave circuits have been used for many years for frequencies higher than those possible with silicon technology. At the present time manufacturers are developing power devices for ever higher frequencies using GaAs MESFET's and heterojunction bipolar devices constructed with III-V compounds on GaAs substrates. There is also interest in integrating power devices on Monolithic Microwave Integrated Circuits (MMIC's). A problem with the technology is the low thermal conductivity of Gallium Arsenide and this gives rise to thermal design problems which must be solved if good reliability is to be achieved. The paper uses a three-dimensional numerical simulator to study this problem and in particular examines the approximations which are possible in performing realistic assessments of the thermal resistance of typical GaAs power device structures under steady-state conditions.

  15. Economics of wind-farm power generation in India

    SciTech Connect

    Sinha, C.S.; Kandpal, T.C. . Centre of Energy Studies)

    1990-01-01

    The financial aspects of wind power generation in India are examined. The cost estimate scaling function for horizontal axis wind turbines (HAWT) is empirically obtained. Other cost components have also been examined and effort is made to generate a cost function for wind farms with grid connected HAWT wind energy conversion systems. The cost function is then used to compute the cost of wind generated electricity from the wind farms in India and the results are compared with the reported cost of generation from the wind farms. The potential of wind-farm power generation is discussed in the light of the cost of power generation by selected conventional technologies in India.

  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. Alternative power generation concepts for space

    SciTech Connect

    Brandhorst, H.W. Jr.; Juhasz, A.J.; Jones, B.I.

    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.

  18. 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.

  19. 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.

  20. Non-Equilibrium Plasma MHD Electrical Power Generation at Tokyo Tech

    SciTech Connect

    Murakami, T.; Okuno, Y.; Yamasaki, H.

    2008-02-21

    This paper reviews the recent activities on radio-frequency (rf) electromagnetic-field-assisted magnetohydrodynamic (MHD) power generation experiments at the Tokyo Institute of Technology. An inductively coupled rf field (13.56 MHz) is continuously supplied to the disk-shaped Hall-type MHD generator. The first part of this paper describes a method of obtaining increased power output from a pure Argon plasma MHD power generator by incorporating an rf power source to preionize and heat the plasma. The rf heating enhances ionization of the Argon and raises the temperature of the free electron population above the nominally low 4500 K temperatures obtained without rf heating. This in turn enhances the plasma conductivity making MHD power generation feasible. We demonstrate an enhanced power output when rf heating is on approximately 5 times larger than the input power of the rf generator. The second part of this paper is a demonstration of a physical phenomenon of the rf-stabilization of the ionization instability, that had been conjectured for some time, but had not been seen experimentally. The rf heating suppresses the ionization instability in the plasma behavior and homogenizes the nonuniformity of the plasma structures. The power-generating performance is significantly improved with the aid of the rf power under wide seeding conditions. The increment of the enthalpy extraction ratio of around 2% is significantly greater than the fraction of the net rf power, that is, 0.16%, to the thermal input.

  1. 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.

  2. Aberration athermal optics for second-generation FIR thermal imagers

    NASA Astrophysics Data System (ADS)

    Barron, Don R.

    1996-06-01

    The new generation of FIR thermal imagers require extremely high optical image quality to fully exploit the very high sensitivity available from detector arrays of several thousands of very small elements. Earlier optical designs and builds for FIR cameras generally suffer from a change in image quality arising from the change in refractive index of germanium. This paper shows that there are optical configurations whose image quality is virtually independent of temperature. A demonstrator using these optical designs is presently under construction jointly funded by the UK DRA and Pilkington Optronics. The demonstrator will be used to assess the practical performance of a camera designed to meet the very high specifications demanded of the next generation of thermal cameras.

  3. Generator and rechargeable battery system for pedal powered vehicles

    SciTech Connect

    Ryan, D.

    1985-11-26

    A generator and rechargeable battery system for use with pedal powered vehicles, such as bicycles, and where either the generator or battery can intermittently power a load such as a lighting system of the vehicle in one mode of operation, and in which the generator can recharge the battery in another mode of operation. A simple selection switch which is manually operable by the operator of the vehicle enables selection between powering of the load or recharging of the battery.

  4. Characteristics of carbon nanotubes based micro-bubble generator for thermal jet printing.

    PubMed

    Zhou, Wenli; Li, Yupeng; Sun, Weijun; Wang, Yunbo; Zhu, Chao

    2011-12-01

    We propose a conceptional thermal printhead with dual microbubble generators mounted parallel in each nozzle chamber, where multiwalled carbon nanotubes are adopted as heating elements with much higher energy efficiency than traditional approaches using noble metals or polysilicon. Tailing effect of droplet can be excluded by appropriate control of grouped bubble generations. Characteristics of the corresponding micro-fabricated microbubble generators were comprehensively studied before the formation of printhead. Electrical properties of the microheaters on glass substrate in air and performance of bubble generation underwater focusing on the relationships between input power, device resistance and bubble behavior were probed. Proof-of-concept bubble generations grouped to eliminate the tailing effect of droplet were performed indicating precise pattern with high resolution could be realized by this kind of printhead. Experimental results revealed guidance to the geometric design of the printhead as well as its fabrication margin and the electrical control of the microbubble generators. PMID:22408940

  5. 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.

  6. Second generation thermal imaging system design trades modeling

    NASA Astrophysics Data System (ADS)

    Vroombout, Leo O.

    1990-10-01

    The Night Vision Laboratory static performance model is considered for thermal viewing systems. Since the model is not initially intended to be a design tool and is not usable for conducting system or component design trades, it has to be restructured. The approach to updating the first-generation static performance model and to configuring it as a design tool is presented. Second-generation imaging systems exploit infrared focal-plane arrays, high-reliability cryogenic coolers, precision scanning devices, and high-speed digital electronics. They also use optical materials and coatings and optomechanical and electronics packaging techniques.

  7. 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.

  8. Secondary electric power generation with minimum engine bleed

    NASA Technical Reports Server (NTRS)

    Tagge, G. E.

    1983-01-01

    Secondary electric power generation with minimum engine bleed is discussed. Present and future jet engine systems are compared. The role of auxiliary power units is evaluated. Details of secondary electric power generation systems with and without auxiliary power units are given. Advanced bleed systems are compared with minimum bleed systems. A cost model of ownership is given. The difference in the cost of ownership between a minimum bleed system and an advanced bleed system is given.

  9. Finite element thermal study of the Linac4 plasma generator.

    PubMed

    Faircloth, D; Kronberger, M; Kchler, D; Lettry, J; Scrivens, R

    2010-02-01

    The temperature distribution and heat flow at equilibrium of the plasma generator of the rf-powered noncesiated Linac4 H(-) ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW rf power, 2 Hz repetition rate, and 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of the Superconducting Proton Linac (SPL), an extrapolation of the heat load toward 100 kW rf power, 50 Hz repetition rate, and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in the high-power mode of SPL. PMID:20192391

  10. Efficient millimeter wave 1140 GHz/ diode for harmonic power generation

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Epitaxial gallium arsenide diode junction formed in a crossed waveguide structure operates as a variable reactance harmonic generator. This varactor diode can generate power efficiently in the low-millimeter wavelength.

  11. 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.

  12. Self-Excitation and Harmonics in Wind Power Generation

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Romanowitz, H.; Yinger, R.

    2005-11-01

    Traditional wind turbines are commonly equipped with induction generators because they are inexpensive, rugged, and require very little maintenance. Unfortunately, induction generators require reactive power from the grid to operate; capacitor compensation is often used. Because the level of required reactive power varies with the output power, the capacitor compensation must be adjusted as the output power varies. The interactions among the wind turbine, the power network, and the capacitor compensation are important aspects of wind generation that may result in self-excitation and higher harmonic content in the output current. This paper examines the factors that control these phenomena and gives some guidelines on how they can be controlled or eliminated.

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

    SciTech Connect

    Not Available

    1984-04-01

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

  14. 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.

  15. 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%.

  16. 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.

  17. JPL - Small Power Systems Applications Project. [for solar thermal power plant development and commercialization

    NASA Technical Reports Server (NTRS)

    Ferber, R. R.; Marriott, A. T.; Truscello, V.

    1978-01-01

    The Small Power Systems Applications (SPSA) Project has been established to develop and commercialize small solar thermal power plants. The technologies of interest include all distributed and central receiver technologies which are potentially economically viable in power plant sizes of one to 10 MWe. The paper presents an overview of the SPSA Project and briefly discusses electric utility involvement in the Project.

  18. 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.

  19. Experimental and numerical investigation of hydro power generator ventilation

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  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. Modular Analysis of Automobile Exhaust Thermoelectric Power Generation System

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    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.

  2. Generating expansion model incorporating compact DC power flow equations

    SciTech Connect

    Nderitu, D.G.; Sparrow, F.T.; Yu, Z.

    1998-12-31

    This paper presents a compact method of incorporating the spatial dimension into the generation expansion problem. Compact DC power flow equations are used to provide real-power flow coordination equations. Using these equations the marginal contribution of a generator to th total system loss is formulated as a function of that generator`s output. Incorporating these flow equations directly into the MIP formulation of the generator expansion problem results in a model that captures a generator`s true net marginal cost, one that includes both the cost of generation and the cost of transport. This method contrasts with other methods that iterate between a generator expansion model and an optimal power flow model. The proposed model is very compact and has very good convergence performance. A case study with data from Kenya is used to provide a practical application to the model.

  3. 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)

  4. 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.

  5. Synchrophasor Applications for Wind Power Generation

    SciTech Connect

    Muljadi, E.; Zhang, Y. C.; Allen, A.; Singh, M.; Gevorgian, V.; Wan, Y. H.

    2014-02-01

    The U.S. power industry is undertaking several initiatives that will improve the operations of the electric power grid. One of those is the implementation of wide-area measurements using phasor measurement units to dynamically monitor the operations and status of the network and provide advanced situational awareness and stability assessment. The overviews of synchrophasors and stability analyses in this report are intended to present the potential future applications of synchrophasors for power system operations under high penetrations of wind and other renewable energy sources.

  6. Microwave power generation by magnetic superlattices

    NASA Astrophysics Data System (ADS)

    Littlejohn, S.; Nogaret, A.; Davies, S. R.; Henini, M.; Beere, H. E.; Ritchie, D. A.

    2011-12-01

    We report on microwave power emission by ballistic electrons as they cross a region of spatially inhomogeneous magnetic field. Magnetic finger gates were fabricated at the surface of high mobility GaAs/AlGaAs Hall bars embedded in a coplanar waveguide. By modulating the current injected through the Hall bar and measuring the second harmonic of the signal rectified by a Schottky detector, we obtain the microwave power emitted by the superlattice. This power (˜6 W m-2) is compared to the fluorescence of electron spins that undergo spin resonance as they cross domains of opposite magnetic field.

  7. Thermal management to avoid the collapse of current gain in power heterojunction bipolar transistors

    SciTech Connect

    Liu, W.

    1995-12-31

    One undesirable thermal phenomenon occurring in power heterojunction bipolar transistor is the collapse of current gain. This paper presents the electrical, electrical-thermal, thermal, and material approaches to avoid the collapse, and thus to improve the transistor output power.

  8. 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.

  9. Coal gasification for electric power generation.

    PubMed

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

    1982-03-26

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

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

    NASA Astrophysics Data System (ADS)

    Prakash, S.; Sinha, S. K.

    2015-09-01

    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.

  11. 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.

  12. 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.

  13. Thermal energy conversion to motive power

    SciTech Connect

    Meador, J.T.

    1980-01-01

    Performance evaluations of both ideal and actual organic Rankine cycle (ORC) and steam Rankine cycles (SRC) are presented for systems that may be candidates for Solar Total Energy Systems (STES). Many organic fluids and heat engines (turbines or expanders) are being developed; therefore, performance of a few representative ORCs are evaluated. The electrical power outputs range from several kW to <10 MW with maximum cycle temperatures of 482/sup 0/C (900 F). Conclusions from basic Rankine cycle analyses are that the Carnot cycle concept should not be used as a standard of comparison for different cycle fluids, even when they are operating at the same inlet and exhaust temperatures. The ideal Rankine cycle with the maximum conversion efficiency, when based on exact physical properties of fluids, should provide a better standard for actual cycles. Three sets of maximum (ideal) Rankine cycle efficiency (n/sub r/) curves are estimated for steam and several organic fluids for exhaust temperatures of 38/sup 0/C, 100/sup 0/C, and 149/sup 0/C (100 F, 212 F, and 300F). These curves of n/sub r/ versus peak temperature at the expander inlet are referred to as Criterion Curves for basic Rankine cycles, in which corresponding inlet pressures are selected such that n/sub r/ will be a maximum. Basic cycle efficiencies indicate some fluids preferred for solar total energy applications.

  14. 43 CFR 431.6 - Power generation estimates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Power generation estimates. 431.6 Section... BOULDER CANYON PROJECT, ARIZONA/NEVADA § 431.6 Power generation estimates. Reclamation shall submit annually on or before April 15 to Western and Contractors, an estimated annual operation schedule for...

  15. 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.

  16. Thermal-hydraulic analysis of the combustion engineering system 80 steam generator. Final report

    SciTech Connect

    Carlucci, L.N.

    1980-09-01

    This report presents the results of a thermal-hydraulic analysis of the Combustion Engineering SYSTEM 80 recirculating-type steam generator using THIRST - a three-dimensional, steady state, incompressible, homogeneous, two-phase flow computer code. The analysis was done for operating conditions corresponding to 100%, 60% and 20% of the nominal full power. Results are presented in the form of detailed printouts and computer-generated plots of quality, velocity and mass flux distributions. The printout data include calculated values of overall heat transfer, circulation ratio, hot-side cold-side flow split, inlet temperature, as well as velocity, quality, temperature, pressure and density fields.

  17. Power generation from conductive droplet sliding on electret film

    NASA Astrophysics Data System (ADS)

    Yang, Zhaochu; Halvorsen, Einar; Dong, Tao

    2012-05-01

    Generating electrical power from low frequency vibration to power portable devices is a challenge that potentially can be met by nonresonant electrostatic energy harvesters. We propose a generator employing a conductive droplet sliding on a microfabricated electret film which is sputtered onto an interdigital electrode and charged already during deposition. Droplet motion causes a capacitance variation that is used to generate electric power. A prototype of the fluidic energy harvester demonstrated a peak output power at 0.18 µW with a single droplet having a diameter of 1.2 mm and sliding on a 2 -µm thick electret film.

  18. Nuclear power generation and fuel cycle report 1997

    SciTech Connect

    1997-09-01

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

  19. Optical Property Evaluation of Next Generation Thermal Control Coatings

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Deshpande, Mukund S.; Pierson, Edward A.

    2010-01-01

    Next generation white thermal control coatings were developed via the Small Business Innovative Research program utilizing lithium silicate chemistry as a binder. Doping of the binder with additives yielded a powder that was plasma spray capable and that could be applied to light weight polymers and carbon-carbon composite surfaces. The plasma sprayed coating had acceptable beginning-of-life and end-of-live optical properties, as indicated by a successful 1.5 year exposure to the space environment in low Earth orbit. Recent studies also showed the coating to be durable to simulated space environments consisting of 1 keV and 10 keV electrons, 4.5 MeV electrons, and thermal cycling. Large scale deposition was demonstrated on a polymer matrix composite radiator panel, leading to the selection of the coating for use on the Gravity Recovery And Interior Laboratory (GRAIL) mission.

  20. 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

  1. Speed tolerant alternator system for wind or hydraulic power generation

    SciTech Connect

    Jallen, G.A.

    1984-07-24

    A wind electric generator employs a freewheeling clutch and an induction generator having several synchronous speeds. By selecting the synchronous speed as a function of the ambient wind speed, the generator can be made to operate more efficiently and without overloading. The freewheeling clutch which connects the generator to the wind turbine prevents the generator from acting as a motor when connected to a power grid, and wasting energy in turning the wind turbine.

  2. 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.

  3. Generation of Turbulent Inlet Conditions for Thermal Boundary Layer Simulations

    NASA Astrophysics Data System (ADS)

    Araya, Juan G.

    2005-11-01

    Realistic environments generally imply spatially evolving turbulent boundary layers, being the flat plate the typical example. In this case, periodic boundary conditions cannot be established in the streamwise direction as in fully developed flows in channels. For this reason, it is necessary to generate turbulent fluctuations at the inlet of the computational domain at every time step. Lund et al. (1998) proposed an ingenious method for accounting spatial growth in the inflow condition based on the similarity of the velocity profiles at different streamwise locations. They extracted a velocity field, from a downstream plane, rescaled it and reintroduced it as a boundary condition at the inlet of the domain. In a posterior study, Kong et al. (2000) extended the previous concept to thermal inflow generation predictions. This research proposes different scales in the inner and outer regions for simulating actual turbulent temperature fluctuations at the entrance of a computational domain based on the Lund's idea: the velocity scales are based on the work of George and Castillo (1997), meanwhile the temperature scaling is derived from investigations performed by Wang and Castillo (2003). Finally, Direct Numerical Simulations of evolving turbulent thermal boundary layers on a flat plate are performed to test the proposed inflow generation model.

  4. A global fouling factor methodology for analyzing steam generator thermal performance degradation

    SciTech Connect

    Kreider, M.A.; White, G.A.; Varrin, R.D. Jr.

    1998-06-01

    Over the past few years, steam generator (SG) thermal performance degradation has led to decreased plant efficiency and power output at numerous PWR nuclear power plants with recirculating-type SGs. The authors have developed and implemented methodologies for quantitatively evaluating the various sources of SG performance degradation, both internal and external to the SG pressure boundary. These methodologies include computation of the global fouling factor history, evaluation of secondary deposit thermal resistance using deposit characterization data, and consideration of pressure loss causes unrelated to the tube bundle, such as hot-leg temperature streaming and SG moisture separator fouling. In order to evaluate the utility of the global fouling factor methodology, the authors performed case studies for a number of PWR SG designs. Key results from two of these studies are presented here. In tandem with the fouling-factor analyses, a study evaluated for each plant the potential causes of pressure loss. The combined results of the global fouling factor calculations and the pressure-loss evaluations demonstrated two key points: (1) that the available thermal margin against fouling, which can vary substantially from plant to plant, has an important bearing on whether a given plant exhibits losses in electrical generating capacity, and (2) that a wide variety of causes can result in SG thermal performance degradation.

  5. Generation of quantum steering and interferometric power in the dynamical Casimir effect

    NASA Astrophysics Data System (ADS)

    Sabín, Carlos; Adesso, Gerardo

    2015-10-01

    We analyze the role of the dynamical Casimir effect as a resource for quantum technologies, such as quantum cryptography and quantum metrology. In particular, we consider the generation of Einstein-Podolsky-Rosen steering and Gaussian interferometric power, two useful forms of asymmetric quantum correlations, in superconducting waveguides modulated by superconducting quantum interferometric devices. We show that while a certain value of squeezing is required to overcome thermal noise and give rise to steering, any nonzero squeezing produces interferometric power which in fact increases with thermal noise.

  6. Choosing Actuators for Automatic Control Systems of Thermal Power Plants

    SciTech Connect

    Gorbunov, A. I.; Serdyukov, O. V.

    2015-03-15

    Two types of actuators for automatic control systems of thermal power plants are analyzed: (i) pulse-controlled actuator and (ii) analog-controlled actuator with positioning function. The actuators are compared in terms of control circuit, control accuracy, reliability, and cost.

  7. 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.

  8. Prospects for solving environmental problems pertinent to thermal power stations

    NASA Astrophysics Data System (ADS)

    Tumanovskii, A. G.; Kotler, V. R.

    2007-06-01

    Possible ways to protect the atmosphere and water basin against harmful emissions and effluent waters discharged from thermal power stations are considered. Data on the effectiveness of different methods for removing NO x , SO2, and ash particles, as well as heavy metals and CO2, from these emissions and discharges are presented.

  9. Optical fiber instrumentation of a high power generator and turbine

    NASA Astrophysics Data System (ADS)

    da Silva, Erlon Vagner; Dreyer, Uilian José; de Morais Sousa, Kleiton; Babinski, Valderi Junot; Somenzi, Jonas; Mezzadri, Felipe; de Lourenço Junior, Ivo; Martelli, Cicero; Cardozo da Silva, Jean Carlos

    2013-05-01

    The instrumentation of a high power generator and its complementary systems including the turbine bearings is presented and discussed. The generator consists of a 175MW hydroelectric generator installed in the Salto Osório power plant in the southern region of Brazil. Results show good agreement with the already existing instrumentation and demonstrate the technology potential for a full optical fiber sensing system to monitor these large machines.

  10. Nuclear power generation and fuel cycle report 1996

    SciTech Connect

    1996-10-01

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

  11. Protective, Modular Wave Power Generation System

    SciTech Connect

    Vvedensky, Jane M.; Park, Robert Y.

    2012-11-27

    The concept of small wave energy conversion modules that can be built into large, scalable arrays, in the same vein as solar panels, has been developed. This innovation lends itself to an organic business and development model, and enables the use of large-run manufacturing technology to reduce system costs. The first prototype module has been built to full-scale, and tested in a laboratory wave channel. The device has been shown to generate electricity and dissipate wave energy. Improvements need to be made to the electrical generator and a demonstration of an array of modules should be made in natural conditions.

  12. Lifetime prediction modeling of airfoils for advanced power generation

    NASA Astrophysics Data System (ADS)

    Karaivanov, Ventzislav Gueorguiev

    The use of gases produced from coal as a turbine fuel offers an attractive means for efficiently generating electric power from our Nation's most abundant fossil fuel resource. The oxy-fuel and hydrogen-fired turbine concepts promise increased efficiency and low emissions on the expense of increased turbine inlet temperature (TIT) and different working fluid. Developing the turbine technology and materials is critical to the creation of these near-zero emission power generation technologies. A computational methodology, based on three-dimensional finite element analysis (FEA) and damage mechanics is presented for predicting the evolution of creep and fatigue in airfoils. We took a first look at airfoil thermal distributions in these advanced turbine systems based on CFD analysis. The damage mechanics-based creep and fatigue models were implemented as user modified routine in commercial package ANSYS. This routine was used to visualize the creep and fatigue damage evolution over airfoils for hydrogen-fired and oxy-fuel turbines concepts, and regions most susceptible to failure were indentified. Model allows for interaction between creep and fatigue damage thus damage due to fatigue and creep processes acting separately in one cycle will affect both the fatigue and creep damage rates in the next cycle. Simulation results were presented for various thermal conductivity of the top coat. Surface maps were created on the airfoil showing the development of the TGO scale and the Al depletion of the bond coat. In conjunction with model development, laboratory-scale experimental validation was executed to evaluate the influence of operational compressive stress levels on the performance of the TBC system. TBC coated single crystal coupons were exposed isothermally in air at 900, 1000, 1100oC with and without compressive load. Exposed samples were cross-sectioned and evaluated with scanning electron microscope (SEM). Performance data was collected based on image analysis. Energy-dispersive x-ray (EDX) was employed to study the elemental distribution in TBC system after exposure. Nanoindentation was used to study the mechanical properties (Young's modulus and hardness) of the components in the TBC system and their evolution with temperature and time.

  13. Metal hydrides for concentrating solar thermal power energy storage

    NASA Astrophysics Data System (ADS)

    Sheppard, D. A.; Paskevicius, M.; Humphries, T. D.; Felderhoff, M.; Capurso, G.; Bellosta von Colbe, J.; Dornheim, M.; Klassen, T.; Ward, P. A.; Teprovich, J. A.; Corgnale, C.; Zidan, R.; Grant, D. M.; Buckley, C. E.

    2016-04-01

    The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost of concentrating solar thermal power. We focus on the underlying technology that allows metal hydrides to function as thermal energy storage (TES) systems and highlight the current state-of-the-art materials that can operate at temperatures as low as room temperature and as high as 1100 °C. The potential of metal hydrides for thermal storage is explored, while current knowledge gaps about hydride properties, such as hydride thermodynamics, intrinsic kinetics and cyclic stability, are identified. The engineering challenges associated with utilising metal hydrides for high-temperature TES are also addressed.

  14. High power density alkali metal thermal to electric converter

    NASA Astrophysics Data System (ADS)

    Sievers, R. K.; Wright, R. F.

    A description is given of the alkali metal thermal-to-electric converter (AMTEC), an emerging technology for static power conversion that has the potential of matching dynamic system efficiency. This high efficiency is produced when cells of beta double prime alumina solid electrolyte (BASE) are series connected, packed in a space-efficient manner, and designed to minimize parasitic heat loss. Design studies have shown that power densities of up to 400 W/kg and efficiencies of up to 35 percent are feasible. This is higher than power densities and efficiencies reported for other AMTEC designs, but continued design studies are necessary to assess applications.

  15. Heat engine development for solar thermal power systems

    NASA Technical Reports Server (NTRS)

    Pham, H. Q.; Jaffe, L. D.

    1981-01-01

    The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

  16. Thermal control of power supplies with electronic packaging techniques

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The analysis, design, and development work to reduce the weight and size of a standard modular power supply with a 350 watt output was summarized. By integrating low cost commercial heat pipes in the redesign of this power supply, weight was reduced by 30% from that of the previous design. The temperature was also appreciably reduced, increasing the environmental capability of the unit. A demonstration unit with a 100 watt output and a 15 volt regulator module, plus simulated output modules, was built and tested to evaluate the thermal performance of the redesigned power supply.

  17. Alternative power generation concepts for space

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.; Juhasz, Albert J.; Jones, Barbara I.

    1986-01-01

    Trade and optimization studies that highlight the potential of solar and nuclear dynamic systems relative to photovoltaic power systems are summarized. The solar dynamic case is the LEO Stirling system, while the nuclear system is the SP-100 system goal. Nuclear systems have the potential for the lightest weight, least area, sunlight independent, radiation-durable system. Solar dynamic systems pose a stiff challenge to photovoltaic systems in the midaltitudes because of their insensitivity to the Van Allen radiation belts. While the initial operational capability space station power system is only slightly superior to the SOA PV system, with development focused on the key technologies, advanced solar dynamic systems are fully competitive in LEO midaltitudes with the advanced photovoltaic systems. Advances in energy storage systems (100 Whrs/kg required) are essential.

  18. Power generating system and method utilizing hydropyrolysis

    DOEpatents

    Tolman, R.

    1986-12-30

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

  19. Solar powered Stirling cycle electrical generator

    NASA Technical Reports Server (NTRS)

    Shaltens, Richard K.

    1991-01-01

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

  20. Solar powered Stirling cycle electrical generator

    NASA Astrophysics Data System (ADS)

    Shaltens, Richard K.

    1991-03-01

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

  1. Active thermal control for an advanced power platform

    NASA Technical Reports Server (NTRS)

    Owen, J. W.; Stein, D. S.

    1981-01-01

    Effective use of the Shuttle Orbiter during the operational phase will require the provision of electrical power from free-flying power platforms which will interface with the Orbiter. Such platforms present unique requirements for active thermal control based upon the long life and high heat load requirements which will be necessary to provide 25 kW or more of electricity to the Orbiter and payloads. This paper will present key issues in the design of these active thermal control systems (ATCS) and will discuss potential solutions intended to ensure maximum effectiveness of advanced power platforms. Such issues include proper selection of coolant fluid for the power platform and payload loops; selection and development of thermal control surfaces for five-year life; the use of off-the-shelf hardware vs development of unique hardware, central vs decentralized control of the ATCS; system life and reliability as a factor in determining redundancy and the possibility of on-orbit EVA maintenance; and the interfaces between the power platform and the Orbiter and payloads.

  2. Electricity generation and transmission planning in deregulated power markets

    NASA Astrophysics Data System (ADS)

    He, Yang

    This dissertation addresses the long-term planning of power generation and transmission facilities in a deregulated power market. Three models with increasing complexities are developed, primarily for investment decisions in generation and transmission capacity. The models are presented in a two-stage decision context where generation and transmission capacity expansion decisions are made in the first stage, while power generation and transmission service fees are decided in the second stage. Uncertainties that exist in the second stage affect the capacity expansion decisions in the first stage. The first model assumes that the electric power market is not constrained by transmission capacity limit. The second model, which includes transmission constraints, considers the interactions between generation firms and the transmission network operator. The third model assumes that the generation and transmission sectors make capacity investment decisions separately. These models result in Nash-Cournot equilibrium among the unregulated generation firms, while the regulated transmission network operator supports the competition among generation firms. Several issues in the deregulated electric power market can be studied with these models such as market powers of generation firms and transmission network operator, uncertainties of the future market, and interactions between the generation and transmission sectors. Results deduced from the developed models include (a) regulated transmission network operator will not reserve transmission capacity to gain extra profits; instead, it will make capacity expansion decisions to support the competition in the generation sector; (b) generation firms will provide more power supplies when there is more demand; (c) in the presence of future uncertainties, the generation firms will add more generation capacity if the demand in the future power market is expected to be higher; and (d) the transmission capacity invested by the transmission network operator depends on the characteristic of the power market and the topology of the transmission network. Also, the second model, which considers interactions between generation and transmission sectors, yields higher social welfare in the electric power market, than the third model where generation firms and transmission network operator make investment decisions separately.

  3. Thermal design studies of high-power heterojunction bipolar transistors

    NASA Astrophysics Data System (ADS)

    Gao, Guang-Bo; Wang, Ming-Zhu; Gui, Xiang; Morkoc, Hadis

    1989-05-01

    A theoretical thermoelectro-feedback model has been developed for the thermal design of high-power GaAlAs/GaAs heterojunction bipolar transistors (HBTs). The power-handling capability, thermal instability, junction temperature, and current distributions of HBTs with multiple emitter fingers have been numerically studied. The calculated results indicate that power HBTs on Si substrates (or with Si as the collector) have excellent potential power performance and reliability. The power-handling capability on Si is 3.5 and 2.7 times as large as that on GaAs and InP substrates, respectively. The peak junction temperature and temperature difference on the chip decrease in comparison to the commonly used Si homostructure power transistors with the same geometry and power dissipation. Thereby HBTs are promising for high-speed microwave and millimeter-wave applications. It has been also found that the nonuniform distribution of junction temperature and current can be greatly improved by a balasting technique that uses unequal-value emitter resistors.

  4. Effect of thermal power plant emissions on Catharanthus roseus L

    SciTech Connect

    Khan, A.M.; Pandey, V.; Shukla, J.; Singh, N.; Yunus, M.; Singh, S.N.; Ahmad, K.J. )

    1990-06-01

    Most of the industrialized nations depend largely on the combustion of fossil fuels for their energy requirements. During the past few years in India quite a few thermal power plants have been commissioned to cater to the increasing energy requirements. As most of the power plants are coal-fired, a complex mixture of several pollutants is released in the atmosphere on the combustion of coal. Leaves by virtue of their unique position on plants and their functions, experience the maximum brunt of exposure and undergo certain changes in form, structure and function with the changes in surrounding environs, and such modifications are likely to serve as markers of environmental pollution. The present paper deals with the long term exposure effects of thermal power plant emissions on Catharanthus roseus L. - a common perennial shrub, with glossy leaves and white, mauve or pink colored flowers and of great medicinal value is grown as an ornamental plant all over the country.

  5. Thermal effects in high average power optical parametric amplifiers.

    PubMed

    Rothhardt, Jan; Demmler, Stefan; Hädrich, Steffen; Peschel, Thomas; Limpert, Jens; Tünnermann, Andreas

    2013-03-01

    Optical parametric amplifiers (OPAs) have the reputation of being average power scalable due to the instantaneous nature of the parametric process (zero quantum defect). This Letter reveals serious challenges originating from thermal load in the nonlinear crystal caused by absorption. We investigate these thermal effects in high average power OPAs based on beta barium borate. Absorption of both pump and idler waves is identified to contribute significantly to heating of the nonlinear crystal. A temperature increase of up to 148 K with respect to the environment is observed and mechanical tensile stress up to 40 MPa is found, indicating a high risk of crystal fracture under such conditions. By restricting the idler to a wavelength range far from absorption bands and removing the crystal coating we reduce the peak temperature and the resulting temperature gradient significantly. Guidelines for further power scaling of OPAs and other nonlinear devices are given. PMID:23455291

  6. Towards optimizing the efficiency of electrical power generation

    SciTech Connect

    Al-Zubaidy, S.; Bhinder, F.S.

    1996-12-31

    The thermal efficiency of a gas turbine engine, which ranges between 28% to 33%, may be raised by recovering some of the low grade thermal energy from the exhaust gas to heat the high pressure air leaving the compressor. The overall thermal efficiency of a combined power and power (CCP) cogeneration plant can be raised to about 60%. This is twice the value that may be reached by a modern gas turbine and nearly one and a half times the value that may be reached by a modern steam turbine. The work presented in this paper is an initial and preliminary study of a sponsored project that examines the effect of design parameters on overall performance of the power cycle with the view of producing a code that enables researchers to produce a complete computer simulation of the CCP for the purpose of developing control strategies.

  7. A mechatronic power boosting design for piezoelectric generators

    NASA Astrophysics Data System (ADS)

    Liu, Haili; Liang, Junrui; Ge, Cong

    2015-10-01

    It was shown that the piezoelectric power generation can be boosted by using the synchronized switch power conditioning circuits. This letter reports a self-powered and self-sensing mechatronic design in substitute of the auxiliary electronics towards a compact and universal synchronized switch solution. The design criteria are derived based on the conceptual waveforms and a two-degree-of-freedom analytical model. Experimental result shows that, compared to the standard bridge rectifier interface, the mechatronic design leads to an extra 111% increase of generated power from the prototyped piezoelectric generator under the same deflection magnitude excitation. The proposed design has introduced a valuable physical insight of electromechanical synergy towards the improvement of piezoelectric power generation.

  8. Combined fuel and air staged power generation system

    SciTech Connect

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

    2014-05-27

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

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

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

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

  10. Power plant V - Thek generating station

    NASA Astrophysics Data System (ADS)

    Pons, M.

    The design and operating features of a 10 MWe parabolic dish concentrator steam-cycle generating plant are described. The dishes which have 75 sq m area with a concentration factor of 265, were proved in the Themis project. The total field for the 10 MWe would cover 63,100 sq m and require 842 units. Using a water-steam cycle at 50 bars, temperature would never surpass 264 C, with an after-generator condition of 33 bars at 204 C. Preheating the water is intended with a fused salt reservoir containing 570 tons in 350 cu m container, around which condensed water would flow. Maintaining the primary loop at mildly elevated temperatures would permit uninterrupted operation during cloudy periods. A total shutdown would occur if cloudy conditions last more than one hour, and start-up would involve reheating the primary loop, recharging the storage, and then respinning the turbine.

  11. Plasma plume MHD power generator and method

    DOEpatents

    Hammer, James H.

    1993-01-01

    Highly-conducting plasma plumes are ejected across the interplanetary magnetic field from a situs that is moving relative to the solar wind, such as a spacecraft or an astral body, such as the moon, having no magnetosphere that excludes the solar wind. Discrete plasma plumes are generated by plasma guns at the situs extending in opposite directions to one another and at an angle, preferably orthogonal, to the magnetic field direction of the solar wind plasma. The opposed plumes are separately electrically connected to their source by a low impedance connection. The relative movement between the plasma plumes and the solar wind plasma creates a voltage drop across the plumes which is tapped by placing the desired electrical load between the electrical connections of the plumes to their sources. A portion of the energy produced may be used in generating the plasma plumes for sustained operation.

  12. Neural-net based real-time economic dispatch for thermal power plants

    SciTech Connect

    Djukanovic, M.; Milosevic, B.; Calovic, M.; Sobajic, D.J.

    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.

  13. Role of heat generation and thermal diffusion during frontal photopolymerization.

    PubMed

    Hennessy, Matthew G; Vitale, Alessandra; Cabral, João T; Matar, Omar K

    2015-08-01

    Frontal photopolymerization (FPP) is a rapid and versatile solidification process that can be used to fabricate complex three-dimensional structures by selectively exposing a photosensitive monomer-rich bath to light. A characteristic feature of FPP is the appearance of a sharp polymerization front that propagates into the bath as a planar traveling wave. In this paper, we introduce a theoretical model to determine how heat generation during photopolymerization influences the kinetics of wave propagation as well as the monomer-to-polymer conversion profile, both of which are relevant for FPP applications and experimentally measurable. When thermal diffusion is sufficiently fast relative to the rate of polymerization, the system evolves as if it were isothermal. However, when thermal diffusion is slow, a thermal wavefront develops and propagates at the same rate as the polymerization front. This leads to an accumulation of heat behind the polymerization front which can result in a significant sharpening of the conversion profile and acceleration of the growth of the solid. Our results also suggest that a novel way to tailor the dynamics of FPP is by imposing a temperature gradient along the growth direction. PMID:26382412

  14. Hydrogen-based power generation from bioethanol steam reforming

    NASA Astrophysics Data System (ADS)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  15. Cascade Failures in Power Grids with Distributed Generation

    NASA Astrophysics Data System (ADS)

    Scala, Antonio; Pahwa, Sakshi; Scoglio, Caterina; ISC InstituteComplex Systems Team; Department of Electrical and Computer Engineering Team

    2013-03-01

    Power grids are nowadays experiencing a transformation due to the introduction of Distributed Generation based on Renewable Sources. At difference with classical Distributed Generation, where local power sources mitigate anomalous user consumption peaks, Renewable Sources introduce in the grid intrinsically erratic power inputs. By introducing a simple schematic (but realistic) model for power grids with stochastic distributed generation, we study the effects of erratic sources on the robustness of several IEEE power grid test networks with up to 2 103 buses. We find that increasing the penetration of erratic sources causes the grid to fail with a sharp transition. We compare such results with the case of failures caused by the natural increasing power demand. US grant HDTRA1-11-1-0048, CNR-PNR National Project Crisis-Lab, US Department of Energy grant EE-0003812

  16. 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.

  17. Nernst advection and the field-generating thermal instability revisited

    NASA Astrophysics Data System (ADS)

    Bissell, J. J.

    2015-01-01

    It is widely held that the Nernst effect can drive instability in un-magnetised laser-plasmas by laterally compressing seed B-fields arising from the field-generating thermal instability [Tidman & Shanny, Phys. Fluids, 12:1207 (1974)]. Indeed, for wavelike perturbations, differential compression by the Nernst mechanism is thought to be most pronounced in the limit of low wave-number k -> 0, and is considered particularly important given that it can ostensibly lead to instability when the more usual field-generating mechanism is stable. However, as part of a recent article [Bissell et al., New J. Phys., 15:025017 (2013)] we noted some irregularities to the Nernst mechanism which obscure its operation. For example, by taking characteristic density and temperature length-scales ln and lT respectively, we observed that consistent analytical treatment of the instability requires kln,T >> 1, preventing the peak-growth limit k -> 0. Furthermore, the Nernst term-which compresses magnetic field perturbations-does not couple to a corresponding term acting on thermal perturbations, and as such does not describe an unstable feedback mechanism. In this article we probe the origin of such ambiguities more formally, and in so doing argue (contrary to reports existing elsewhere in the literature) that the Nernst effect does not drive instability in un-magnetised conditions, at least not in the fashion typically cited.

  18. Possible ways of reducing the effect of thermal power facilities on the environment

    NASA Astrophysics Data System (ADS)

    Zroichikov, N. A.; Prokhorov, V. B.; Tupov, V. B.; Arkhipov, A. M.; Fomenko, M. V.

    2015-02-01

    The main trends in the integrated solution of thermal power engineering environmental problems are pointed out taking the Mosenergo power company as an example, and the data are given with respect to the structure of the power engineering equipment of the city of Moscow and its change, energy consumption, and generation of heat and electric energy. The dynamics of atmospheric air pollution of Moscow from 1990 to 2010, as well as the main measures on reducing the adverse effect of the power engineering equipment operation, is given. The results of original designs by the Department of Boiler Installations and Power Engineering Ecology (KU&EE) are given concerning the reduction of nitrogen oxides emissions and the decrease of the noise impact produced by the power engineering equipment.

  19. Thermally regenerative hydrogen/oxygen fuel cell power cycles

    NASA Technical Reports Server (NTRS)

    Morehouse, J. H.

    1986-01-01

    Two innovative thermodynamic power cycles are analytically examined for future engineering feasibility. The power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The TDS (thermal dissociation system) uses a thermal energy input at over 2000 K to thermally dissociate the water. The other cycle, the HTE (high temperature electrolyzer) system, dissociates the water using an electrolyzer operating at high temperature (1300 K) which receives its electrical energy from the fuel cell. The primary advantages of these cycles is that they are basically a no moving parts system, thus having the potential for long life and high reliability, and they have the potential for high thermal efficiency. Both cycles are shown to be classical heat engines with ideal efficiency close to Carnot cycle efficiency. The feasibility of constructing actual cycles is investigated by examining process irreversibilities and device efficiencies for the two types of cycles. The results show that while the processes and devices of the 2000 K TDS exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development. The requirements for very high electrolyzer and fuel cell efficiencies are seen as determining the feasbility of the HTE system, and these high efficiency devices are currently being developed. It is concluded that a proof-of-concept HTE system experiment can and should be conducted.

  20. A Feasibility Study of Oscillating-Wing Power Generators

    NASA Astrophysics Data System (ADS)

    Lindsey, Keon

    2002-09-01

    Mankind is continually searching for new sources of energy or methods to harness known sources. Recently, renewable and zero-pollution energy supplies are of great interest. Consequently, power generation from a fluttering wing is studied numerically and experimentally. Previous studies have suggested that an oscillating-wing used to extract energy from a fluid flow could deliver power comparable to windmills. Several studies are examined. An oscillating-wing power generator is designed and tested. The experimental results are compared with numerical predictions. Finally, commercial applications of the "environmentally friendly" oscillating-wing generator are investigated.

  1. Forecasting Electric Power Generation of Photovoltaic Power System for Energy Network

    NASA Astrophysics Data System (ADS)

    Kudo, Mitsuru; Takeuchi, Akira; Nozaki, Yousuke; Endo, Hisahito; Sumita, Jiro

    Recently, there has been an increase in concern about the global environment. Interest is growing in developing an energy network by which new energy systems such as photovoltaic and fuel cells generate power locally and electric power and heat are controlled with a communications network. We developed the power generation forecast method for photovoltaic power systems in an energy network. The method makes use of weather information and regression analysis. We carried out forecasting power output of the photovoltaic power system installed in Expo 2005, Aichi Japan. As a result of comparing measurements with a prediction values, the average prediction error per day was about 26% of the measured power.

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

    SciTech Connect

    ST.LAURENT,STEVEN J.

    2000-08-14

    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 this technology in large-scale (10MW to 100MW) solar thermal power plants. Since December 1999, solar engineers at Sandia National Laboratories' National Solar Thermal Test Facility (NSTTF) have designed and are constructing a thermal storage test called the thermocline system. This technology, which employs a single thermocline tank, has the potential to replace the traditional and more expensive two-tank storage systems. The thermocline tank approach uses a mixture of silica sand and quartzite rock to displace a significant portion of the volume in the tank. Then it is filled with the heat transfer fluid, a molten nitrate salt. A thermal gradient separates the hot and cold salt. Loading the tank with the combination of sand, rock, and molten salt instead of just molten salt dramatically reduces the system cost. The typical cost of the molten nitrate salt is $800 per ton versus the cost of the sand and rock portion at $70 per ton. Construction of the thermocline system will be completed in August 2000, and testing will run for two to three months. The testing results will be used to determine the economic viability of the single-tank (thermocline) storage technology for large-scale solar thermal power plants. Also discussed in this paper are the safety issues involving molten nitrate salts and other heat transfer fluids, such as synthetic heat transfer oils, and the impact of these issues on the system design.

  3. Optimal generator bidding strategies for power and ancillary services

    NASA Astrophysics Data System (ADS)

    Morinec, Allen G.

    As the electric power industry transitions to a deregulated market, power transactions are made upon price rather than cost. Generator companies are interested in maximizing their profits rather than overall system efficiency. A method to equitably compensate generation providers for real power, and ancillary services such as reactive power and spinning reserve, will ensure a competitive market with an adequate number of suppliers. Optimizing the generation product mix during bidding is necessary to maximize a generator company's profits. The objective of this research work is to determine and formulate appropriate optimal bidding strategies for a generation company in both the energy and ancillary services markets. These strategies should incorporate the capability curves of their generators as constraints to define the optimal product mix and price offered in the day-ahead and real time spot markets. In order to achieve such a goal, a two-player model was composed to simulate market auctions for power generation. A dynamic game methodology was developed to identify Nash Equilibria and Mixed-Strategy Nash Equilibria solutions as optimal generation bidding strategies for two-player non-cooperative variable-sum matrix games with incomplete information. These games integrated the generation product mix of real power, reactive power, and spinning reserve with the generators's capability curves as constraints. The research includes simulations of market auctions, where strategies were tested for generators with different unit constraints, costs, types of competitors, strategies, and demand levels. Studies on the capability of large hydrogen cooled synchronous generators were utilized to derive useful equations that define the exact shape of the capability curve from the intersections of the arcs defined by the centers and radial vectors of the rotor, stator, and steady-state stability limits. The available reactive reserve and spinning reserve were calculated given a generator operating point in the P-Q plane. Four computer programs were developed to automatically perform the market auction simulations using the equal incremental cost rule. The software calculates the payoffs for the two competing competitors, dispatches six generators, and allocates ancillary services for 64 combinations of bidding strategies, three levels of system demand, and three different types of competitors. Matrix Game theory was utilized to calculate Nash Equilibrium solutions and mixed-strategy Nash solutions as the optimal generator bidding strategies. A method to incorporate ancillary services into the generation bidding strategy, to assure an adequate supply of ancillary services, and to allocate these necessary resources to the on-line units was devised. The optimal generator bid strategy in a power auction was shown to be the Nash Equilibrium solution found in two-player variable-sum matrix games.

  4. The generation of pollution-free electrical power from solar energy.

    NASA Technical Reports Server (NTRS)

    Cherry, W. R.

    1971-01-01

    Projections of the U.S. electrical power demands over the next 30 years indicate that the U.S. could be in grave danger from power shortages, undesirable effluence, and thermal pollution. An appraisal of nonconventional methods of producing electrical power is conducted, giving particular attention to the conversion of solar energy into commercial quantities of electrical power by solar cells. It is found that 1% of the land area of the 48 states could provide the total electrical power requirements of the U.S. in the year 1990. The ultimate method of generating vast quantities of electrical power would be from a series of synchronous satellites which beam microwave power back to earth to be used wherever needed. Present high manufacturing costs of solar cells could be substantially reduced by using massive automated techniques employing abundant low cost materials.

  5. Entropy production and thermodynamic power of the squeezed thermal reservoir

    NASA Astrophysics Data System (ADS)

    Manzano, Gonzalo; Galve, Fernando; Zambrini, Roberta; Parrondo, Juan M. R.

    2016-05-01

    We analyze the entropy production and the maximal extractable work from a squeezed thermal reservoir. The nonequilibrium quantum nature of the reservoir induces an entropy transfer with a coherent contribution while modifying its thermal part, allowing work extraction from a single reservoir, as well as great improvements in power and efficiency for quantum heat engines. Introducing a modified quantum Otto cycle, our approach fully characterizes operational regimes forbidden in the standard case, such as refrigeration and work extraction at the same time, accompanied by efficiencies equal to unity.

  6. Thermal power spectrum in the CFT driven cosmology

    SciTech Connect

    Barvinsky, A.O.

    2013-10-01

    We present an overview of the recently suggested cosmological model driven by conformal field theory (CFT) with the initial conditions in the form of the microcanonical density matrix. In particular, we discuss the origin of inflationary stage in this model and a novel feature — the thermal nature of the primordial power spectrum of the CMB anisotropy. The relevant effect of ''temperature of the relic temperature anisotropy'' can be responsible for a thermal contribution to the red tilt of this spectrum, additional to its conventional vacuum component. The amplification of this effect due to recently established a-theorem in CFT is briefly discussed.

  7. 76 FR 36914 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... LLC, Astoria Gas Turbine Power LLC, Dunkirk Power LLC, Huntley Power LLC, Oswego Harbor Power LLC, TC..., 2011, Astoria Generating Company, NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

  8. In Hot Water: Thermoelectric Power and Thermal Pollution

    NASA Astrophysics Data System (ADS)

    Madden, N. T.

    2010-12-01

    The use of surface water for thermoelectric power plant cooling significantly impacts river water temperatures, posing risks to aquatic ecosystems. In addition, surface water temperatures in summer can exceed limits for power plant compliance with thermal effluent limitations, jeopardizing energy security during periods of peak power demand. For example, Brown's Ferry Nuclear Plant in Alabama curtailed power production by 50% for over 40 days in July-August of 2010 when river temperatures exceeded 90°F. Future increases in surface water temperatures due to climate change may further endanger energy security. This study examines summer intake and outflow water temperature data reported by power plants during peak production months across the United States to determine the impact of thermoelectric power plants on surface water temperatures in the summer. Initial results indicate that U.S. coal plants (n= 625) raised water temperatures by an average of 17°F (± 12°F) and discharged cooling water with median peak temperatures of 100°F (± 13°F) in the summer of 2005, the last year when this data was reliably reported. Further analysis will extend the time period of this study from 2000-2005 and expand the scope to various energy sources and cooling technologies. In addition, we explore regional variation to assess the relative threat that thermal pollution poses to energy security across the U.S.

  9. Comparison of electrochemical and thermal storage for hybrid parabolic dish solar power plants

    NASA Technical Reports Server (NTRS)

    Steele, H. L.; Wen, L.

    1981-01-01

    The economic and operating performance of a parabolic point focus array of solar electricity generators combined with either battery or thermal energy storage are examined. Noting that low-cost, mass-producible power generating units are under development for the point focus of distributed dishes, that Zn-Cl battery tests will begin in 1981 and a 100 kWh Na-S battery in 1983, the state of thermal storage requires acceleration to reach the prototype status of the batteries. Under the assumptions of 10,000 units/yr with an expected 30 yr lifetime, cost comparisons are developed for 10 types of advanced batteries. A 5 MWe plant with full thermal or 80% battery storage discharge when demand occurs in conditions of no insolation is considered, specifically for Fe-Cr redox batteries. A necessity for the doubling of fuel prices from 1980 levels by 1990 is found in order to make the systems with batteries economically competitive.

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

    SciTech Connect

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

    1981-01-01

    The NASA Lewis Research Center (LeRC) as Project Manager of the Department of Energy's Automotive Heat Energy Program, is developing advanced gas turbine and Stirling engines for automobiles. To accomplish the program goals of improved fuel economy, reduced emissions, and broad alternative fuel capability, major development programs have been undertaken for both engines. These programs are described along with the predicted characteristics of the engines under development and the key technology problems that must be resolved to achieve these objectives. NASA LeRC is also responsible for the development of the power conversion systems for the Parabolic Dish Solar Thermal Power Systems being developed for the Department of Energy by NASA Jet Propulsion Laboratory. The requirements of this solar thermal application are reviewed and compared with the predicted characteristics of the automobile engines under development. A good match was found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65 to 100 kW (87 to 133 hp) were operated to the nominal 20 to 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. However, in-depth studies are required to determine the extent of modifications required to adapt the engines for the solar application, and to fully assess the probable life, durability and resultant efficiency that can realistically be achieved in this application.

  11. Multirail electromagnetic launcher powered from a pulsed magnetohydrodynamic generator

    NASA Astrophysics Data System (ADS)

    Afonin, A. G.; Butov, V. G.; Panchenko, V. P.; Sinyaev, S. V.; Solonenko, V. A.; Shvetsov, G. A.; Yakushev, A. A.

    2015-09-01

    The operation of an electromagnetic multirail launcher of solids powered from a pulsed magnetohydrodynamic (MHD) generator is studied. The plasma flow in the channel of the pulsed MHD generator and the possibility of launching solids in a rapid-fire mode of launcher operation are considered. It is shown that this mode of launcher operation can be implemented by matching the plasma flow dynamics in the channel of the pulsed MHD generator and the launching conditions. It is also shown that powerful pulsed MHD generators can be used as a source of electrical energy for rapid-fire electromagnetic rail launchers operating in a burst mode.

  12. Pressurized circulating fluidized-bed combustion for power generation

    SciTech Connect

    Weimer, R.F.

    1995-08-01

    Second-generation Pressurized Circulating Fluidized Bed Combustion (PCFBC) is the culmination of years of effort in the development of a new generation of power plants which can operate on lower-quality fuels with substantially improved efficiencies, meet environmental requirements, and provide a lower cost of electricity. Air Products was selected in the DOE Clean Coal Technology Round V program to build, own, and operate the first commercial power plant using second-generation PCFBC technology, to be located at an Air Products chemicals manufacturing facility in Calvert City, Kentucky. This paper describes the second-generation PCFBC concept and its critical technology components.

  13. Microcombustor-thermoelectric power generator for 10-50 watt applications

    NASA Astrophysics Data System (ADS)

    Marshall, Daniel S.; Cho, Steve T.

    2010-04-01

    Fuel-based portable power systems, including combustion and fuel cell systems, take advantage of the 80x higher energy density of fuel over lithium battery technologies and offer the potential for much higher energy density power sources - especially for long-duration applications, such as unattended sensors. Miniaturization of fuel-based systems poses significant challenges, including processing of fuel in small channels, catalyst poisoning, and coke and soot formation. Recent advances in micro-miniature combustors in the 200Watt thermal range have enabled the development of small power sources that use the chemical energy of heavy fuel to drive thermal-to-electric converters for portable applications. CUBE Technology has developed compact Micro-Furnace combustors that efficiently deliver high-quality heat to optimized thermal-to-electric power converters, such as advanced thermoelectric power modules and Stirling motors, for portable power generation at the 10-50Watt scale. Key innovations include a compact gas-gas recuperator, innovative heavy fuel processing, coke- & soot-free operation, and combustor optimization for low balance-of-plant power use while operating at full throttle. This combustor enables the development of robust, high energy density, miniature power sources for portable applications.

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

    NASA Astrophysics Data System (ADS)

    Huovilainen, Reino; Alamaeki, Jarmo; Tarjanne, Risto

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

  15. The Feasibility of a Current-Source Thermoelectric Power Generator and Its Corresponding Structure Design

    NASA Astrophysics Data System (ADS)

    Wu, Guangxi; Yu, Xiong

    2015-06-01

    Traditional thermoelectric power generators consist of thermoelectric elements connected electrically in series and thermally in parallel. Current flowing inside the thermoelectric power generator is conventionally considered to be driven by the Seebeck effect-induced electric field and the output voltage-induced reverse electric field. This paper proposes a more comprehensive model that implies that current is also driven by chemical potential and carrier density variation. Therefore, the thermoelectric power generator can be treated as a current-source power supplier when the current driven by carrier density variation dominates. This paper performs holistic finite element implementation of the new holistic model where a thermoelectric power generator unit behaves like a current-source while the working temperature conditions maintain stability. This result validates that the thermoelectric element shows the behaviors of a current-source power supply under certain conditions. This discovery brings a new perspective on the behaviors of thermoelectric elements, which potentially will lead to the development of novel thermoelectric power generator design.

  16. Thermal Cycling and High Temperature Reverse Bias Testing of Control and Irradiated Gallium Nitride Power Transistors

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    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 and testing under high temperature reverse bias conditions in order to address their reliability for use in space missions. Result of the experimental work are presented and discussed.

  17. A power conditioning system for radioisotope thermoelectric generator energy sources

    NASA Technical Reports Server (NTRS)

    Gillis, J. A., Jr.

    1974-01-01

    The use of radioisotope thermoelectric generators (RTG) as the primary source of energy in unmanned spacecraft is discussed. RTG output control, power conditioning system requirements, the electrical design, and circuit performance are also discussed.

  18. APPLICATION OF MEMBRANE TECHNOLOGY TO POWER GENERATION WATERS

    EPA Science Inventory

    Three membrane technlogies (reverse osmosis, ultrafiltration, and electrodialysis) for wastewater treatment and reuse at electric generating power plants were examined. Recirculating condenser water, ash sluice water, coal pile drainage, boiler blowdown and makeup treatment waste...

  19. UF6 breeder reactor power plants for electric power generation

    NASA Technical Reports Server (NTRS)

    Rust, J. H.; Clement, J. D.; Hohl, F.

    1976-01-01

    The reactor concept analyzed is a U-233F6 core surrounded by a molten salt (Li(7)F, BeF2, ThF4) blanket. Nuclear survey calculations were carried out for both spherical and cylindrical geometries. Thermodynamic cycle calculations were performed for a variety of Rankine cycles. A conceptual design is presented along with a system layout for a 1000 MW stationary power plant. Advantages of the gas core breeder reactor (GCBR) are as follows: (1) high efficiency; (2) simplified on-line reprocessing; (3) inherent safety considerations; (4) high breeding ratio; (5) possibility of burning all or most of the long-lived nuclear waste actinides; and (6) possibility of extrapolating the technology to higher temperatures and MHD direct conversion.

  20. Studies of the thermal circuit of an advanced integrated gasification combined-cycle power plant

    NASA Astrophysics Data System (ADS)

    Grigoruk, D. G.; Turkin, A. V.

    2010-02-01

    The results obtained from a study of the thermal circuit of a combined-cycle plant with coal gasification are presented, and a new-generation gas-turbine unit furnished with different fuel supply systems and using different methods for incorporating an air separation plant into the process circuit is described. Data on the composition of producer gas and calculated values of the combined-cycle power plant efficiency are given.

  1. Aluminide Coatings for Power-Generation Applications

    SciTech Connect

    Zhang, Y

    2003-11-17

    Aluminide coatings are of interest for many high temperature applications because of the possibility of improving the oxidation of structural alloys by forming a protective external alumina scale. In order to develop a comprehensive lifetime evaluation approach for aluminide coatings used in fossil energy systems, some of the important issues have been addressed in this report for aluminide coatings on Fe-based alloys (Task I) and on Ni-based alloys (Task II). In Task I, the oxidation behavior of iron aluminide coatings synthesized by chemical vapor deposition (CVD) was studied in air + 10vol.% H{sub 2}O in the temperature range of 700-800 C and the interdiffusion behavior between the coating and substrate was investigated in air at 500-800 C. Commercial ferritic (Fe-9Cr-1Mo) and type 304L (Fe-18Cr-9Ni, nominally) austenitic stainless steels were used as the substrates. For the oxidation study, the as-deposited coating consisted of a thin (<5 {micro}m), Al-rich outer layer above a thicker (30-50 {micro}m), lower Al inner layer. The specimens were cycled to 1000 1-h cycles at 700 C and 500 1-h cycles at 800 C, respectively. The CVD coating specimens showed excellent performance in the water vapor environment at both temperatures, while the uncoated alloys were severely attacked. These results suggest that an aluminide coating can substantially improve resistance to water vapor attack under these conditions. For the interdiffusion study, the ferritic and austenitic steels were coated with relatively thicker aluminide coatings consisting of a 20-25 {micro}m outer layer and a 150-250 {micro}m inner layer. The composition profiles before and after interdiffusion testing (up to 5,000h) were measured by electron probe microanalysis (EPMA). The decrease of the Al content at the coating surface was not significant after extended diffusion times ({le} 5,000h) at temperatures {le} 700 C. More interdiffusion occurred at 800 C in coatings on both Fe- 9Cr-1Mo and 304L alloys; a two-phase microstructure was formed in the outer coating layer on 304L after interdiffusion of 2,000h at 800 C. The interdiffusion behavior was simulated using a computer model COSIM (Coating Oxidation and Substrate Interdiffusion Model), which was originally developed for MCrAlY overlay coatings by NASA. Complimentary modeling work using a mathematic model from Heckel et al. also was conducted. Reasonable agreement was observed between the simulated and experimental composition profiles, particularly for aluminide coatings on Fe-9Cr-1Mo ferritic steels. In Task II, the research focused on the CVD aluminide bond coats for thermal barrier coatings (TBC). The martensitic phase transformation in single-phase {beta}-NiAl and (Ni,Pt)Al coatings was studied and compared. After isothermal exposure to 1150 C for 100 hours, the {beta} phase in both types of coatings was transformed to a martensite phase during cooling to room temperature. Martensitic transformation also was observed in the (Ni,Pt)Al bond coat with and without the ceramic top layer after thermal cycling at 1150 C (700 1-h cycles). Such transformation resulted from Al depletion in the coating due to the formation of the Al{sub 2}O{sub 3} scale on coating surface and interdiffusion between the coating and superalloy substrate. The volume changes associated with the martensitic transformation could affect the coating surface stability (''rumpling'') and thus contributing to TBC failure. To elucidate the effect of Hf levels in the superalloy substrate on the oxidation performance, directionally-solidified Rene 142 superalloys containing three different Hf contents with and without aluminide coatings were cyclically oxidized at 1100 and 1150 C in air. Poor scale adhesion was observed for all bare and NiAl-coated Rene 142 superalloys, as compared with single-crystal superalloys such as Rene N5. Spallation occurred at relatively early stages disregarding the Hf contents in the superalloys. Finally, a platinum plating system has been set up at Tennessee Technological University to carefully control the Pt plating process for synthesizing (Ni,Pt)Al and other Pt-containing coatings. The effects of the Pt electroplating parameters such as plating current density on Pt adhesion and uniformity were examined. The plating rate increased nearly linearly with the increased current density from 0.2 to 0.6A/dm{sup 2}. More Pt was built up near the specimen edges/corners than on the flat surface at high current density; the thicker Pt near specimen edges/corners over the flat surfaces led to localized spallation of the Pt layer in these areas.

  2. Novel power saving architecture for FBG based OCDMA code generation

    NASA Astrophysics Data System (ADS)

    Osadola, Tolulope B.; Idris, Siti K.; Glesk, Ivan

    2013-10-01

    A novel architecture for generating incoherent, 2-dimensional wavelength hopping-time spreading optical CDMA codes is presented. The architecture is designed to facilitate the reuse of optical source signal that is unused after an OCDMA code has been generated using fiber Bragg grating based encoders. Effective utilization of available optical power is therefore achieved by cascading several OCDMA encoders thereby enabling 3dB savings in optical power.

  3. A modular optically powered floating high voltage generator.

    PubMed

    Antonini, P; Borsato, E; Carugno, G; Pegoraro, M; Zotto, P

    2013-02-01

    The feasibility of fully floating high voltage (HV) generation was demonstrated producing a prototype of a modular HV system. The primary power source is provided by a high efficiency semiconductor power cell illuminated by a laser system ensuring the floating nature of each module. The HV is then generated by dc-dc conversion and a HV multiplier. The possibility of series connection among modules was verified. PMID:23464232

  4. Solar parabolic dish thermal power systems - Technology and applications

    NASA Technical Reports Server (NTRS)

    Lucas, J. W.; Marriott, A. T.

    1979-01-01

    Activities of two projects at JPL in support of DOE's Small Power Systems Program are reported. These two projects are the Point-Focusing Distributed Receiver (PFDR) Technology Project and the Point-Focusing Thermal and Electric Applications (PFTEA) Project. The PFDR Technology Project's major activity is developing the technology of solar concentrators, receivers and power conversion subsystems suitable for parabolic dish or point-focusing distributed receiver power systems. Other PFDR activities include system integration and cost estimation under mass production, as well as the testing of the hardware. The PFTEA Project's first major activity is applications analysis, that is seeking ways to introduce PFDR systems into appropriate user sectors. The second activity is systems engineering and development wherein power plant systems are analyzed for specific applications. The third activity is the installation of a series of engineering experiments in various user environments to obtain actual operating experience

  5. Wireless thermal sensor network with adaptive low power design.

    PubMed

    Lee, Ho-Yin; Chen, Shih-Lun; Chen, Chiung-An; Huang, Hong-Yi; Luo, Ching-Hsing

    2007-01-01

    There is an increasing need to develop flexible, reconfigurable, and intelligent low power wireless sensor network (WSN) system for healthcare applications. Technical advancements in micro-sensors, MEMS devices, low power electronics, and radio frequency circuits have enabled the design and development of such highly integrated system. In this paper, we present our proposed wireless thermal sensor network system, which is separated into control and data paths. Both of these paths have their own transmission frequencies. The control path sends the power and function commands from computer to each sensor elements by 2.4GHz RF circuits and the data path transmits measured data by 2.4GHz in sensor layer and 60GHz in higher layers. This hierarchy architecture would make reconfigurable mapping and pipeline applications on WSN possibly, and the average power consumption can be efficiently reduced about 60% by using the adaptive technique. PMID:18003354

  6. Opportunities for ice storage to provide ancillary services to power grids incorporating wind turbine generation

    NASA Astrophysics Data System (ADS)

    Finley, Christopher

    Power generation using wind turbines increases the electrical system balancing, regulation and ramp rate requirements due to the minute to minute variability in wind speed and the difficulty in accurately forecasting wind speeds. The addition of thermal energy storage, such as ice storage, to a building's space cooling equipment increases the operational flexibility of the equipment by allowing the owner to choose when the chiller is run. The ability of the building owner to increase the power demand from the chiller (e.g. make ice) or to decrease the power demand (e.g. melt ice) to provide electrical system ancillary services was evaluated.

  7. Regolith thermal energy storage for lunar nighttime power

    NASA Technical Reports Server (NTRS)

    Tillotson, Brian

    1992-01-01

    A scheme for providing nighttime electric power to a lunar base is described. This scheme stores thermal energy in a pile of regolith. Any such scheme must somehow improve on the poor thermal conductivity of lunar regolith in vacuum. Two previous schemes accomplish this by casting or melting the regolith. The scheme described here wraps the regolith in a gas-tight bag and introduces a light gas to enhance thermal conductivity. This allows the system to be assembled with less energy and equipment than schemes which require melting of regolith. A point design based on the new scheme is presented. Its mass from Earth compares favorably with the mass of a regenerative fuel cell of equal capacity.

  8. Development of Light Powered Sensor Networks for Thermal Comfort Measurement

    PubMed Central

    Lee, Dasheng

    2008-01-01

    Recent technological advances in wireless communications have enabled easy installation of sensor networks with air conditioning equipment control applications. However, the sensor node power supply, through either power lines or battery power, still presents obstacles to the distribution of the sensing systems. In this study, a novel sensor network, powered by the artificial light, was constructed to achieve wireless power transfer and wireless data communications for thermal comfort measurements. The sensing node integrates an IC-based temperature sensor, a radiation thermometer, a relative humidity sensor, a micro machined flow sensor and a microprocessor for predicting mean vote (PMV) calculation. The 935 MHz band RF module was employed for the wireless data communication with a specific protocol based on a special energy beacon enabled mode capable of achieving zero power consumption during the inactive periods of the nodes. A 5W spotlight, with a dual axis tilt platform, can power the distributed nodes over a distance of up to 5 meters. A special algorithm, the maximum entropy method, was developed to estimate the sensing quantity of climate parameters if the communication module did not receive any response from the distributed nodes within a certain time limit. The light-powered sensor networks were able to gather indoor comfort-sensing index levels in good agreement with the comfort-sensing vote (CSV) preferred by a human being and the experimental results within the environment suggested that the sensing system could be used in air conditioning systems to implement a comfort-optimal control strategy.

  9. Airline requirements on aircraft electrical power generation and distribution

    NASA Astrophysics Data System (ADS)

    Glashagen, Claus

    Attention is given to airline requirements to aircraft electrical power generation and distribution, such as electrical power generation, namely, basic consideration of conventional AC generator, the Integrated Drive Generator, and the Variable Frequency Generator, including quality of regulation and mechanical mounting; airworthiness requirements to achieve redundancy for normal, stand-by, and emergency systems; maintainability of components and interconnecting systems; and access to internal subcomponents. Another requirement is interconnection and installation, which involve undervalued efforts required for the maintenance and repair of interconnecting and installation components. This includes hardware selection of cables, clamps, connectors, and terminals. Environmental considerations. Also discussed are electrical power distribution components, involving electro-mechanical switches and remote controlled circuit breakers in a cost-effective distribution system.

  10. Lamp for generating high power ultraviolet radiation

    DOEpatents

    Morgan, Gary L.; Potter, James M.

    2001-01-01

    The apparatus is a gas filled ultraviolet generating lamp for use as a liquid purifier. The lamp is powred by high voltage AC, but has no metallic electrodes within or in contact with the gas enclosure which is constructed as two concentric quartz cylinders sealed together at their ends with the gas fill between the cylinders. Cooling liquid is pumped through the volume inside the inner quartz cylinder where an electrically conductive pipe spaced from the inner cylinder is used to supply the cooling liquid and act as the high voltage electrode. The gas enclosure is enclosed within but spaced from a metal housing which is connected to operate as the ground electrode of the circuit and through which the treated fluid flows. Thus, the electrical circuit is from the central pipe, and through the cooling liquid, the gas enclosure, the treated liquid on the outside of the outer quartz cylinder, and to the housing. The high voltage electrode is electrically isolated from the source of cooling liquid by a length of insulated hose which also supplies the cooling liquid.

  11. VIPIR and VIPIR-S: next generation infantry thermal sights

    NASA Astrophysics Data System (ADS)

    Bigwood, Chris; Eccles, Lee; Jones, Arwyn; Jones, Berwyn; Meakin, David; Rickard, Steve; Robinson, Rob

    2005-05-01

    Thales Optics Ltd. have been involved in a joint funded technology demonstrator program between UK MOD and Thales called Thermal Imager for Dismounted Infantry, run in conjunction with QinetiQ. The aim of this program was to evaluate and demonstrate a cost effective route to equipping the infantry soldier with a small, lightweight, rugged, short range, weapon mounted thermal imaging sight, intended for mass deployment. To address the requirements of this program, Thales Optics Ltd. performed a detailed trade-off analysis considering the effect of using alternative sensors, displays and optical configurations on the sight cost, mass, volume, power and performance. This effort was supported with equipment trials and user assessments. Based on this work, six technical demonstrator sights have been manufactured and delivered to UK MOD for evaluation on several programmes including the UK's FIST soldier modernisation program. Thales Optics has since progressed the TIDI concept further into two product streams, a family of weapon sights called VIPIR and a surveillance sight called VIPIR-S. This paper will summarise the work undertaken on the TIDI program and how this has been applied to the VIPIR and VIPIR-S family of products.

  12. Atmospheric pressure gasification process for power generation

    SciTech Connect

    Morris, M.

    1996-12-31

    Since 1987 TPS Termiska Processer AB has been working on the development of both a biomass-fueled circulating fluidized bed (CFB) gasification process and a downstream dolomite catalytic tar removal process. The combined process has been developed in a 2 MWth pilot plant which was built originally for investigating the use of the product gas in a diesel motor cogeneration plant. A prototype gasification plant comprising two waste-fueled 15 MWth CFB gasifiers has been installed in Greve-in-Chianti, Italy. Since 1990, TPS has been working on the development of a biomass-fueled integrated gasification combined-cycle scheme utilizing both a CFB gasifier and a CFB tar cracker. In 1992, TPS was contracted by the Global Environmental Facility (GEF) to perform work for Phase II of the Brazilian BIG-GT (Biomass Integrated Gasification-Gas Turbine) project. This stage of the project involved both experimental and engineering studies and the basic engineering for a 30 MWe eucalyptus-fueled power plant in Brazil. The plant is based on the GE LM 2500 gas turbine. During this stage of the project the TPS process was in competition with a process from a pressurized gasification technology vendor. However, in 1995 TPS was selected for participation in Phase III of the project. Phase III of the project includes construction and commissioning of the plant. Involvement in the Brazilian BIG-GT project has served as a springboard for the participation of TPS in similar projects in the Netherlands and the UK. In the UK, ARBRE Energy Limited is constructing a coppice-fueled 8 MWe plant with support from the EU THERMIE program and the UKs NFFO (Non Fossil Fuel Obligation). The design contract will be awarded in late 1996. In the Netherlands, a number of projects for biomass and wastes are being pursued by TPS in cooperation with Royal Schelde of the Netherlands.

  13. A Course Case Study: Nuclear Power Generation and the Environment

    ERIC Educational Resources Information Center

    Schlesinger, Allen B.

    1975-01-01

    Describes a course that uses the Ft. Calhoun nuclear power plant as a case study. The course involves three component parts: physics of fission events, engineering requirements, and economic considerations; environmental impact from radiation and thermal effluents; and the impact of social, political and legal factors. (GS)

  14. Improved Thermal Stability of RF Power BJT with Ballast Circuits

    NASA Astrophysics Data System (ADS)

    Guo, Benqing; Zhang, Qingzhong

    2013-12-01

    To improve thermal stability and relieve current convergence in rf power bjts, an embedded active CMOS ballast circuit is proposed. By detecting the inhomogeneous temperature through distributed temperature sensors, the adjacent ballast circuit is triggered to shunt the base convergence current of the power BJT cell, performing the ballast protection for the device. Simulations and measurements validate the effectiveness of the proposed ballast circuit. Compared to conventional ballast resistor methods, the improved device integrated with ballast circuits exhibits superior electrical performance. The single ballast circuit only consumes 6.5 mW with additional occupied area of 2530 um2.

  15. Low-Cost Radiator for Fission Power Thermal Control

    NASA Technical Reports Server (NTRS)

    Maxwell, Taylor; Tarau, Calin; Anderson, William; Hartenstine, John; Stern, Theodore; Walmsley, Nicholas; Briggs, Maxwell

    2014-01-01

    NASA Glenn Research Center (GRC) is developing fission power system technology for future Lunar surface power applications. The systems are envisioned in the 10 to 100kW(sub e) range and have an anticipated design life of 8 to 15 years with no maintenance. NASA GRC is currently setting up a 55 kW(sub e) non-nuclear system ground test in thermal-vacuum to validate technologies required to transfer reactor heat, convert the heat into electricity, reject waste heat, process the electrical output, and demonstrate overall system performance. Reducing the radiator mass, size, and cost is essential to the success of the program. To meet these goals, Advanced Cooling Technologies, Inc. (ACT) and Vanguard Space Technologies, Inc. (VST) are developing a single facesheet radiator with heat pipes directly bonded to the facesheet. The facesheet material is a graphite fiber reinforced composite (GFRC) and the heat pipes are titanium/water. By directly bonding a single facesheet to the heat pipes, several heavy and expensive components can be eliminated from the traditional radiator design such as, POC(TradeMark) foam saddles, aluminum honeycomb, and a second facesheet. A two-heat pipe radiator prototype, based on the single facesheet direct-bond concept, was fabricated and tested to verify the ability of the direct-bond joint to withstand coefficient of thermal expansion (CTE) induced stresses during thermal cycling. The thermal gradients along the bonds were measured before and after thermal cycle tests to determine if the performance degraded. Overall, the results indicated that the initial uniformity of the adhesive was poor along one of the heat pipes. However, both direct bond joints showed no measureable amount of degradation after being thermally cycled at both moderate and aggressive conditions.

  16. Enron Corporation bets $150 million on solar-powered generation

    SciTech Connect

    1995-09-01

    This nation`s largest natural gas company is betting $150 million that it can produce solar power at rates competitive with those of energy generated from oil, gas and coal. The Enron Corporation plans to build a photovoltaic power plant in the southern Nevada desert that would be the largest operation in the country making electricity directly from sunlight, producing enough to power a city of 100,000 people. It is expected to begin operating in two to three years. Some of the nation`s leading solar power experts say Enron`s optimistic goal probably is reachable. The cost of solar power generation has quietly declined by two-thirds. Far from depending on some wondrous breakthrough, the experts say, Enron can offer commercially competitive solar power by inexpensively mass-producing solar panels and then employing thousands of them in the Nevada desert.

  17. HOM Power Generation and Propagation in the PEP II Rings

    SciTech Connect

    Lin, Xintian; Ng, Cho-Kuen; Ko, Kwok; /SLAC

    2011-08-26

    Most of the HOM power that propagates in the PEP-II rings is generated in the RF cavities but its content in terms of TE and TM components has not been accurately determined. For purpose of estimating power deposition at the cavity HOM loads, and also of shielding beamline components such as bellows from TE power penetration, this HOM power content and its distribution profile around the rings are needed. We calculate the TE and TM contributions of the RF cavity to the circulating HOM power and their transmission properties at another cavity downstream. By taking into account the generation in, and scattering by the cavities, as well as the attenuation along the vacuum chamber, a realistic estimate of the HOM power propagating out of a RF station is obtained. The formulation can include the HOM contributions of other beamline components such as collimators.

  18. Modelling of segmented high-performance thermoelectric generators with effects of thermal radiation, electrical and thermal contact resistances

    PubMed Central

    Ouyang, Zhongliang; Li, Dawen

    2016-01-01

    In this study, segmented thermoelectric generators (TEGs) have been simulated with various state-of-the-art TE materials spanning a wide temperature range, from 300 K up to 1000 K. The results reveal that by combining the current best p-type TE materials, BiSbTe, MgAgSb, K-doped PbTeS and SnSe with the strongest n-type TE materials, Cu-Doped BiTeSe, AgPbSbTe and SiGe to build segmented legs, TE modules could achieve efficiencies of up to 17.0% and 20.9% at ΔT = 500 K and ΔT = 700 K, respectively, and a high output power densities of over 2.1 Watt cm−2 at the temperature difference of 700 K. Moreover, we demonstrate that successful segmentation requires a smooth change of compatibility factor s from one end of the TEG leg to the other, even if s values of two ends differ by more than a factor of 2. The influence of the thermal radiation, electrical and thermal contact effects have also been studied. Although considered potentially detrimental to the TEG performance, these effects, if well-regulated, do not prevent segmentation of the current best TE materials from being a prospective way to construct high performance TEGs with greatly enhanced efficiency and output power density. PMID:27052592

  19. Modelling of segmented high-performance thermoelectric generators with effects of thermal radiation, electrical and thermal contact resistances

    NASA Astrophysics Data System (ADS)

    Ouyang, Zhongliang; Li, Dawen

    2016-04-01

    In this study, segmented thermoelectric generators (TEGs) have been simulated with various state-of-the-art TE materials spanning a wide temperature range, from 300 K up to 1000 K. The results reveal that by combining the current best p-type TE materials, BiSbTe, MgAgSb, K-doped PbTeS and SnSe with the strongest n-type TE materials, Cu-Doped BiTeSe, AgPbSbTe and SiGe to build segmented legs, TE modules could achieve efficiencies of up to 17.0% and 20.9% at ΔT = 500 K and ΔT = 700 K, respectively, and a high output power densities of over 2.1 Watt cm‑2 at the temperature difference of 700 K. Moreover, we demonstrate that successful segmentation requires a smooth change of compatibility factor s from one end of the TEG leg to the other, even if s values of two ends differ by more than a factor of 2. The influence of the thermal radiation, electrical and thermal contact effects have also been studied. Although considered potentially detrimental to the TEG performance, these effects, if well-regulated, do not prevent segmentation of the current best TE materials from being a prospective way to construct high performance TEGs with greatly enhanced efficiency and output power density.

  20. Modelling of segmented high-performance thermoelectric generators with effects of thermal radiation, electrical and thermal contact resistances.

    PubMed

    Ouyang, Zhongliang; Li, Dawen

    2016-01-01

    In this study, segmented thermoelectric generators (TEGs) have been simulated with various state-of-the-art TE materials spanning a wide temperature range, from 300 K up to 1000 K. The results reveal that by combining the current best p-type TE materials, BiSbTe, MgAgSb, K-doped PbTeS and SnSe with the strongest n-type TE materials, Cu-Doped BiTeSe, AgPbSbTe and SiGe to build segmented legs, TE modules could achieve efficiencies of up to 17.0% and 20.9% at ΔT = 500 K and ΔT = 700 K, respectively, and a high output power densities of over 2.1 Watt cm(-2) at the temperature difference of 700 K. Moreover, we demonstrate that successful segmentation requires a smooth change of compatibility factor s from one end of the TEG leg to the other, even if s values of two ends differ by more than a factor of 2. The influence of the thermal radiation, electrical and thermal contact effects have also been studied. Although considered potentially detrimental to the TEG performance, these effects, if well-regulated, do not prevent segmentation of the current best TE materials from being a prospective way to construct high performance TEGs with greatly enhanced efficiency and output power density. PMID:27052592