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1

Solar energy thermally powered electrical generating system  

NASA Technical Reports Server (NTRS)

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.

Owens, William R. (Inventor)

1989-01-01

2

MultiUse solar thermal power generators  

NASA Astrophysics Data System (ADS)

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. .

Abbott, Russell

2001-02-01

3

Phase Change Material Thermal Power Generator  

NASA Technical Reports Server (NTRS)

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.

Jones, Jack A.

2013-01-01

4

Low-cost distributed solar-thermal-electric power generation  

E-print Network

Low-cost distributed solar-thermal-electric power generation A. Der Minassians, K. H. Aschenbach discuss the technical and economic feasibility of a low-cost distributed solar-thermal-electric power conversion efficiency, the proposed system can be a cost-effective alternative to solar photovoltaic (PV

Sanders, Seth

5

Device for thermal transfer and power generation  

DOEpatents

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.

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

2011-04-19

6

Solar thermal power generation. A bibliography with abstracts  

NASA Technical Reports Server (NTRS)

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.

1979-01-01

7

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

8

A thermally efficient micro-reactor for thermophotovoltaic power generation  

E-print Network

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

Nielsen, Ole Mattis, 1977-

2006-01-01

9

Low-cost distributed solar-thermal-electric power generation  

NASA Astrophysics Data System (ADS)

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.

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

2004-01-01

10

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

SciTech Connect

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

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

2009-05-15

11

The choice between hydro and thermal power generation under uncertainty  

Microsoft Academic Search

\\u000a Norway has abundant energy supplies consisting of hydro power, crude oil and natural gas and is one of the few countries of\\u000a the world in which the electricity supply is more than 99% based on hydro power. This reflects that hydro power until recently\\u000a has been the cheapest source for covering a steadily increasing demand for electricity. The fall in

T. Ř. Kobila

12

Novel Thermal Storage Technologies for Concentrating Solar Power Generation  

SciTech Connect

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.

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

2013-06-20

13

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 ...

14

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

NASA Technical Reports Server (NTRS)

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.

Amos, D. J.

1977-01-01

15

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

SciTech Connect

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.

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

1995-09-01

16

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

E-print Network

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

Paris-Sud XI, Université de

17

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

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

18

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

NASA Astrophysics Data System (ADS)

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.

Funatsu, Tetsuya; Natsume, Hiroaki

19

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

DOEpatents

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.

Bowman, Charles D. (Los Alamos, NM)

1992-01-01

20

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

NASA Astrophysics Data System (ADS)

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.

Sasaki, Keiichi; Horikawa, Daisuke; Goto, Koichi

2015-01-01

21

Performance and economics of a solar thermal power generation plant in Jubail, Saudi Arabia: Parabolic trough collector  

Microsoft Academic Search

The study explores the technical and economic feasibility of a thermal solar power generation plant using parabolic trough collectors (Euro Trough) in Jubail Industrial City, Saudi Arabia. Total annual available solar radiation is calculated at 1,970 kWhr. The size of the proposed solar thermal power plant is 50 MW. The designed solar field is composed of 100 loops with a

Adel M. Al-Nasser

2010-01-01

22

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

NASA Astrophysics Data System (ADS)

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.

Pham, John Dinh Chuong

23

Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation  

SciTech Connect

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 (<222şC) 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.

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

2013-10-23

24

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

SciTech Connect

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.

None

2011-12-05

25

Solar Thermal Power.  

ERIC Educational Resources Information Center

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…

McDaniels, David K.

26

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

Microsoft Academic Search

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

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

1978-01-01

27

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

SciTech Connect

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.

D. Y. Goswami

2012-09-04

28

An innovative approach to generation scheduling in large-scale hydro-thermal power systems with fuel constrained units  

Microsoft Academic Search

An extensive technology is presented for scheduling MW generation in power systems which consist of thermal, fuel constrained, and hydro units. The development of the solution method is based on the Lagrangian relaxation approach. The demand and reserve constraints, the minimum up and down time constraints, the fuel utilization constraints, and the hydro constraints are all considered in the problem

S. K. Tong; S. M. Shahidehpour

1989-01-01

29

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

Microsoft Academic Search

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

Siddig A. Omer; David G. Infield

2000-01-01

30

Generation scheduling with volatile wind power generation  

Microsoft Academic Search

A stochastic optimization approach is proposed for the unit commitment problem with the uncertainty of wind power generation taken into account, based on mixed-integer linear programming (MILP). The problem is formulated to minimize the total operation cost of thermal units. In considering wind power generation, scenarios are generated by Latin hypercube sampling (LHS) and the stochastic optimization problem is then

Yong Yan; Shouhui Yang; Fushuan Wen; Iain MacGill

2009-01-01

31

An application of reflected diffusions to the problem of choosing between hydro and thermal power generation  

Microsoft Academic Search

It is shown that a certain type of stochastic control problems has a solution (optimal stochastic process) which can be realized as a diffusion with vertical reflection on the boundary of a planar set. The stochastic control problem is motivated by the specific question whether further expansion of the electricity supply system should be based on thermal power (where only

T. Ř. Kobila

1993-01-01

32

Power generation, operation, and control  

SciTech Connect

This book discusses the economic and engineering aspects used in the planning, operating, and controlling of power generation and transmission systems for electric utilities. It presents advanced mathematical and operations research methods used for electric power engineering problems. It covers methods currently applied in the control and operation of electric power systems. The contents are characteristics of power generation units. Economic Dispatch of Thermal Units and Methods of Solution. Transmission Losses. Unit Commitment. Generation with Limited Energy Supply. Hydrothermal Coordination. Energy Production Cost Models for Fuel Budgeting and Planning. Control of Generation. Interchange Evaluation and Power Pools. Power System Security. An introduction to State Estimation in Power Systems and Appendixes.

Wood, A.J.; Wollenberg, B.F.

1984-01-01

33

Solar thermal electricity generation  

NASA Astrophysics Data System (ADS)

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.

Gasemagha, Khairy Ramadan

1993-01-01

34

Solar Thermal Power Technologies  

NSDL National Science Digital Library

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

Groenendaal, B. J.

2002-01-01

35

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

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

36

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

37

Solar Thermal Electricity Generating System  

NASA Astrophysics Data System (ADS)

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 ń 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 EarthĄs surface. The higher the concentration, the higher the temperatures we can achieve when converting solar radiation into thermal energy

Mishra, Sambeet; Tripathy, Pratyasha

2012-08-01

38

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)

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.

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

2015-01-01

39

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

SciTech Connect

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 Ă?ÂşC to 600 Ă?ÂşC) 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.

R. Panneer Selvam, Micah Hale and Matt strasser

2013-03-31

40

Generating random thermal momenta  

E-print Network

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

Denes Molnar

2012-12-09

41

Environmental benefits of DGs and comparing their generation costs with thermal power plants considering production pollution on human health  

Microsoft Academic Search

The increase of DG presence in distribution network is the immediate result of technology development and power crisis in the world. Nowadays, using renewable energy sources and high efficiency electrical systems (Combined Heat and Power Generation) is increasing rapidly all over the world. However, exploitation systems and old managing in industry have lead to a misunderstanding of DG benefits. This,

M. Massaeli; S. A. M. Javadian; N. Khalesi

2011-01-01

42

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

Microsoft Academic Search

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,

Ismael Prieto-Fernández; José M Santurio-D??az; Belén Folgueras-D??az; M. Rosario López-Bobo; Pedro Fernández-Viar

2004-01-01

43

Magnetohydrodynamic power generation  

NASA Technical Reports Server (NTRS)

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.

Smith, J. L.

1984-01-01

44

Multivariable adaptive control for a thermal generator  

SciTech Connect

A new digital control system employing the optimal control has been developed for a thermal power generator. In order to increase the generator control performance for improving the power system stability, this system supplies the excitation system directly with control signals and provides the governor system with control signals for a conventional governor and supplemental control signals as well. This system utilized adaptive control for changes in generator non-linear characteristics as well as in power system characteristics. This paper describes the principles and the applications of this system and also presents the results of simulation tests using an 1000MVA thermal power plant model on a high-reliability a.c./d.c. electric power system simulator. The results of the tests verify the high performance of this system as well as the high applicability of the system to actual plants.

Yokokawa, S.; Ueki, Y. (Fuji Electric Corp., Research and Development, Ltd., 1 Fuji, Hino, Tokyo (JP)); Tanaka, H.; Doi, H. (Technical Research Center, Kansai Electric Power Co., Ltd., 3-11-20 Nakoji, Amagasaki (JP)); Ueda, K.; Taniguchi, N. (Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwadokita, Komae, Tokyo (JP))

1988-09-01

45

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

SciTech Connect

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.

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

1989-01-01

46

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

PubMed

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

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

2004-05-01

47

Peak power ratio generator  

DOEpatents

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.

Moyer, Robert D. (Albuquerque, NM)

1985-01-01

48

HEITSCH, R OMISCH --HYDRO-STORAGE SUBPROBLEMS IN POWER GENERATION 1 Hydro-Storage Subproblems in Power Generation  

E-print Network

HEITSCH, R ¨OMISCH -- HYDRO-STORAGE SUBPROBLEMS IN POWER GENERATION 1 Hydro-Storage Subproblems that owns a hydro-thermal generation sys- tem and trades on the power market often lead to complex stochas for a power utility that owns a hydro-thermal power generation system and the application of the new algo

Römisch, Werner

49

Oscillating fluid power generator  

DOEpatents

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.

Morris, David C

2014-02-25

50

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

SciTech Connect

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.

Phillip Hutton; Nikhil Patel; Kyle Martin; Devinder Singh

2008-02-01

51

Spectrophotovoltaic orbital power generation  

NASA Technical Reports Server (NTRS)

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.

Onffroy, J. R.

1980-01-01

52

Wind power. [electricity generation  

NASA Technical Reports Server (NTRS)

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.

Savino, J. M.

1975-01-01

53

Investing in Power Generation  

Microsoft Academic Search

\\u000a In light of considerable political and market risk emanating from energy market liberalization, global warming, and rapid\\u000a technological change, adequate investment in power generation capacity is of paramount importance for ensuring the security\\u000a of electricity supply and a smooth transition to a more decentralized, energy-efficient and renewable energy system. Consequently,\\u000a investors have to use more sophisticated approaches to determine optimal

Reinhard Madlener; Rik W. De Doncker

54

Microfabricated thermoelectric power-generation devices  

NASA Technical Reports Server (NTRS)

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.

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

55

Microfabricated thermoelectric power-generation devices  

NASA Technical Reports Server (NTRS)

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.

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

56

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...

57

GEOTHERMAL POWER GENERATION PLANT  

SciTech Connect

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.

Boyd, Tonya

2013-12-01

58

Power Electronics Thermal Control (Presentation)  

Microsoft Academic Search

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

Narumanchi

2010-01-01

59

Power Electronics Thermal Control (Presentation)  

SciTech Connect

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.

Narumanchi, S.

2010-05-05

60

Innovative technologies for full utilization of ash generated at coal-fired thermal power stations for producing alumina and construction materials  

NASA Astrophysics Data System (ADS)

The possibility of full 100% usage of ash from coal-fired thermal power stations for producing raw materials for the cement and alumina industries is considered, and it is shown that comprehensive processing of ash from coal-fired thermal power stations is required for this purpose.

Delitsyn, L. M.; Vlasov, A. S.; Borodina, T. I.; Ezhova, N. N.; Sudareva, S. V.

2013-04-01

61

Power generation, operation, and control  

Microsoft Academic Search

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

A. J. Wood; B. F. Wollenberg

1984-01-01

62

Aircraft Photovoltaic Power-Generating System.  

NASA Astrophysics Data System (ADS)

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

Doellner, Oscar Leonard

63

Thermal Power Plant Micro Module  

NSDL National Science Digital Library

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

2009-11-05

64

An innovative approach to generations scheduling in large-scale hydro-thermal power systems with fuel constrained units  

Microsoft Academic Search

A methodology for short-term unit commitment is proposed. The development of the solution method is based on the Lagrangian relaxation approach. Thermal, fuel-constrained, and hydro units are modeled in the formulation of the problem, and restrictions on fuel and water utilization as well as limits on the storage levels of reservoirs are included. This procedure is especially applicable to systems

S. K. Tong; S. M. Shahidehpour

1990-01-01

65

Dynamic Power Systems for Power Generation  

NASA Technical Reports Server (NTRS)

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.

English, R. E.

1984-01-01

66

Dynamic power systems for power generation  

NASA Astrophysics Data System (ADS)

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.

English, R. E.

1984-04-01

67

Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

68

Automotive Power Generation and Control  

E-print Network

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

Caliskan, Vahe

69

Low pellet gain and high efficiency icf power plant model by MHD power generation  

Microsoft Academic Search

We propose a low pellet gain and high efficiency inertial confinement fusion (ICF) power generation system using a magnetohydrodynamic (MHD) power generation, and employ analytical comparative studies for power generation system options. When the thermal output at high temperature (about 2000–2400K) can be extracted from a fusion reactor, only an MHD generator can be used and can convert efficiently ICF

Takashi Kikuchi; Nob. Harada

2000-01-01

70

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

E-print Network

station in Fife, and Rye House combined cycle gas turbine (CCGT) station in Hertfordshire. The results presented here are focused on the Rye House CCGT plant. Opened in 1993 by Scottish Power it has a capacity The mean air temperature changes applicable to the Rye House CCGT were taken for the closest grid cell

Harrison, Gareth

71

MHD power generation  

Microsoft Academic Search

In a magnetohydrodynamic (MHD) generator an electrically conducting gas replaces the rotating copper coil of the currently used electric generator. This substitution involves a principle which was recognized 150 years ago by Faraday. Development of the MHD process as an industrial method of generating electricity, however, had to wait until a better understanding of the dynamics and handling of hot

F. A. Hals; D. B. Stickler; R. Kessler; R. E. Gannon

1978-01-01

72

Thermal management system for high performance PowerPCTM microprocessors  

Microsoft Academic Search

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

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

1997-01-01

73

Thermal energy storage for power plant applications  

SciTech Connect

This study was conducted by Pacific Northwest Laboratory (PNL) to evaluate alternative methods of using coal to generate peak and intermediate load power. The approach was to review the technical and economic feasibility of using thermal energy storage (TES) with a conventional coal-fired power plant and an integrated gasification combined cycle (IGCC) power plant. In the first case, conventional pulverized coal combustion equipment was continuously operated to heat molten nitrate salt which was then stored in a tank. During peak demand periods, hot salt was withdrawn from storage and used to generate steam for a Rankine steam power cycle. This coal-fired salt heater can be approximately one-third the size of a coal-fired boiler in a conventional cycling plant. The use of nitrate salt TES also reduces the levelized cost of power from 5-24 percent depending on the operating schedule. The second case evaluates the use of thermal energy storage with an integrated gasification combined cycle (IGCC) power plant. In this case, the nitrate salt was heated by a combination of the gas turbine exhaust and the hot fuel gas. The IGCC plant also contained a low-temperature storage unit that uses a mixture of oil and rock as the thermal storage medium. Thermal energy stored in the low-temperature TES was used to preheat the feedwater after it leaves the condenser and to produce process steam for other applications in the IGCC plant. This concept study also predicted lower cost power compared to the natural gas-fired alternative if significant escalation rates in the price of fuel were assumed. A sensitivity analysis showed a significant reduction in the installed capital cost of a direct-contact heat exchanger instead of the conventional finnned-tube design.

Somasundaram, S.; Drost, M.K.; Antoniak, Z.I.; Brown, D.R. (Pacific Northwest Lab., Richland, WA (United States))

1990-01-01

74

Power generation systems and methods  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

75

Biomass combustion for power generation  

Microsoft Academic Search

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

Richard van den Broek; Ad van Wijk

1996-01-01

76

Automotive power generation and control  

Microsoft Academic Search

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

David J. Perreault; Vahe Caliskan

2004-01-01

77

Mesofluidic magnetohydrodynamic power generation  

E-print Network

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

Fucetola, Jay J

2012-01-01

78

Geothermal power generation  

SciTech Connect

The Southern California Edison Co. geothermal program is described in general. The individual power plant projects are described: Brawley 10 MW, Heber 45 MW and Salton Sea 9 MW. Related geothermal activities are mentioned.

Crane, G.K.

1981-01-01

79

POWER SCHEDULING IN A HYDRO-THERMAL SYSTEM UNDER UNCERTAINTY  

E-print Network

POWER SCHEDULING IN A HYDRO-THERMAL SYSTEM UNDER UNCERTAINTY C.C. Car e1, M.P. Nowak2, W. Romisch2- gramming model for power scheduling un- der uncertainty in a generation system comprising thermal and pumped-storage hydro units is developed. For its compu- tational solution two di erent decompo- sition

Römisch, Werner

80

Aircraft photovoltaic power-generating system  

NASA Astrophysics Data System (ADS)

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

Doellner, Oscar Leonard

81

Wind Power Charged Aerosol Generator  

SciTech Connect

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.

Marks, A.M.

1980-07-01

82

Thermal Sciences The thermal sciences area involves the study of energy conversion and transmission, power  

E-print Network

in virtually all energy conversion devices and systems. One may think of the jet engine as a mechanical deviceThermal Sciences The thermal sciences area involves the study of energy conversion and transmission, power generation, the flow of liquids and gases, and the transfer of thermal energy (heat) by means

New Hampshire, University of

83

Spectrophotovoltaic orbital power generation  

NASA Technical Reports Server (NTRS)

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.

Knowles, G.; Carroll, J.

1983-01-01

84

High power microwave generator  

DOEpatents

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).

Minich, Roger W. (Patterson, CA)

1988-01-01

85

Tide operated power generating apparatus  

SciTech Connect

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.

Kertzman, H. Z.

1981-02-03

86

Coal and Nuclear Power Generation  

Microsoft Academic Search

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

Jeff W. Eerkens

87

Synopsis of Magnetohydrodynamic Power Generation  

NASA Technical Reports Server (NTRS)

Concise summary of magnetohydrodynamic (MHD) theory, history, and future trends presented in report. Worldwide research on MHD covered, and selected data from key research projects included. Magnetohydrodynamic generator produces electric current by passing fluid at high speed through strong magnetic field. Fluid ionized gas, plasma, or liquid metal. Magnetohydrodynamic generators offer potential for high efficiency, low power cost, and cleaner emissions.

Smith, J. L.

1986-01-01

88

Financing Solar Thermal Power Plants  

SciTech Connect

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.

Price, H. W.; Kistner, R.

1999-11-01

89

Thermoelectric power generation in a thermoacoustic refrigerator  

Microsoft Academic Search

Commercially available solid-state thermoelectric devices may be used for their electrical power generation capabilities when coupled to a thermoacoustic refrigerator or heat pump. General performance characteristics as well as bulk thermal conductivity for a selection of thermoelectric elements was first found by using a two-plate apparatus to maintain a constant temperature difference across the element. Further studies of an element’s

W. V. Slaton; J. C. H. Zeegers

2006-01-01

90

Electrical power generation systems - Combat aircraft perspective  

NASA Astrophysics Data System (ADS)

The electrical power generation system requirements of combat aircraft are briefly examined. In particular, attention is given to customer requirements, development of the installed electrical power in aircraft, electrical load analysis for designing the power generation system, and definition of aircraft electrical power supply characteristics and consumer qualities. The discussion also covers reliability requirements for power generation systems, design of a power generation system, control and protection equipment in power generation systems, and helicopter electrical power systems.

Moeller, R.

91

Solid state pulsed power generator  

DOEpatents

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.

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

2014-02-11

92

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  

Microsoft Academic Search

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

Charles J. Finley

1994-01-01

93

Electric generating water power device  

Microsoft Academic Search

The invention discloses a submerged water power machine in which a plurality of vertical blades are connected to two endless chains, one located at the top ends and the other located at the bottom ends of the blades. The blades drive the chains about two endless horizontal tracks, and the chains are drivingly coupled to electric generators. Each blade is

Davison

1979-01-01

94

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

NASA Astrophysics Data System (ADS)

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

Komiyama, Ryoichi; Fujii, Yasumasa

95

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)

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.

Finley, Charles J.

1994-07-01

96

Kinetics of thermal donor generation in silicon  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

97

Heat generating compositions for thermal batteries  

NASA Astrophysics Data System (ADS)

Thermal batteries are widely used as independent current sources with long storage life and the ability to operate over a wide ambient temperature range. A number of pyrotechnic materials may as rule be used as sources of thermal energy to provide ionic conduction in a molten electrolyte and to maintain the working temperature of the battery during the discharge of the electrochemical elements. The requirements for heat sources in thermal batteries are described and different heat generating compositions are reviewed.

Sheptunov, V. N.

1991-03-01

98

Thermal control system for Space Station Freedom photovoltaic power module  

NASA Technical Reports Server (NTRS)

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

Hacha, Thomas H.; Howard, Laura S.

1992-01-01

99

Thermal control system for Space Station Freedom photovoltaic power module  

NASA Technical Reports Server (NTRS)

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.

Hacha, Thomas H.; Howard, Laura

1994-01-01

100

Investigations for biogas operated MHD power generators  

SciTech Connect

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

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

1983-12-01

101

GREENHOUSE GAS ANALYSIS OF SOLAR-THERMAL ELECTRICITY GENERATION  

Microsoft Academic Search

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

M. LENZEN

1999-01-01

102

INTEGRATED CONTROL OF NEXT GENERATION POWER SYSTEM  

SciTech Connect

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

None

2010-02-28

103

Unified model of solar thermal electric generation systems  

Microsoft Academic Search

In this paper a unified model of a solar electric generation system (SEGS) is developed using a thermo-hydrodynamic model of a trough collector combined with a model of a traditional steam power-house. The model evaluates thermal properties, steam flow rate and pressure drop in a direct steam generation (DSG) or an oil based collector field. The SEGS’s performance in different

Saad D. Odeh

2003-01-01

104

Pseudorandom sequences constructed by the power generator  

E-print Network

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

Katalin, Gyarmati

105

Problem 118: Power Generation Matthew Grum  

E-print Network

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

St Andrews, University of

106

Impact of Power Generation Uncertainty on Power System Static Performance  

E-print Network

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

Liberzon, Daniel

107

IEEE POWER ENGINEERING SOCIETY ENERGY DEVELOPMENT AND POWER GENERATION COMMITTEE  

E-print Network

IEEE POWER ENGINEERING SOCIETY ENERGY DEVELOPMENT AND POWER GENERATION COMMITTEE Latin America Sponsored by: International Practices for Energy Development and Power Generation Chairs: Luiz Barroso, PSR utilities (Discos) that buy power supply from generators in both the long term and sport markets. For more

Catholic University of Chile (Universidad CatĂłlica de Chile)

108

Thermal management of large pulsed power systems  

NASA Astrophysics Data System (ADS)

Current thermal control technology is reviewed and limitations assessed compared to a typical high pulse power application. Thermal management is a significant weight factor (approximately 50%) of even medium power systems which points to a large potential payback from innovative techniques. Thermal research is recommended in the areas of concentrating and thermovoltaic solar arrays, two phase heat transport loops, direct contact heat exchangers and advanced radiator systems. Air Force space power trends indicate requirements for systems with 10 to 200 KW average power with pulse/average power ratios of 10/1 to 1000/1. Thermal system definition is complicated by the variety of possible power systems although solar and nuclear (Brayton and Thermionic) appear to be the leading candidates.

Haslett, B.

109

Wind wheel electric power generator  

NASA Technical Reports Server (NTRS)

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.

Kaufman, J. W. (inventor)

1980-01-01

110

A COMBUSTION-BASED MEMS THERMOELECTRIC POWER GENERATOR  

Microsoft Academic Search

SUMMARY A thermoelectric generator with integrated catalytic combustion has been microfabricated and successfully tested. The device consists of a high-temperature silicon-germanium thermopile supported on a thermally insulating silicon nitride membrane. Heat is supplied by catalytic combustion of fuels on the underside of the membrane. Power output has been generated from on- chip autothermal combustion of hydrogen, ammonia and butane, with

Samuel B. Schaevitz; Aleksander J. Franz; Klavs F. Jensen; Martin A. Schmidt

2001-01-01

111

Holographic investigation of thermal nonequilibrium vapor generation  

NASA Astrophysics Data System (ADS)

The vapor generation rate and associated thermal hydraulic parameters in a rapidly depressurizing, steady water flow was measured for understanding of the thermal nonequilibrium vapor generation process. This phenomenon is important for prediction and analysis of blowdown and flashing processes which may occur in nuclear reactor safety analysis (Loss of Coolant Accidents), in characterizing the expansion and flow of Liquified Gas (LNG) and develops alternative energy sources such as solar and geothermal. The development of advanced predictive capabilities for design and analysis of these and other similar systems is considered. The holographic recording and image analysis methods may evolve into a reliable and useful tool for two phase flow investigations.

Bates, J. M.

1984-04-01

112

Power Generation: The Next 30 Years  

ERIC Educational Resources Information Center

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)

Holcomb, Robert W.

1970-01-01

113

Electronic load for testing power generating devices  

NASA Technical Reports Server (NTRS)

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.

Friedman, E. B.; Stepfer, G.

1968-01-01

114

Analysis of power generation processes using petcoke  

E-print Network

higher carbon content than other hydrocarbons like coal, biomass and sewage residue. This gives petcoke a great edge over other feedstocks to generate power. Models for the two most common processes for power generation, namely combustion and gasification...

Jayakumar, Ramkumar

2009-05-15

115

Solar thermal organic rankine cycle for micro-generation  

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

116

Aircraft Power Generators: Hybrid Modeling and  

E-print Network

Aircraft Power Generators: Hybrid Modeling and Simulation for Fault Detection ASHRAF TANTAWY. INTRODUCTION The Integrated drive generator (IDG) is the primary source for electrical power in the aircraft. The system draws its power from the main aircraft engines and comprises two synchronous generators

Koutsoukos, Xenofon D.

117

Power generator design for the billings MHD demonstration project  

SciTech Connect

The proposed design of the MHD Power generator for the Billings MHD Demonstration Project is presented. The Billings MHD Demonstration Project, proposed by the MHD Development Corporation (MDC) for the U.S. Department of Energy`s Clean Coal Technology V Program, will demonstrate the significant environmental advantages and efficiency potential of MHD electric power generation. A diagonally-loaded, supersonic MHD generator channel is proposed. The generator channel has a thermal input of 250 MW, is 11 meters long and produces 28.5 MW gross power output at the nominal design operating condition. The gasdynamic, gas-side, and mechanical designs of the proposed generator are derived from the design of the 50 MW{sub t} proof-of-concept MHD generator, currently undergoing long duration testing at the CDIF test facility. The design and operation of the proposed generator will be typical of those anticipated in future commercial MHD generator channels.

Pian, C.C.P.; Kessler, R.; Schmitt, E.W.; Morrison, D.J. [Textron Defense Systems/Subsidiary of Textron, Inc., Everett, MA (United States)

1993-12-31

118

Scanning thermal plumes. [from power plant condensers  

NASA Technical Reports Server (NTRS)

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.

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

1974-01-01

119

Seventh Power Plan: Generating Resources Advisory  

E-print Network

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

120

Storage systems for solar thermal power  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

121

Low cost space power generation  

NASA Technical Reports Server (NTRS)

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.

Olsen, Randall B.

1991-01-01

122

FUTURE POWER GRID INITIATIVE Next Generation Network  

E-print Network

FUTURE POWER GRID INITIATIVE Next Generation Network Simulations for Power System Applications resources. To operate the future power grids these will need to take into account » the integration of high communications directly into a power domain solver. Simulating a large scale power and communications network

123

Electrical power generation by mechanically modulating electrical double layers.  

PubMed

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

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

2013-01-01

124

Miniature Gas-Turbine Power Generator  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

125

Thermal battery for aircraft emergency power  

Microsoft Academic Search

The authors undertook the development of a thermal battery system to supply aircraft emergency power. The system was developed as an alternative to the oxygen-methanol or hydrazine emergency systems. Two batteries were developed: TB1 to provide power to an electrohydraulic pump and TB2 to provide power to aircraft electronics. For both batteries the LiAl\\/FeS2 system was used, along with ternary

S. Kaufmann; G. Chagnon

1992-01-01

126

Electronic power generators for ultrasonic frequencies  

NASA Technical Reports Server (NTRS)

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

Ciovica, D.

1974-01-01

127

Identifying and bounding uncertainties in nuclear reactor thermal power calculations  

SciTech Connect

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)

Phillips, J.; Hauser, E.; Estrada, H. [Cameron, 1000 McClaren Woods Drive, Coraopolis, PA 15108 (United States)

2012-07-01

128

Power Generation Capabilities of Tie Tube Assemblies  

NASA Astrophysics Data System (ADS)

Second generation nuclear thermal rocket engine designs, employing solid core reactors and expander engine cycles, generally rely on some form of nuclear-driven heater to supply the major portion of thermal energy required to preheat the turbine-drive gases. If adequate heat transfer occurs, not only will efficiency-enhancing turbine-inlet temperatures be realized, but sufficient energy will be available to enable engine operation at chamber pressures ranging to at least 2,000 psia. For the case of reactor cores employing prismatic fuel elements, the utilization of tie tube assemblies, as first employed in the core-support subsystem of the Phoebus II reactor, can provide the basis of an array of propellant (hydrogen) preheaters that offer an ample supply of energy and temperature to enable candidate expander engine cycles over a wide range of operating parameters, without reducing the total enthalpy of the core-exit gas and its attendant effect on specific impulse. By modifying the tie tube design concept set forth in LASL's Nuclear Rocket Engine definition study, a powerful, weight and packaging-effective, preheater assembly can be realized. The design features of these tie tube assemblies reflect their functional objectives, core criticality considerations, and space constraints. Since the core pressure and inertial mass loads are carried by these assemblies, the structural tubular element(s) also provide coolant passage(s) for the hydrogen. The transfer of heat to the coolant surfaces is controlled by the effective thermal conductivity of the filler structure and ``insulating sleeves,'' which surround the tubular elements and are in controlled thermal contact with the surrounding core fuel elements. An option exists to further increase the transported heat to the coolant walls by the selective loading of the filler structure, ``insulating sleeves,'' and the moderator annular element with fissionable material.

Gunn, Stanley V.; Hedstrom, James; Hundal, Rolv

1994-07-01

129

Space Station Freedom solar dynamic power generation  

NASA Technical Reports Server (NTRS)

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.

Springer, T.; Friefeld, Jerry M.

1990-01-01

130

Pulse power applications of flux compression generators  

SciTech Connect

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.

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

1981-01-01

131

Thermoelectric power generator with intermediate loop  

DOEpatents

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.

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

2009-10-27

132

Thermoelectric power generator with intermediate loop  

SciTech Connect

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.

Bell, Lon E; Crane, Douglas Todd

2013-05-21

133

Piezoelectric micro-power generation interface circuits  

Microsoft Academic Search

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

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

2006-01-01

134

Uninterrupted power supply using slip-power recovery induction generator  

Microsoft Academic Search

This paper describes an uninterrupted power supply (UPS) using a slip-power recovery induction generator with a battery-inverter system. This UPS has the following merits. The induction generator is started and accelerated quickly without load, since the UPS function is realized by a battery-inverter system. Once the generator is accelerated to a substantial speed, connection to the power system is performed

N. Kimura; K. Taniguchi

1995-01-01

135

Integrated engine generator for aircraft secondary power  

NASA Technical Reports Server (NTRS)

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.

Secunde, R. R.

1972-01-01

136

Small spacecraft power and thermal subsystems  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

137

Generator thermal sensitivity analysis with Support Vector Regression  

Microsoft Academic Search

Generator thermal sensitivity issue is studied in this paper. Currently, thermal sensitivity test is usually adopted in industries to determine if a generator has been experiencing thermal sensitivity problem. However, this kind of tests has its own disadvantages. In this paper, Support Vector Regression is utilized to provide some valuable information regarding thermal sensitivity in a rotating machine based on

Youliang Yang; Qing Zhao

2010-01-01

138

Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

139

El Salvador plans geothermal power generation  

Microsoft Academic Search

A recently completed United Nations study has concluded that geothermal power represents a significant source of indigenous energy in El Salvador, which lies within the main volcanic belt of Central America. At present the principal source of electricity in El Salvador is hydropower, supplemented by imported fuel-based thermal power.Due to the rapid pace of industrialization and rural electrification now in

Anonymous

1971-01-01

140

Photoconductive switching for high power microwave generation  

SciTech Connect

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

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

1990-10-01

141

Closed loop hermetically sealed solar power generator  

Microsoft Academic Search

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

1983-01-01

142

Harnessing microbially generated power on the seafloor  

Microsoft Academic Search

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

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

2002-01-01

143

Pneumatic tire-based piezoelectric power generation  

NASA Astrophysics Data System (ADS)

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.

Makki, Noaman; Pop-Iliev, Remon

2011-03-01

144

The merits of thermal storage in an unregulated power marketplace  

SciTech Connect

For many years, it was in the best interests of the electric power industry to financially support the installation of thermal storage systems for off-peak air-conditioning. By shifting electrical usage to night hours generating reserve was maintained at a far lower cost than the construction of new generating equipment would have required. This additional support from the utility industry influenced designers of commercial buildings to fully exploit the available rate structures by maximizing cool storage capacities. However, deregulation is seen by some as a threat to the continuation of incentive programs. Additionally, questions regarding the future structure of time-of-use rates, as well as the introduction of other rate variants such as real-time pricing (RTP), has introduced considerable uncertainty into the economic forecasting necessary to justify large thermal storage systems with enough capacity to meet the entire cooling load of typical applications. By minimizing or eliminating a first cost penalty, one can focus on the features of thermal storage that not only protect customers from uncertainties in utility rate structures, but also provide them with the flexibility to take advantage of the optimum available rate. By consuming a significant fraction of their power needs at night, customers become more attractive to generators anxious to fully utilize their power producing capacity in a competitive marketplace. With very few exceptions, it is unquestionably more economical to produce electrical power at night. A properly selected, implemented and controlled thermal storage system creates a preferred customer who is prepared to respond to the inevitable market forces that will shape electrical power rate structures in an uncertain and unregulated power marketplace.

Silvetti, B.M. [Calmac Manufacturing Corporation (United States)

1999-07-01

145

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

NASA Technical Reports Server (NTRS)

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.

1979-01-01

146

Power electronics as efficient interface in dispersed power generation systems  

Microsoft Academic Search

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

Frede Blaabjerg; Zhe Chen; S. B. Kjaer

2004-01-01

147

Method for combined cycle electrical power generation  

SciTech Connect

A method for combined cycle electrical power generation is disclosed wherein electrical power is generated by an electrical generator driven by a gas turbine, which is in turn driven by two gaseous products of a coal gasification process. The first gaseous product is produced with hot char by the reduction of a coal/water slurry by stream in a gasifier. The second gaseous product is produced by oxidation of the hot char in a combustor.

Mitchell, D.S.; Sageman, D.R.

1984-04-24

148

Characteristics of carbon nanotube based micro-bubble generators for thermal jet printing  

Microsoft Academic Search

This paper proposes a novel thermal printhead with multiwalled carbon nanotubes as heating elements and presents characteristics of the corresponding MEMS-fabricated microbubble generators. Electrical properties of the microheaters in air and performance of bubble generation under water are comprehensively studied. Relationships between input power, resistance and bubble behavior are characterized. For a conceptional design, two microbubble generators are neighbored as

Wenli Zhou; Yupeng Li; Weijun Sun; Sanping Wan

2010-01-01

149

An Implanted, Stimulated Muscle Powered Piezoelectric Generator  

NASA Technical Reports Server (NTRS)

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.

Lewandowski, Beth; Gustafson, Kenneth; Kilgore, Kevin

2007-01-01

150

Characterization and quantification of persistent organic pollutants in fly ash from coal fueled thermal power stations in India  

Microsoft Academic Search

The burning of pulverized coal to produce energy for generation of electricity in thermal power plants results in huge quantity of coal ash of varying properties. In India the coal based thermal power plants have been the major source of power generation in the past and would continue for decades to come. Because of the increase in electricity production, the

S. K. Sahu; R. C. Bhangare; P. Y. Ajmal; S. Sharma; G. G. Pandit; V. D. Puranik

2009-01-01

151

PRIMAL AND DUAL METHODS FOR UNIT COMMITMENT IN A HYDRO-THERMAL POWER SYSTEM  

E-print Network

PRIMAL AND DUAL METHODS FOR UNIT COMMITMENT IN A HYDRO-THERMAL POWER SYSTEM R. Gollmer1 , A. Moller Linden 6, D-10099 Berlin, Germany Abstract: For unit commitment in a real power generation system comprising thermal and pumped-storage hydro units a large-scale mixed-integer optimization model is developed

Römisch, Werner

152

Probabilistic production costing simulation of a thermal system with a pumped-storage power plant  

Microsoft Academic Search

The paper presents a model and two algorithms for the calculation of the additional pumping generation of thermal power plants and the discharging energy of a pumped-storage power plant in a thermal system. Both algorithms lead to the solution of a univariate global optimization problem. One of these problems provides an optimal result. The other is suboptimal, as it is

J. Hoffer

1995-01-01

153

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

NASA Astrophysics Data System (ADS)

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.

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

154

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

E-print Network

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

Dragoti-Ă?ela, Eranda

155

Electrical machines technology for aerospace power generators  

NASA Astrophysics Data System (ADS)

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

Vaidya, Jayant G.

156

Hybrid solar-fossil fuel power generation  

E-print Network

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

Sheu, Elysia J. (Elysia Ja-Zeng)

2012-01-01

157

Aircraft Photovoltaic Power-Generating System  

Microsoft Academic Search

Photovoltaic cells, appropriately cooled and operating in the combustion-created high radiant-intensity environment of gas-turbine and jet engines, may replace the conventional (gearbox-driven) electrical power generators aboard jet aircraft. This study projects significant improvements not only in aircraft electrical power-generating-system performance, but also in overall aircraft performance. Jet -engine design modifications incorporating this concept not only save weight (and thus fuel),

Oscar Leonard Doellner

1991-01-01

158

Aircraft photovoltaic power-generating system  

Microsoft Academic Search

Photovoltaic cells, appropriately cooled and operating in the combustion-created high radiant-intensity environment of gas-turbine and jet engines, may replace the conventional (gearbox-driven) electrical power generators aboard jet aircraft. This study projects significant improvements not only in aircraft electrical power-generating-system performance, but also in overall aircraft performance. Jet-engine design modifications incorporating this concept not only save weight (and thus fuel), but

Oscar Leonard Doellner

1991-01-01

159

Thermal Analysis of the Z-Pinch Power Plant Concept  

SciTech Connect

In this work, a preliminary thermal model for the Z-Pinch Power Plant is presented. This power plant utilizes fusion energy to generate electric energy in the GW range. The Z-Pinch Technology consists of compressing high-density plasma to produce X-rays to indirectly heat to ignition a deuterium/tritium fusion capsule. This ignition releases a minimum of 3 GJ every 10 seconds. The thermal energy generated is absorbed by the primary cycle fluid, and it is later used to power a Brayton or Rankine cycle. An advanced heat exchanger is used as the interface between the two cycles. This heat exchanger plays an important role in power plant performance. Three fluids (Flibe, Pb-17Li, and Li) were used for the plant performance analysis. The thermodynamic properties of the selected fluids determine the maximum operating temperature of the power cycles. Model results show that high temperatures (over 1000 deg. C) are developed in the primary cycle as needed to efficiently run the secondary cycle. The results of the performance parametric study demonstrated that the Brayton cycle exhibits better performance characteristics than the Rankine cycle for this type of application.

Modesto, M.A.; Lindgren, E.R.; Morrow, C.W. [Sandia National Laboratories (United States)

2005-04-15

160

Novel Thermal Powered Technology for UUV Persistent Surveillance  

NASA Technical Reports Server (NTRS)

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.

Jones, Jack A.; Chao, Yi

2006-01-01

161

Generation of sonic power during welding  

NASA Technical Reports Server (NTRS)

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.

Mc Campbell, W. M.

1969-01-01

162

Power electronics and alternative energy generation  

Microsoft Academic Search

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

James P Lyons; Vlatko Vlatkovic

2004-01-01

163

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

E-print Network

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

John, Lizy Kurian

164

Concepts for central solar electric power generation  

NASA Technical Reports Server (NTRS)

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.

Kintigh, J. K.

1974-01-01

165

Network integration of distributed power generation  

Microsoft Academic Search

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

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

2002-01-01

166

Prognostic Health Management of Aircraft Power Generators  

Microsoft Academic Search

In this paper, prognostic tools are developed to detect the onset of electrical failures in an aircraft power generator, and to predict the generator's remaining useful life (RUL). Focus is on the rotor circuit since failure mode, effects, and criticality analysis (FMECA) studies indicate that it is a high priority candidate for condition monitoring. A signature feature is developed and

Todd D. Batzel; David C. Swanson

2009-01-01

167

Where solar thermal meets photovoltaic for high-efficiency power conversion  

E-print Network

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

Bierman, David M. (David Matthew)

2014-01-01

168

Carbon nanotubes based coatings for laser power and energy measurements using thermal detectors  

Microsoft Academic Search

We describe the spectral responsivity, spatial uniformity, and other properties of thermal-detector coatings based on carbon nanotubes. Such coatings may form the basis of the next generation of standards for laser power and energy metrology.

J. H. Lehman; A. C. Dillon; C. Engtrakul

2004-01-01

169

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

170

Concentrating solar thermal power as a viable alternative in China's electricity supply  

Microsoft Academic Search

Study of low-carbon and pollution renewable alternatives for China revealed that concentrating solar thermal (CST) electric power generation was underemphasized in China's renewable energy plan. The analysis shows the competitive viability of CST: (1) China has the key prerequisites to make CST power generation economical including high-quality insolation and appropriate land, (2) CST's proven history, scale, and dispatchability makes it

John Chung-Ling Chien; Noam Lior

2011-01-01

171

Generator-battery dc power supply system  

Microsoft Academic Search

A generator-battery dc power supply system comprises a plurality of sub-systems each including a battery and a temperature sensor sensing the temperature of the battery and controlling the generator regulating means to decrease the generator output voltage in response to an increase in the sensed battery temperature, to thereby prevent overheating of the battery by over-charging same. The system further

1983-01-01

172

Low thermal resistance power module assembly  

DOEpatents

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.

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

2007-03-13

173

Geothermal power generation - An aggressive utility program  

NASA Astrophysics Data System (ADS)

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.

Crane, G. K.

1981-05-01

174

High power terahertz generation using 1550 nm plasmonic photomixers  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

175

High power terahertz generation using 1550?nm plasmonic photomixers  

SciTech Connect

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

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

2014-07-07

176

Coupled Electro-Thermal Simulations of Single Event Burnout in Power Diodes  

E-print Network

Coupled Electro-Thermal Simulations of Single Event Burnout in Power Diodes 1. Department;Motivation · Cosmic rays can cause Single event Burnout (SEB) in power electronic devices in space (e image of burnout in an IRF 150 power MOSFET #12;· Ion-generated charge is multiplied by avalanching

Walker, D. Greg

177

Solar thermal electric power information user study  

SciTech Connect

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.

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

1981-02-01

178

Dislocation Generation by Thermal Stresses in Si: Modeling and Experiments  

SciTech Connect

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.

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

2005-11-01

179

43 CFR 431.4 - Power generation responsibilities.  

...2014-10-01 2014-10-01 false Power generation responsibilities. 431.4...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

2014-10-01

180

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2011-04-01

181

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2012-04-01

182

43 CFR 431.6 - Power generation estimates.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

183

43 CFR 431.6 - Power generation estimates.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

184

18 CFR 801.12 - Electric power generation.  

...2014-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2014-04-01

185

43 CFR 431.4 - Power generation responsibilities.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Power generation responsibilities. 431.4...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

2013-10-01

186

43 CFR 431.4 - Power generation responsibilities.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2011-10-01 true Power generation responsibilities. 431.4...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

2012-10-01

187

43 CFR 431.6 - Power generation estimates.  

...2014-10-01 2014-10-01 false Power generation estimates. 431.6 Section...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.6 Power generation estimates....

2014-10-01

188

43 CFR 431.6 - Power generation estimates.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

189

43 CFR 431.4 - Power generation responsibilities.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Power generation responsibilities. 431.4...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

2010-10-01

190

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2013 CFR

...2012-04-01 true Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2013-04-01

191

43 CFR 431.6 - Power generation estimates.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2011-10-01 true Power generation estimates. 431.6 Section...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.6 Power generation estimates....

2012-10-01

192

18 CFR 801.12 - Electric power generation.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Electric power generation. 801.12 Section 801...POLICIES § 801.12 Electric power generation. (a) Significant uses...waters of the basin for the generation of electric power at hydro, pumped...

2010-04-01

193

43 CFR 431.4 - Power generation responsibilities.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Power generation responsibilities. 431.4...INTERIOR GENERAL REGULATIONS FOR POWER GENERATION, OPERATION, MAINTENANCE...ARIZONA/NEVADA § 431.4 Power generation responsibilities. (a)...

2011-10-01

194

Phase change material thermal power generator  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

195

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

SciTech Connect

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.

J. C. Giglio; A. A. Jackson

2012-03-01

196

Biomass gasifier gas turbine power generating technology  

Microsoft Academic Search

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

R. H. Williams; E. D. Larson

1996-01-01

197

Economical photovoltaic power generation with heat recovery  

NASA Technical Reports Server (NTRS)

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.

Ascher, G.

1977-01-01

198

Advanced Coal-Based Power Generations  

NASA Technical Reports Server (NTRS)

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.

Robson, F. L.

1982-01-01

199

Heat generating compositions for thermal batteries  

Microsoft Academic Search

Thermal batteries are widely used as independent current sources with long storage life and the ability to operate over a wide ambient temperature range. A number of pyrotechnic materials may as rule be used as sources of thermal energy to provide ionic conduction in a molten electrolyte and to maintain the working temperature of the battery during the discharge of

V. N. Sheptunov

1991-01-01

200

Thermal and power characterization of field-programmable gate arrays  

Microsoft Academic Search

In this paper we propose new techniques for thermal and power characterization of Field Programmable Gate Arrays (FPGAs) using infrared imaging techniques. For thermal characterization, we capture the thermal emissions from the backside of an FPGA chip during operation. We analyze the captured emissions and quantify the extent of thermal gradients and hot spots in FPGAs. Given that FPGAs are

Abdullah Nazma Nowroz; Sherief Reda

2011-01-01

201

Environmental effects of tidal power generating schemes  

Microsoft Academic Search

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

C. Mettam

1978-01-01

202

Thermoelectric unicouple used for power generation  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

203

Wave and tide powered generation apparatus  

Microsoft Academic Search

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

Suggs

1985-01-01

204

Plasma plume MHD power generator and method  

DOEpatents

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.

Hammer, J.H.

1993-08-10

205

Solar power generator and water purifier  

Microsoft Academic Search

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

1981-01-01

206

Photovoltaic Technologies for Commercial Power Generation  

Microsoft Academic Search

Photovoltaic power generation is an attractive source of energy since it involves the direct conversion of sunlight into electricity with no moving parts and no pollution. Following the demonstration of the first solar cell 35 years ago at Bell Laboratories, a steady stream of scientific and commercial progress has led to a rapid increase in applications in recent years. The

D E Carlson

1990-01-01

207

Molten carbonate fuel cell power generation systems  

Microsoft Academic Search

Research and development of molten carbonate fuel cells (MCFC) have been conducted by Hitachi, Ltd since 1981 under contracts with the Agency of New Energy and Industrial Science (NEDO). Hitachi has already completed a 100 kW MCFC test plant and in 1994 moved on to construct a 1000 kW pilot plant. Features of MCFC power generation systems are the high

Y. Hishinuma; M. Kunikata

1997-01-01

208

Solving the Unit Commitment Problem in Power Generation by Primal and Dual Methods  

E-print Network

on the shares of nuclear, conventional thermal, hydro and pumped-storage hydro power in the underlyingSolving the Unit Commitment Problem in Power Generation by Primal and Dual Methods D. Dentcheva1, R. Gollmer1, A. Moller1, W. Romisch1 and R. Schultz2 Abstract. The unit commitment problem in power plant

Römisch, Werner

209

An advanced zero emission power cycle with integrated low temperature thermal energy  

Microsoft Academic Search

An innovative zero emission hybrid cycle named HICES (hybrid and improved CES cycle) is presented in this paper. It can utilize fossil fuel and low quality thermal energy such as waste heat from industrial processes and solar thermal energy for highly efficient electric power generation. In the HICES cycle, natural gas is internally combusted with pure oxygen. External low quality

Chenhua Gou; Ruixian Cai; Guoqiang Zhang

2006-01-01

210

Method of operating a thermal engine powered by a chemical reaction  

DOEpatents

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.

Ross, J.; Escher, C.

1988-06-07

211

Method of operating a thermal engine powered by a chemical reaction  

DOEpatents

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.

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

1988-01-01

212

Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

213

Thermoelectric Power Generator Design for Maximum Power: It's All About ZT  

NASA Astrophysics Data System (ADS)

There is a significant amount of literature that discusses thermoelectric power generator (TEG) design, but much of it overly simplifies the design space and therefore the results have limited use in designing real-life systems. This paper develops a more comprehensive model of the thermal and electrical interactions of a TEG in a system with known hot-side and cold-side thermal resistances and corresponding constant system temperature differential. Two design scenarios are investigated for common TEG system applications. In one method, the power from a TEG is maximized for a given electrical load, simulating a case where the TEG is electrically in series with a known load such as a fan. In the second design scenario, the power from a TEG is maximized for a given electrical load resistance ratio, n (the ratio between the external load resistance and the internal TEG resistance), simulating an application where the TEG is electrically in series with a load-matching converter. An interesting conclusion from this work is that, in the first design scenario, the electrical load resistance ratio, n, that maximizes TEG power occurs at ?{1 + ZT} (where ZT is the thermoelectric figure of merit) instead of 1 as reported previously in literature. Equally interesting is that, if you define an analogous thermal resistance ratio, m' (representing the ratio between the TEG thermal resistance at open-circuit conditions and the system thermal resistance), the maximum power in both design scenarios occurs at ?{1 + ZT} instead of the commonly cited value of 1. Furthermore, results are presented for real-life designs that incorporate electrical and thermal losses common to realistic TEG systems such as electrical contact resistance and thermal bypass around the TEG due to sealing.

McCarty, R.

2013-07-01

214

Apollo experience report: Power generation system  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

215

Low thermal resistance power module assembly  

DOEpatents

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.

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

2010-12-28

216

Photovoltaic Power Generation in the Stellar Environments  

E-print Network

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

T. E. Girish; S. Aranya

2010-12-03

217

Thermoelectric power generation for hybrid-electric vehicle auxiliary power  

NASA Astrophysics Data System (ADS)

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.

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

2009-03-01

218

A thermoelectric generator using porous Si thermal isolation.  

PubMed

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

Hourdakis, Emmanouel; Nassiopoulou, Androula G

2013-01-01

219

A Thermoelectric Generator Using Porous Si Thermal Isolation  

PubMed Central

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

Hourdakis, Emmanouel; Nassiopoulou, Androula G.

2013-01-01

220

Value of Concentrating Solar Power and Thermal Energy Storage  

SciTech Connect

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.

Sioshansi, R.; Denholm, P.

2010-02-01

221

New Generation Perovskite Thermal Barrier Coating Materials  

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

222

DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS  

SciTech Connect

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.

Paul Tubel

2003-04-24

223

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

Federal Register 2010, 2011, 2012, 2013

...Constellation NewEnergy, Inc.; Constellation Power Source Generation, Inc.; Criterion Power Partners, LLC; Notice of Petition for...Constellation NewEnergy, Inc., Constellation Power Source Generation, Inc. and Criterion Power...

2013-05-30

224

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

SciTech Connect

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.

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

2013-09-26

225

On Distinguishing between Internet Power Law Topology Generators  

E-print Network

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

Massachusetts at Amherst, University of

226

On Distinguishing between Internet Power Law Topology Generators  

E-print Network

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

Massachusetts at Amherst, University of

227

Electrical power generation from insect flight  

NASA Astrophysics Data System (ADS)

This article presents an implementation of a miniature energy harvester (weighing 0.292 grams) on an insect (hawkmoth Manduca sexta) in un-tethered flight. The harvester utilizes a piezoelectric transducer which converts the vibratory motion induced by the insect's flight into electrical power (generating up to 59 ?WRMS). By attaching a low-power management circuit (weighing 0.200 grams) to the energy harvester and accumulating the converted energy onboard the flying insect, we are able to visually demonstrate pulsed power delivery (averaging 196 mW) by intermittently flashing a light emitting diode. This self-recharging system offers biologists a new means for powering onboard electronics used to study small flying animals. Using this approach, the lifetime of the electronics would be limited only by the lifetime of the individuals, a vast improvement over current methods.

Reissman, Timothy; MacCurdy, Robert B.; Garcia, Ephrahim

2011-03-01

228

Thermophotovoltaic and thermoelectric portable power generators  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

229

Isotope powered stirling generator for terrestrial applications  

NASA Astrophysics Data System (ADS)

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

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

1995-01-01

230

ON THE PERIODS OF THE LINEAR CONGRUENTIAL AND POWER GENERATORS  

E-print Network

ON THE PERIODS OF THE LINEAR CONGRUENTIAL AND POWER GENERATORS P¨AR KURLBERG AND CARL POMERANCE 1 congruential generator and the power generator. For the former, we are given integers e, b, n (with e, n > 1 as a pseudorandom number generator by D. H. Lehmer. For the power generator we are given integers e, n > 1

Kurlberg, Par

231

An electromagnetic micro power generator for wideband environmental vibrations  

Microsoft Academic Search

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

Ibrahim Sari; Tuna Balkan; Haluk Kulah

2008-01-01

232

Nano-thermotunneling systems for efficient power generation  

NASA Astrophysics Data System (ADS)

Thermoelectrics have been investigated for their cooling and energy harvesting uses over the last six decades. Those devices can be bought from a number of commercial suppliers. Thermotunneling (TT) devices, on the other hand, have been known only for the last two decades, and nobody has been able to practically manufacture or demonstrate the performance of those devices. In this study, we will discuss the high thermodynamic efficiency of these systems and design bottlenecks to reach the high efficiencies such as thermal back path and electrical losses. Concepts for possible device designs will be discussed in detail. Efficiency of those devices will be compared with the conventional power generation as well as solid-state power generation systems. Thermodynamic limits of TT systems will be compared, and first order economic analysis will be performed.

Arik, Mehmet; Bray, Jim; Weaver, Stanton

2010-04-01

233

ZERO EMISSION POWER GENERATION TECHNOLOGY DEVELOPMENT  

SciTech Connect

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.

Ronald Bischoff; Stephen Doyle

2005-01-20

234

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

Code of Federal Regulations, 2012 CFR

... 4 2012-10-01 2012-10-01 false Power requirements, generating sources. 111.10-4...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

2012-10-01

235

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

Code of Federal Regulations, 2013 CFR

... 4 2013-10-01 2013-10-01 false Power requirements, generating sources. 111.10-4...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

2013-10-01

236

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

Code of Federal Regulations, 2010 CFR

... 4 2010-10-01 2010-10-01 false Power requirements, generating sources. 111.10-4...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

2010-10-01

237

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

Code of Federal Regulations, 2011 CFR

... 4 2011-10-01 2011-10-01 false Power requirements, generating sources. 111.10-4...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

2011-10-01

238

Electrokinetic Power Generation from Liquid Water Microjets  

SciTech Connect

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%.

Duffin, Andrew M.; Saykally, Richard J.

2008-02-15

239

Ash from thermal power plants as secondary raw material.  

PubMed

The basic characteristic of thermal power plants in the Republic of Serbia is that they use low-grade brown coal (lignite) as a fuel. Depending on the location of coal mines, lignite may have different properties such as heating value, moisture, and mineral content, resulting in different residue upon combustion. Because of several million tonnes of ash and slag generated every year, their granularmetric particle size distribution, and transport and disposal methods, these plants have a negative impact on the environment. According to the waste classification system in the Republic of Serbia, ash and slag from thermal power plants are classified as hazardous waste, but with an option of usability. The proposed revision of waste legislation in Serbia brings a number of simple and modern solutions. A procedure is introduced which allows for end-of-waste criteria to be set, clarifying the point where waste ceases to be waste, and thereby introducing regulatory relief for recycled products or materials that represent low risk for the environment. The new proposal refocuses waste legislation on the environmental impacts of the generation and management of waste, taking into account the life cycle of resources, and develops new waste prevention programmes. Stakeholders, as well as the general public, should have the opportunity to participate in the drawing up of the programmes, and should have access to them. PMID:17562607

Cudi?, Vladica; Kisi?, Dragica; Stojiljkovi?, Dragoslava; Jovovi?, Aleksandar

2007-06-01

240

Safety of next generation power reactors  

SciTech Connect

This book is organized under the following headings: Future needs of utilities regulators, government, and other energy users, PRA and reliability, LMR concepts, LWR design, Advanced reactor technology, What the industry can deliver: advanced LWRs, High temperature gas-cooled reactors, LMR whole-core experiments, Advanced LWR concepts, LWR technology, Forum: public perceptions, What the industry can deliver: LMRs and HTGRs, Criteria and licensing, LMR modeling, Light water reactor thermal-hydraulics, LMR technology, Working together to revitalize nuclear power, Appendix A, luncheon address, Appendix B, banquet address.

Not Available

1988-01-01

241

Fresnel Concentrators for Space Solar Power and Solar Thermal Propulsion  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

242

A Power-Driven Thermal Sensor Placement Algorithm for Dynamic Thermal Management  

E-print Network

estimation with the new thermal sensor placement method. Fig. 1. Comparison of the traditional sensor basedA Power-Driven Thermal Sensor Placement Algorithm for Dynamic Thermal Management Hai Wang, Sheldon sensors play a vital role for accurately estimating the full-chip thermal profile. How to place physical

Tan, Sheldon X.-D.

243

Modeling of solar thermal selective surfaces and thermoelectric generators  

E-print Network

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

McEnaney, Kenneth

2010-01-01

244

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

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

245

Turbine sizing of a solar thermal power plant  

NASA Technical Reports Server (NTRS)

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.

Manvi, R.; Fujita, T.

1979-01-01

246

Complementary power output characteristics of electromagnetic generators and triboelectric generators  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

247

Complementary power output characteristics of electromagnetic generators and triboelectric generators.  

PubMed

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

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

2014-04-01

248

Wave and tide powered generation apparatus  

SciTech Connect

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.

Suggs, L. F.

1985-09-03

249

Simulation of Piezoelectric Jellyfish Power Generator  

NASA Astrophysics Data System (ADS)

The energy problem is getting increasingly serious. As such, unused energy recovery technology is crucial for environmental protection, which has been investigated extensively. Several methods have been developed to utilize scavenged energy from the environment, such as waste heat, solar energy, wind energy, and tides energy to convert into useful power. There is a new idea of piezoelectric jellyfish generator which combines the utilization of sea wave and vibration energy. When sea wave passes through the jellyfish, the wave causes the tentacles to vibrate. The tentacles is made of piezoelectric polymer which can convert the strain energy into electrical energy. This paper discusses about the piezoelectric jellyfish's tentacles being disturbed by wave in the sea. We employed the commercial CFD software CFD-ACE+ 2006 to simulate this phenomenon. The parameters including its tentacle length (L) and wave propagating function (Y) are studied which affect the piezoelectric jellyfish capacity to generate power.

Wu, Yeong-Jen; Lai, Wei-Hsiang

250

Coupled Monte Carlo neutronics and thermal hydraulics for power reactors  

SciTech Connect

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)

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

2012-07-01

251

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

Microsoft Academic Search

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

Reino Huovilainen; Jarmo Alamaeki; Risto Tarjanne

1987-01-01

252

Utility interconnection issues for wind power generation  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

253

Options for Control of Reactive Power by Distributed Photovoltaic Generators  

E-print Network

High penetration levels of distributed photovoltaic(PV) generation on an electrical distribution circuit present several challenges and opportunities for distribution utilities. Rapidly varying irradiance conditions may cause voltage sags and swells that cannot be compensated by slowly responding utility equipment resulting in a degradation of power quality. 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 discuss and compare via simulation various design options for control systems to manage the reactive power generated by these inverters. An important design decision that weighs on the speed and quality of communication required is whether the control should be centralized or distributed (i.e. local). In general, we find that local control schemes are capable for maintaining voltage within acceptable bounds. We consider the benefits of choosing different local variables on which to control and how the control system can be continuously tuned between robust voltage control, suitable for daytime operation when circuit conditions can change rapidly, and loss minimization better suited for nighttime operation.

Petr Sulc; Konstantin Turitsyn; Scott Backhaus; Michael Chertkov

2010-08-04

254

Cummins Power Generation SECA Phase 1  

SciTech Connect

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.

Charles Vesely

2007-08-17

255

Solar Power Satellite Thermal Control Approach  

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

256

Gravitational wave generation in power-law inflationary models  

E-print Network

We investigate the generation of gravitational waves in power-law inflationary models. The energy spectrum of the gravitational waves is calculated using the method of continuous Bogoliubov coefficients. We show that, by looking at the interval of frequencies between 10^(-5) and 10^5 Hz and also at the GHz range, important information can be obtained, both about the inflationary period itself and about the thermalization regime between the end of inflation and the beginning of the radiation-dominated era. We thus deem the development of gravitational wave detectors, covering the MHz/GHz range of frequencies, to be an important task for the future.

Paulo M. Sá; Alfredo B. Henriques

2008-04-21

257

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

E-print Network

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

Tomkins, Andrew

258

Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

259

OPTIMAL DISTRIBUTED POWER GENERATION UNDER NETWORK LOAD CONSTRAINTS,  

E-print Network

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

Frank, Jason

260

High thermal power density heat transfer. [thermionic converters  

NASA Technical Reports Server (NTRS)

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.

Morris, J. F. (inventor)

1980-01-01

261

Rapid modeling of power electronics thermal management technologies  

Microsoft Academic Search

A methodology was developed to rapidly evaluate trade-offs associated with alternative packaging configurations and thermal management technologies for power electronics packaging. The methodology includes the integration of available experimental correlations, computational fluid dynamics results, parametric 3D finite element analysis (FEA) thermal models, and established heat exchanger analysis techniques. The parametric 3D FEA model enables sensitivity studies related to the power

Kevin Bennion; Kenneth Kelly

2009-01-01

262

Thermal-To-Electric Converter With Greater Power Density  

NASA Technical Reports Server (NTRS)

Proposed design for alkali-metal thermal-to-electric converter (AMTEC) incorporates refinements to increase power density and reduce input temperature below typical prior design. Converter has compact, planar configuration. Cells stacked densely with remote condenser for thermal efficiency and high power density. Either liquid- or vapor-fed cells utilized. Heat fed-in at lower temperature.

Williams, Roger M.; Suitor, Jerry W.; Jeffries-Nakamura, Barbara; Underwood, Mark L.; Ryan, Margaret A.; O'Connor, Dennis

1992-01-01

263

Future Photovoltaic Power Generation for Space-Based Power Utilities  

NASA Astrophysics Data System (ADS)

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.

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

2002-01-01

264

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...

265

Solar salt pond potential site survey for electrical power generation  

NASA Technical Reports Server (NTRS)

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.

Hurick, M. G.

1982-01-01

266

A high power spacecraft thermal management system  

NASA Technical Reports Server (NTRS)

This paper describes the design and test results of an ammonia hybrid capillary pumped loop thermal control system. As a hytbrid, the system can operate as either a passive, capillary pumped loop, or, as a mechanically pumped system. The system is comprised of an evaporator section, a condenser section, 10 meters of liquid and vapor transport lines, a mechanical pump, and a reservoir. In the evaporator section, four capillary pumps are each integrated into three cold plates. The mechanical pump is installed in the liquid line and is in series with the capillary pumps. Testing has demonstrated that in the capillary pumped mode, the HPSTM can acquire and transport a total heat load of between 120 W and 24 kW, with a maximum heat flux density of 4.3 W/sq cm in the evaporator section. In the mechanically pumped configuration, a heat acquisition potential of 50 kW (9 W/sq cm heat flux density) has been demonstrated. The hybrid system still retains the proven capillary capabilities of temperature control, heat load sharing and fluid flow control between evaporator plates, rapid power cycling, and pressure priming recovery of deprimed evaporators.

Ku, J.; Kroliczek, E. J.; Mccabe, M. E., Jr.; Benner, S. M.

1988-01-01

267

New Generation Perovskite Thermal Barrier Coating Materials  

Microsoft Academic Search

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

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

2008-01-01

268

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

Microsoft Academic Search

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

J. P. Reichling; F. A. Kulacki

2008-01-01

269

Power Generator with Thermo-Differential Modules  

NASA Technical Reports Server (NTRS)

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.

Saiz, John R.; Nguyen, James

2010-01-01

270

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

Microsoft Academic Search

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

T. Tani; T. Horigome

1974-01-01

271

Applicability of advanced automotive heat engines to solar thermal power  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

272

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...

273

Effects of Thermal Characterisics of Aircraft Generators on Load Analysis  

Microsoft Academic Search

The elaborate electric systems in modern long-range aircraft have made accuracy of load analysis more important than ever before. A more precise evaluation of the adequacy of proposed generating equipment can be made by averaging expected loads over several different periods which are chosen on the basis of the generators' thermal characteristics. These averages are compared graphically with curves which

Stanley Rogers

1946-01-01

274

Airline requirements on aircraft electrical power generation and distribution  

Microsoft Academic Search

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

Claus Glashagen

1992-01-01

275

Comparison of advanced engines for parabolic dish solar thermal power plants  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

276

Truncated thermalization of optical waves through supercontinuum generation in photonic crystal fibers  

E-print Network

Truncated thermalization of optical waves through supercontinuum generation in photonic crystal the process of optical wave thermalization through supercontinuum generation in pho- tonic crystal fibers. We

Garnier, Josselin

277

Neutron generator power supply modeling in EMMA  

SciTech Connect

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.

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

1996-12-01

278

Journal of Power Sources 160 (2006) 662673 Power and thermal characterization of a lithium-ion battery  

E-print Network

to explore pulse power limitations and thermal behavior of a 6 Ah, 72 cell, 276 V nominal Li-ion hybrid generation 1. Introduction While much understanding of internal processes and limi- tations of Li-ion-ion battery pack for hybrid-electric vehicles Kandler Smith, Chao-Yang Wang Electrochemical Engine Center

279

High-power Broadband Organic THz Generator  

PubMed Central

The high-power broadband terahertz (THz) generator is an essential tool for a wide range of THz applications. Here, we present a novel highly efficient electro-optic quinolinium single crystal for THz wave generation. For obtaining intense and broadband THz waves by optical-to-THz frequency conversion, a quinolinium crystal was developed to fulfill all the requirements, which are in general extremely difficult to maintain simultaneously in a single medium, such as a large macroscopic electro-optic response and excellent crystal characteristics including a large crystal size with desired facets, good environmental stability, high optical quality, wide transparency range, and controllable crystal thickness. Compared to the benchmark inorganic and organic crystals, the new quinolinium crystal possesses excellent crystal properties and THz generation characteristics with broader THz spectral coverage and higher THz conversion efficiency at the technologically important pump wavelength of 800?nm. Therefore, the quinolinium crystal offers great potential for efficient and gap-free broadband THz wave generation. PMID:24220234

Jeong, Jae-Hyeok; Kang, Bong-Joo; Kim, Ji-Soo; Jazbinsek, Mojca; Lee, Seung-Heon; Lee, Seung-Chul; Baek, In-Hyung; Yun, Hoseop; Kim, Jongtaek; Lee, Yoon Sup; Lee, Jae-Hyeok; Kim, Jae-Ho; Rotermund, Fabian; Kwon, O-Pil

2013-01-01

280

Thermoelectric Analysis for Helical Power Generation Systems  

NASA Astrophysics Data System (ADS)

The performance of a three-dimensional helical thermoelectric generation (TEG) system is examined by exposing it to a temperature difference with hot and cold sources. The helical paths for the two thermal fluids give the TEG device the potential to efficiently convert thermal energy. The characteristic performance of the helical system is numerically analyzed by using the finite-volume method in a compact system. The helical system is compared with a straight system in which all the thermoelectric (TE) elements present equivalent geometry. The difference in the TE performance between the two systems is not significant when the TE surfaces are maintained at constant temperatures. Both the electromotive force and the current in the TEG system increase linearly with the temperature difference ? T applied at the two module surfaces. The current preferentially flows through a main path determined by the geometry of the TE element. The merits of the helical design are its compactness, space saving, and smooth fluid flow due to gravity, compared with the straight system.

Meng, Xiangning; Fujisaka, Takeyuki; Suzuki, Ryosuke O.

2014-06-01

281

WIMP matter power spectra and small scale power generation  

E-print Network

Dark Matter (DM) is generally assumed to be massive, cold and collisionless from the structure formation point of view. A more correct statement however is that DM indeed experiences collisional damping, but on a scale which is supposed to be too small to be relevant for structure formation. The aim of this paper is to present a Cold (although ``collisional'') Dark Matter particle whose matter power spectrum is damped and see whether it is distinguishable from standard candidates. To achieve this purpose, we calculate the collisional damping and free-streaming scales of neutralinos and non conventional candidates (say light particles heavier than ~1 MeV but lighter than O(10) GeV). The latter can be considered as Cold Dark Matter (CDM) particles in the sense that they become non relativistic before their thermal decoupling epoch. Unlike neutralinos, however, their linear matter power spectrum can be damped on scales of ~ 10^3 Msol due to their interactions. Since these scales are of cosmological interest for structure formation, we perform a series of numerical simulations to obtain the corresponding non linear matter power spectra P(k)_{nl} at the present epoch. We show that because of small scale regeneration, they all resemble each other at low redshifts, i.e. become very similar to a typical CDM matter power spectrum on all but the smallest scales. Therefore, even if lensing measurements at redshift below unity were to yield a P(k)_{nl} consistent with CDM models, this would not constitute a sufficiently robust evidence in favour of the neutralino to rule out alternative DM candidates.

C. Boehm; H. Mathis; J. Devriendt; J. Silk

2003-09-24

282

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

NASA Astrophysics Data System (ADS)

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.

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

283

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

PubMed

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

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

284

Generating thermal stable variants of protein domains through phage display.  

PubMed

Often in protein design research, one desires to generate thermally stable variants of a protein or domain. One route to identifying mutations that yield domains that remain folded and active at a higher temperature is through the use of directed evolution. A library of protein domain variants can be generated by mutagenic PCR, expressed on the surface of bacteriophage M13, and subjected to heat, such that the unfolded forms of the domain, showing reduced or no binding activity, are lost during subsequent affinity selection, whereas variants that still retain binding to their target are selected and enriched with each subsequent round of affinity selection. This approach takes advantage of the fact that bacteriophage M13 particles are heat stable and resistant to many proteases and protein denaturants. We present the application of this general approach to generating thermally stable variants of a eukaryotic peptide-binding domain. The benefits of producing such variants are that they typically express at high levels in Escherichia coli (30-60 mg/L shake flask) and remain soluble in solution at higher concentrations for longer periods of time than the wild-type form of the domain. The process of library generation and screening generally requires about one month of effort, and yields variants with >10 °C increase in thermal stability, as measured in a simple fluorescence-based thermal shift assay. It is anticipated that thermally stable variants will serve as excellent scaffolds for generating affinity reagents to a variety of targets of interest. PMID:23276752

Pershad, Kritika; Kay, Brian K

2013-03-15

285

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

E-print Network

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

Nagurney, Anna

286

Thermal grease replacement for the modular power subsystem  

NASA Technical Reports Server (NTRS)

A comparative thermal conductance test was conducted to evaluate thermal interface materials for use on the Modular Power Subsystem. Materials tested included three thermal pads, four RTV adhesives, bare metal, and one thermal grease. The tests were conducted in a bell jar at vacuum conditions using a 1400 square centimeter footprint and two relatively low contact pressures, 207 kPa and 620 kPa. Power inputs ranged from 100 to 500 watts, and the thermal interface conductance values ranged from 100 to 1700 W/m2 C for the interstitial materials tested. In general, the thermal pads performed a little better than bare metal, while the RTV adhesives performed significantly better than the bare metal and comparable to the thermal grease.

Lapinski, John R., Jr.; Ousley, Gilbert W., Jr.

1990-01-01

287

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

NASA Technical Reports Server (NTRS)

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.

Ramakumar, R.

1979-01-01

288

Generation mechanism of power line harmonic radiation  

NASA Astrophysics Data System (ADS)

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.

Kostrov, Alexander; Gushchin, Mikhail; Korobkov, Sergei

289

Power Modeling and Thermal Management Techniques for Manycores  

E-print Network

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

Simunic, Tajana

290

Exergy analysis of solar thermal supercritical Rankine power cycle  

Microsoft Academic Search

Solar power system has been widely investigated, but both the cost of the installation and the time-dependence of the solar irradiation make the solar power system economically unfeasible. Using the solar thermal energy to indirectly heat the working medium of a power cycle has been used in many solar heating or cooling systems, which is adopted in this paper to

W. H. Huang; C. C. Lee

1983-01-01

291

Review Article Solar-Thermal Powered Desalination: Its Significant  

E-print Network

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

Reif, John H.

292

Low Power Wind Generation System based on variable speed permanent magnet synchronous generators  

Microsoft Academic Search

This paper presents a Low Power Wind Generation System based on a permanent magnet synchronous generator and a High Power Factor rectifier. To achieve a high power factor in the generator side, it is proposed a power processing scheme that uses a passive rectifier and a DC-DC converter working in discontinuous conduction mode. This circuit is known as a boost

O. Carranza; E. Figueres; G. Garcera; R. Ortega; D. Velasco

2011-01-01

293

43 CFR 418.16 - Using water for power generation.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

294

Electromagnetic Generators for Portable Power Applications Matthew Kurt Senesky  

E-print Network

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

Sanders, Seth

295

43 CFR 418.16 - Using water for power generation.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

296

Optimal distributed power generation under network load constraints  

E-print Network

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

Utrecht, Universiteit

297

43 CFR 418.16 - Using water for power generation.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

298

Design of a Power Saving Methodology for Next Generation  

E-print Network

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

Jantsch, Axel

299

43 CFR 418.16 - Using water for power generation.  

Code of Federal Regulations, 2012 CFR

...2011-10-01 true Using water for power generation. 418.16 Section 418.16 Public...Management § 418.16 Using water for power generation. All use of Project water for power generation must be incidental to releases...

2012-10-01

300

43 CFR 418.16 - Using water for power generation.  

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

2014-10-01

301

A Thermal and Electrical Analysis of Power Semiconductor Devices  

NASA Technical Reports Server (NTRS)

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.

Vafai, Kambiz

1997-01-01

302

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

E-print Network

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

Ireland, Melissa Kara

2014-01-01

303

Investigation of Maximum Power Point Tracking for Thermoelectric Generators  

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

304

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)

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.

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

305

On the procurement of reactive power support services from generators  

NASA Astrophysics Data System (ADS)

Reactive power is an important system support service in the current electric power market. This support service should be procured competitively from and remunerated fairly to the service providers. The objective of this thesis is to research the reactive power procurement issues related to the generators, the main provider and user of the reactive power support service in a power market. The thesis first investigates and clarifies the functions of a generator's reactive power output. It is found that the reactive power output of a generator has two functions. One is to support the transmission of the active power produced by itself and the other is to provide system voltage support. It is, therefore, possible that a generator provides no system support even if it generates reactive power. This situation occurs when the generator outputs less reactive power than what is needed to support the transmission of its own active power. Based on the findings, the thesis proposes the concept of minimum reactive power requirement for generators. This is a quantitative index to measure the amount of true reactive power support available from each generator. If a generator's reactive power output is less than the minimum requirement, the generator actually draws reactive support from the system. A method is developed to determine the this index for a given generator. Test results on actual power systems have verified the validity of the proposed concept and method. Several related issues are also investigated by this thesis. Possible methods to include the proposed index in transmission cost allocation are presented. The issue of how to model a generator's reactive power limit is clarified. Reactive support shortage and associated voltage instability are found to be the sole cause of ill-conditioned power flow problems. In summary, the work presented in this thesis will help to establish a sound technical foundation for compensating reactive power support service in a competitive electricity market.

Wang, Yuanning

306

Thermal management methods for compact high power LED arrays  

NASA Astrophysics Data System (ADS)

The package and system level temperature distributions of a high power (>1W) light emitting diode (LED) array has been investigated using numerical heat flow models. For this analysis, a thermal resistor network model was combined with a 3D finite element submodel of an LED structure to predict system and die level temperatures. The impact of LED array density, LED power density, and active versus passive cooling methods on device operation were calculated. In order to help understand the role of various thermal resistances in cooling such compact arrays, the thermal resistance network was analyzed in order to estimate the contributions from materials as well as active and passive cooling schemes. An analysis of thermal stresses and residual stresses in the die are also calculated based on power dissipation and convection heat transfer coefficients. Results show that the thermal stress in the GaN layer are compressive which can impact the band gap and performance of the LEDs.

Christensen, Adam; Ha, Minseok; Graham, Samuel

2007-09-01

307

Reliability Evaluation for Power Electronics Device using Electrical Thermal and Mechanical Analysis  

Microsoft Academic Search

For power electronics devices, the reliability of thermal fatigue induced by power cycling has been prioritized as an important concern. Since power cycling produces non-uniform temperature distribution in the device, coupled thermal- structure analysis is required to evaluate thermal fatigue mechanism. The thermal expansion difference between a package and a substrate causes thermal fatigue. Many studies on thermal fatigue in

T. Anzawa; Qiang Yu; T. Shibutani; M. Shiratori

2007-01-01

308

Performance evaluation of solar thermal electric generation systems  

Microsoft Academic Search

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

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

2003-01-01

309

Diagnostics on the COBRA pulsed power generator  

SciTech Connect

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.

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. [Laboratory of Plasma Studies, Cornell University, Rhodes Hall, Ithaca, New York 14853 (United States)

2006-10-15

310

Diagnostics on the COBRA pulsed power generator  

NASA Astrophysics Data System (ADS)

The COBRA pulsed power generator has a variable current pulse wave form and amplitude (95-180ns rise time, up to 1MA 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.

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.

2006-10-01

311

Power Generation from Nuclear Reactors in Aerospace Applications  

NASA Technical Reports Server (NTRS)

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.

English, Robert E.

1982-01-01

312

Power generation from nuclear reactors in aerospace applications  

SciTech Connect

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.

English, R.E.

1982-01-01

313

Acoustic Harmonic Generation Due to Thermal Embrittlement of Inconel 718  

Microsoft Academic Search

This paper describes an attempt to characterize the deterioration of a structural material's mechanical properties by nonlinear acoustics. In this particular case, the damage was caused by “thermal embrittlement” during which the material, here the nickel-based alloy Inconel 718, loses a significant fraction of its fracture toughness. Harmonic generation was the experimental method used to characterize the microstructural changes in

D. J. Barnard; G. E. Dace; O. Buck

1997-01-01

314

Infrared Sensing of Ultrasonically Generated Thermal Waves for NDE Applications  

Microsoft Academic Search

The ultrasonic nondestructive evaluation (NDE) of composites (e.g., graphite reinforced epoxy GR\\/E) for delamination and porosity is difficult because of high a ttenuation of the material, which ultimately converts the ultrasonic energy to heat via the generation of thermal waves. The technique described here seeks to take advantage of this energy conversion by detecting and characterizing surface temperature contours produced

B. R. Tittmann; R. S. Linebarger

1984-01-01

315

Generation of charged clusters during thermal evaporation of gold  

Microsoft Academic Search

Investigating the generation of charged clusters during thermal evaporation of gold at 1523K has created a new understanding of film growth. In order to verify the presence of charged clusters in the gas phase and their polarity biases of +200, 0 and ?200V were applied to the substrate. The charge on the majority of clusters was shown to be positive

Mark C Barnes; In-D Jeon; Doh-Y Kim; Nong M Hwang

2002-01-01

316

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

ScienceCinema

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.

None

2013-05-28

317

Treatment and reuse of industrial effluents: case study of a thermal power plant  

Microsoft Academic Search

This paper presents a study of the potential of industrial wastewater reuse in Jordan's Al Hussein thermal power station. A comprehensive review of the processes involved, industrial waste generation and water requirements was carried out, and areas of potential improvment were identified. They include a water treatment system, blow-down system, flue gas desulfurization and finding alternative process water sources such

Mousa S. Mohsen

2004-01-01

318

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

Microsoft Academic Search

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

Nobuyoshi Mutoh; Takatoshi Matuo; Kazuhito Okada; Masahiro Sakai

2002-01-01

319

Self-powered signal processing using vibration-based power generation  

Microsoft Academic Search

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

Rajeevan Amirtharajah; Anantha P. Chandrakasan

1998-01-01

320

Short term operation and power exchange planning of hydro-thermal power systems  

Microsoft Academic Search

This paper considers a unified problem of short-term operation planning and power exchange scheduling of large hydro-thermal power systems including: unit commitment, hydro power plant operation planning, pumped-storage hydro power plant operation planning and scheduling of power exchange with other power utilities. The criterion function is the total variable profit incurred by energy production, sales of energy to the users

M. V. Rakic; Z. M. Markovic

1994-01-01

321

Calculation of guaranteed mean power from wind turbine generators  

NASA Technical Reports Server (NTRS)

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.

Spera, D. A.

1981-01-01

322

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

Microsoft Academic Search

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

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

2005-01-01

323

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

NASA Astrophysics Data System (ADS)

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.

Kai, Takaaki; Tanaka, Akio

324

Thermal testing of a high powered communications satellite  

NASA Technical Reports Server (NTRS)

Thermal Vacuum and Thermal Balance tests were successfully conducted on the high power Communications Technology Satellite (CTS). The mission required testing for two distinct thermal environments; spin stabilized at 60 rpm with a minimum of 55 watts of dissipated power, and three-axis stabilized with as much as a tenfold increase of dissipation. The test program verified the adequacy of the spacecraft thermal design and demonstrated functional operation over a wide temperature range for all of the components. Special test hardware incorporating water-cooling systems was required to accomodate the heatpipes and high RF output power. Objectives, test facilities, special hardware, spacecraft configurations, and results of the tests are discussed. Preliminary flight results and conclusions drawn from the test experience are reported.

Caswell, R. D.; Edelman, E. A.

1976-01-01

325

Rankline-Brayton engine powered solar thermal aircraft  

DOEpatents

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.

Bennett, Charles L. (Livermore, CA)

2012-03-13

326

Rankine-Brayton engine powered solar thermal aircraft  

DOEpatents

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.

Bennett, Charles L. (Livermore, CA)

2009-12-29

327

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

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

328

Thermal management of power electronics using thermoelectric coolers  

Microsoft Academic Search

Many high power electronic devices, such as power amplifies and multiprocessors, operate at high temperatures close to or at the edge of their reliability, which could severely impact performance and operating lifetime. These devices thus need cooling to improve performance and reliability. Conventional thermal management techniques, most of which are discussed, are not well suited to the specific problem of

J. W. Vandersande; J.-P. Fleurial

1996-01-01

329

Sustainable Power Generation in Microbial Fuel Cells Using  

E-print Network

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

Tullos, Desiree

330

Analysis of waste-heat thermoelectric power generators  

Microsoft Academic Search

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

Chih Wu

1996-01-01

331

On Distinguishing between Internet Power Law Topology Generators  

Microsoft Academic Search

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

Tian Bu; Donald F. Towsley

2002-01-01

332

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

333

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...

334

Integrated engine-generator concept for aircraft electric secondary power  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

335

Thermal, hydraulic, and corrosion aspects of PWR steam generator problems  

SciTech Connect

Two types of PWR steam generators are in use: recirculating steam generators (RSGs) and once-through steam generators (OTSGs). Most of the units and vertical and this review will be limited to vertical units. Some of these steam generators have operated with a minimum of problems while other steam generator designs have experienced a variety of corrosion and mechanically induced problems. The discussion will focus more on the designs that have experienced problems and the effort expended to correct them. Corrosion problems include denting, wastage, intergranular attack, stress corrosion cracking, corrosion fatigue, pitting on the outside surfaces of the tubes, and stress corrosion cracking the inner surfaces of the tubes. Mechanical concerns have included water hammer, thermal stratification in feed-water pipes, fretting and wear of the tubes caused by excessive tube vibration, and erosion-corrosion. These problems have caused unscheduled outages and expensive repairs.

Green, S.J.

1988-01-01

336

Power MOSFET Thermal Instability Operation Characterization Support  

NASA Technical Reports Server (NTRS)

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.

Shue, John L.; Leidecker, Henning

2010-01-01

337

Generator powered electrically heated diesel particulate filter  

DOEpatents

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.

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

2014-03-18

338

Direct charge radioisotope activation and power generation  

DOEpatents

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.

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

2002-01-01

339

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

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

340

A comparison of different entransy flow definitions and entropy generation in thermal radiation optimization  

NASA Astrophysics Data System (ADS)

In thermal radiation, taking heat flow as an extensive quantity and defining the potential as temperature T or the blackbody emissive power U will lead to two different definitions of radiation entransy flow and the corresponding principles for thermal radiation optimization. The two definitions of radiation entransy flow and the corresponding optimization principles are compared in this paper. When the total heat flow is given, the optimization objectives of the extremum entransy dissipation principles (EEDPs) developed based on potentials T and U correspond to the minimum equivalent temperature difference and the minimum equivalent blackbody emissive power difference respectively. The physical meaning of the definition based on potential U is clearer than that based on potential T, but the latter one can be used for the coupled heat transfer optimization problem while the former one cannot. The extremum entropy generation principle (EEGP) for thermal radiation is also derived, which includes the minimum entropy generation principle for thermal radiation. When the radiation heat flow is prescribed, the EEGP reveals that the minimum entropy generation leads to the minimum equivalent thermodynamic potential difference, which is not the expected objective in heat transfer. Therefore, the minimum entropy generation is not always appropriate for thermal radiation optimization. Finally, three thermal radiation optimization examples are discussed, and the results show that the difference in optimization objective between the EEDPs and the EEGP leads to the difference between the optimization results. The EEDP based on potential T is more useful in practical application since its optimization objective is usually consistent with the expected one.

Zhou, Bing; Cheng, Xue-Tao; Liang, Xin-Gang

2013-08-01

341

Generating Functions for the Powers of Fibonacci Sequences  

ERIC Educational Resources Information Center

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

Terrana, D.; Chen, H.

2007-01-01

342

Fuel cells-the clean and efficient power generators  

Microsoft Academic Search

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

M. Farooque; H. C. Maru

2001-01-01

343

A new generation of high voltage pulsed power converters  

Microsoft Academic Search

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

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

2010-01-01

344

Energy Storage System Sizing for Smoothing Power Generation , P. Bydlowski  

E-print Network

in such a way that the power ca hydro-pneumatic storage as in the Pelamis, for example. Furthermore, the controlEnergy Storage System Sizing for Smoothing Power Generation of Direct J. Aubry1 , P. Bydlowski 1 E as the SEAREV. The ESS is to insure a smoothed output power profile. First, the output set point power

Boyer, Edmond

345

Improvement of financial efficiency and cost effectiveness in energy sector: A case study from Indian thermal power plant  

Microsoft Academic Search

Electricity is generated based on potential resources like coal, crude oil, water, wind, solar and nuclear energy. India depends largely on thermal power using coal as raw material despite the reality that indigenous stock of this raw material is depleting fast. At the same time coal based thermal stations are losing out financial viability gradually in terms of deteoriating efficiency,

S. Ghosh; S. C. Basu; P. P. Sengupta

2010-01-01

346

Ames Lab 101: Next Generation Power Lines  

SciTech Connect

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.

Russell, Alan

2010-01-01

347

Ames Lab 101: Next Generation Power Lines  

ScienceCinema

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.

Russell, Alan

2012-08-29

348

Secondary electric power generation with minimum engine bleed  

NASA Technical Reports Server (NTRS)

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.

Tagge, G. E.

1983-01-01

349

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

NASA Astrophysics Data System (ADS)

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%.

Hirawata, Ryoya; Kai, Takaaki

350

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

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

351

Exergetic comparison of two different cooling technologies for the power cycle of a thermal power plant  

Microsoft Academic Search

Exergetic analysis is without any doubt a powerful tool for developing, evaluating and improving an energy conversion system. In the present paper, two different cooling technologies for the power cycle of a 50MWe solar thermal power plant are compared from the exergetic viewpoint. The Rankine cycle design is a conventional, single reheat design with five closed and one open extraction

Ana M. Blanco-Marigorta; M. Victoria Sanchez-Henríquez; Juan A. Peńa-Quintana

2011-01-01

352

Reliability study of thermal cycling stress on smart power devices  

NASA Astrophysics Data System (ADS)

In this paper, we describe a smart power device degradation behavior under thermal cycling stress. An innovative test structure was developed, which faithfully reflects a stress state caused by the smart power device during operation. From our experiment, the device degraded after millions of fast thermal cycling pulses. We discovered that via destruction was the cause of the device degradation. For the duration of thermal cycling stress, the via resistance increased gradually, and finally increased rapidly at the point of millions of cycles. A failure via was observed, which was broken into two parts. Therefore, the via disconnection was considered to be due to thermo-mechanical stress or electro-migration. Some experiments were conducted, and we demonstrated that the via destruction dominated to the thermo-mechanical stress introduced by the thermal cycling stress.

Zhang, Ming; Yoshihisa, Yasuki; Furuya, Keiichi; Imai, Yukari; Hatasako, Kenichi; Ipposhi, Takashi; Maegawa, Shigeto

2014-01-01

353

Acoustic harmonic generation due to thermal embrittlement of inconel 718  

Microsoft Academic Search

This paper describes an attempt to characterize the deterioration of a structural material's mechanical properties by nonlinear\\u000a acoustics. In this particular case, the damage was caused by “thermal embrittlement” during which the material, here the nickel-based\\u000a alloy Inconel 718, loses a significant fraction of its fracture toughness. Harmonic generation was the experimental method\\u000a used to characterize the microstructural changes in

D. J. Barnard; G. E. Dace; O. Buck

1997-01-01

354

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

NASA Astrophysics Data System (ADS)

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.

Prakash, S.; Sinha, S. K.

2014-08-01

355

Underwater vehicle propulsion and power generation  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

356

Power Control and Monitoring Requirements for Thermal Vacuum/Thermal Balance Testing of the MAP Observatory  

NASA Technical Reports Server (NTRS)

The specific heater control requirements for the thermal vacuum and thermal balance testing of the Microwave Anisotropy Probe (MAP) Observatory at the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland are described. The testing was conducted in the 10m wide x 18.3m high Space Environment Simulator (SES) Thermal Vacuum Facility. The MAP thermal testing required accurate quantification of spacecraft and fixture power levels while minimizing heater electrical emissions. The special requirements of the MAP test necessitated construction of five (5) new heater racks.

Johnson, Chris; Hinkle, R. Kenneth (Technical Monitor)

2002-01-01

357

The trillion dollar power project jackpot. [Independent Power Generation  

Microsoft Academic Search

International power needs, if not insatiable, are certainly of a magnitude beyond anything heretofore imagined. The international opportunities for independent power development are huge: Power Plants -- $700 to $800 billion worth of the new facilities will be needed by the year 2000; Transmission and Distribution -- Expansion of services will require an additional $300 to $400 billion; and Repowering

Roseman

2009-01-01

358

Thermal-hydraulics for space power, propulsion, and thermal management system design  

SciTech Connect

The present volume discusses thermal-hydraulic aspects of current space projects, Space Station thermal management systems, the thermal design of the Space Station Free-Flying Platforms, the SP-100 Space Reactor Power System, advanced multi-MW space nuclear power concepts, chemical and electric propulsion systems, and such aspects of the Space Station two-phase thermal management system as its mechanical pumped loop and its capillary pumped loop's supporting technology. Also discussed are the startup thaw concept for the SP-100 Space Reactor Power System, calculational methods and experimental data for microgravity conditions, an isothermal gas-liquid flow at reduced gravity, low-gravity flow boiling, computations of Space Shuttle high pressure cryogenic turbopump ball bearing two-phase coolant flow, and reduced-gravity condensation.

Krotiuk, W.J.

1990-01-01

359

Experimental and numerical investigation of hydro power generator ventilation  

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

360

A review of power battery thermal energy management  

Microsoft Academic Search

This paper reviews the development of clean vehicles, including pure electric vehicles (EVs), hybrid electric vehicles (HEVs) and fuel cell electric vehicles (FCEVs), and high energy power batteries, such as nickel metal hydride (Ni-MH), lithium-ion (Li-ion) and proton exchange membrane fuel cells (PEMFCs). The mathematical models and thermal behavior of the batteries are described. Details of various thermal management techniques,

Zhonghao Rao; Shuangfeng Wang

2011-01-01

361

Power Electronics Thermal Management R&D (Presentation)  

SciTech Connect

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.

Waye, S.

2014-11-01

362

Modular Analysis of Automobile Exhaust Thermoelectric Power Generation System  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

363

Load Frequency Control in Power System with Distributed Generation  

NASA Astrophysics Data System (ADS)

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

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

364

Microfabrication of a tapered channel for isoelectric focusing with thermally generated pH gradient.  

PubMed

A simple microfabrication technique for the preparation of a tapered microchannel for thermally generated pH gradient isoelectric focusing (IEF) has been demonstrated. The tapered channel was cut into a plastic sheet (thickness was 120 microm), and the channel was closed by sandwiching the plastic sheet between two glass microscope slides. The length of the microchannel was 5 cm. The width of the separation channel was 0.4 mm at the narrow end and 4 mm at the wide end. The channel was coated with polyacrylamide to prevent electroosmotic flow (EOF) during focusing. Two electrolyte vials were mounted on top of each end of the channel with the wide end of the channel connected to the cathodic vial and the narrow to the anodic vial. The feasibility of the thermally generated pH gradient in a tapered channel was demonstrated. Important parameters that determined the feasibility of using a thermally generated pH gradient in a tapered channel were analyzed. Parameters to be optimized were control of EOF and hydrodynamic flow, selection of power supply mode and prevention of local overheating and air bubble formation. Tris-HCl buffer, which has a high pK(a) dependence with temperature, was used both to dissolve proteins and as the electrolyte. The thermally generated pH gradient separation of proteins was tested by focusing dog, cat and human hemoglobins with a whole column detection capillary IEF (CIEF) system. PMID:12412118

Huang, Tiemin; Pawliszyn, Janusz

2002-10-01

365

A Vector Control for Grid-connected Wind Power Generation with Doubly Fed Induction Generator  

NASA Astrophysics Data System (ADS)

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.

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

366

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

SciTech Connect

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)

Not Available

1980-06-01

367

Status report on MHD electrical power generation–IAEA\\/ENEA International Liaison Group on MHD Electrical power generation  

Microsoft Academic Search

The present status of commercial large-scale MHD electrical power generation is reviewed in the light of information presented at the Third International Symposium on MHD Electrical Power Generation (Salzburg, 1966) and of subsequent developments. Research and development activities, and the state of evaluation of engineering and economic factors are assessed in respect of open-cycle MHD power plant, closed-cycle MHD power

B. C. Lindley

1967-01-01

368

Power Maximization Control of Variable Speed Wind Generation System Using Permanent Magnet Synchronous Generator  

NASA Astrophysics Data System (ADS)

This paper proposes the sensorless output power maximization control of the wind generation system. A permanent magnet synchronous generator (PMSG) is used as a variable speed generator in the proposed system. The generator torque is suitably controlled according to the generator speed and thus the power from a wind turbine settles down on the maximum power point by the proposed MPPT control method, where the information of wind velocity is not required. Moreover, the maximum available generated power is obtained by the optimum current vector control. The current vector of PMSG is optimally controlled according to the generator speed and the required torque in order to minimize the losses of PMSG considering the voltage and current constraints. The proposed wind power generation system can be achieved without mechanical sensors such as a wind velocity detector and a position sensor. Several experimental results show the effectiveness of the proposed control method.

Morimoto, Shigeo; Nakamura, Tomohiko; Takeda, Yoji

369

Integrated power clock generators for low energy logic  

Microsoft Academic Search

Low-energy (adiabatic) logic families have been proposed to reduce energy consumption of VLSI logic devices. Instead of the conventional DC power supply, these logic families require AC power supplies (power clocks) that allow energy recovery and also serve as timing clocks for the logic. In this paper, high-frequency resonant DC\\/AC inverters are proposed as power clock generators where all power

D. Maksimovic; V. G. Oklobdzija

1995-01-01

370

Self-Consistent Approach to Leakage Power and Temperature Estimation to Predict Thermal Runaway in FinFET Circuits  

Microsoft Academic Search

In this paper, we propose a methodology to solve leakage power self-consistently with temperature to predict thermal runaway. We target 28-nm-technology-node FinFET-based circuits as they are more prone to thermal runaway because of self-heating and less efficient heat dissipation compared to bulk metal-oxide-semiconductor field-effect transistors. We have generated thermal models for logic cells-inverter, NAND, and NOR-to self-consistently determine the temperature

Jung Hwan Choi; Aditya Bansal; Mesut Meterelliyoz; Jayathi Murthy; Kaushik Roy

2007-01-01

371

Terrestrial Solar Thermal Power Plants: On the Verge of Commercialization  

NASA Astrophysics Data System (ADS)

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.

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

2004-12-01

372

Stochastic Co-optimization for Hydro-Electric Power Generation  

E-print Network

1 Stochastic Co-optimization for Hydro-Electric Power Generation Shi-Jie Deng, Senior Member, IEEE the optimal scheduling problem faced by a hydro-electric power producer that simultaneously participates in multiple markets. Specifically, the hydro-generator participates in both the electricity spot market

373

Consequences of deregulation on nuclear power generating stations  

Microsoft Academic Search

Historically, the electric utilities are responsible for electric power generation, transmission and distribution. With the implementation of deregulation, the electric power system will split into separate disciplines for generation, transmission and distribution. The suppliers would be able to sell electricity directly to the consumers using electric utilities transmission and distribution lines. Deregulation takes place at a time when the transmission

Narinder K. Trehan

1998-01-01

374

Distributed Power Generation: Requirements and Recommendations for an ICT Architecture  

E-print Network

. In the future of energy markets, the distributed energy production through wind and hydroelectric power plants distribution faces various new challenges. Most of those challenges have a strong impact on the ICT), distrib- uted generation, energy management systems (EMS) , IEC standards 1 Power Generation

Appelrath, Hans-JĂĽrgen

375

Heat Transfer and Thermophotovoltaic Power Generation in Oil-fired Heating Systems  

SciTech Connect

The focus of this study is the production of electric power in an oil-fired, residential heatingsystem using thermophotovoltaic (TPV) conversion devices. This work uses experimental, computational, and analytical methods to investigate thermal mechanisms that drive electric power production in the TPV systems. An objective of this work is to produce results that will lead to the development of systems that generate enough electricity such that the boiler is self-powering. An important design constraint employed in this investigation is the use of conventional, yellow-flame oil burners, integrated with a typical boiler. The power production target for the systems developed here is 100 W - the power requirement for a boiler that uses low-power auxiliary components. The important heattransfer coupling mechanisms that drive power production in the systems studied are discussed. The results of this work may lead to the development of systems that export power to the home electric system.

Butcher, T.; Hammonds, J.S.; Horne, E.; Kamath, B.; Carpenter, J.; Woods, D.R.

2010-10-21

376

Spin current generated by thermally driven ultrafast demagnetization.  

PubMed

Spin current is the key element for nanoscale spintronic devices. For ultrafast operation of such nano-devices, generation of spin current in picoseconds, a timescale that is difficult to achieve using electrical circuits, is highly desired. Here we show thermally driven ultrafast demagnetization of a perpendicular ferromagnet leads to spin accumulation in a normal metal and spin transfer torque in an in-plane ferromagnet. The data are well described by models of spin generation and transport based on differences and gradients of thermodynamic parameters. The temperature difference between electrons and magnons is the driving force for spin current generation by ultrafast demagnetization. On longer timescales, a few picoseconds following laser excitation, we also observe a small contribution to spin current by a temperature gradient and the spin-dependent Seebeck effect. PMID:25007978

Choi, Gyung-Min; Min, Byoung-Chul; Lee, Kyung-Jin; Cahill, David G

2014-01-01

377

Power enhancement of heat engines via correlated thermalization in multilevel systems  

E-print Network

We analyze a heat machine based on a periodically-driven quantum system permanently coupled to hot and cold baths. It is shown that the maximal power output of a degenerate $V$-type three-level heat engine is that generated by two independent two-level systems. For $N$ levels, this maximal enhancement is $(N-1)$-fold. Hence, level degeneracy is a thermodynamic resource that may effectively boost the power output. The efficiency, however, is not affected. We find that coherence is not an essential asset in multilevel-based heat machines. The existence of multiple thermalization pathways sharing a common ground state suffices for power enhancement.

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

2014-11-05

378

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER  

SciTech Connect

OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil fuels has trace contaminants (primarily carbon monoxide) that are detrimental to precious metal catalyzed fuel cells, as is now recognized by many of the world's largest automobile companies. Thermochemical hydrogen will not contain carbon monoxide as an impurity at any level. Electrolysis, the alternative process for producing hydrogen using nuclear energy, suffers from thermodynamic inefficiencies in both the production of electricity and in electrolytic parts of the process. The efficiency of electrolysis (electricity to hydrogen) is currently about 80%. Electric power generation efficiency would have to exceed 65% (thermal to electrical) for the combined efficiency to exceed the 52% (thermal to hydrogen) calculated for one thermochemical cycle. Thermochemical water-splitting cycles have been studied, at various levels of effort, for the past 35 years. They were extensively studied in the late 70s and early 80s but have received little attention in the past 10 years, particularly in the U.S. While there is no question about the technical feasibility and the potential for high efficiency, cycles with proven low cost and high efficiency have yet to be developed commercially. Over 100 cycles have been proposed, but substantial research has been executed on only a few. This report describes work accomplished during a three-year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.'' The emphasis of the first phase was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen from water in which the primary energy input is high temperature heat from an advanced nuclear reactor and to select one (or, at most three) for further detailed consideration. During Phase 1, an exhaustive literature search was performed to locate all cycles previously proposed. The cycles located were screened using objective criteria to determine which could benefit, in terms of efficien

BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

2003-06-01

379

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

SciTech Connect

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.

Djukanovic, M.; Milosevic, B. [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems] [Inst. Nikola Tesla, Belgrade (Yugoslavia). Dept. of Power Systems; Calovic, M. [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering] [Univ. of Belgrade (Yugoslavia). Dept. of Electrical Engineering; Sobajic, D.J. [Electric Power Research Inst., Palo Alto, CA (United States)] [Electric Power Research Inst., Palo Alto, CA (United States)

1996-12-01

380

Synchrophasor Applications for Wind Power Generation  

SciTech Connect

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.

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

2014-02-01

381

Synthetic thermal image generation for combat vehicle identification  

NASA Astrophysics Data System (ADS)

There is a need for a cost-effective approach to training ground forces in combat vehicle identification (CVI), especially under thermal sighting conditions. Computer image generation (CIG) provides many advantages for the development of cost effective CVI training: 3-D and thermal modeling of vehicles, thermal rendering of landscape scenes, and a wide assortment of training scenarios. But the extent of computation required for CIG makes it impossible to combine real-time presentation and interactive control, except on very expensive, high-end graphics systems. We describe a solution in which we have separated CIG and presentation, allowing the computation-intensive processes to run `off-line'' on virtually any computer (high- end graphics or general-purpose). The presentation is provided by digital video interactive (DVI) technology, a flexible, low-cost, PC-based system for delivering high quality graphics, photo quality imagery, motion video, and audio. We have developed and demonstrated a specialized animation algorithm which combines landscape scenes and vehicle imagery to produce animated scenarios in which trainees face varying degrees of difficulty in vehicle identification. The simulation is intended to replicate the appearance and controls of common thermal sights in tanks. The animation has been integrated with a complete training program, which includes guided instruction in vehicle recognition.

Montgomery, James I.; Graff, David; Landell, B. P.

1992-04-01

382

A new resonant link aircraft power generating system  

Microsoft Academic Search

A 400 Hz aircraft power generating system which has been designed to achieve significant improvements in power density and reliability is introduced. Design targets for this exploratory development program include system (generator-plus-converter) power density of 1 kVA\\/lb and mean-time-between-failure (MTBF) of 500 h. At the heart of the new variable-speed constant-frequency (VSCF) configuration is a high-frequency resonant link inverter designed

T. M. Jahns; M. A. Maldonado

1993-01-01

383

Micromachined CMOS thermoelectric generators as on-chip power supply  

Microsoft Academic Search

As the power consumption of a large number of microelectronic devices has been continuously reduced in recent years, power supply units of a few microwatts have become sufficient for their operation. Our improved micro-scale thermoelectric generator (?-TEG) is based on polysilicon surface micromachining and is designed to convert waste heat into electrical power. Since this device is compatible with standard

M. Strasser; R. Aigner; C. Lauterbach; T. F. Sturm; M. Franosch; G. Wachutka

2004-01-01

384

24 DTU International Energy Report 2013 Stochastic power generation  

E-print Network

that their power output can be curtailed if necessary. Renewable energy sources such as wind, solar, wave and tidal24 DTU International Energy Report 2013 Stochastic power generation Introduction Our path towards intheformofheatandelectricity.ByJune2012,cumula- tive installed wind power capacity worldwide had reached 254

Paris-Sud XI, Université de

385

Primary electric power generation systems for advanced-technology engines  

NASA Technical Reports Server (NTRS)

The advantages of the all electric airplane are discussed. In the all electric airplane the generator is the sole source of electric power; it powers the primary and secondary flight controls, the environmentals, and the landing gear. Five candidates for all electric power systems are discussed and compared. Cost benefits of the all electric airplane are discussed.

Cronin, M. J.

1983-01-01

386

An electromagnetic, vibration-powered generator for intelligent sensor systems  

Microsoft Academic Search

This paper describes the design of miniature generators capable of converting ambient vibration energy into electrical energy for use in powering intelligent sensor systems. Such a device acts as the power supply of a microsystem which can be used in inaccessible areas where wires can not be practically attached to provide power or transmit sensor data. Two prototypes of miniature

P. Glynne-Jones; M. J. Tudor; S. P. Beeby; N. M. White

2004-01-01

387

Hybrid fuel-cell strategies for clean power generation  

Microsoft Academic Search

A hybrid power system consists of a combination of two or more power generation technologies to make best use of their operating characteristics and to obtain efficiencies higher than that could be obtained from a single power source. Since fuel cells directly convert fuel and an oxidant into electricity through an electrochemical process, they produce very low emissions and have

Kaushik Rajashekara

2005-01-01

388

A proposal of efficiency improvement with solar power generation system  

Microsoft Academic Search

This paper deals with energy conversion efficiency improvement of solar power application systems. In order to extensively use solar power generation system in all aspects of lifestyle, including moving vehicles, efficiency tracking control systems are necessary for solar power condition change. In this paper, the authors have proposed two kinds of efficiency tracking system: one is the feedforward type which

Tetsumi Harakawa; T. Tujimoto

2001-01-01

389

Sizing Storage and Wind Generation Capacities in Remote Power Systems  

E-print Network

Sizing Storage and Wind Generation Capacities in Remote Power Systems by Andy Gassner B capital investment costs of renewable energy technologies. Specifically, wind power represents the most and small power systems. However, the variability due to the stochastic nature of the wind resource

Victoria, University of

390

Optical fiber instrumentation of a high power generator and turbine  

NASA Astrophysics Data System (ADS)

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.

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

391

Coal gasification for electric power generation.  

PubMed

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

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

1982-03-26

392

Packaging and thermal analysis of power electronics modules  

Microsoft Academic Search

The Intermediate Data Format (IDF) is a specification designed to provide a neutral representation for exchanging printed circuit assembly (PCA) data among mechanical design (MCAD), PCA layout (ECAD), and physical design analysis (MCAE) applications. Powerful analysis software, like Ansys, Maxwell, Semcad, Altium Designer or SolidWorks - CircuitWorks, can import the idf files and use the model for electromagnetic or thermal

L. Man; C. Farcas; R. Fizesan

2010-01-01

393

Parabolic Dish Solar Thermal Power Annual Program Review Proceedings  

NASA Technical Reports Server (NTRS)

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.

Lucas, J. W.

1982-01-01

394

Numerical simulations of a low power microchannel thermal cycling reactor  

Microsoft Academic Search

A roadblock to the development of stand-alone microscale biomedical and chemical analysis systems is the relatively high heating power requirement of the microscale reactors, which typically exceeds the capability of low cost batteries. In this study, a microchannel thermal cycling reactor design using in-channel heating and passive cooling is proposed and a numerical model has been developed. Numerical simulations were

David Erickson; Dongqing Li

2002-01-01

395

Thermal spike model in the electronic stopping power regime  

Microsoft Academic Search

Two models have been proposed in order to explain the appearance of latent tracks induced in matter by the slowing down process of ions in the electronic stopping power regime. The first one was the thermal spike proposed by Desauer and reconsidered for metals by Seitz and Koehler. The second one was the ionic spike proposed by Fleischer et al

M. Toulemonde; E. Paumier; C. Dufour

1993-01-01

396

Assessment of the potential of solar thermal small power systems in small utilities  

NASA Technical Reports Server (NTRS)

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.

Steitz, P.; Mayo, L. G.; Perkins, S. P., Jr.

1978-01-01

397

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

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

398

harmonic generation at a critical power in inhomogeneous doubly  

E-print Network

(2) and (3) harmonic generation at a critical power in inhomogeneous doubly resonant cavities- and third-harmonic generation via (2) and (3) nonlinearities. We find that conversion efficiency. Drummond, K. J. McNeil, and D. F. Walls, "Non-equilibrium transitions in sub/second harmonic generation I

Soljaèiæ, Marin

399

The status of world geothermal power generation 1995–2000  

Microsoft Academic Search

In order to assess the current status of international geothermal power generation, the author has reviewed the Country Update (CU) papers submitted to the World Geothermal Conference 2000 in Japan from nations generating or planning to generate electricity. Salient facts in these papers have been synthesized and summary descriptions of geothermally-related activities written. Finally, following a brief discussion, conclusions are

Gerald W. Huttrer

2001-01-01

400

Propellant-powered actuator for gas generators  

NASA Technical Reports Server (NTRS)

Hydrazine operated monopropellant generators are used for spacecraft rocket engines and propellant pressurization systems. Measured work output of monopropellant actuators compares favorably with output of squib-type actuators.

Makowski, M. J.

1972-01-01

401

EFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS  

E-print Network

of these systems is that the induction generators require reactive power from the grid or capacitor banks to meetEFFECT OF PITCH CONTROL AND POWER CONDITIONING ON POWER QUALITY OF VARIABLE SPEED WIND TURBINE GENERATORS Hari Sharma* Trevor Pryor* Syed Islam** *Murdoch University Energy Research Institute (MUERI

402

PLATO Power--a robust, low environmental impact power generation system for the Antarctic plateau  

E-print Network

PLATO Power--a robust, low environmental impact power generation system for the Antarctic plateau, Australia 2052; b Solar Mobility Pty Ltd, PO Box 951, Epping, NSW, Australia 2121 ABSTRACT PLATO (PLATeau the power generation and management system of PLATO. Two redundant arrays of solar panels and a multiply

Ashley, Michael C. B.

403

Lifetime prediction modeling of airfoils for advanced power generation  

NASA Astrophysics Data System (ADS)

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.

Karaivanov, Ventzislav Gueorguiev

404

Heat engine development for solar thermal power systems  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

405

Thermal control of power supplies with electronic packaging techniques  

NASA Technical Reports Server (NTRS)

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.

1975-01-01

406

Powering a Generation of Change: A Smithsonian Documentation Project  

NSDL National Science Digital Library

Powering a Generation of Change is a Smithsonian Institution documentation project that is a response to the coming deregulation of the electric power industry in the United States and Canada. The site is interesting almost as much for its information on electricity and the history of electric power regulation, as for its information explaining deregulation and its societal impacts. One of the highlights of the site is the Visions of Power section, with in-depth interviews with Joseph P. Kearney of US Generating, Andre Caille of Hydro-Quebec, and William T. McCormick, Jr. of CMS Energy. Visions of Power offers numerous links to information provided by a variety of participants in the deregulation debate. The Powering the Past section provides a fascinating tour through the history of electric power, accompanied by images from various Smithsonian museums. A large bibliography on electric power is also available.

1997-01-01

407

Thermal effects in high average power optical parametric amplifiers.  

PubMed

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

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

2013-03-01

408

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

NASA Technical Reports Server (NTRS)

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.

Cherry, W. R.

1971-01-01

409

Combined fuel and air staged power generation system  

SciTech Connect

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.

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

2014-05-27

410

High voltage solar cell power generating system  

NASA Technical Reports Server (NTRS)

A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kW), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2,560 series-connected cells. Each light source consists of twenty 500-watt tungsten iodide lamps providing plus or minus 5 percent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water-cooled plate, a vacuum hold-down system, and air flushing.

Levy, E., Jr.; Opjorden, R. W.; Hoffman, A. C.

1974-01-01

411

Protective, Modular Wave Power Generation System  

SciTech Connect

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.

Vvedensky, Jane M.; Park, Robert Y.

2012-11-27

412

Siting Power Generation Facilities: Environmental Justice Concerns  

NSDL National Science Digital Library

The Advanced Technology Environmental and Energy Center (ATEEC) provides this PowerPoint document on environmental justice concerns. The document includes ten classroom activities on related topics such as participatory mapping, energy consumption and demographics. Worksheets are included in the document. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

Crawford, Charles

413

Planning available capacity in electrical power generation  

Microsoft Academic Search

In planning for the utilisation of available capacity, an electrical company needs to know the power requirements of the system. The load versus duration curve provides information on past demand patterns and thus forms a basis for planning future supply needs. Since electrical supply is discrete by nature, the load versus duration curve only approximates to the true supply requirements.

John S. Maybee; Paul H. Randolph; Noel D. Uri

1981-01-01

414

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

NASA Astrophysics Data System (ADS)

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.

Huovilainen, Reino; Alamaeki, Jarmo; Tarjanne, Risto

415

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

NASA Astrophysics Data System (ADS)

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.

Wu, Guangxi; Yu, Xiong

2015-01-01

416

Microcombustor-thermoelectric power generator for 10-50 watt applications  

NASA Astrophysics Data System (ADS)

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.

Marshall, Daniel S.; Cho, Steve T.

2010-04-01

417

Thermally regenerative hydrogen/oxygen fuel cell power cycles  

NASA Technical Reports Server (NTRS)

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.

Morehouse, J. H.

1986-01-01

418

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

SciTech Connect

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.

ST.LAURENT,STEVEN J.

2000-08-14

419

Self-powered wireless sensor system using MEMS piezoelectric micro power generator (PMPG)  

E-print Network

A thin-film lead zirconate titanate, Pb(Zr,Ti)03, MEMS Piezoelectric Micro Power Generator (PMPG) has been integrated with a commercial wireless sensor node (Telos), to demonstrate a self-powered RF temperature sensor ...

Xia, YuXin, M.B.A. Sloan School of Management.

2006-01-01

420

Low-Power Maximum Power Point Tracker with Digital Control for Thermophotovoltaic Generators  

E-print Network

This paper describes the design, optimization, and evaluation of the power electronics circuitry for a low-power portable thermophotovotaic (TPV) generator system. TPV system is based on a silicon micro-reactor design and ...

Pilawa, Robert

421

High-average-power (15-W) 255-nm source based on second-harmonic generation of a copper laser master oscillator power amplifier system in cesium lithium borate  

NASA Astrophysics Data System (ADS)

We have generated 15 W of UV (255-nm) radiation with an optical conversion efficiency of 28% by frequency doubling the 510.6-nm output of a high-beam-quality, high-power copper laser system in cesium borate lithium (CLBO). We found that the superior performance of CLBO relative to ?-barium borate is attributable largely to the small UV absorption and wide temperature acceptance bandwidth of CLBO, which reduces thermal dephasing during high-power UV generation.

Brown, Daniel J. W.; Withford, Michael J.

2001-12-01

422

In Hot Water: Thermoelectric Power and Thermal Pollution  

NASA Astrophysics Data System (ADS)

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.

Madden, N. T.

2010-12-01

423

Alternative power generation concepts for space  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

424

Power generating system and method utilizing hydropyrolysis  

DOEpatents

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.

Tolman, R.

1986-12-30

425

Pressurized circulating fluidized-bed combustion for power generation  

SciTech Connect

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.

Weimer, R.F.

1995-08-01

426

Solar powered Stirling cycle electrical generator  

NASA Technical Reports Server (NTRS)

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.

Shaltens, Richard K.

1991-01-01

427

Solar powered Stirling cycle electrical generator  

NASA Astrophysics Data System (ADS)

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.

Shaltens, Richard K.

1991-03-01

428

Plasma plume MHD power generator and method  

DOEpatents

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.

Hammer, James H. (Livermore, CA)

1993-01-01

429

UF6 breeder reactor power plants for electric power generation  

Microsoft Academic Search

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

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

1976-01-01

430

Multiple-Antenna Microwave Ablation: Spatially Distributing Power Improves Thermal Profiles and Reduces Invasiveness  

PubMed Central

Background Microwave ablation is an emerging tumor ablation modality. To date, microwave systems have generally utilized single large-diameter antennas to deliver high input powers. Objective To determine whether spatially distributing power through an array of multiple smaller antennas creates a more uniform thermal profile and increases peripheral tissue temperatures when compared with microwave ablation using a single larger antenna. Methods Microwave ablations were performed in ex vivo bovine liver using a single 2.45-GHz magnetron generator and a constant total input power (90 W) delivered through either a single 13-gauge antenna, two 17-gauge antennas, or three 18-gauge antennas. Multiple antennas were driven coherently. Temperatures were recorded at 5-mm radial distances and the resulting thermal profiles and ablation zones were compared using analysis of variance. Results Multiple-antenna configurations were less invasive (ie, the area of tissue punctured was smaller) than the single-antenna configuration; despite this, ablation zones created using multiple smaller antennas were larger and as circular when compared with those created using a single larger antenna. Multiple-antenna configurations resulted in more uniform thermal profiles and higher peripheral tissue temperatures. Conclusion Distributing power evenly among multiple smaller antennas resulted in larger ablation zones with more uniform thermal profiles than more invasive ablations with a larger single antenna. PMID:21857888

Laeseke, Paul F; Lee, Fred T; van der Weide, Daniel W; Brace, Christopher L

2011-01-01

431

Improving heat capture for power generation in coal gasification plants  

E-print Network

Improving the steam cycle design to maximize power generation is demonstrated using pinch analysis targeting techniques. Previous work models the steam pressure level in composite curves based on its saturation temperature ...

Botros, Barbara Brenda

2011-01-01

432

Integration of decentralized generators with the electric power grid  

E-print Network

This report develops a new methodology for studying the economic interaction of customer-owned electrical generators with the central electric power grid. The purpose of the report is to study the reciprocal effects of the ...

Finger, Susan

1981-01-01

433

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...

434

Generation of high power tunable multicycle teraherz pulses  

E-print Network

We demonstrate generation of high-power, multicycle, and frequency-tunable terahertz pulses with microjoule energies by tilting the intensity front of a quasi-sinusoidal intensity-modulated optical waveform. The spatiotemporally ...

Chen, Zhao

435

Handbook of photovoltaic power generating design for introduction  

NASA Astrophysics Data System (ADS)

The purpose of this handbook is to survey the ways to introduce photovoltaic power generation with specifying a certain region of introduction by international cooperation. Various cases of load requirements and load patterns are taken up for more efficient designing of equipment. When actually introducing photovoltaic power generating facilities, more detailed analyses of the situation would be necessary, but this handbook is effective in investigating and comparing basic designs and possible regions of introduction. Presented are illustrated overall designing procedures of photovoltaic power generating facilities and examples in cases of DC load and AC load. This handbook includes assumed load formats, calculation of storage battery capacity, required capacity of photovoltaic cell, selection of photovoltaic cell module, selection of storage battery, selection of inverter, selection of charge controller, list of possible regions, and amounts and durations of insolation in the selected regions, as data for designing photovoltaic power generation for introduction.

1993-03-01

436

Very short-term wind forecasting for Tasmanian power generation  

Microsoft Academic Search

This paper describes very short-term wind prediction for power generation, utilizing a case study from Tasmania, Australia. Windpower presently is the fastest growing power generation sector in the world. However, windpower is intermittent. To be able to trade efficiently, make the best use of transmission line capability, and address concerns with system frequency in a re-regulated system, accurate very short-term

Cameron W. Potter; Michael Negnevitsky

2006-01-01

437

Novel power saving architecture for FBG based OCDMA code generation  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

438

Airline requirements on aircraft electrical power generation and distribution  

NASA Astrophysics Data System (ADS)

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.

Glashagen, Claus

439

Wind Power: Creating a Wind Generator  

NSDL National Science Digital Library

This lesson challenges groups of learners to design and construct a wind generator with the most electrical output. The lesson focuses on the engineering design process and how it is used to identify a question (solve a problem), develop a design or change a design, test that design, observe and collect data, analyze that data, and finally, form a conclusion that can inform another round of design. In this activity, learners attempt to maximize the voltage obtained from a wind-driven turbine by conducting several experimental designs.

Lutz, Demetrius

2012-01-01

440

Regolith thermal energy storage for lunar nighttime power  

NASA Technical Reports Server (NTRS)

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.

Tillotson, Brian

1992-01-01

441

Development of Light Powered Sensor Networks for Thermal Comfort Measurement  

PubMed Central

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.

Lee, Dasheng

2008-01-01

442

Design study of wave power generator for power supply to islands in Far East  

SciTech Connect

Wave power density near Japan is not so high as Europe where Wave power is under development by Joule II project. But multi purpose wave power generator can be designed to generate electricity and promote fishing business near shore. It is improved floating type wave power device. Cylinder Float Backward Bent Duct Buoy (BBDB) is the design. When it is installed in Japanese Island Area such as Izu Seven Islands or South West Islands or Islands in South China Sea including Taiwan. Power cost is estimated about 14 cent/KWh which is economical for Island Power supply.

Masuda, Yoshio [Ryokuseisha Corp., Tokyo (Japan)

1994-12-31

443

The critical power to maintain thermally stable molecular junctions.  

PubMed

With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 10(9)?kW(-1). Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design. PMID:25005801

Wang, Yanlei; Xu, Zhiping

2014-01-01

444

The critical power to maintain thermally stable molecular junctions  

NASA Astrophysics Data System (ADS)

With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 109?kW-1. Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design.

Wang, Yanlei; Xu, Zhiping

2014-07-01

445

Kinetics and Lumped Parameter Model of Tardive Excess Thermal Power  

NASA Astrophysics Data System (ADS)

The time-integral of tardive excess thermal power (TETP) was previously misnamed "heat after death"ootnotetextPons, S., Fleischman, M., Trans Fusion Tech, 26, 4T, Part 2, p. 87 (1994).. We have examined the kinetics of tardive excess thermal power (TETP) which occurs after driving, fully loaded, activated, spiral wound cold fusion Phusor cathodes (Pd/D2O/Pt;ootnotetextSwartz. M., G. Verner, Proc. ICCF-10 (2004).^,ootnotetextSwartz. M., Proc.ICCF-10 (2003).) at their optimal operating pointootnotetextSwartz, M., Fusion Technology, 31, 63-74 (1997).. TETP, after input electrical power produced an excess power (compared to an ohmic joule control) of 165+/-15 percent [excess power 1.3 Watts], had kinetics suggestive of two distinct sources or physical active regions within the latticeootnotetextSwartz. M., G. Verner, ICCF-11 (2004).. An electrical engineering TETP model had good correlation. The active palladium lattice has a deuteron-loading capacitance of 64 micromoles per volt*. The lattice admittance for the TETP reactions ( 7 picomoles/[sec-volt*]) is dwarfed by the admittance for outgassing deuteron loss ( 15 nanomoles/[sec-volt*]).

Swartz, Mitchell

2005-03-01

446

Heat engine development for solar thermal power systems  

NASA Technical Reports Server (NTRS)

The technical status of three heat engines (Stirling, high-temperature Brayton, and Combined cycle) for use in solar thermal power systems is presented. Performance goals necessary to develop a system competitive with conventional power requirements include an external heated engine output less than 40 kW, and efficiency power conversion subsystem at least 40% at rated output, and a half-power efficiency of at least 37%. Results show that the Stirling engine can offer a 39% efficiency with 100 hours of life, and a 20% efficiency with 10,000 hours of life, but problems with seals and heater heads exist. With a demonstrated efficiency near 31% at 1500 F and a minimum lifetime of 100,000 hours, the Brayton engine does not offer sufficient engine lifetime, efficiency, and maintenance for solar thermal power systems. Examination of the Rankine bottoming cycle of the Combined cycle engine reveals a 30 year lifetime, but a low efficiency. Additional development of engines for solar use is primarily in the areas of components to provide a long lifetime, high reliability, and low maintenance (no more than $0.001/kW-hr).

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

1981-01-01

447

New generation MOSFET design for battery powered portable applications  

NASA Astrophysics Data System (ADS)

This article reviews some of challenges that the Power MOSFET designers need to address to meet the ever growing market demand for reducing power consumption in battery-powered portable applications. The critical power MOSFET design parameters such as threshold voltage (Vth), drain-source breakdown voltage (BVdss), on-resistance (Rdson), package footprint, gate-drive voltage, and Figure of Merit (FOM) have been discussed. It has been highlighted that the scaling features and ultra-low on-resistance of the Trench Power MOSFETs can be advantageously utilized for powerloss management. The MOSFET design requirements in battery protection circuits and load switches have been presented. It has been emphasized that the Power MOSFET designers need to trade-off between on-resistance and maximum current capability in smaller footprint packages. The merits of Wafer Level Chip Scale Package (WLCSP) in achieving minimum foot print, ultra-low on-resistance, and improved thermal characteristics have been discussed.

Deb Roy, Sukhendu; Sodhi, Ritu; Sapp, Steven

2012-10-01

448

Augmentation of thermal power stations with solar energy  

Microsoft Academic Search

A new concept of integration of a solar concentrator field with a modern thermal power station is proposed. Such a configuration\\u000a would utilise the existing equipment and infrastructure as a base load facility and solar energy to reduce the fuel consumption\\u000a during periods of insolation. The methodology suggested involves feed water heating using a solar concentrator field and consequent\\u000a reduction

BR Pai

1991-01-01

449

HOM Power Generation and Propagation in the PEP II Rings  

SciTech Connect

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.

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

2011-08-26

450

High average power supercontinuum generation in photonic crystal fibers  

Microsoft Academic Search

We report on the generation of a high average power, flat supercontinuum using a compact ytterbium-doped fiber amplifier. The femto- and picosecond pulses delivered by the amplifier are coupled into two different photonic crystal fibers. By using picosecond pulses the highest output power of 5 W with a spectrum ranging from below 500 nm up to above 1800 nm is

T. Schreiber; J. Limpert; H. Zellmer; A. Tünnermann; K. P. Hansen

2003-01-01

451

Design features of Advanced Power Reactor (APR) 1400 steam generator  

Microsoft Academic Search

Advanced Power Reactor 1400 (APR 1400) which is to achieve the improvement of the safety and economical efficiency has been developed by Korea Hydro and Nuclear Power Co., Ltd. (KHNP) with the support from industries and research institutes. The steam generator for APR 1400 is an evolutionary type from System 80{sup +}, which is the recirculating U-tube heat exchanger with

Tae-Jung Park; Jun-Soo Park; Moo-Yong Kim

2004-01-01

452

Co-generative power source for electric car  

Microsoft Academic Search

The low power, variable speed, generating unit with liquid cooled internal combustion engine is proposed in pilot project to heat the battery-operated vehicle primarily. Additional advantage of battery charging can enlarge the cruising range and can also serve as emergency power source.

V. Brslica

2005-01-01

453

The Homopolar Generator as a Pulsed Industrial Power Supply  

E-print Network

of these application areas is discussed in detail including, technical advantages of the pulsed homopolar generator power, supply, as well as economic advantages of the system based on time and energy savings as compared with conventional power and heat sources. Each...

Weldon, J. M.; Weldon, W. F.

1979-01-01

454

Risk optimization: siting of nuclear power electricity generating units  

Microsoft Academic Search

Radiological doses from nuclear power plant accidents can extend to great distances away from the site. These technical and perceived risks of nuclear power generation are addressed in an optimization of the siting of additional nuclear units primarily in the middle Atlantic and northeastern United States of America. This study relies on a constrained optimization of long-term latent cancer and

Timothy S. Margulies

2004-01-01

455

The Environmental Impact of Electrical Power Generation: Nuclear and Fossil.  

ERIC Educational Resources Information Center

This text was written to accompany a course concerning the need, environmental costs, and benefits of electrical power generation. It was compiled and written by a committee drawn from educators, health physicists, members of industry and conservation groups, and environmental scientists. Topics include: the increasing need for electrical power,…

Pennsylvania State Dept. of Education, Harrisburg.

456

Possible developments in large scale electrical power generation  

Microsoft Academic Search

Although the basic principles of electrical power generation have remained unchanged over the years there have been great improvements in detail. Power station efficiencies are now in the region of 35% and their capital cost has steadily reduced in real terms as the size of the station and steam pressures have increased. With the growing realization of the importance of

J. K. Wright

1975-01-01

457

Automatic generation control in a deregulated power system  

Microsoft Academic Search

Load frequency control (LFC) has been used for many years as part of the automatic generation control (AGC) in power systems around the world. In the synchronous Nordic power system, however, this function (termed secondary control) has so far been handled with manual control actions. Increased operational strain due to new HVDC connections in the next decade will make it

Bjorn H. Bakken; Ove S. Grande

1998-01-01

458

Stability analysis of free piston Stirling engine power generation system  

Microsoft Academic Search

This paper presents a stability analysis of the free-piston Stirling engine and linear alternator power generation system. Such a system operates under sustained mechanical oscillators, stability of the system is important for proper operation, and as a criterion in selecting the tuning capacitor. The stability criterion of the system is that the rate of change in power dissipation and electric

Z. X. Fu; S. A. Nasar; Mark Rosswurm

1992-01-01

459

Simulating the Value of Concentrating Solar Power with Thermal Energy Storage in a Production Cost Model  

SciTech Connect

Concentrating solar power (CSP) deployed with thermal energy storage (TES) provides a dispatchable source of renewable energy. The value of CSP with TES, as with other potential generation resources, needs to be established using traditional utility planning tools. Production cost models, which simulate the operation of grid, are often used to estimate the operational value of different generation mixes. CSP with TES has historically had limited analysis in commercial production simulations. This document describes the implementation of CSP with TES in a commercial production cost model. It also describes the simulation of grid operations with CSP in a test system consisting of two balancing areas located primarily in Colorado.

Denholm, P.; Hummon, M.

2012-11-01

460

New-generation concentrator modules based on cascade solar cells: Design and optical and thermal properties  

NASA Astrophysics Data System (ADS)

New-generation concentrator modules use III-V nanoheterostructure cascade solar cells the efficiency of which can be raised to 50% for the number of cascades exceeding three. To obtain a high overall efficiency of photovoltaic conversion in power plants and extend their service time, it is necessary that the design of the modules be optimal in terms of optics and thermal engineering. In this work, main challenges in designing solar modules, such as optical concentration of radiation and residual heat removal, are considered. The results of pilot works that have been recently done in the Ioffe Physical Technical Institute are primarily reported.

Andreev, V. M.; Davidyuk, N. Yu.; Malevski, D. A.; Pan'chak, A. N.; Rumyantsev, V. D.; Sadchikov, N. A.; Chekalin, A. V.; Luque, A.

2014-11-01

461

A Course Case Study: Nuclear Power Generation and the Environment  

ERIC Educational Resources Information Center

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)

Schlesinger, Allen B.

1975-01-01

462

Thermoelectric Power Generation Allison Duh and Joel Dungan  

E-print Network

Thermoelectric Power Generation Allison Duh and Joel Dungan May 15, 2013 #12;Introduction A thermoelectric generator (TEG) is a device that converts heat energy directly into electrical energy. Thermoelectric systems capitalize on semiconductor charge carriers excited by a temperature difference to convert

Lavaei, Javad

463

Reactive Power Generation and Control by Thyristor Circuits  

Microsoft Academic Search

Generally, static var generators function as variable reactances (capacitive or inductive impedances) or controllable ac current and voltage sources. Possible methods of var generation and control by static thyristor circuits are reviewed, and new approaches are described in which power frequency changers (cycloconverters) are employed. Oscillographic recordings illustrate the operation and performance of practical systems, including a 35-Mvar arc furnace

Laszlo Gyugyi

1979-01-01

464

Piezoelectric and Semiconducting Coupled Power Generating Process of a  

E-print Network

as acoustic/ultrasonic wave), and hydraulic energy (such as flow of body fluid, blood flow, contractionPiezoelectric and Semiconducting Coupled Power Generating Process of a Single ZnO Belt observation of piezoelectric generation from a single ZnO wire/belt for illustrating a fundamental process

Wang, Zhong L.

465

Aircraft Power Generators: Hybrid Modeling and Simulation for Fault Detection  

Microsoft Academic Search

Integrated drive generators (IDGs) are the main source of electrical power for a number of critical systems in aircraft. Fast and accurate fault detection and isolation (FDI) are necessary components for safe and reliable operation of the IDG and the aircraft. IDGs are complex systems, and a majority of the existing FDI techniques for the electrical subsystem (brushless generator) are

Ashraf Tantawy; Xenofon Koutsoukos; Gautam Biswas

2012-01-01

466

UF6 breeder reactor power plants for electric power generation  

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

467

Performance assessment of OTEC power systems and thermal power plants, volume 1  

NASA Astrophysics Data System (ADS)

The focus of this report is on closed-cycle ocean thermal energy conversion (OTEC) power systems under research at Purdue University. The working operations of an OTEC power plant are briefly discussed. Methods of improving the performance of OTEC power systems are presented. Brief discussions on the methods of heat exchanger analysis and design are provided, as are the thermophysical properties of the working fluids and seawater. An interactive code capable of analyzing OTEC power system performance is included for use with an IBM personal computer.

Leidenfrost, W.; Liley, P. E.; McDonald, A. T.; Mudawwar, I.; Pearson, J. T.

1985-05-01

468

Radiated power measurement during the thermal quench phase of a density limit disruption  

E-print Network

disruption can be described as occurring in two stages: a thermal quench, where the plasma thermal energyRadiated power measurement during the thermal quench phase of a density limit disruption E. M April 2003 Radiated power measurements taken during the thermal quench of a density limit disruption

California at San Diego, University of

469

Using gas-turbine power stations with aircraft engines for power-and-heat generation  

Microsoft Academic Search

The purpose is to determine certain power engineering indices of gas turbine engines used to generate electricity and heat. The RD-3M-500 engine is discussed. It is concluded that the engine would be useful for the generation of heat and electricity in regions located far from large power sources when these regions had limited water and fuel supplies.

A. A. Margaryan

1984-01-01

470

An expert system for power generation scheduling in multi-chain hydro power stations  

Microsoft Academic Search

The authors describe an expert system for producing daily power generation schedules for the next day for multi-chain hydro power stations along a river. Rules acquired from experienced operators are combined with statistical data for each station to determine generation schedules. These statistical data are stored in the frame base for each station, and the expert system is coupled with

Takao TERANO; Hachirou ISODA

1988-01-01

471

Characterization of synthetic IR scene generator thermal pixel array  

NASA Astrophysics Data System (ADS)

With the increased demand for IR sensor and surveillance systems, there is a growing need for technologies to support their operational readiness. Measurement of sensor characteristics such as sensitivity, MRTD, and dynamic range should be standard in all mission critical systems. The Real-Time Infrared Test Set (RTIR) is a portable system designed to provide in-the-field calibration and testing of IR imaging systems and seekers. RTIR uses the high volume manufacturing processes of the Very Large Scale Integration and the Micro Electromechanical Systems technology to produce a Thermal Pixel Array (TPA). State-of-the-art CMOS processes define all the necessary on-chip digital and analog electronics. When properly driven, this array generates variable temperature, synthetic IR scenes. A nonuniformity measurement of several TPAs is presented.

Schumann, Alan; Perkins, Gordon C.; Marlin, H. Ronald; Offord, Bruce W.; Bates, Richard L.; Hutchens, Chris; Huang, Derek Y.

2001-08-01

472

Generation of charged clusters during thermal evaporation of gold  

NASA Astrophysics Data System (ADS)

Investigating the generation of charged clusters during thermal evaporation of gold at 1523 K has created a new understanding of film growth. In order to verify the presence of charged clusters in the gas phase and their polarity biases of +200, 0 and -200 V were applied to the substrate. The charge on the majority of clusters was shown to be positive by observing their deposition behaviors under the applied electric field. These charged clusters were shown to be the major flux for gold film formation. The charge carried by clusters could be detected on a Faraday cup as an electric current. From the temperature dependence of the current, the activation energy for positive charging was estimated to be 1.56 eV. Such a low activation energy suggests that the charging mechanism of clusters is the surface ionization described by the Saha-Langmuir equation.

Barnes, Mark C.; Jeon, In-D.; Kim, Doh-Y.; Hwang, Nong M.

2002-07-01

473

NOVEL IONIC LIQUID THERMAL STORAGE FOR SOLAR THERMAL ELECTRIC POWER SYSTEMS  

Microsoft Academic Search

Feasibility of ionic liquids as liquid thermal storage media and heat transfer fluids in a solar thermal power plant was investigated. Many ionic liquids such as (C4min)(PF6), (C8mim)(PF6), (C4min)(bistrifluromethane sulflonimide), (C4min)(BF4), (C 8mim)(BF4), and (C4min)( bistrifluromethane sulflonimide) were synthesized and characterized using thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), nuclear magnetic resonance (NMR), viscometry, and some other methods. Properties such

Banqiu Wu; Ramana G. Reddy; Robin D. Rogers

474

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

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

475

MEMS-based power generation techniques for implantable biosensing applications.  

PubMed

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient. PMID:22319362

Lueke, Jonathan; Moussa, Walied A

2011-01-01

476

MEMS-Based Power Generation Techniques for Implantable Biosensing Applications  

PubMed Central

Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient. PMID:22319362

Lueke, Jonathan; Moussa, Walied A.

2011-01-01

477

Flexible Active Power Control of Distributed Power Generation Systems During Grid Faults  

Microsoft Academic Search

The increasing penetration of distributed power generation into the power system leads to a continuous evolution of grid interconnection requirements. In particular, active power control will play an important role both during grid faults (low-voltage ride-through capability and controlled current injection) and in normal conditions (reserve function and frequency regulation). The aim of this paper is to propose a flexible

Pedro Rodriguez; Adrian V. Timbus; Remus Teodorescu; Marco Liserre; Frede Blaabjerg

2007-01-01

478

Stability analysis of free piston Stirling engine power generation system  

NASA Astrophysics Data System (ADS)

This paper presents a stability analysis of the free-piston Stirling engine and linear alternator power generation system. Such a system operates under sustained mechanical oscillators, stability of the system is important for proper operation, and as a criterion in selecting the tuning capacitor. The stability criterion of the system is that the rate of change in power dissipation and electric power output is always faster than the rate of the power generated by the engine. The dynamic equations and model of the system are developed in this paper. Frequency domain analysis and Bode plot techniques are utilized in the study. The stable operating frequency region corresponding to different levels of power output are then determined.

Fu, Z. X.; Nasar, S. A.; Rosswurm, Mark

479

Measurement of thermal distortion in high power laser glass elements using ptychography  

NASA Astrophysics Data System (ADS)

The heat generated in the cavity of the high power slab laser amplifier makes it less stable and induces a thermal-lens effect which adds a spherical phase distribution to the wave-front of the laser beam. The commonly employed interferometry or Hartmann–Shack sensor based measurements are unable to provide an accurate measurement of the thermal distortion of the gain medium. It is demonstrated that this problem can be solved using a scheme based on ptychographical iterative engine. The complex transmittance of the outgoing laser is obtained by the proposed scheme while the amplifier is set at its turned off and turned on state and the thermal distortion caused by the pumping light is calculated from the obtained transmittance.

Wang, H.; Veetil, Suhas P.; Liu, C.; Wang, J.; Huang, W.; Zhang, Y.; Pan, X.; Zhu, J.

2015-02-01

480

Integrated engine-generator for aircraft secondary power.  

NASA Technical Reports Server (NTRS)

The integrated engine-generator 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 conveniently located in the aircraft. When properly rated, the generator serves as an engine starter as well as a source of electric power. The available generating capacity permits use of electrically driven engine accessories. This reduces or eliminates the need for an external gearbox on the engine, thereby simplifying the engine and nacelle assembly and increasing aircraft design flexibility. The nacelle diameter can then be decreased, resulting in less aerodynamic drag and reduced takeoff gross weight.

Secunde, R. R.

1972-01-01

481

Sea thermal power; A survey study for the Arab coastal waters  

SciTech Connect

One of the promising types of renewable energy resource that has potential applications in the Arab world is proposed and described in this article. Known as ocean thermal energy conversion (OTEC), its feasibility is investigated for the Red Sea and the Arabian Gulf/Gulf of Oman. Data on thermal gradients are surveyed, collected, and reported. Promising parameters have been identified for some specific locations along these coastal waters. The proposed system can serve the dual purpose of providing electric power and desalinated water, which is needed by the Arab world. Construction strategies for the OTEC systems are introduced. Building plant-ship for utilizing the generated power in the production of hydrogen is recommended. Thus energy could be transported as LH{sub 2} (liquid hydrogen), MeOH (methanol), or NH{sub 3} (ammonia) for end-use consumption or export.

Abdell-AAL, H.K.; Khan, M.M. (Dept. of Chemical Engineering, King Fahd Univ. of Petroleum and Minerals, Dhahran 31261 (SA))

1990-01-01

482

Large-scale terrestrial solar cell power generation cost: A preliminary assessment  

NASA Technical Reports Server (NTRS)

A cost study was made to assess the potential of the large-scale use of solar cell power for terrestrial applications. The incentive is the attraction of a zero-pollution source of power for wide-scale use. Unlike many other concepts for low-pollution power generation, even thermal pollution is avoided since only the incident solar flux is utilized. To provide a basis for comparison and a perspective for evaluation, the pertinent technology was treated in two categories: current and optimistic. Factors considered were solar cells, array assembly, power conditioning, site preparation, buildings, maintenance, and operation. The capital investment was assumed to be amortized over 30 years. The useful life of the solar cell array was assumed to be 10 years, and the cases of zero and 50-percent performance deg-radation were considered. Land costs, taxes, and profits were not included in this study because it was found too difficult to provide good generalized estimates of these items. On the basis of the factors considered, it is shown that even for optimistic projections of technology, electric power from large-sclae terrestrial use of solar cells is approximately two to three orders of magnitude more costly than current electric power generation from either fossil or nuclear fuel powerplants. For solar cell power generation to be a viable competitor on a cost basis, technological breakthroughs would be required in both solar cell and array fabrication and in site preparation.

Spakowski, A. E.; Shure, L. I.

1972-01-01

483

On-line diagnostic system for power generators  

SciTech Connect

A novel approach to diagnostics of a power generator is developed. It utilizes readily available data acquired by the existing computer-based monitoring/control system. Diagnostic procedures detect various trends in the generator data and interpret these trends in the generator data and interpret these trends as changes in the generator performance caused by incipient failures. Results of trend analyses, subjected to statistical validation, facilitate failure prediction and identification thus providing the justification for service when needed. The procedures are incorporated in a diagnostic system implemented in a PC interfaced with the existing VAX-based process monitoring and control system. The diagnostic system provides graphical display of the diagnostic messages.

Skormin, V.A. [Binghamton Univ., NY (United States). Watson School; Goodenough, G.S. [New York State Electric and Gas Corp., Binghamton, NY (United States); Huber, R.K. [Eastman Kodak Co., Rochester, NY (United States)

1996-12-31

484

76 FR 11436 - Application to Export Electric Energy; Ontario Power Generation  

Federal Register 2010, 2011, 2012, 2013

...Export Electric Energy; Ontario Power Generation AGENCY: Office of Electricity...SUMMARY: Ontario Power Generation Inc. (OPG) has applied to...Corporate Strategy, Ontario Power Generation Inc., [[Page 11437

2011-03-02

485

78 FR 4873 - Electrical Protective Equipment Standard and the Electric Power Generation, Transmission, and...  

Federal Register 2010, 2011, 2012, 2013

...Equipment Standard and the Electric Power Generation, Transmission, and Distribution...CFR 1910.137) and Electric Power Generation, Transmission, and Distribution...1910.137) and the Electric Power Generation, Transmission, and...

2013-01-23