Download or read book Design Analysis and Optimization of a Radio isotrope Thermo photovoltaic RTPV Generator and Its Applicability to an Illustrative Space Mission written by A. Schock and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Analysis and Optimization of a Radioisotope Thermophotovoltaic RTPV Generator and Its Applicability to an Illustrative Space Mission written by and published by . This book was released on 1994 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paper presented at the 45th Congress of the IAF in Jerusalem, Israel, October 1994. The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the authors. To focus the design effort, it was decided to direct it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by the JPL, envisages a direct eight to nine-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a six-week post-encounter cruise.

Download or read book Analysis Optimization and Assessment of Radioisotope Thermophotovoltaic System Design for an Illustrative Space Mission written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A companion paper presented at this conference described the design of a Radioisotope Thermophotovoltaic (RTPV) Generator for an illustrative space mission (Pluto Fast Flyby). It presented a detailed design of an integrated system consisting of a radioisotope heat source, a thermophotovoltaic converter, and an optimized heat rejection system. The present paper describes the thermal, electrical, and structural analyses which led to that optimized design, and compares the computed RTPV performance to that of a Radioisotope Thermoelectric Generator (RTG) designed for the same mission. RTPV's are of course much less mature than RTGs, but our results indicate that - when fully developed - they could result in a 60% reduction of the heat source's mass, cost, and fuel loading, a 50% reduction of generator mass, a tripling of the power system's specific power, and a quadrupling of its efficiency. The paper concludes by briefly summarizing the RTPV's current technology status and assessing its potential applicability for the PFF mission. For other power systems (e.g. RTGs), demonstrating their flight readiness for a long mission is a very time-consuming process to determine the long-term effect of temperature-induced degradation mechanisms. But for the case of the described RTPV design, the paper lists a number of factors, primarily its cold (0 to 10 degrees C) converter temperature, that may greatly reduce the need for long-term tests to demonstrate generator lifetime. In any event, our analytical results suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the Pluto mission but also for other future missions requiring small, long-lived, low mass generators. Another copy is in the Energy Systems files.

Download or read book Radioisotope Thermophotovoltaic RTPV Generator and Its Applicability to an Illustrative Space Mission written by and published by . This book was released on 1994 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the author. Instead of conducting a generic study, it was decided to focus the design effort by directing it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a post-encounter cruise lasting up to one year.

Download or read book Radioisotope Thermophotovoltaic RTPV Generator and Its Application to the Pluto Fast Flyby Mission written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator. Instead of conducting a generic study, it was decided to focus the design by directing it at a specific space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a one-year post-encounter cruise. Because of Pluto's long distance from the sun (30-50 A.U.) and the mission's large energy demand, JPL has baselined the use of a radioisotope power system for the PFF spacecraft. The chief advantage of Radioisotope Thermophotovoltaic (RTPV) power systems over current Radioisotope Thermoelectric Generators (RTGs) is their much higher conversion efficiency, which greatly reduces the mass and cost of the required radioisotope heat source. Those attributes are particularly important for the PFF mission, which - like all NASA missions under current consideration - is severely mass- and cost-limited. The paper describes the design of the radioisotope heat source, the thermophotovoltaic converter, and the heat rejection system; and presents the results of the thermal, electrical, and structural analysis and the design optimization of the integrated RTPV system. It briefly summarizes the RTPV system's current technology status, and lists a number of factors that my greatly reduce the need for long-term tests to demonstrate generator lifetime. Our analytical results show very substantial performance improvements over an RTG designed for the same mission, and suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the PFF mission but also for other future missions requiring small, long-lived, low-mass generators. There is a duplicate copy.

Download or read book Advanced Thermophotovoltaic Cells Modeling Optimized for Use in Radioisotope Thermoelectric Generators RTGs for Mars and Deep Space Missions written by Bradley P. Davenport and published by . This book was released on 2004-06-01 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: To accommodate the need for power on deep space missions, satellites must carry a source capable of providing adequate power for the life of the mission. This is currently done using radioisotope thermoelectric generators (RTGs). Current RTGs consist of a heat source, Pu-238, and a thermocouple that inefficiently converts heat into electricity. To improve the overall efficiency of RTGs, a better thermoelectric converter is needed to replace the thermocouple. This thesis examines the possible use of thermophotovoltaic (TPV) cells in RTGs. Two cells were developed and optimized for the spectrum from a 1300K blackbody that simulates the spectrum of an RTG heat source. Current TPV cells are built and tested with different thicknesses and doping levels to the most efficient design, an expensive and time-consuming method. This thesis presents a model that can predict the output of a cell under various spectra. The model can easily be changed to simulate different cell thicknesses and doping levels, and it can be changed to simulate cells of different materials. The models presented in this thesis were built using the Silvaco Virtual Wafer Fabrication software package. To prove the capabilities of this software package in designing TPV models, an initial cell was designed using a well-documented material: gallium arsenide (GaAs). Voltage-current characteristics and frequency response data were recorded from this model and compared with experimental data from a similar cell. Once the model was verified, more exotic materials could be examined: gallium antimonide (GaSb) and indium gallium arsenide (InGaAs). As with the GaAs cell model, the GaSb and InGaAs models were first optimized for the AM0 spectrum and compared to experimental results. Programs were written using Matlab to run iterations of Silvaco to change layer thicknesses and doping levels. Other programs also were used to help determine the most efficient TPV cell design. (41 figures, 48 refs.)

Download or read book Toward High Efficiency Radioisotope Thermophotovoltaic System by Spectral Control written by Xiawa Wang and published by . This book was released on 2017 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the design, modeling, and measurement results of a radioisotope thermophotovoltaic system (RTPV) using a two-dimensional photonic crystal emitter and low bandgap thermophotovoltaic (TPV) cell to realize spectral control. The RTPV generator aims to use the decay heat released by plutonium-238 fuel to heat up the emitter to incandescence and convert the infrared radiation to electricity in the TPV cell. With spectral control, high energy photons above the cell bandgap ([lambda] 2.25 [mu]m for InGaAsSb cell) are emitted to produce more electrical power while low energy photons ([lambda] 2.25 [mu]m) in far infrared are suppressed to reduce waste heat. We validated a system simulation using the measurements of a prototype system powered by an electrical heater equivalent to one plutonium fuel pellet. The thermal insulation design used multilayer insulation, which was found to be both efficient and chemically compatible with the photonic crystal emitter. We compared the system performance using a photonic crystal emitter to the one using a polished flat tantalum emitter and found that spectral control with the photonic crystal was four times more efficient. Based on the simulation, we further extended the design and performance estimates to real life RTPV generators optimized for both space and terrestrial applications. With the experimentally tested InGaAsSb TPV cell, the system efficiency can potentially reach above 8% with a specific power of 7.5 W/kg. With more advanced InGaAs monolithic-integrated-modules, the system efficiency can reach around 20% with a specific power above 17 W//kg.

Download or read book Radioisotope Power Systems written by National Research Council and published by National Academies Press. This book was released on 2009-07-14 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spacecraft require electrical energy. This energy must be available in the outer reaches of the solar system where sunlight is very faint. It must be available through lunar nights that last for 14 days, through long periods of dark and cold at the higher latitudes on Mars, and in high-radiation fields such as those around Jupiter. Radioisotope power systems (RPSs) are the only available power source that can operate unconstrained in these environments for the long periods of time needed to accomplish many missions, and plutonium-238 (238Pu) is the only practical isotope for fueling them. Plutonium-238 does not occur in nature. The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world.The total amount of 238Pu available for NASA is fixed, and essentially all of it is already dedicated to support several pending missions-the Mars Science Laboratory, Discovery 12, the Outer Planets Flagship 1 (OPF 1), and (perhaps) a small number of additional missions with a very small demand for 238Pu. If the status quo persists, the United States will not be able to provide RPSs for any subsequent missions.

Download or read book Design and Fabrication of a Stirling Thermal Vacuum Test written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Stirling Radioisotope Generator (SRG110) is being developed for potential use on future NASA space science missions. The development effort is being conducted by Lockheed Martin under contract to the Department of Energy (DOE). The Stirling Technology Company supplies the free-piston Stirling power convertors, and NASA Glenn Research Center (GRC) provides support to the effort in a range of technologies. This generator features higher efficiency and specific power compared to the currently used alternatives. One potential application for the generator would entail significant cruise time in the vacuum of deep space. A test has been conceived at GRC to demonstrate functionality of the Stirling convertors in a thermal vacuum environment. The test article resembles the configuration of the SRG, however the requirement for low mass was not considered. This test will demonstrate the operation of the Stirling convertors in the thermal vacuum environment, simulating deep space, over an extended period of operation. The analysis, design, and fabrication of the test article will be described in this paper. Oriti, Salvatore M. and Schreiber, Jeffrey G. Glenn Research Center NASA/TM-2004-213372, AIAA Paper 2004-5561, E?14841

Download or read book Parametric Study of Radiator Concepts for a Stirling Radioisotope Power System Applicable to Deep Space Mission written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-16 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy (DOE) and the NASA Glenn Research Center are developing a Stirling converter for an advanced radioisotope power system to provide spacecraft onboard electric power for NASA deep space missions. This high-efficiency converter is being evaluated as an alternative to replace the much lower efficiency radioisotope thermoelectric generator (RTG). The current power requirement (six years after beginning of mission (BOM) for a mission to Jupiter) is 210 W(sub e) (watts electric) to be generated by two separate power systems, one on each side of the spacecraft. Both two-converter and four-converter system designs are being considered, depending on the amount of required redundancy.Juhasz, Albert J. and Tew, Roy C. and Thieme, Lanny G.Glenn Research CenterSPACECRAFT POWER SUPPLIES; POWER CONVERTERS; SYSTEMS ENGINEERING; RADIOISOTOPE BATTERIES; RESEARCH AND DEVELOPMENT; STIRLING CYCLE; SPACE MISSIONS; THERMOELECTRIC GENERATORS

Download or read book Thermophotovoltaic Energy Conversion Development Program written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely integrated thermophotovoltaic (TPV) power sources in the range of 100 to 500 watts are being developed. The technical approach taken in this project focuses on optimizing the integrated performance of the primary subsystems in order to yield high energy conversion efficiency and cost effectiveness. An important aspect of the approach is the use of a narrow band fibrous emitter radiating to a bandgap matched photovoltaic array to minimize thermal and optical recuperation requirements, as well as the non-recoverable heat losses. For the prototype system, fibrous ytterbia emitters radiating in a narrow band centered at 980 nm are matched with high efficiency silicon photoconverters. The integrated system includes a dielectric stack filter for optical energy recovery and a ceramic recuperator for thermal energy recovery. The prototype TPV system uses a rapid mix distributed fuel delivery system with controlled feeding of the fuel and heated air into a flame at the surface of the emitter. This makes it possible to operate at air preheat temperatures well above the auto-ignition temperature of the fuel thereby substantially increasing the system efficiency. The system has been operated with air preheat temperatures up to 1367 K and has produced a uniform narrow band radiation over the surface of the emitter with this approach. The design of the system is described and test data for the system and some of the key components are presented. The results from a system model, which show the impact of various parameters on system performance, are also discussed. Shukla, Kailash and Doyle, Edward and Becker, Frederick Glenn Research Center...

Download or read book NASA Radioisotope Power Conversion Technology Nra Overview written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-27 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of the National Aeronautics and Space Administration's (NASA) Radioisotope Power Systems (RPS) Development program is aimed at developing nuclear power and technologies that would improve the effectiveness of space science missions. The Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) is an important mechanism through which research and technology activities are supported in the Advanced Power Conversion Research and Technology project of the Advanced Radioisotope Power Systems Development program. The purpose of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide higher efficiencies and specific powers than existing systems. These advances would enable a factor of two to four decrease in the amount of fuel and a reduction of waste heat required to generate electrical power, and thus could result in more cost effective science missions for NASA. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100 W(sub e) scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, a summary of the power conversion technologies approaches being pursued, and a brief digest of first year accomplishments. Anderson, David J. Glenn Research Center NASA/TM-2005-213981, E-15303

Download or read book Nasa s Advanced Radioisotope Power Conversion Technology Development Status written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2019-01-13 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: NASA's Advanced Radioisotope Power Systems (ARPS) project is developing the next generation of radioisotope power conversion technologies that will enable future missions that have requirements that cannot be met by either photovoltaic systems or by current radioisotope power systems (RPSs). Requirements of advanced RPSs include high efficiency and high specific power (watts/kilogram) in order to meet future mission requirements with less radioisotope fuel and lower mass so that these systems can meet requirements for a variety of future space applications, including continual operation surface missions, outer-planetary missions, and solar probe. These advances would enable a factor of 2 to 4 decrease in the amount of fuel required to generate electrical power. Advanced RPS development goals also include long-life, reliability, and scalability. This paper provides an update on the contractual efforts under the Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) for research and development of Stirling, thermoelectric, and thermophotovoltaic power conversion technologies. The paper summarizes the current RPCT NRA efforts with a brief description of the effort, a status and/or summary of the contractor's key accomplishments, a discussion of upcoming plans, and a discussion of relevant system-level benefits and implications. The paper also provides a general discussion of the benefits from the development of these advanced power conversion technologies and the eventual payoffs to future missions (discussing system benefits due to overall improvements in efficiency, specific power, etc.). Anderson, David J. and Sankovic, John and Wilt, David and Abelson, Robert D. and Fleurial, Jean-Pierre Glenn Research Center; Jet Propulsion Laboratory WBS 138494.01.04.01

Download or read book Radioactive isotope fueled thermo electric generators for space missions written by Ernst de Haas and published by . This book was released on 1964 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The preceding paper described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Special Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to ~110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its engines fails. In fact, the latter system could deliver as much as 115 watts(e) if desired by the mission planners. There are 5 copies in the file.

Download or read book Design and Construction of a Thermophotovoltaic Generator Using Turbine Combustion Gas written by and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This US Naval Academy project involves the development of a prototype thermophotovoltaic (TPV) generator that uses a General Electric T-58 helicopter gas turbine as the heat source. The goals of this project were to demonstrate the viability of using TPV and external combustion gases to generate electricity, and develop a system which could also be used for materials testing. The generator was modularly designed so that different materials could be tested at a later date. The combustion gas was tapped from the T-58's combustor through one of the two igniter ports and extracted through a silicon carbide matrix ceramic composite tube into a similarly constructed ceramic composite radiant emitter. The ceramic radiant emitters is heated by the combustion gas via convection, and then serves the TPV generator by radiating the heat outwards where it can be absorbed by thermophotovoltaic cells and converted directly into electricity. The gas turbine and generator module are monitored by a data acquisition system that performs both data collection and control functions. This paper details the design of the TPV generator. It also gives results of initial tests with the gas turbine.

Download or read book Design Characterization and Optimization of High efficiency Thermophotovoltaic TPV Device Using Near field Thermal Energy Conversion written by Anil Yuksel and published by . This book was released on 2013 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermophotovoltaic (TPV) devices, also known as (nano-TPVs) are energy-conversion systems which generate electric current from thermal radiation energy by a heat source. Although their conversion efficiency is limited in the far field by the Schockley-Queisser limit, in near field the heat flux transferred to a TPV cell can be significantly enchanced due to the contribution of evanescent waves, in particular supporting a surface mode. Unfortunately, spectral mismatch between the emitter and the TPV cell spectrum limits the TPV conversion efficiency. Photons with energy lower than the TPV cell bandgap may not be able to create electron-hole pairs because mobile carriers start diffusing and drifting between conductance and valence band, and try to exceed the upper limit of the band. This destroys the thermal equilibrium of the semiconductor and results in excess heat. Also, for high energy photons, the difference between the photon's energy and the bandgap energy is lost in Joule heating. Thus, quasimonochromatic, narrow-band and coherent emitters at a frequency near the energy bandgap of the converter is an ideal source to achieve high conversion efficiency. Nano-TPV device consisting of tungsten thermal emitter, maintained at 1200K, and the cell made of GaInAsSb are considered; thermal management system is reviewed assuming a constant heat flux boundary due to heat generation by the cell with a fluid temperature fixed at 293K. Tungsten thermal selective emitters are designed, characterized and optimized based on two-dimensional (2D) tungsten PhC by controlling periodic triangular grooves such that channel plasmon polaritons (CPPs) are coupled efficiently into these grooves to excite a localized groove modes which are well-matched to the GaInAsSb cell external quantum efficiency (EQE). The results show that power output and the 2D TE normal efficiency of the system are predicted to be 0.82x104 W/m2 and 43.8%, respectively. This leads to a promising device for many different sectors such as military, space and semiconductor industry.