Advanced Technology Development for Stirling Convertors

Thieme, Lanny G.; Schreiber, Jeffrey G.

doi:10.1063/1.1649603

Cited by 19 publications

(5 citation statements)

References 12 publications

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“…It can be seen from the figure that plant efficiency decreases significantly with the increase of cooler temperature. And it becomes almost zero net output power when the cooler temperature reaches 800 K. Because the radiated power depends strongly on radiation cooler temperature as T 4 , lower temperature requires much larger area of the radiation cooler. We have to clarify adequate radiation cooler temperature.…”

Section: Analysis Of Nfr/ccmhd Systemmentioning

confidence: 99%

“…So far, thermoelectric converters 2,3 , Stirling engines 4 and turbo-Brayton Cycles 5,6 are considered and studied as a power generation system combined with advanced radioisotope power for relatively smaller missions and with NFR for larger ones. In particular, for larger missions over 1 MWe electric power, gas-cooled NFR with CCMHD system has also been considered and studied.…”

Section: Introductionmentioning

confidence: 99%

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Basic Studies on Closed Cycle MHD Power Generation System for Space Application

Hishikawa

2004

35th AIAA Plasmadynamics and Lasers Conference

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Multi-megawatt class nuclear fission reactor powered closed cycle MHD single cycle for space applications using helium and xenon mixture as a working gas has been studied. System analysis was carried out. Total plant efficiency was expected to be 55.2 % including pre-ionization power. Effects of compressor stage number, regenerator efficiency and radiation cooler temperature on plant efficiency were studied. Specific mass of power generation plant was examined. Specific mass of 3 kg/kWe at the net electrical output power of 1 MWe and less than 2 kg/kWe for the output of larger than 3 MWe were expected. Three phases of research and development plan were proposed; Phase-I, Proof of Principle, Phase-II Demonstration of Power Generation, and Phase-III Prototypical Closed Loop Test.

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Section: Analysis Of Nfr/ccmhd Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Basic Studies on Closed Cycle MHD Power Generation System for Space Application

Hishikawa

2004

35th AIAA Plasmadynamics and Lasers Conference

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“…The technology options currently being considered for fractionally converting the reactor thermal power to electricity are advanced thermoelectrics (TE) (El-Genk, Saber and Caillat, 2002), Closed Brayton Cycle (CBC) engines (Barrett and Reid, 2004), potassium Rankine Cycle (PRC) (Yoder and Graves, 1985;Bevard and Yoder, 2003), and Free Piston Stirling Engines (FPSEs) (Thieme and Schreiber, 2004). These choices of reactor type and conversion technology provide a 3 x 4 matrix of possible combinations.…”

Section: Introductionmentioning

confidence: 99%

Radiator Heat Pipes with Carbon-Carbon Fins and Armor for Space Nuclear Reactor Power Systems

Tournier¹,

El‐Genk²

2005

AIP Conference Proceedings

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Technologies for Space Reactor Power Systems are being developed to enable future NASA's missions early next decade to explore the farthest planets in the solar system. The choices of the energy conversion technology for these power systems require radiator temperatures that span a wide range, from 350 K to 800 K. Heat pipes with carbon-carbon fins and armor are the preferred choice for these radiators because of inherent redundancy and efficient spreading and rejection of waste heat into space at a relatively small mass penalty. The performance results and specific masses of radiator heat pipes with cesium, rubidium, and potassium working fluids are presented and compared in this paper. The heat pipes operate at 40% of the prevailing operation limit (a design margin of 60%), typically the sonic and/or capillary limit. The thickness of the carbon-carbon fins is 0.5 mm but the width is varied, and the evaporator and condenser sections are 0.15 and 1.35 m long, respectively. The 400-mesh wick and the heat pipe thin metal wall are titanium, and the carbon-carbon armor (~ 2 mm-thick) provides both structural strength and protection against meteoroids impacts. The cross-section area of the Dshaped radiator heat pipes is optimized for minimum mass. Because of the low vapor pressure of potassium and its very high Figure-Of-Merit (FOM), radiator potassium heat pipes are the best performers at temperatures above 800 K, where the sonic limit is no longer an issue. On the other hand, rubidium heat pipes are limited by the sonic limit below 762 K and by the capillary limit at higher temperature. The transition temperature between these two limits for the cesium heat pipes occurs at a lower temperature of 724 K, since cesium has lower FOM than rubidium. The present results show that with a design margin of 60%, the cesium heat pipes radiator is best at 680-720 K, the rubidium heat pipes radiator is best at 720-800 K, while the potassium heat pipes radiator is the best performer and lightest at higher temperatures > 800 K.

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“…These options typically operate at high hot side temperatures from 1100 to 1900 K, and some operate at low cold side temperatures, increasing the radiator area and mass. Dynamic options of free-piston stirling engines (FPSEs) (Thieme and Schreiber, 2004) and potassium rankine cycle (PRC) (Bevard and Yoder, 2003) are also suitable for use with liquid-metal heat pipes or circulating liquid metal-cooled reactors. CBC engines (Barrett and Reid, 2004), however, are more suitable for use with gas-cooled reactors.…”

Section: Introductionmentioning

confidence: 99%