Technology for Brayton-cycle space powerplants using solar and nuclear energy

Technical Report · Sat Feb 01 04:00:00 EST 1986

DOI:https://doi.org/10.2172/10180994· OSTI ID:10180994

English, R E

Brayton-cycle gas turbines have the potential to use either solar heat or nuclear reactors to generate from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power-generating system. Their development for solar-energy dynamic power generation for the space station could be the first step in an evolution of such powerplants for a very wide range of applications. At the low power level of only 10 kWe, a power-generating system has already demonstrated overall efficiency of 0.29 and operated for 38,000 hr. Tests of improved components show that, if installed in the power-generating system, these components would raise that efficiency to 0.32; this efficiency is twice that so far demonstrated by any alternate concept, a characteristic especially important for solar power systems. Because of this high efficiency, solar-heat Brayton-cycle power generators offer the potential to increase power per unit of solar-collector area to levels exceeding four times that from photovoltaic powerplants based on present technology for silicon solar cells. For the heat source, paraboloidal mirrors have been assembled from sectors here on Earth. One mirror, 1.5-m diameter, had a standard error for its surface of only 1 arc-min and a specific mass of only 1.3 kg/m 2. A heavier mirror (nearly 5 kg/m{sup 2}), assembled from 12 sectors, had a standard surface error of 3 arc-min but was 6 m in diameter. Either of these mirrors is sufficiently accurate for use with the Brayton cycle, but the techniques for actually assembling large mirrors in space must yet be worked out. For use during the shadow period of a low Earth orbit (LEO), heat could be stored in LiF, a salt that melts at 1121 K (1558{degrees}F) and whose latent heat of fusion exceeds 1 MJ/kg. Because of the prior experience with its fabrication and of its tolerance of the thermal cycling in LEO, Nb-1Zr was selected to contain the LiF.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• Sponsoring Organization: USDOE, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
• DOE Contract Number: AI03-86SF16310
• OSTI ID: 10180994
• Report Number(s): NASA-TP--2558; ON: DE94051192
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
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21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
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42 ENGINEERING
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BRAYTON CYCLE POWER SYSTEMS
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NESDPS Office of Nuclear Energy Space and Defense Power Systems
PHOTOVOLTAIC POWER SYSTEMS
POWER REACTORS, MOBILE, PROPULSION, PACKAGE, AND TRANSPORTABLE
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