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Results for “THERMIONIC CONVERSION SYSTEM”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

An improved thermionic power conversion system for space propulsion

A concept of an out-of-core thermionic nuclear electric power conversion system for 400 Kwe power level is being investigated for space propulsion applications. Two key features distinguish the power system design from previous thermionic power conversion concepts. First, the thermionic converters are located outside a nuclear reactor with a neutron shield inserted to reduce the radiation level on the thermionic converter matrix. Second, multiple liquid-metal heat pipes are used exclusively for both thermal power transport (from the nuclear reactor to the thermionic converters) and waste heat removal (from the thermionic converters to the space radiator); no mechanical or electromagnetic pumps are involved. The system characteristics are are compared to those of the in-core thermionic reactor system concept. In many aspects, the system characteristics, including specific weight, lifetime, dynamics control and safety features are found to be more desirable than those of the in-core system concept.

Hsieh, T. M.↗
NASA NTRS1975

Terrestrial solar thermionic energy conversion systems concept

Results obtained from studies of a (1) solar concentrator, (2) solar energy receiver - thermionic converter system, and (3) solar thermionic topping system are described. Peripheral subsystems, which are required for any solar energy conversion system, are also discussed.

Shimada, K.↗
NASA NTRS1976

Heat pipe nuclear reactor for space power

A heat-pipe-cooled nuclear reactor has been designed to provide 3.2 MWth to an out-of-core thermionic conversion system. The reactor is a fast reactor designed to operate at a nominal heat-pipe temperature of 1675 K. Each reactor fuel element consists of a hexagonal molybdenum block which is bonded along its axis to one end of a molybdenum/lithium-vapor heat pipe. The block is perforated with an array of longitudinal holes which are loaded with UO2 pellets. The heat pipe transfers heat directly to a string of six thermionic converters which are bonded along the other end of the heat pipe. An assembly of 90 such fuel elements forms a hexagonal core. The core is surrounded by a thermal radiation shield, a thin thermal neutron absorber, and a BeO reflector containing boron-loaded control drums.

Koening, D. R.↗
NASA NTRS1989

A look at the Soviet space nuclear power program

The Soviet Union has been flying nuclear power sources in space since about 1965. For the most part these nuclear power sources have been low-power nuclear reactors using a thermoelectric conversion principle. Recently the Soviet Union has flown two satellites using a higher power reactor that employs a thermionic conversion system. Reentry of two of the earlier reactors on board Cosmos 954 and Cosmos 1402 plus the recent potential accident involving Cosmos 1900 have focused world attention on Soviet usage of space nuclear power. Despite these problems the evidence points toward a continued Soviet usage of nuclear power sources in space.

Inductors↗
NASA NTRS1963

HOW MUCH FUTURE FOR ELECTRIC PROPULSION

Low powerplant weight and elimination of waste heat in order to provide adequate endurance are the primary aims of electric propulsion system design

ROCKET ENGINE↗
NASA NTRS1976

Nuclear thermionic power system for spacecraft

Mission studies have shown that nuclear electric propulsion is necessary for providing the needed propulsion system for detailed outer planet exploration. The study is centered around thermionic conversion based on an out-of-core approach employing heat pipes to thermally couple the nuclear reactor with the thermionic converters. Emphasis is on a parametric study to size a 500 kWe thermionic power conversion system suitable for a single shuttle launch. It is shown that out-of-core thermionic conversion results in a large L/D system that produces minimum weight. This evolving thermionic technology is compatible with developing insulator technology allowing operation at temperatures compatible with both molybdenum and insulators while retaining a sufficiently high heat rejection temperature to minimize radiator size and weight.

Phillips, W. M.↗