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Orientational Effects on the Performance of a Heat Pipe Coupled Thermionic Converter
ISSN: 0148-7191, e-ISSN: 2688-3627
Published August 03, 1992 by SAE International in United States
Annotation ability available
The effects of collector heat pipe orientation upon the electrical and thermal performance of a planar thermionic converter were investigated. The high heat throughput of the converter must be carried away from the collector following electrical power production.
The planar thermionic converter tested employs chemical-vapor-deposited rhenium on molybdenum electrodes, a separately heated two-phase cesium reservoir, and a radiantly coupled, electric emitter heater. The collector also functions as the evaporator end cap for the liquid sodium heat pipe. The converter fixture places the heat pipe in the reflux mode (evaporator below the condenser) and allows orientational changes of 15, 30, 45, and 60 degrees from the vertical.
It was determined that the thermionic output performance is a relatively weak function of orientation angle in the range of 0 to 60°. As the emitter temperature increased, the effect of orientation on the converter performance increases. The trend is that maximum power and output voltage decreases as orientation increases.
The performance of the heat pipe was also monitored at various emitter temperatures and orientations. The difference in the temperatures of the heat pipe evaporator and condenser increased as the angle of inclination from the vertical increased. Instabilities due to a lack of heat throughput and the inability to reprime the wick define a region of safe operation of the heat pipe with respect to heat input and tilt angle.
CitationYoung, T., Ramalingam, M., and Tsao, B., "Orientational Effects on the Performance of a Heat Pipe Coupled Thermionic Converter," SAE Technical Paper 929359, 1992, https://doi.org/10.4271/929359.
- Dick, R.S., 1984, “Thermionic Cogeneration Burner Assessment,” Proc. 19th Intersociety Energy Conversion Engineering Conference, American Nuclear Society, Vol.4, pp. 2307-2312.
- Dunn, P.D. and Reay D.A., 1982, Heat Pipes, 3rd ed., Oxford: Pergamon Press, pp. 264-265.
- Goodale, D. and Lieb D., 1983, “Combustion Converter Development for Topping and Cogeneration Applications,” Proc. 18th Intersociety Energy Conversion Engineering Conference, American Institute of Chemical Engineers, Vol.1, pp. 192-197.
- Goodale, D.B. and Miskolczy G., 1984, “Combustion Converter Design Evolution,” Proc. 19th Intersociety Energy Conversion Engineering Conference, American Nuclear Society, Vol.4, pp. 2270-2275.
- Grover, G.M., Cotter T.P., and Erickson G.F., 1964, “Structures of Very High Thermal Conductance,” J. Applied Physics, Vol.35, No.6, pp. 1990-1991.
- Hatsopoulos, G.N. and Gyftopoulos E.P., 1973, Thermionic Energy Conversion Vol.I: Processes and Devices, Cambridge, MA: MIT Press, pp. 175-216.
- Hatsopoulos, G.N. and Gyftopoulos E.P., 1979, Thermionic Energy Conversion Vol.II: Theory, Technology, and Application, Cambridge, MA: MIT Press, pp. 533-540.
- Jalichandra, P., Hamerdinger R.W., Anderson E.A., Lamp T.R., and Donovan B.D., 1991, “Thermionic Critical Technology Investigation,” Proc. 26th Intersociety Energy Conversion Engineering Conference, American Nuclear Society, Vol.3, pp. 148-153.
- Kleinbach, M.H. and Salvagin C.E., 1986, Energy Technologies and Conversion Systems, Englewood Cliffs, NJ: Prentice-Hall, Inc., pp. 350-351.
- Miskolczy, G., Wang C.C., Margulis A.E., and Fusegni L.J., 1980, “Thermionic Topping of Combined Cycle Powerplants and Cogeneration Applications,” Proc. 15th Intersociety Energy Conversion Engineering Conference, AIAA, Vol.3, pp. 1783-1787.
- Peters, R.R. and Jekel T.B., 1992, “Thermionic Diode Subsystem Model,” Proc. 9th Symposium on Space Nuclear Power Systems, American Institute of Physics, Vol.3, pp. 1114-1122.
- Rasor, N.S. and Warner C., 1964, “Correlation of Emission Processes for Adsorbed Alkali Films on Metal Surfaces,” J. of Applied Physics, Vol.35, No.9, pp.2589-2600.
- Redd, F.J. and Powell G.E., 1992, “Project Thermion: Demonstration of a Thermionic Heat Pipe in Microgravity,” Proc. 9th Symposium on Space Nuclear Power Systems, American Institute of Physics, Vol.3, pp. 1351-1358.
- Veltkamp, W.B., Wolff L.R., Schoonen J.M.W.M., Bakker R., Houtermans M.P.A., and de Pijper A.M., 1989, “Design and Testing of a Heat Pipe Cooled Thermionic Energy Convertor,” Proc. 24th lntersociety Energy Conversion Engineering Conference, IEEE, Vol.2, pp.1171-1175.
- Young, T.J., Lamp T.R., Tsao B.H., and Ramalingam M.L., 1992, “A Heat Pipe Coupled Planar Thermionic Converter,” USAF Wright Laboratory Technical Report WL-TR-92-2033.