Analysis of Low-Temperature Direct-Condensing Vapor-Chamber Fin and Conducting Fin Radiators
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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An analytical comparison of flat, direct-condensing finned-tube space radiators employing vapor- chamber, double, and central fin-tube geometries was made for a low power output, low-temperature Rankine space power system. The descriptive equations for the radiator investigation included in addition to the heat-transfer analysis, consideration of vapor and liquid headers, pressure drop in the headers and radiator tubes, meteoroid protection for the tubes, headers, and vapor-chamber fins, and temperature drop in the tube armor. The heat-transfer, weight, and geometry characteristics of the three radiator fin-tube configurations were determined over a wide range of variables for design conditions descriptive of a 30-kilowatt powerplant that used steam as the thermodynamic cycle fluid. he thermal degradation of the vapor-chamber fin-tube radiator due to puncture of the individual fin segments, and the vapor chamber heat transfer and capillary fluid flow requirements were also investigated. For the example case chosen, which employed a tube meteoroid nonpenetration probability of 0. 90, the vapor-chamber fin radiator was clearly not superior in heat rejection per unit weight to the central and double fin geometries. The largest values of heat rejection per unit weight were obtained for the double-fin geometry radiator.
- Electrical and Electronic Equipment
- Metallurgy and Metallography
- Nuclear Radiation Shielding, Protection and Safety