A two-phase heat transport system, the Thermal Bus Technology Demonstrator (TBTD), has been built and tested for NASA Johnson Space Center for application on Space Station. The loop is a separated two-phase system that uses evaporator flow control valves and liquid condenser flooding to achieve temperature control. Both ambient and thermal vacuum tests have been computed in NASA's Chamber A initially using Freon-II and then ammonia as the working fluid. Overall, the tests were quite successful, with the bus achieving all major test objectives, including operation at 19.5 kW and set points at 35 F (1.7 Cel), 70 F (21.1 Cel) and 104 F (40.0 Cel), load sharing, asymmetrical heating and isothermally around the loop. Low plate to vapor temperature drops, e.g., 4 F (2.2 Cel) at 5 kW were obtained for the monogroove cold plate using ammonia and are indicative of the high evaporative film coefficients obtainable with this design. As expected, testing uncovered areas where loop performance could be improved, such as use of a reservoir sensed cold plate, and possible elimination of the regenerator and subcooler.
Thermal test results of the two-phase thermal bus technology demonstration loop
Waermeversuchsergebnisse mit einem Demonstrationskreislauf der Zweiphasen Thermal Bus Technologie
AIAA-Papers ; Jun ; 1-8
1987
8 Seiten, 16 Bilder, 8 Quellen
Aufsatz (Konferenz)
Englisch
Thermal Test of an Ammonia Two-Phase Loop Results of Condenser Study
SAE Technical Papers | 1991
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