Research Study of Thermodynamic Systems for Temperature Control of Heat Sinks in Space Simulation Chambers

摘要

Several systems which could be utilized for effecting temperature control of the heat sink surfaces in the range between 20K and 373K were examined. Also, where several systems could provide the same temperatures, an economical comparison was made. Thus, the first cost and operating cost of an air separation plant was compared to a nitrogen reliquefier, and the break-even point between a nitrogen reliquefier and a nitrogen subcooled circulation system was evaluated. Considerable attention was also given to a more basic consideration, that is, to determine the relationship between the heat sink temperature and/or temperature profile and the simulator performance or capability. The areas of cryopumping, vehicle equilibrium temperature and the simulation temperature error as determined by an electrical network analogy were investigated. In addition, several generalized parameters were developed regarding the heat sink warm-up process from operating temperatures to some elevated temperature utilizing helium or nitrogen gas for the heat transfer fluid. (Author)