COMPARATIVE STUDY OF HEAT PIPES WITH DIFFERENT WORKING FLUIDS UNDER NORMAL GRAVITY AND MICROGRAVITY CONDITIONS

摘要

The performances of different heat pipes, with composite wick or wickless, filled with pure water are compared with the performances of the same heat pipes filled with water/alcohol binary mixtures under normal gravity and low gravity conditions. The reduced gravity experiments have been carried out during the 45th ESA parabolic flight campaign onboard the Airbus A-300. The experimental set up was based on a dedicated testing bench built to perform thermal tests on heat pipes instrumented with thermocouples and heated by cartridge heaters. To measure the temperature gradients along the pipe and the thermal resistance the surface temperatures have been also detected by an infared thermocamera. The results show that the heat pipes filled with the binary mixtures are more efficient when compared to the same heat pipes filled with pure water. Based on these results, the development of high performances heat pipes for next generation satellites will be carried out through a research and development activity programme funded by the Italian Space Agency (ASI).