Design And Experimental Investigation In Miniature Disc Loop Heat Pipe System

The LHP (Loop Heat Pipe) is such a thermal controlling device, of which the driven potential depends on the phase change of the working fluid and the capillary force. It has those characters that make it very suitable to the thermal management on the satellite and electronic component cooling, such as strong ability heat transfer, low thermal resistance, and passively transporting heat over large distances with minimal temperature losses, high efficiency and contain no moving parts. Based on the analysis of the existing LHP system, a small disc type of LHP system was designed and developed, and advantages and disadvantages were discussed, and some improving approaches were also proposed.After reviewing the researching status of system, the operation principle of LHP system and operation characteristic were introduced, and LHP's advantages in realizing the heat dissipation of high flux were described. On the basis of analysis, a small-scale plane disc LHP system was designed. Due to the flat plate evaporator had the advantages of perfect thermal contact between evaporator surface and electronics devices surface, it reduced the thermal resistance, enhanced the efficiency of heat transfer and made the isothermal of heated surface more better. The evaporator cover with vapor grooves can not only reduce the vapor flow resistance, but also enhance the strength of the evaporator cover. A structure of fin was designed at bottom of evaporator, on the one hand the intensity of evaporator was increased, and on the other hand the system's cooling capacity was enhanced, and reliability of the mini-disc LHP system was improved.An experimental platform for the designed small disc LHP system was established, and start-up experiment at different heat flux and changing heat flux operation experiment were conducted. The experimental results demonstrated that the side wall effect of evaporator was very serious, and produced bubbles at the evaporator's bottom, which prevented the liquid coming back, and led to failure of the system star-up. But the system showed outstanding thermal behaviors and no dry-out phenomena in the condition of restraining the side wall effect.It is well known that radiation is the major cooling method in space. For simulating space environment, a vacuum radiation was designed, which laid the experimental foundation of simulating cold vacuum source.