Heat transfer analysis of a loop heat pipe with biporous wicks

Abstract

Because the evaporative heat transfer of a wick structure in a loop heat pipe is exceedingly sensitive to the internal volume fractions of liquid and vapor phases, the purpose of this study was to investigate the evaporative heat transfer of various biporous wick parameters by controlling the particle size of pore former, the pore former content, and the sintering temperature. A statistical experiment was carried out to analyze the evaporative heat transfer of the biporous wicks and to understand the effects of the parameters more effectively. The statistical analysis indicated a clear and strong relationship between the effect of the pore former content and the evaporative heat transfer of a biporous wick. This is because the pore former content had a great influence on the probability of large interconnecting pores and an extended surface area for liquid film evaporation in a biporous wick. Experimental results also showed that, at the sink temperature of 10°C and the allowable evaporator temperature of 85°C, the evaporative heat transfer coefficient of the biporous wick, which reached a maximum value of 64,000W/m2K, was approximately six times higher than that of the monoporous wick.