Experimental and theoretical analysis of the thermal performance of aluminum and polytetrafluoroethylene wicks.

The wick is the most crucial element of loop heat pipes (LHPs). At present, wick materials are limited to copper, stainless steel, nickel, and so on. Little research has been carried out on new wick materials. This paper reports the fabrication of aluminum wicks and performance tests of LHPs using aluminum wicks. Experimental data show that this LHP is capable of transferring a heating load of 130 W, while the thermal resistance is only approximately 0.04 K/W. Then, the experimental data were compared with those for LHPs using a polytetrafluoroethylene (PTFE) wick. Based on the SIMPLE algorithm, a 2-D unsteady-state heat transfer model and a 2-D steady-state flow model of the wicks are established to analyze the effects of wick material, pore size and porosity on the performance of the evaporator. The experimental data for LHPs with PTFE wicks are from the literature. The simulation results show that a PTFE wick can effectively reduce heat leakage, while an aluminum wick has better temperature uniformity and a lower casing temperature. However, wicks with large porosities have lower flow resistance. [ABSTRACT FROM AUTHOR]