Manufacturing of complex bi-porous wick and applying to a loop heat pipe

The purpose of this paper is to develop an innovative complex capillary structure and to enhance the heat transfer capacity of a loop heat pipe´s evaporator. The wick had two layers porous structures. The outer layer was biporous structure, which formed micro-vapor channels. The inner layer was the monoporous wick, which provided high capillary force and increased the strength of the whole wick. Experimental results showed: at 85°Cas a tolerant temperature of evaporator wall, the maximum heat load of the complex wick reached 700W (36W/cm in heat flux). The heat transfer coefficient of evaporator was 116 kW/m, and the thermal resistance of the system was 0.08°C/W. Comparing with the performance of the monoporous wick, the biporous wick increased the maximum heat load in 67% (420W of monoporous wick) and lowered the total thermal resistance in about 100% (0.17°C/W of monoporous wick).