Abstract: A flat loop heat pipe (FLHP) with a mixed sintered wick was designed for cooling off high concentration photovoltaic (HCPV) solar cells. The effect of heat load, inclination angle and condenser parameters on the start-up and operating performance of the heat pipe was experimentally studied. It was found that the heat pipe can basically meet the needs of HCPV cooling both in heat load and installation angle requirements. The maximum heat load is up to 320 W (40 W/cm2) when the temperature of the heating surface is under 100 ℃. Relative positions between evaporator and accumulator, evaporator and condenser have important influences on the start-up and operating performance of the heat pipe. The pipe may start more easily when the compensation chamber is under the evaporator. The start-up temperature of low heat load drops when the condenser is placed above the evaporator. The capability of anti-gravity start-up performance of the heat pipe can be improved by reducing the flow rate of cooling water in the condenser.

Key words: high concentration photovoltaic (HCPV), flat loop heat pipe (FLHP), start-up and operating performance with different heat loads, anti-gravity capability, condenser