Heat transport characteristics of capillary pumped loop with plate-type evaporator

A tube-type evaporator requires capillary force in order to lift liquid refrigerant to circumference direction under a gravity field, which reduces thermal performance. Therefore, a capillary pumped loop with a plate-type evaporator was newly manufactured to improve the performance and reduce the thickness of the evaporator. The plate-type evaporator is flat disk shaped with an effective diameter of 46 mm. The wick with equivalent diameter of 5 mum and 2 mm thickness is embedded in it. The vapor line and liquid line are both 750 mm in length, and the condenser is 1000 mm in length. The condenser is soaked in a water bath set to a constant temperature by the refrigerator. The total heat transport length is 2500 mm. Using HFC134a as the working fluid, the heat transport characteristics were experimentally investigated by changing the heat load to the evaporator from 8 to 24.5 W. The plate-type evaporator achieved a higher evaporative heat transfer coefficient with higher heat flux into the evaporator than the tube-type evaporator.