Heat transfer characteristics and LED heat sink application of aluminum plate oscillating heat pipes

An experimental study was carried out to investigate the heat transfer characteristics of aluminum plate oscillating heat pipes (OHPs), which consisted of parallel and square channels. Sizes, different cross-sections and different number of turns were considered. In the experiments, acetone was used as working fluid. The study on the effect of heating mode orientations, cooling conditions and internal structures had been done through visualization observation and thermal performance tests. The flow visualization showed that the aluminum plate OHPs can maintain the heat transfer characteristics of liquid and vapor slug oscillation as well as the conventional tubular OHPs. The flow pattern changed and OHPs’ thermal performance improved with the increase of heating power. The trend in one-way direction circulation of working fluid emerged. The tests showed that the gravity greatly influenced the thermal performance of plate OHPs. Increasing the cooling temperature decreased the thermal resistance of plate OHPs. Increasing the number of turns and area of channel cross-section could improve the heat transport capability of plate OHPs. A heat sink with a plate OHP was developed for LED (Light Emitting Diode) cooling, TDP (Thermal Design Power) of which was 64 W. The result showed that the temperature of the LED significantly decreased while being cooled by natural convection when a plate OHP was used in LED heat sink.