Experimental Study of a Pulsating Heat Pipe with Combined Circular and Square Section Channels

Pulsating heat pipes (PHPs) have already found some applications in cooling power / micro electronic components. It was investigated whether a flat plate closed loop pulsating heat pipe can be applied for power electronics cooling. The measured thermal resistances were strongly influenced by the tilt angle, fill rate and working fluid. The best PHP performance was observed with fill rates around 30% in vertical orientation. The maximum heat throughput was 1400 W using water as tested fluid. Methanol results were very close to water performances, even the device was able to work against gravity. Consequently, it was found that the typical PHP concept could be applied with some limitations for power electronics applications with water or methanol as working fluid.