Heat Transport Characteristics of an Oscillating Heat Pipe with Al2O3 Nano-fluid

Experimental investigation was conducted to exam the heat transport characteristics of an oscillating heat pipe (OHP) by using Al2O3 nano-fluid and pure water as working fluid. The test pipe consists of a copper tube with external diameter of 2.5 mm, inner diameter of 1.3 mm, and is welded into a four-turn oscillating heat pipe. The heat transport characteristics of the OHP have been studied under different liquid filling rates, different heat loads and different inclination angles(0 degrees and 90 degrees) when using water as working fluid. The results show that when heat load increases to a certain magnitude, the thermal resistance almost has little difference regardless of vertical bottom heat mode or horizontal heat mode. Comparing with pure water, Al2O3 nano-fluid as working fluid can enhance its heat-transport capability. When using vertical bottom heat mode and horizontal heat mode, the best concentration of Al2O3 nano-fluid is 0.5wt% and 0.1wt%, respectively.