Effect of Filling Ratio on Thermal Performance of Closed Loop Pulsating Heat Pipe

Abstract

Pulsating heat pipe is an effective method of heat transfer through passive two phase mechanism. In the present research work, experimental studies were performed on pulsating heat pipe made from copper tube having internal and external diameter of 2 mm and 3 mm respectively. The pulsating heat pipe is charged with acetone as working fluid with different filling ratios of 50%, 60%, 70%, 80%, and 90% of its volume. The evaporator zone is electrically heated by means of mica heater with a range of 10 to 60 Watt and condenser section is cooled by means of cooling water at a constant flow rate. The effect of filling ratio on thermal performance of closed loop pulsating heat pipe was investigated. The result shows that, the thermal resistance decreases rapidly with the increase in the heating input and it is observed that lower value of thermal resistance is obtained at a filling ratio of 60%. Hence Acetone exhibits better performance at a filling ratio of 60%.