Experimental Investigations for Start up and Maximum Heat Load of Closed Loop Pulsating Heat Pipe

Startup heat load, maximum heat load and optimum fill ratio of Pulsating Heat Pipe (PHP) of 16 turn, 1 mm ID, 2 mm OD and 9.6 m total length are found out experimentally for water and ethanol as working fluids. PHP is operated in vertical bottom heat mode. Evaporator and condenser temperatures are maintained at 100 °C and 28 °C respectively. Temperature fluctuations of adiabatic section at startup and maximum heat loads are reported. Experimental results indicate that, startup heat load is independent of fill ratio, but maximum heat load depends on fill ratio. Optimum fill ratio for maximum heat load depends on working fluid for a given PHP and operating temperatures.