Experimental study of a pulsating heat pipe using nanofluid as a working fluid

In this study, as a passive energy conversion/transport device, the performance of a pulsating heat pipe (PHP) using nanofluid is experimentally investigated. It has been suggested that nanofluids could improve the performance of wickless self-sustaining heat pipes. The transparent fused quartz tubing with 3 mm diameter is used to visualize the oscillations within the adiabatic section of the pipe. For the evaporator and condenser sections, copper tubing is used. A heater with a rating ranging from 20 to 120 Watts is used to provide the energy to the device along with some insulation to reduce the heat being lost to the environment. Two pressure transducers are used located in the evaporator and condenser section in order to record the pressure fluctuations. The operating temperature of the PHP varies from 30-100°C, with the power rates of 61 W and 119 W. The fill ratio of 30%, 50%, and 70% were tested. Several thermocouples along the pipe are used to measure the surface and fluid temperatures in order to calculate the heat transfer performance in the evaporator and condenser sections as well as the overall PHP performance.