Experimental Study On Heat Transfer Performance And Correlations Of Pulsating Heat Pipe

Pulsating heat pipe (PHP) is a new style of heat pipes, which has excellent heat transfer performance and simple structure. It has been successfully applied on cooling of micro electronics, which also has a potential in thermal control for space and other terrestrial applications.Highlighting major progress and milestones achieved in the PHPs, this paper continued to investigate the heat transfer performance of PHPs through experiments. Two sets of PHPs have been fabricated and tested. Both specimens consisted of a total of 40 serpentine copper tubes with the inner/ outer diameter of 1 mm /2 mm and 2 mm/3 mm respectively. Ethanol, water, and R123 were employed as working fluids. The filling ratio and inclination angles could be adjusted. Both sets could be switched into open loop and closed loop by controlling the valve. Here are two major aspects of research work: Firstly, experiments have been performed on the PHPs to investigate the thermal performance and its influences at normal states, such as the effects of inner diameters, heat loads, thermal properties of the working fluid and its filling ratios, loop types and inclination angles on PHPs. Moreover, some experimental correlations were established to predict the heat flux of PHPs at normal states.Secondly, operational characteristics of PHPs at critical states were investigated and compared with that of PHPs at the normal ststes. Some correlations were established to predict the critical heat fluxes of PHPs.