Effect of Structural Shape of Heat Pipe Inside Surface on Performance and Heat Transfer Characteristics


The Heat Pipe and Thermosyphon have been designed, fabricated and tested to investigate the heat that transfers by two-phase natural convection. Different affecting parameters on temperature distribution and heat transfer coefficient are experimentally investigated including the power input (300 to 700W), the filling ratio of the working fluid(water), represented by a volumetric ratio with respect to evaporator volume (15%,50%&85%). Two pipes with different inside surface shape were tasted. All tests were fulfilled at a pressure, a proximity, near atmospheric pressure (1 bar) during steady state conditions. The experimental results showed that the best filling ratio is (50%) and the heat transfer coefficient in heat pipe is found to be maximal compared with The heat transfer coefficient in thermosyphon. The mean temperature difference between the evaporator and condenser at steady state in heat pipe is found to be minimal compared with thermosyphon. A comparison is fulfilled between the current study results and the empirical, theoretical correlations by other researchers showed that the experimental results were in good agreement with those correlations