Heat Transfer Characteristics of Self-Rewetting Fluid and its Application in Heat Pipe

Abstract

Self-rewetting fluids (SRWFs) are non-azeotropic solutions enjoy a particular surface tension behavior — an increase in the surface tension with increasing temperature. Due to the unique property, the SRWF can spontaneously wet hotter region and enhance heat transfer. The interesting behavior makes the SRWF become the research hotspot in phase change heat transfer research field. To clarify the heat transfer characteristics of SRWF, a series of boiling experiments have been carried out by employing dilute heptanol aqueous solution as SRWF. It is found out that, the bubble size of the SRWF is much smaller than that of pure water, and the critical heat flux of SRWF is much higher than that of water, which is beneficial for application in heat pipes. To find out the heat transfer performance of SRWF in heat pipes, experimental studies are performed on oscillating heat pipe (OHP) consisting of 4 meandering turns, with heat transfer length (L) of 150 mm and inner diameter (Di) of 1.3 mm. Compared with the water, the SRWF exhibits much better thermal performance, which indicates that SRWF is a promising and useful working liquid for the application in high efficient cooling devices with micro structure.