Effect of micro encapsulated phase change material on the anti-dry-out ability of pulsating heat pipes

Abstract

Anti-dry-out ability is one of the key performance indexes of the Pulsating Heat Pipe (PHP). In order to improve the anti-dry-out ability, the Micro Encapsulated Phase Change Material (MEPCM) suspension is added to the closed PHP. The Computational Fluid Dynamics (CFD) technique is used to establish the numerical model and analyze the anti-dry-out ability of the PHPs with water and with MEPCM suspension as the working fluids respectively. By changing the phase change temperature range of the MEPCM suspension, the effect of the MEPCM suspension with different phase change temperatures on the anti-dry-out ability, start-up performance and heat transfer performance of the PHP is further studied. The results show that the MEPCM suspension within a certain phase change temperature range can effectively improve the anti-dry-out ability of the PHP. The appropriate phase change temperature range should be selected around the evaporation section temperature when the PHP transforms from the circulating flow state to the dry-out state. After the MEPCM suspension is used as the working fluid, the start-up time and thermal resistance of the PHP are also increased, but the changes are not significant.