Experimental and theoretical analysis of a closed loop two-phase thermosiphon under various states for latent heat storage

Abstract

A closed loop two-phase thermosiphon is supposed as an effective heat transfer unit for improving the heat transfer in the latent heat storage devices, which has a simple structure and natural circulation. An experimental study and theoretical analysis were conducted to evaluate the heat transfer performance. The effects of height difference, filling ratio, and condenser temperature were investigated relative to changes in pressure and evaporator temperature. The results indicate that heat transfer performance is improved with an increase in height difference and a decrease in condenser temperature. Meanwhile, a closed loop thermosiphon with medium filling ratios of 44.5% and 49.9% shows the best heat transfer performance. Furthermore, the subcooling phenomenon occurs at large filling ratios of 68.1% and 67.1% and the superheating phenomenon occurs at small filling ratios of 27.3% and 31.1%.