Analysis of thermosiphon working with eco-friendly refrigerant under various fill ratios

Abstract

Passive cooling techniques which are employed to prevent overheating and ensure peak performance of devices have gained attention in the recent years. The challenge to identify eco-friendly and efficient heat transfer fluids have forced researchers to look beyond the conventionally used fluids for operations involving heat transfer. The work focuses on experimentation of a thermosiphon charged with a low Global Warming Potential (GWP), eco-friendly refrigerant R600a which could be used for heat transfer applications. The range of input from heating element was increased in steps from 20 W to 140 W while the thermosiphon was oriented vertically upright. Experimentation was performed to determine the best fill ratio which would positively influence the performance of the thermosiphon heat pipe. The results suggest that resistance of the device was minimum when charged with 50% fill ratio of working fluid. When the best fill ratio was employed in the thermosiphon, a maximum reduction in resistance of 9% and 13% were obtained when compared to 60% and 70% fill. The calculated values of evaporator and condenser heat transfer coefficients were encouraging.