Thermal performance study of a closed looped parallel thermosyphon

This paper presents an experimental investigates of the heat transfer performance of looped parallel thermosyphon which consists of two single tube thermosyphon connected by two U tubes of same diameter at the top and bottom ends. For this purpose, the copper tube of 5.78 mm ID used with ethanol, methanol, acetone and water as the working fluid. Heat transfer characteristics are determined experimentally, based on the principle of phase change at different heat flux and different coolant flow rates. An analysis of the experimental data gives that the axial wall temperature of both condenser and evaporator sections decreases with the increase of coolant flow rate. The wall temperature increases with increase of heat flux. The thermal resistance decreases with the increase of both coolant flow rate and thermal load. Overall heat transfer coefficient increases with the increase of both coolant flow rate and heat flux. There is no significant variation of thermal resistance and overall heat transfer coefficient between left and right side thermosyphon.