Heat Pipe Thermal Performance Analysis by Using Different Working Fluids

Abstract

This study investigated the thermal performance of the heat pipe and conducted on the effects of working fluids with wick and vertical position. The experiments were conducted using a copper heat pipe with ) a 20.8( mm inner diameter, and the length of the evaporator, the condenser, and the adiabatic regions were 300 mm, 350 mm, and 300 mm, respectively. The working fluids selected were water, Methanol, Ethanol, and different binary mixtures (50: 50) %, (30: 70) %, and (70: 30) % mixing ratios. The filling ratio for all working fluids remained constant with the value of 50% of the evaporator volume, and the heat input values were 20, 30, 40, and 50 watts. The results show that the heat pipe charged with Methanol has a thermal resistance of (0.7666 oC/W) which is the lowest value of thermal resistance. The lowest thermal resistance of using mixtures is (0.7466 oC/W) for (70 % methanol: 30% ethanol). Both are achieved at 50 W heat input. Also, the highest value of heat transfer coefficient when using water as a working fluid is (519.1073 W/m2. oC), and for using a mixture (70 % water: 30% methanol) is (805.89 W/m2. oC). Both are achieved at 50 W heat input.