Thermal Performance of a Top Heat Mode Closed-Loop Oscillating Heat Pipe with a Check Valve (THMCLOHP/CV)
The aim of this research is to investigate the heat transfer characteristics of a top heat mode closed-looped oscillating heat pipe with check valves (THMCLOHP/CV). Ethanol is used as a working fluid with filling ratios of 30, 50, and 80% of the total volume of the tube. The THMCLOHP/CV is made of a copper tube with an inside diameter of 2.03 mm. The angle of inclination is 90 oC from the horizontal axis with 40 turns, two check valves, and an evaporator length of 50, 100, and 150 mm. The operating temperatures are 44 and 55 oC. It is found that the thermal resistance decreases significantly as the working temperature is increased. Thus, the evaporator length affects the thermal resistance of the THMCLOHP/CV. The presence of the THMCLOHP/CV is clearly demonstrated to contribute to thermal performance improvement.