Heat transfer rate of close-loop oscillating heat pipe with check valve using NiO as working fluid

Abstract

This Research studied the heat transfer characteristics of the closed-looped oscillating heat pipe with check valves (CLOHP/CV), examining effectiveness, considering the effects of heat transfer rates and studying the internal pressure of the (CLOHP/CV). That install the fins and do not install the fins by using a heat pipe made of copper pipe, inner diameter of 5 mm, with two check valves. The evaporator section, condenser section and adiabatic section lengths were 20, 20 and 10 cm, respectively. Heat pipe had two check valves and 24 turns. Nickel oxide (NiO) was used at a working filling ratio and concentration 50% by volume and 0.14 g of the tube respectively. Hot air was at 60 70 and 80 degree Celsius, at a wind speed of 1.0 m/s. The fins were copper with radian size of 0.5 cm, and thickness of the fins was 1 mm. From the experiment, it was found that the heat flux of the CLOHP/CV heat exchanger set with the fins was the highest at 80 degree Celsius, with a value of 9, 743.11 W/m2. The effectiveness is 0.3 and the internal pressure is 123.59 kPa.