Fundamental Study on Heat Transport Device for Effective Utilization of Unused Heat

Abstract

Recently, many countries have become increasingly interested in unused but possibly useful energy resources. Among these unused resources, the thermal energy produced around us can be used as a potential energy source for heating, cooling and power generation. This thermal energy is relatively stable on the supply side as waste heat in the industrial field. Heat transport devices are one of the important technology for the effective use of unused heat energy. This paper conducts basic research on devices that effectively transport heat below 200ºC. A pulsating heat pipe (PHP) is an excellent heat transport device based on the phase change of a working fluid. Experiments are performed to investigate the thermal performance of a PHP using different working fluids. The PHP consists of 20 parallel channels made of a copper capillary tube with an internal diameter of 1.8 mm. The PHP is filled with deionized water and an aqueous solution of 1-butanol as working fluids, with different filling ratios (FRs) in the range 50-60 vol.%. The 1-butanol aqueous solution is known as a self-rewetting fluid. The experimental results indicate that, in the case of self-rewetting fluid, stable oscillating motion in the PHP arises at the heat load regime lower than that with water. In addition, the effective thermal conductivity of the PHP with the highest concentration of self-rewetting fluid is higher than that with other fluids in the high heat load regime.