Effect of working fluid in heat transport characteristics of pulsating heat pipe

Abstract

Recently, electronics thermal management faces problems in the wake of component miniaturization, which has led to higher demands on heat flux dissipation. Pulsating heat pipe (PHP) can be used for cooling devices of electronics because of its potential for removing high heat flux. It is well known that various parameters affect the performance of the pulsating heat pipe. Therefore, many researchers have done research on the improvement of performance. This paper presents heat transfer characteristics of the open-loop pulsating heat pipe (OLPHP) using a self-rewetting fluid as working fluids. The heat transfer characteristic results were obtained by PHP that was made of copper tubes of internal diameters 1.8 mm. On the other hand, flow visualization tests were conducted by the use of a PHP that was made of Pyrex-glass tubes with the dimension of the copper tubes PHP. The experimental results indicate that OLPHP using self-rewetting fluid as working fluids can be observed anomalous liquid film behavior in adiabatic section. Especially, it was found that the liquid film was strong wavy when liquid slug moved to cooling section from heating section. The findings showed that the wavy liquid films and liquid slug behavior contributed to the thermal performance improvement.

Keywords

• pulsating heat pipe
• open loop
• self-rewetting fluid
• thermal resistance
• flow visialization
• liquid film