Performance test of natural and forced convection on closed loop pulsating heat pipe.

Abstract

With the advancement of science and engineering the need for space restricted cooling devices has increased. Closed loop pulsating heat pipe (CLPHP) is a new promising technology for heat transfer of microelectronics. In it by simple mechanism heat is transferred effectively and efficiently. The combination of processes like bubble nucleation, collapse, formation of vapor plugs and slugs, agglomeration, dynamic instabilities and temperature/pressure perturbation, etc. leads to exceptional heat transfer capability of the heat pipe. The aim of this research paper is to better understand the operation of PHP through experimental investigations and obtain comparative results for different parameters. A series of experiments are conducted on a closed loop PHP (CLPHP) with 6 loops made of copper capillary tube of 2 mm inner diameter. The heat pipe structure is using normal, CLPHP. Ethanol, DI Water and Ethylene Glycol is taken as the working fluid. The operating characteristics are studied for the variation of heat input, filling ratio (FR) and orientation. The single filling ratios are 25%, 50%, 75% based on its total volume. Natural Convection and Forced Convection are measure this. This paper attempts to demonstrate the effect of variation of different parameters on the same structure as well as the variation of thermal performance depending on the presence of wire insert and fins on different structures.