Effect of Annealing Pretreatment on Performance of Pulsating Heat Pipe

Abstract

Experimental work was carried out to clarify the thermal performance of a pulsating heat pipe (PHP) with the tube body was pretreated by a muffle furnace at 500℃for 5 hours. It is found that the annealing of the pipe body improves the wettability of the working fluid on the tube wall, thus enhance heat transfer between the tube wall and working fluid due to the increase in the liquid film area. Experimental results show that after annealing, the PHP starts to accelerate. Comparing to the original PHP, the starting time of the surface annealed PHP can be shortened by 78s at 30W while the minimum starting power is reduced from 30W to 16Wand the starting temperature can be reduced by about 10°C.