The Experimental Study On Re-wetting Fluid Of The Pulsating Heat Pipe For Transfer Performance Influence

With the development of science and technology in recent years,the higher level of electronic components integration leads to the concentration of the heat release.The life of components greatly depends on the heat transfer,which is very important to the equipment reliability.So it is urgently to address the effective heat dissipation.The re-wetting fluid as working fluid in pulsating heat pipe (PHP) is suited for the micro-electronics cooling of high heat flux.This kind of working medium is different most liquids which surface tension decreased with the increase of temperature that the phenomenon called "Marangoni effecf".While the re-wetting fluid surface tension do as other fluid at first, then when the temperature rises to a certain value, the surface tension will increase with temperature rising.The phenomenon called inverse marangoni effect, which makes easier to backflow from the evaporate side for the liquid,causing the re-wetting phenomenon.In this paper, experimental study on re-wetting fluid as working medium which contains butanol,pentanol and heptanol solution of four kinds of concentration(0.05wt%,0.10wt%,0.15wt%,0.20wt%) impact on heat transfer of pulsating heat pipe in the horizontal and vertical conditions. Which the filling ration is 50%.It measures the re-wetting fluid surface tension with temperature changes. The result founds that surface tension with temperature change trend is different with various concentrations or kinds and 0.15wt%,0.20wt% butanol and pentanol solution and all heptanol solution have re-wetting characteristics.The experimental results with stable pulsing indicated that:in horizontal orientation,0.10wt% butanol solution in higher power and 0.15wt%,0.20wt% butanol and pentanol solution in lower power exhibited a little better thermal performance and promoted the start.In terms of alcohol solution, the higher surface tension of solution is better and 0.15wt%,0.20wt% butanol and pentanol solution can promote the start.While in vertical orientation, the enhancement effect was not obvious.