Heat Transfer Performance Of Oscillating Heat Pipe With Nano-fluid And Self-rewetting Fluid As Working Fluid

Now human being is pursuing higher level of portable and integrated equipment,then over-temperature phenomena of all kinds of products or equipment occurs frequently,and the over-temperature phenomena are influencing our normal production and lives.Oscillating heat pipe can improve the heat dissipation of equipment effectively.Especially oscillating heat pipe has the advantages on compact structure,bend easily and better heat transfer performance,it contributes to improve the heat dissipation to adapt to high heat flux.So we need more experimental and theoretical research about oscillating heat pipe urgently.In this paper,an experiment system was built which aim to discuss the heat transfer performance of stainless steel oscillating heat pipe filled with distilled water,Al2O3-H₂ O nano-fluid or 1-Pentanol.The experiment observed the temperature oscillation characteristic,starting characteristic and heat transfer performance of oscillating heat pipe with different inclination?0°?45°?60°?90°?and heating power?40W?60W?80W?100W?120W?.In addition to this,the experiment used different working fluid with different mass concentration.Specific conclusions are as follows:1.When water or 1-Pentanol as working fluid,oscillating heat pipe is difficult to start-up in the horizontal direction.In other inclination angles,lower heating power,the temperature oscillation frequency is slower,then oscillation became faster when the heating power increasing.And if the heating power arrives the limit value,increasing the heating power won't accelerate the oscillation.2.The start-up characteristics of oscillating heat pipe were affected by various factors such as inclination angle,heating power,working fluid and so on.Generally,the starting time was shortened with the increasing of heating power,and the optimum starting angle of each working fluid was different.Higher heating power,the effect of inclination angle on the start-up characteristics was weakened,basically only affected by the heating power.3.The heat transfer resistance is mainly affected by the heating power.In most cases,the heat transfer resistance had a negative correlation with the heating power.Oscillating heat pipe exists a critical angle.The heat transfer resistance affected by the gravity generated from inclination angle when the angle below the critical valve in lower heating power,and it affected by heating power only when the angle above the limit valve.In addition to that,a higher heating power was existed which make the heat transfer resistance wasn't affected by inclination angle.4.Alumina-water nano-fluid allowed oscillating heat pipe to start-up and stable operation in the horizontal direction,and in the other inclinations,the variation on the temperature oscillation of Alumina-water nano-fluid is very similar to that of distilled water,just a slight increase in temperature.And nano-fluid can improve the start-up characteristic when the heating power above 60 W,which showed the shorten start-up time.Moreover,the appropriate concentration of nano-fluid can improve the start-up characteristics,reduce the heat transfer resistance and increase the heat transfer power of oscillating heat pipe.The best mass concentration of this experiment was 3.0%.5.The oscillation temperature of 1-Pentanol was higher than other working fluid,because the boiling point is lower and the specific heat is higher.Although the oscillating heat pipe with 1-Pentanol couldn't start in the horizontal direction,the appropriate mass concentration of 1-Pentanol can reduce the heat transfer heat resistance.The 0.3% and 0.5% 1-Pentanol had better consequence in the paper.