Experimental Study Of Closed-cycle Spray Cooling In Non-boiling Regime

The rapid development of semiconductor industry is accompanied by the rapid increase of heat flux,and high surface temperature of electronic components has become the biggest obstacle to the development of the industry.Therefore,it is urgent to use efficient and energy-saving heat dissipation to break down the barrier.Spray cooling has attracted more and more scholars' attention because of its advantages such as higher exchange efficiency,smaller amount of working fluid,uniform temperature on heating surface and so on.Based on the description above,the closed-cycle spray cooling experiment has been designed in this paper,and the factors that affect the spray cooling heat transfer were studied as well,besides,the corresponding non-dimensional experimental correlation has been also obtained.The closed-cycle spray cooling experiment has been designed,which contains spray part,heating part and measurement part.The spray part contains a nozzle which could adjust spray height and a visualized spray chamber that heat transfer of spray cooling could be observed.The heating part is composed of a processed copper which is wrapped by mineral wools whose thermal conductivity is very low,so that the internal heat conduction of copper with excellent thermal conductivity can be similar to one dimension heat conduction process.The measurement part is mainly used to record the temperature gradient inside the heat source and temperature of liquid.According to the Fourier's law of heat conduction,the temperature and heat flux of the heat source surface could be determined.At the same time,the temperature of the cooling fluid before flowing into the nozzle is measured and its heat transfer coefficient could also be calculated.The experiment of spray cooling has been carried out by using control variable method.The variation curves between the temperature,heat flux and heat transfer coefficient of the simulated heat source under different heating power were obtained.And the variation curves between surface temperature of heat source,heat flux and heat transfer coefficient with heating power,liquid mass flow rate,nozzle height and nozzle pressure were obtained as well.Moreover,the influence of parameters mentioned above on spray cooling heat transfer performance has been analyzed in this paper.On the basis of a large amount of data,the parameters that affect the heat transfer performance of the spray cooling were dimensionless,and the software was used to obtain the non-dimensional experimental correlation of Nu number,Re number,We number and ?,and taking a group of data into experimental correlation,resulting shows that the relative error of the Nu number obtained by the correlation is less than 15% in the experimental Nu number.Therefore,the experimental correlation has a certain reference valueIn this paper,the parameters affecting the heat transfer performance of spray cooling are preliminarily studied and non-dimensional experimental correlation is obtained,which lays a foundation for further study on spray cooling,on the basis of experimental study of spray cooling.