Research On Waste Heat Recovery Of Single Cabinet In Data Center

With the rapid development of information technology such as artificial intelligence and big data in the current era,data centers as their indispensable infrastructure are also growing at a high speed.As the power consumption of the data centers increases year by year,the waste heat discharged from the data centers also increases.The waste heat of direct discharge will accumulate locally,which will affect the air conditioning energy efficiency and increase energy consumption in the data center.The significance of recycling these waste heat of data centers is not only to reduce the energy consumption of air conditioning,but also to reuse it in response to "China’s’ two-carbon policy"and make some contributions to the carbon neutralization of society.Heat pipes have excellent thermal conductivity.Gravity heat pipes can transfer heat by gravity without external drive,so it will not increase the energy consumption of the data centers when recovering waste heat.In this paper a waste heat recovery system with gravity heat pipes is designed for the single cabinet of data centers,and the experimental and simulation research is carried out.Firstly,a waste heat recovery system of single cabinet is designed.According to the characteristics of heat pipe,the structure,size and material of the single cabinet box and the waste heat recovery box are designed.The two boxes are connected through the heat pipe.Heat pipes are used to conduct the heat of the cabine,which will heat the air in the upper waste heat recovery box in order to recovery the waste heat of the cabinet.The 600W cast aluminum heating plate is used as the system heat source in the single cabinet.In order to increase the heat transfer area between the heat pipe and the air in the cabinet,copper fins are also added on the surface of the heat pipe.Secondly,the waste heat recovery experiments are carried out.Three independent variables of different pipe diameters(8mm,10mm,12mm),different liquid filling rates(10%,20%,30%)and different working medium(methanol,ethanol,water)are set up in the experiments,which are 27 working conditions.According to the experimental data,the equivalent thermal conductivity of heat pipes of different working conditions is calculated,and the optimal heat transfer performance is the heat pipe with liquid filling rate of 30%,tube working medium of methanol,diameter of 8mm.Its equivalent thermal conductivity is 3674.3W/(m·K).Thirdly,mathematical modeling and grid division were carried out for the waste heat recovery system,and then equivalent thermal conductivity of heat pipe with optimal heat transfer performance was brought into Fluent for simulated calculation,and the simulation data was compared with the experimental data to verify the accuracy of the simulation.Finally,according to the established mathematical model,two,three and four heat pipes are simulated to participate in waste heat recovery.A total of 10 heat pipe layout schemes including a single heat pipe system are simulated,and the simulation results are analyzed and compared,and the optimal layout of different number of heat pipes in the waste heat recovery system was obtained.In the waste heat recovery box,the best arrangement of two heat pipes is B,the temperature rise is 21.1%faster than that of a single one;the best arrangement of three heat pipes is D,the temperature rise is 44.1%faster than that of a single one;the best arrangement of four heat pipes is G,the temperature rise is 52.5%faster than that of a single heat pipe.