Numerical Simulation And Experimental Research On Thermal Performance Of Data Center

As one of the most important modern infrastructures,data center is the hardware basis of cloud computing,artificial intelligence and other information services.Its reliability and efficiency have been the focus of attention of the industry and academia,especially the research on the cooling system of data centers.According to the United Nations Environment Programme,the information services consume about 7 percent of energy in the world,and the cooling systems consume 45%energy of data center.The thermal performance of data center is closely related to its reliability and efficiency,and it also has more energy saving potential.Researches on that potential would be able to help provide more reliability margin for data center and achieve better operating stability and economy.The thermal performance of data center is its performance in the high density environment.In this paper,the air velocity and temperature are used to reflect the thermal performance of data center.By means of numerical simulation and experimental investigation,the effects of several different geometric structures and operating parameters on the thermal performance of data center are respectively discussed.In this study,16 models with the plenum height of 300/400/500/600mm and perforation rate of 20/30/40/50%were simulated on the basis of underfloor air distribution system data center with cold air containment system.Commercial CFD software Airpak was used for the numerical simulation.The results show that increasing the plenum height and decreasing the perforation rate can improve the airflow and temperature uniformity in the data center in different ways and improve the thermal performance as well.On the other hand,considering the space utilization and fan power,this method should be reasonably applied to optimize the thermal performance of the data center.This study selected a financial data center in the hot-summer and cold-winter zone to test different scenarios.The basic models with supply air temperature of 16/18/20? and supply air volume of 2.9/3.5/4.4 m3/s are tested.The air outlet velocity of perforated tiles and the temperature of the inlet and outlet airflow of the racks at the height of 1.3 m were measured.The results show that reducing the air supply temperature has a better improvement on the tile's outlet airflow and reducing hot spots near the CRACs.However,the remote tile's outlet airflow and rack temperatures are more sensitive to the air volume,which complement each other.In order to improve the thermal performance of the data center,two kinds of plenum containment systems are proposed to optimize the performance of airflow in the plenum.In this paper,Airpak was used to simulate 4 plenum containment models with local baffles near the CRAC,which significantly improved the thermal performance of the proximal racks.In the experimental investigation,the thermal performance of the inclined partitions of 5 different operating conditions was investigated,and the airflow and temperature uniformity along the cold aisle are also improved to some extent.