Research On Optimization Of Airflow Organization And Thermal Safety Performance In Data Center

In recent years,energy consumption of data centers has increased rapidly with the development in China.Optimizing the airflow organization of the data center room can help reduce the energy consumption of the data center.In order to make the data center operate efficiently and safely and improve the energy utilization rate of the cooling system,based on CFD numerical simulation,the airflow organization and related influence factors in the data center room was studied in this thesis.The factors that affect the airflow organization of the data center mainly include the location of air conditioners,the air duct hood,the height of the raised floor,the opening rate of the floor grille,and the forms of different closed aisles.Taking the data center with a raised floor height of 0.6m and a floor grille opening rate of 50%as example,numerical simulation studies were carried out.The influence of air-conditioning position,air duct hood,height of raised floor,opening rate of floor grille,and different forms of closed aisles on air distribution was analyzed.The conclusions are as follows:(1)The optimal thermal environment is obtained when the air conditioner is arranged on both sides.The distance between the air conditioner and the nearest cabinet is 1.2m without air duct hood.The height of the raised floor is 0.6m.The opening rate of the floor grille is 35%.The cold and hot aisles are closed.When the hot and cold aisles are open,the RCI increases by 9.2%,and the CROI decreases by 18.9%compared with the air conditioner at one side with air duct hood.When the cold aisle is closed,the arrangement of the air conditioner,on both side with a distance to the nearest cabinet of 1.2m without air duct hood,the maximum inlet temperature of the cabinet is reduced by 2.9℃.On this basis,the height of the raised floor is 0.6m and the opening rate of the floor grille is 35%,which results in the best thermal environment.The maximum inlet temperature variance value is reduced by 87.9%.On the basis of the above,different closed aisle forms are arranged,and the optimal closed aisle layout is that both the cold aisle and the hot aisle are closed.Compared with the closed hot aisle,the maximum inlet temperature variance of the cabinet is reduced by 96.6%.The thermal environment index of the computer room is reduced by 73.8%compared to the top form of the closed cold aisle.(2)In order to evaluate the thermal environment of the cabinet,this paper proposes an overheating index to express the number of overheated IT equipment in the cabinet and quantifies the degree of overheating in the equipment room.It is proposed to use the variance to evaluate the maximum inlet temperature of the cabinet and the uniformity of the net flow of the floor grille,which effectively expresses the thermal environment of the whole cabinet in the computer room.A thermal environment index of the computer room is present to evaluate the temperature gradient of the air inlet and outlet sections of the cabinet,which determines the probability of local hot spots in the data center.(3)It is effective to reduce the overheating phenomenon to transfer the IT equipment in the cabinet near the air conditioner to the other cabinets.Moreover,the power of the IT equipment could be increased to reduce the number of IT equipment in the cabinet to reduce the overheating.For the closed cold aisle,the maximum inlet temperature variance of the cabinet is reduced by a maximum of 83.8%after improvement,and the thermal environment index of the equipment room is reduced by a maximum of 8.8%.