Numerical Simulation And Optimization Of Thermal Environment In Data Center

Over the past decade,high-density data centers around the world have begun to expand rapidly due to the increasing demand for cloud computing.Data center energy has attracted the attention of many at home and abroad,air distribution and management and typical underfloor air supply is closely related to the thermal performance of a data center.To create a good thermal environment can improve data center cooling effect and reduce the system energy consumption,therefore,the domestic and foreign experts put forward a lot of structure under different operating conditions and methods to improve the thermal performance of a data center.For the data center using underfloor air supply,the air distribution in the static pressure layer under the floor affects the operation of the whole data center,so it is very important to improve the air distribution in the static pressure layer under the floor.There are many factors that affect the air distribution in the static pressure layer under the plate.At present,the research focus at home and abroad is mainly on the closed condition of the cold / hot channel and the optimization of the air duct structure under the floor.In this paper,the fundamental goal of this paper is to improve the air distribution and cooling effect of the data center,and take the sub module of a data center in Nanjing with two rows of cabinets as the research object.Because of the particularity of the cabinet layout of the data center,there are two cases: the cold channel is closed and the cold channel is not closed.First of all,the simulation and actual measurement of the two rows of cabinets of the sub module are compared and analyzed.There is a certain deviation between them,but the overall trend of the temperature field image measured by numerical simulation method is consistent with the measured results,which can be used for reference in the optimization design.In view of the problems existing in the internal air distribution of the data center in the cold channel closed underfloor air supply scheme,the measures to change the internal structure of the data center,including the floor perforation rate and the setting of return air deflector,are proposed.By comparing and analyzing the distribution of velocity field and temperature field,it is concluded that the best perforation rate of the floor is 30%,and the optimal parameter of return air deflector is d = 1400 mm.This paper also analyzes the thermal environment of the data center under three transient working conditions of server shutdown,air conditioning cold source failure and air conditioning fan failure through simulation,obtains the emergency measures for the thermal environment and the server under different working conditions,and gives the corresponding emergency treatment scheme.When the server is partially shut down,the back of the air conditioning unit is prone to produce local hot spots.The air conditioning load should be adjusted in time and the server without closed cold channel should be closed first to reduce energy consumption.When part of the cold source of the air conditioning fails,hot spots will be generated locally in the server.When the cold source is reduced to 70% of the original cooling capacity,emergency measures can be taken within 10 min to ensure the safety of the data center.If the data center adopts a closed structure of cold channel,the emergency processing time can be increased appropriately.When the air conditioning partially fails,large areas with high air temperature have been generated due to the reduction of air supply volume,which has a great impact on the server.Emergency treatment should be done to the data center within 5min.