Study On Air Distribution Of Cold Channel In Data Center Under Different Redundancy Conditions Of Row-level Air Conditioner Under Raised Floor

In recent years,with the rapid development of the Internet field,the thermal density of data centers keeps increasing,and new cooling technologies keep appearing.also changing.At present,Row-level air conditioner under raised floor to form hot and cold channels is a new air conditioning arrangement in data centers.However,there are still some problems such as uneven flow field and temperature field,high temperature in local areas,and cold and heat offset,which eventually lead to high energy consumption in data centers.In this paper,the airflow distribution of row-level refrigeration equipment under raised floor under different operating parameters and different redundancy conditions is studied.A full-scale experimental platform for data center was built,and the characteristics of the flow field and temperature field in hot and cold channel of data center were studied by combining measurement and numerical simulation,and the influencing factors of thermal environment of data center were discussed.This paper firstly studies the design and operation scheme of redundant number of Row-level air conditioner under raised floor.According to Bernoulli’s method and the law of conservation of energy,the flow equation of server room was established,the fake heat load simulation server was researched,designed and manufactured,the hot air distribution was completed in the experiment,and the influence degree of cooling air flow on the server was verified.The server model can be used in the fixed flow model of"black box".By measuring the cold state velocity field under different redundancy conditions,the air supply model and cabinet model were refined to simplify the simulation process of data center and improve the reliability of simulation results.According to the experimental and simulation results,the air distribution effect is evaluated as a whole.The results show that:The operation scheme of four air conditioners without redundancy and three air conditioners with one backup in the experimental platform of the data center has good refrigeration efficiency,air inlet speed of the cabinet and utilization efficiency of cold quantity.Under the scheme of the air conditioner without redundancy,the average air supply temperature of the air conditioner is 21.25℃,the average cold aisle temperature of the data center is 21.4℃,the value of RCI_HIGHis 99.7%.And the energy efficiency of the room is 95.4%;Under the three-use and one-standby operation scheme,the average air supply temperature of the air conditioner is 21.35℃,the average cold aisle temperature of the data center is 21.8℃,the value of RCI_HIGH is 95%,and the energy efficiency of the room is 92.6%;Under the two-use and two-standby operation scheme,the data center has the best security performance and is obviously poor in various indicators.the average air supply temperature of the air conditioner is 22.46℃,the average cold aisle temperature of the data center is 22.9℃,the RCI_HIGH is 88.5%,and the energy efficiency of the room is 87.8%.Under the condition that the air supply volume of the cold passage remains unchanged,increasing the number of backup stations of the end air conditioner will lead to an increase in the non-uniformity of the flow field in the cold passage,and the mixing of cold and hot air will become more serious.To prevent hot air back flow and reduce cold air leakage,the cold channel is kept at a slightly positive pressure by improving measures.The results provide reference for optimizing air distribution design of row air conditioning in data center.