Study On Unitary A Data Cabinet Cooling System

Nowadays,information technology has enjoyed unprecedented development.The Internetbased production and lifestyle have formed a huge information industry cluster and has shown an overwhelming development trend.As an essential infrastructure for the Internet industry,the data center has grown in both size and capacity.Data centers,especially small and mediumsized data centers,have become a worldwide problem due to high energy consumption and low efficiency of energy use.The PUE of data centers in China is generally greater than 2.2,while the PUE of small and medium-sized data centers in developed countries such as the United States is generally greater than 1.7.On the one hand,due to the long route of cold air flow,the traditional data center air conditioning system is in irrational air distribution,resulting in low energy efficiency.On the other hand,in the hot summer and warm winter zone,because of the high temperature throughout the year and the lack of natural cold resources,the use of dual cooling source chiller in data centers has no advantage over air cooling direct expansion units.On this basis,starting with shortening the airflow distance of the data center air conditioning system and rationally selecting the form of cold and heat sources,this paper studies a unitized data cabinet cooling system for small and medium-sized data centers in hot summer and warm winter zone,aiming to improve the energy use efficiency of small and medium-sized data centers in such area.This paper studys the equipment composition,power trends,and thermal and humid environment requirements of data communication equipment in data centers.A 42 U rack-based unit data cabinet cooling system test bench has been built with the supply air temperature of 21 c,return air temperature of 32℃,and heating power of 4.5kW as design parameters to carry out detailed design calculation of the air distribution.The boundary conditions and discrete methods for CFD numerical simulation are introduced in detail.CFD numerical simulation technology is employed to study and analyze the flow field of cooling system,and the thermodynamic tool entransy is used for quantitative analysis of the system air distribution.The detailed design and calculation of the cold and heat source system of the experimental bench were carried out,including refrigeration cycle design,selection of compressor,heat exchanger design,and throttling device design and selection,etc.CFD simulation results show that the uniformity of slit air supply has nothing to do with the location of data communication equipment.The experimental test results show that the supply air temperature of the data communication equipment in the cooling device is between 20.4~21.5℃,and the return air temperature is between 30.6~32.9℃,which can well meet the thermal environment requirements of data communication equipment.In addition,although the key energy consumption indicators of the cooling system vary according to the heating power of the data communication equipment in the cabinet,they can meet the first-level energy efficiency requirements of China's national standards,and have greater energy saving potential than existing data center cooling systems.