Study On The Performance Of Data Center Evaporative Cooling Composite Air Conditioning System

With the rapid development of data center,the energy consumption of data center has been widely concerned by countries all over the world.The IDC(Internet Data Center)computer room electronic equipment generates a large amount of heat,and the annual cooling energy consumption is high.Based on the comprehensive analysis of the load characteristics,existing problems and energy-saving technology of the computer room,an evaporative cooling composite air conditioning system is proposed.This system combines evaporative cooling technology,heat pipe heat exchange technology and vapor compression refrigeration technology to achieve efficient preparation,distribution and on-demand supply of cooling.This paper takes this system as the research object and carries out the following researches:First,according to the operating characteristics of the evaporative cooling composite air-conditioning system and the problems of the traditional evaporative condenser,the structure of the conventional evaporative condenser has improved,a new type evaporative condensation that suitable for this system are proposed.Through design calculations,the structural parameters of the system components are determined,the mathematical model of the system is constructed,and the accuracy of the system mathematical model was verified by experiments.Next,through the mathematical model of the evaporative cooling composite air conditioning system,the optimal control strategy of the system is calculated and analyzed,which includes the operating frequency of the compressor and refrigerant pump when the cooling capacity is supplied on demand,the optimal outdoor cooling air speed when the system runs safely and the performance of each model is optimized,and the optimal mode switching time when the system reaches efficient performance.Then,the influence of the new type evaporative condenser using water cooled heat exchanger on the overall system performance is studied.It is found that the use of water cooled heat transfer can improve the performance of the vapor compression mode,prolong the operation time of the heat pipe mode,and exert its energy-saving advantages,but it will reduce the performance of the heat pipe mode to a certain extent.Finally,from the perspective of analyzing the annual operating performance of the system,Shenyang,Beijing,Nanjing and Kunming,typical cities of four meteorological regions in China,were selected as the system running environment.Through comparative analysis system operating data such as the annual operating hours of each mode,the total annual power consumption of the system,the power consumption ratio of the equipment,the number of equipment start and stop,and the annual performance factor,we found that the evaporative cooling composite air conditioning system can operate stably in above four cities and has good energy-saving advantages.However,with the city annual average temperature increases,this advantage will reduce by the decreasing annual operation time of the heat pipe mode.Research results in this paper imply that the evaporative cooling composite air conditioning system is a data center temperature control system that takes into account both reliability and energy conservation.The proposal of this system is of great significance for promoting the development of Chinese information industry and building a green and energy-saving data center.