| The free cooling air conditioning system of a data center in Xinjiang studied in this paper utilizes abundant dry air energy and low temperature air in Xinjiang as natural cold sources..Based on direct evaporative cooling technology,indirect evaporative cooling technology and ethylene glycol free cooling technology,the first application of evaporative cooling air-water air conditioning system in the field of air-conditioning system in data center is realized,and 100% free cooling is realized throughout the year.In this paper,the application of the system is studied from the aspects of technical principle,experimental research,engineering application,performance measurement,economic benefit and operation optimization.(1)Technical principle analysis.This paper defines the system and analyses the technical principles and operation modes of the vertical tube indirect evaporative cooler,evaporative water chiller,evaporative cooling fresh air handling unit and the new sensible heat terminal unit in data center room.Then it focuses on the internal and external cooling enhanced heat transfer technology adopted by the chiller,and discusses three operation modes of the system throughout the year(water-side evaporative cooling,water-side and air-side composite evaporative cooling,ethylene glycol free cooling operation mode).It lays the theoretical foundation for the application of the system in engineering.(2)Experimental research and engineering application analysis.The field test bench was built to carry out the performance comparison experiment of single-side/double-side air-intake evaporative water chiller and the performance improvement experiment of single-side air-intake evaporative water chiller.Because the water supply temperature of single-side air chiller is higher than that of the ambient air wet bulb temperature,and the measured value of each performance parameter of double-side air-intake evaporative water chiller meets the design requirements,the double-side air-intake evaporative water chiller is applied to the engineering project.The feasibility of engineering application of the system is verified by the experimental test system,and the configuration scheme of engineering application of the system is analyzed.(3)Summer performance measurement and economic benefit analysis.The performance of the system and the engine room environment are measured and analyzedby non-standard engineering measurement scheme,and the economic benefit is compared with two refrigeration modes commonly used in the engine room air-conditioning system(free cooling air cooled screw chiller and magnitude magnetic bearing centrifugal chiller).The annual power consumption and theoretical PUE of the free cooling air-conditioning system are also analyzed according to the measured performance parameters.The measured results show that the water chilling unit and fresh air units are 0.34m3/h and 0.06 m3/h,respectively.The SCOP and COP of the system are 16.64 and 6.65 respectively.The theoretical PUE of the data center is 1.285.Compared with the two refrigeration modes commonly used in the air conditioning system of the engine room,the maximum annual energy saving rate is 73%,the operating cost is 2.663 million yuan,and the annual benefit of the frame is 5.15 million yuan.The system is safe,reliable,energy-saving and water-saving,and has considerable economic benefits.(4)Operation optimization.Based on the problems of the system during the summer measurement period,the operation optimization of the system is carried out,focusing on the following three aspects: the regulation of the performance and operation strategy of evaporative chillers under different dry air quality,the solution of the problem of excessive relative humidity of the fresh air supply of evaporative cooling fresh air handling unit,and the increase of the air-side evaporative cooling operation mode as the whole year operation of the system.It ensures the reliability of the whole life cycle of the system.There are 60 figures,21 tables and 75 references in this paper. |
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