间接蒸发冷却器在干湿模式下的冷却特性

Cooling performance of indirect evaporative cooler in dry and wet mode

间接蒸发冷却系统因其能充分利用自然冷源,减少数据中心冷却系统能耗进而降低PUE值,被逐步开发应用在数据中心冷却系统中。利用焓差实验室创建冷却器在干模式(二次空气4—20℃)与湿模式(二次空气20—32℃,相对湿度40%—60%)下的温湿度环境开展实验,以研究间接蒸发冷却系统在不同环境工况下的冷却性能。结果表明:干模式下一次空气的冷凝使冷却器对其显热处理能力降低,其冷凝潜热占二次空气吸热量的6.6%—26.4%,二次空气进口温度和风量为4℃与460 m^(3)/h时制冷量最大为1.21 kW,COP为17.5。湿模式下,进口温度为20—26℃的二次空气经过与水的热质传递,其温度低于一次空气的露点温度使得一次空气水蒸气冷凝,相应工况下的湿球效率随冷凝的减弱在47%—68%的范围内逐渐升高,并在二次空气温湿度为32℃与50%的工况下达到最大81%,制冷量和COP在最低相对湿度40%时达到最大值,分别为1.32 kW与14.9。

Indirect evaporative cooling system is gradually developed and applied in data center cooling system because it can make full use of natural cold source to reduce energy consumption and the PUE of data center.In order to study the cooling performance of indirect evaporative cooler under different environmental conditions,the enthalpy difference laboratory was used to create the temperature and humidity environment of the cooler in dry mode(secondary air 4-20℃)and wet mode(secondary air 20-32℃,relative humidity 40%-60%).The results show that the condensation of primary air in dry mode reduces the sensible heat treatment capacity of the cooler,and its condensation latent heat accounts for 6.6%-26.4%of the heat absorption of secondary air.When the inlet temperature of secondary air is 4℃and the air volume is 460 m^(3)/h,the maximum refrigeration capacity is 1.21 kW and COP is 17.5.In the wet mode,the secondary air that the inlet temperature is 20-26℃,after heat and mass transfer with water,the temperature is lower than the dew point temperature of the primary air,which makes the water vapor of primary air condense,and the wet bulb efficiency under corresponding working conditions gradually increases in the range of 47%-68%with the weakening of condensation,and reaches the maximum 81%under the working conditions of 32℃and 50%of secondary temperature and humidity respectively.The refrigerating capacity and COP reach the maximum value when the minimum relative humidity is 40%,which are 1.32 kW and 14.9,respectively.