蒸发冷却技术在数据中心液冷系统中的应用探讨

Discussion on the Application of Evaporative Cooling Technology in Liquid Cooling System of Data Center

数据中心内空调水冷系统能耗是除IT设备能耗外第一大能耗,在国内数据中心,大多采用风冷或水冷的散热方式进行降温,而液冷散热是比风冷或水冷散热更直接效率更高的散热方式。现常采用的冷却塔与液冷技术相结合,由于冷却塔内发生的是直接蒸发冷却过程出水温度在进口空气湿球温度之上。而间接预冷式蒸发冷却冷水机组通过预冷段对进口空气进行预冷,可使出水温度达到进口空气湿球温度以下。夏季极端热湿气象条件下冷却塔出水温度有局限,不能满足液冷散热的需求,无法保证数据中心全年安全运行。故提出利用间接预冷式蒸发冷却冷水机组代替冷却塔与液冷系统结合。并对比了冷却塔与间接蒸发冷却冷水机组的差异及性能。选取典型年气象参数制作了以出水温度为区分的分区地图,结合分区地图对冷却塔与间接预冷式蒸发冷却冷水机组与液冷系统结合的形式做出了分析。

The energy consumption of air conditioning water cooling system in data centers is the largest energy consumption after the energy consumption of IT equipment. In domestic data centers, most of the cooling is carried out by air cooling or water cooling, and liquid cooling is a more direct and efficient cooling method than air cooling or water cooling. Now the cooling tower is often used in combination with liquid cooling technology, because what happens in the cooling tower is direct evaporative cooling process, the outlet water temperature is above the wet bulb temperature of the inlet air. The indirect precooling evaporative cooling chiller precools the inlet air through the precooling section, so that the outlet water temperature can reach below the wet-bulb temperature of the inlet air. Under extreme hot and humid weather conditions in summer, the outlet water temperature of the cooling tower is limited, which cannot meet the demand of liquid cooling and cannot guarantee the safe operation of the data center throughout the year. Therefore, the indirect precooling evaporative cooling chiller is proposed to combine with the liquid cooling system instead of the cooling tower. The difference and performance between cooling tower and indirect evaporative cooling chiller are compared. In this paper, the meteorological parameters of a typical year are selected to make a zonal map with the water outlet temperature as the distinction. Combined with the zonal map, the combination form of cooling tower, indirect precooling evaporative cooling chillers and liquid cooling system is analyzed.