自然冷却是数据中心空调系统中能效较高、应用广泛的冷却方式之一。基于苏州、北京、贵阳、广州、乌鲁木齐的气候特征，通过TRNSYS建立了数据中心自然冷却系统模型，研究了不同地区相同冷冻水供回水温度下数据中心的节能效果。结果表明，冷冻水供／回水温度为15/22 ℃时，完全自然冷却时间最长的为乌鲁木齐，占全年的67.4%，最短为广州，占全年的10.2%；完全机械制冷时间最长为广州，占全年的63.0%，最短为乌鲁木齐，占全年的4.3%；部分自然冷却时间最长的为贵阳，占全年的31.8%，最短为北京，占全年的18.6%。全负荷状态下，年均系统电能利用效率（power usage effectiveness, PUE）最低的是乌鲁木齐，为1.227；PUE最高的是广州，为1.299。五个城市的年均PUE随负载率的升高而降低，且随着负载率的升高，空调能耗对年均PUE的影响变小。研究结论为指导不同地区数据中心自然冷却技术的应用提供了理论支撑。

Natural cooling is one of the more energy-efficient and widely used cooling methods in data center air conditioning systems. Based on the climatic characteristics of Suzhou, Beijing, Guiyang, Guangzhou and Urumqi, the natural cooling system model of data centers was established by TRNSYS, and then the energy saving effect of data centers under the same chilled water supply and return temperatures in different regions was studied. The results show that when the chilled water supply/return temperatures are 15/22℃, the longest time for complete natural cooling is in Urumqi, accounting for 67.4% of the year, and the shortest time is in Guangzhou, accounting for 10.2% of the year; the longest time for complete mechanical cooling is in Guangzhou, accounting for 63.0% of the year, and the shortest time is in Urumqi, accounting for 4.3% of the year; the longest time for part of natural cooling is in Guiyang, accounting for 31.8% of the year, and the shortest time is in Beijing, accounting for 4.3% of the year. The longest part of natural cooling time is in Guiyang, accounting for 31.8% of the year, and the shortest is in Beijing, accounting for 18.6% of the year. At full load, the lowest annual average system power usage effectiveness (PUE) was in Urumqi at 1.227, and the highest PUE was in Guangzhou at 1.299. The average annual PUE of the five cities decreases as the load factor increases, and the effect of air conditioning load on the average annual PUE becomes smaller as the load factor increases. The findings provide theoretical support for guiding the application of natural cooling technology in data centers in different regions.