CO2分离式热管在数据中心的应用

本文通过实验研究了应用于数据中心的CO2分离式热管系统,对比分析了CO2热管与R22热管的最大传热能力、总传热热阻和驱动温差,结果表明:在相同充液率下,CO2热管的最大传热能力明显大于R22热管,当上升管和下降管管径为9 mm时,CO2热管和R22热管的最大传热能力分别为3300 W和1500 W,当管径为12 mm时,CO2热管和R22热管的最大传热能力分别为5400 W和2200 W;CO2热管的正常负荷范围大于R22热管,但总传热热阻小于R22热管;不同传热量下,与R22热管相比,CO2热管所需的驱动温差平均低4℃,即相同条件下CO2热管系统所需的冷源温度可以提高4℃。以小型数据机房为例,结合上海气候条件计算得出,采用CO2热管系统的年耗电量比R22热管系统减少7.425×105 kW·h,比集中送风空调系统减少3.182×106 kW·h。

Application of CO2 Two-phase Thermosyphon Loop in Data Centers

A CO2 two-phase thermosyphon loop(TPTL)system in data centers were investigated in this study.The maximum heat transfer capacity,total thermal resistance,and driving temperature difference were compared between CO2 and R22 TPTLs experimentally.The results indicate that under the same filling ratio,the maximum heat transfer capacity of CO2 TPTL was significantly greater than that of R22 TPTL.When the diameters of the riser and downcomer were 9 mm,the maximum heat transfer capacities of the CO2 and R22 TPTLs were 3300 W and 1500 W,respectively.When the diameter was 12 mm,the maximum heat transfer capacity of the CO2 and R22 TPTLs were 5400 W and 2200 W,respectively.The study also found that the normal working load range of CO2 TPTL was larger than that of R22 TPTL,but the total thermal resistance of CO2 TPTL was lower than that of R22 TPTL.Under different heat transfer capabilities,the driving temperature difference required for CO2 TPTL was 4℃lower than that of R22 TPTL on average;that is,the cooling source temperature required by CO2 TPTL can be increased by 4℃under the same conditions.Taking a small data center as an example,it was calculated that the annual energy consumption of the CO2 TPTL system is 7.425×105 kW·h lower than that of the R22 TPTL system and 3.182×106 kW·h lower than the central air-conditioning system under the climate conditions in Shanghai.