地板下送风方式和几何参数对数据中心热性能的影响

Influence of Floor Air Supply Methods and Impact of Geometric Parameters on the Thermal Performance of Data Centers

数据中心室内热环境取决于送风气流分布,而送风系统的几何结构会显著影响送风气流分布。本文对比了4种常用的送风方式,即冷/热通道开放式系统、热通道封闭式系统、机架下送风系统和冷通道封闭式系统。对于每种送风方式,研究了静压箱高度、穿孔率、挡板位置和挡板角度等几何因素对数据中心气流组织的影响。利用ANSYS Fluent建立了288个不同送风方式和配置的CRAC模型。利用SmartAisle^(TM)冷通道封闭系统的温度测量数据对模型进行了验证。对比了平均机架温度、平均热点温度以及热性能评价系数和回风温度指数。结果表明:在一定范围内增加静压箱高度或降低穿孔率均有助于提高热性能。分析室内截面温度云图和相关评价指标得出,在冷通道封闭情况下总体性能最佳。最后,在冷通道封闭系统模型中对比了采用V型和Λ型挡板时各因素的影响,得到采用V型和Λ型挡板时的最佳穿孔率均为20%,而最佳静压高度分别为0.5 m和0.6 m。总体而言,V型挡板比Λ型挡板温度分布更为均匀。

The indoor thermal environment of data centers is based on the supply airflow distribution,which is significantly affected by the geometric configuration of the air-supply system.This study compares four commonly used air supply layouts,namely the cold/hot-aisle airflow open-ended system,hot aisle containment system,cold aisle under racks system,and cold aisle containment system.For each air supply layout,geometric factors such as the plenum height,perforation rate,baffle position,and baffle angles were investigated.Using ANSYS Fluent,up to 288 models of CRAC with different air supply modes and configurations were built.The models were validated using the temperature measurement data at the SmartAisle^(TM)cold aisle containment system.The average rack and hot spot temperatures,thermal performance evaluation index,and return temperature index were used as the metrics for comparison.The results show that both increasing the plenum height and decreasing the perforation rate within a certain range contribute to thermal performance improvement.Considering the room temperature profile and evaluation metrics,the overall best performance is achieved in the cold aisle containment case.Finally,the effects of various factors when using V-shaped andΛ-shaped baffles were compared using the models of the cold aisle containment system.The results show that when using V-shaped andΛ-shaped baffles,the optimal perforation rate is 20%,while the optimal static pressure height is 0.5 m and 0.6 m,respectively.Overall,V-shaped baffles achieve better temperature uniformity thanΛ-shaped baffles.