This study adopts the computational fluid dynamics software−ANSYS FLUENT to predict the airflow and temperature distribution in a next-generation overhead downward flow (ODF)-type data center (DC). The study's primary objective is to minimize the entropy generation rate of the heat exchanger (HX) used in the ODF system in order to achieve energy savings. The ANSYS DesignXplorer optimization tool is employed to find the optimal design point with the smallest entropy generation rate of the HX. The predicted total exergy destruction of the DC at the optimal design point shows that the proposed A1-grade DC defined by ASHRAE TC 9.9 can save energy effectively. Moreover, the predicted power usage effectiveness (PUE) is lower than the average PUE reported in 2020 and all of the thermal performance metrics fall within the range of ideal conditions. The numerical results show that two approaches can effectively save energy in the ODF-type DC: one is to suitably increase the air-supply temperature; and the other is to suitably increase the temperature difference between the air-supply and return ports. Moreover, the separation of cold and hot aisles can effectively avoid the mixing of cold and hot airflows, resulting in an insignificant exergy destruction in the airspace.

本研究采用计算流体动力学软件ANSYS FLUENT来预测下一代高架向下流（ODF）型数据中心（DC）中的气流和温度分布。该研究的主要目的是使ODF系统中使用的热交换器（HX）的熵产生率最小化，以实现节能。ANSYS DesignXplorer优化工具用于以HX的最小熵生成率找到最佳设计点。在最佳设计点预测的DC的总火用破坏表明，由ASHRAE TC 9.9定义的拟议A1级DC可以有效地节省能源。此外，预测的电源使用效率（PUE）低于2020年报告的平均PUE，并且所有热性能指标均处于理想条件范围内。数值结果表明，有两种方法可以有效地节省ODF型DC的能量：一种是适当提高供气温度。另一个是适当增加供气口和回风口之间的温差。而且，冷通道和热通道的分离可以有效地避免冷气流和热气流的混合，从而导致对空域的明显的火用破坏。