Fan failure of loop thermosyphon systems (LTS) is a major factor affecting thermal safety of data centers. This paper develops a distributed-parameter model to accurately predict the overall and local heat transfer performance of a loop thermosyphon (the terminal equipment of LTS) under fan failure conditions. The simulation results show that the positions of faulty fans have a significant influence on the evaporator's local airside heat transfer coefficient, but have slight influences on the evaporator's local refrigerant heat transfer coefficient and the condenser's overall heat transfer coefficient, which would not increase the risk of heat transfer performance. Thus, fan airflow rate backup can be used to handle fan failure. Then, the effect of operating parameters including backup airflow rate (B), cold water temperature (T) and increment of cold water flow rate (I) on the effectiveness and efficiency of the cooling capacity compensation under fan failure conditions is analyzed by using the Taguchi method with an L16 orthogonal array. The B is the primary factor contributing 81.51% on cooling capacity compensation, with T and I contributing 15.25% and 2.38%, respectively. Considering the energy efficiency, the order of adjustment should be B first, I second, and T last when fan failure occurs.

中文翻译：

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风扇故障条件下环路热虹吸系统的性能和制冷量补偿方案仿真

环路热虹吸系统（LTS）的风扇故障是影响数据中心热安全的主要因素。本文开发了一种分布式参数模型，可以准确预测风扇故障条件下回路热虹吸管（LTS 的终端设备）的整体和局部传热性能。仿真结果表明，故障风扇位置对蒸发器空气侧局部传热系数影响较大，但对蒸发器局部制冷剂传热系数和冷凝器整体传热系数影响较小，不会增加故障风险。传热性能。因此，风扇气流速率备份可用于处理风扇故障。然后，利用以下公式分析了备用风量（B）、冷水温度（T）和冷水流量增量（I）等运行参数对风扇故障情况下冷量补偿效果和效率的影响。采用 L16 正交阵列的田口方法。 B是对冷量补偿贡献81.51%的主要因素，其中T和I分别贡献15.25%和2.38%。考虑到能效，风扇故障时的调节顺序应为先B、后I、后T。