The two-phase thermosyphon loop (TPTL) has been widely used in data center cooling. But there is no practical design method and quantitative guidance to ensure a well-designed TPTL. In this paper, the approaching degree to “ideal cycle” ɛ is adopted as the efficiency indicator, based on which, a practical design method for TPTLs used in HVAC is proposed, ensuring the efficiency as well as the capacity of the designed TPTLs. In the design method, the area of the heat exchanger F is determined by the capacity Q, and the filling ratio FR, height difference ΔH, length L and diameter d of the connecting pipes are determined by the efficiency ɛ. The approaching degrees ɛ of TPTLs with filling ratios of 0.05–0.5, height differences of 0.2–5 m, connecting pipe lengths of 1–20 m, and connecting pipe diameters of 6.35–28.6 mm was simulated. For each TPTL, with capacity from 0 W to 10000 W, the recommended diameter, required minimum height difference, and optimal filling ratio were provided quantitatively, and practical design guidance was presented graphically. Additionally, a simple correction method for working fluids was proposed and validated, using five working fluids. Finally, a design example was provided to elaborate how to use the design method.

两相热虹吸回路（TPTL）已广泛用于数据中心冷却。但是，尚无实用的设计方法和定量指导来确保TPTL的设计良好。在本文中，接近度为“理想周期” ɛ被采用为，提出了一种用于在HVAC使用TPTLs实际的设计方法的效率指标的基础上，保证了效率以及所设计的TPTLs的容量。在该设计方法中，热交换器的面积˚F由容量确定Q，和填充比FR，高度差Δ ħ，长度大号和直径d的连接管由效率确定ɛ。接近度ɛ TPTLs与0.05-0.5填充比率，0.2-5米高度差，连接的1-20米管的长度，以及连接的6.35-28.6毫米管径进行了模拟。对于容量从0 W到10000 W的每个TPTL，定量提供了推荐的直径，所需的最小高度差和最佳填充率，并以图形方式给出了实用的设计指南。此外，提出并验证了一种使用五种工作流体的简单的工作流体校正方法。最后，提供了一个设计示例来详细说明如何使用设计方法。