为了确定再循环两相热虹吸回路的运行特性，进行了实验和计算机模拟研究，其中蒸发器和冷凝器均由一组从入口到出口集管的管组成，再循环是通过在蒸发器集管出口使用分离器实现的，分离器允许收集的液体直接再循环到蒸发器进口集管。实验回路在每个热交换器中使用三根管子。这两个单元都可以用作蒸发器或冷凝器。该系统用于测量管道表面温度、流体温度、流体流速和传热速率。 换热器管的长度是固定的，但是，几乎所有其他参数都可以改变，包括管直径、任一换热器的倾斜角度、工作温差、回路的平均温度、一个换热器相对于另一个换热器的高度、工作流体和回路中的电荷。对ASHRAE项目RP 140下开发的基本计算机模拟程序进行了修改，并将其用作再循环回路研究程序的基础。该程序首次用于模拟实验操作条件下的回路操作。对模拟和实验行为的比较表明，计算机程序能够准确预测此类系统的行为。 还对其他回路配置进行了进一步的模拟研究。研究发现，与类似的非再循环回路相比，再循环两相多管热虹吸回路产生更高的回路电导，并且对运行条件的敏感性要低得多。

An experimental and computer simulation investigation has been carried out to determine the operating characteristics of recirculation two phase thermosiphon loops in which both the evaporator and the condenser consist of a bank of tubes running from an inlet to an outlet header, the recirculation is achieved through the use of a separator at the evaporator header outlet which permits the liquid collected to be recirculated directly to the evaporator inlet header.The experimental loop utilized three tubes in each heat exchanger. Either unit could be used as the evaporator or the condenser. The system was instrumental to permit the measurement of tube surface temperatures, fluid temperatures, fluid flow rates and heat transfer rates. The length of the heat exchanger tubes was fixed, however, nearly all other parameters could be-varied including the tube diameters, the angle of inclination of either heat exchanger independently, the operating temperature difference, the mean temperature of the loop, the elevation of one heat exchanger with respect to the other, the working fluid and the charge in the loop.The basic computer simulation program developed under ASHRAE project RP 140 was modified and used as the basis of the program for the recirculation loop study. This program was first used to simulate loop operation for the experimental operating conditions. A comparison of the simulated and experimental behaviours showed that the computer program was able to accurately predict the behaviour of such systems. Further simulation studies for other loop configurations were also carried out.The recirculation two phase, multi tube thermosiphon loop has been found to yield higher loop conductance and to be much less sensitive to operating conditions than a similar non-recirculation loop.