Abstract: To investigate the effect of condenser location and gravity on operating performance，a miniature loop heat pipe with series flat evaporator were tested. The results show that the loop heat pipe can start up successfully at various positions under a low heat load （20 W） and have good operating performance with Qmax=130 W and R=0.21℃/W. At horizontal position，the loop heat pipe with shorter vapor line has better start-up performance and higher Qmax. Under a higher heat load，the effect of condenser location on operating performance becomes more noticeable. It is found that a loop heat pipe with series flat evaporator has good anti-gravity capability and can operate with all elevations and tilts. When the loop heat pipe is at vertical position with compensation chamber above the evaporator，its operating performance is the best under the gravity field.

Key words: loop heat pipe, flat evaporator, condenser, anti-gravity capability, operating performance

摘要： 针对一款基于并联式平板蒸发器的小型环路热管进行了实验研究，分析了冷凝器位置以及摆放方式对环路热管运行性能的影响。实验表明：该环路热管能在低功率（20 W）时各种摆放方式下顺利启动，并具有良好的工作性能，其最大热负荷达到130 W，此时热阻为0.21 ℃/W；该热管水平放置时，蒸汽管线长度越短，启动性能越好，最大热负荷越大；运行功率越大，蒸汽管线长度对运行性能的影响越明显。并联式平板环路热管具有很好的反重力特性，能够在各种竖直放置状态下正常运行；该环路热管竖直放置且储液器位于蒸发器下方时，系统的运行性能最好。

关键词: 环路热管, 平板式蒸发器, 冷凝器, 反重力性能, 运行特性