长距离环路热管传热性能实验研究

Long distance heat transfer performance of loop heat pipe

中文关键词: 环路热管  长距离传热  加热功率  冷凝温度

英文关键词: loop heat pipe, long distance heat transfer, heat load, cooling temperature

中文摘要:

      基于航空航天等领域对环路热管长距离传热的需求，设计制造了一套传热距离8.1m的圆柱型蒸发器环路热管，试验了不同加热功率、不同冷凝温度下该环路热管的启动和变工况运行性能，并对其热阻及最大传热能力进行了分析。研究结果表明：当其他条件一致、初始气液分布相同和不同时，加热功率由100W增大至160W后，本研究中的环路热管启动时间和启动温升均发生一定程度的下降；加热功率100W时，冷凝温度由10℃降低至-10℃使得环路热管启动时间增加，加热功率160W时，冷凝温度由10℃降至-10℃对环路热管的启动时间影响不大。在冷凝温度0℃下，该环路热管在100~500W范围内均能稳定运行，且200W时环路热管传热效率最高，传热温差最小，稳定运行温度最低；另外，由于系统传输距离较长，每个工况达到稳定所需要的时间也较长，分布于1000至3500S内。随着加热功率的增大，环路热管热阻先减小后逐渐增大，该环路热管传热热阻最大不超过0.09℃/W，最小为0.024℃/W；随着传热距离的增大，管路的热损失增加，总压降和热阻也变大。当传热距离基本相同时，蒸发器容积的大小、冷凝器的冷凝能力及气液管线的布置形状均在一定程度上影响环路热管的最大传热能力。

英文摘要:

      Based on the long-distance heat transfer requirement of loop heat pipe in aerospace and other fields, we designed and manufactured a set of cylindrical evaporator loop heat pipe with heat transfer distance of 4.6m. Under different heating power and cooling temperature, we tested the start-up and variable condition operation performance of the loop heat pipe, and analyzed the working characteristics and thermal re-sistance of the loop heat pipe. The results show that no matter the initial gas-liquid distribution is the same or different, the start-up time and start-up temperature are both decreased to a certain extent in other same conditions when the heating power increases from 100W to 160W; When the condensation temperature decreases from 10℃ to -10℃, the start-up time of the loop heat pipe increases at 100W, and when the heat-ing power is 160W, the effect on the start-up time is little. the loop heat pipe can operate stably in the range of 100~500W at the cooling temperature of 0℃. When the heating power at 200W, the heat transfer effi-ciency of the loop heat pipe is the highest, the heat transfer temperature difference is the smallest, and the stable operation temperature is the lowest; In addition, due to the long transmission distance of the system, it takes a long time to reach stability for each working condition, which is distributed between 1000 and 3500s. With the increase of heating power, the thermal resistance of the loop heat pipe decreases firstly and then increases gradually. The maximum thermal resistance is not more than 0.09℃/W, and the minimum is 0.024℃/W. With the increase of heat transfer distance, the heat loss of the pipeline increases, and the total pressure drop and thermal resistance also increase. When the heat transfer distance is basically same, the volume of evaporator, the condensation capacity of condenser and the layout shape of pipeline all affect the maximum heat transfer capacity of loop heat pipe to a certain extent.