Heat Transport Characteristics and Operating Limit Expansion of Oscillating Heat Pipe

对于在空间环境中使用的振荡热管（ohp），除了高性能之外，非常重要的是它们可以在广泛的条件，温度和热量输入下工作。在本研究中，将灯芯插入OHP （I.D.=φ1.5mm）以扩大该条件范围。邪恶的OHP在更高的输入功率范围内工作良好，而没有灯芯的OHP则无法工作。但在中等范围内，邪恶OHP的有效导热系数低于正常OHP。如果芯芯以对称的方式插入，循环流动就不会发生，OHP也不会很好地工作。虽然2mm口径的普通OHP不能正常工作，但这款邪恶的OHP工作得很好，表现很好。在垂直底加热作业中，没有灯芯的OHP表现出更好的性能，在使用乙醇作为工作流体的水平作业中，灯芯的长度是总OHP的一半。通过将绝热截面长度从270 mm延长到1000 mm，研究了带或不带芯的OHP性能。在水平作业中，wicked OHP表现良好，在绝热段长度为270或500mm时表现良好。此外，为了实际空间使用，在较低温度区域对以氨为工质的OHP进行了研究。在垂直操作中，无芯的氨气OHP的性能优于乙醇OHP。在水平操作中，邪恶的氨OHP工作良好，但在高热输入功率的情况下不稳定。

For use of oscillating heat pipes (OHPs) in a space environment, in addition to a high performance, it is very important that they work in a wide range of conditions, temperature and heat input. In this research, wick was inserted to the OHP (I.D.=φ1.5mm) to expand this range of conditions. The wicked OHP worked well at a range of higher input power, where a OHP without wick didn't work. But at a middle range, the wicked OHP's effective thermal conductivity became lower than that of the normal OHP. If wicks were inserted in a symmetrical configuration, circulating flow didn't occur and OHP didn't worked well. Although a normal OHP of 2mm I.D. didn't work, the wicked OHP worked well and showed a good performance.The OHP showed a better performance both without a wick in a vertical-bottom-heating operation, and with a wick at half-length of overall OHP in a horizontal operation using ethanol as the working fluid. The OHP performance with or without wick was investigated by extending the adiabatic section length from 270 to 1000 mm. In a horizontal operation, the wicked OHP worked well and showed a good performance with the adiabatic section 270 or 500 mm in length. Furthermore, for practical space use, the OHP using ammonia as the working fluid was investigated in the lower temperature region. The ammonia OHP without a wick showed higher performance than the ethanol OHP in a vertical operation. In a horizontal operation, the wicked ammonia OHP worked well, but unstably in the case of higher thermal input power.