通过采用石英补偿器和高速摄像机实现了对丙烯环路热管补偿器的可视化实验研究,重点研究了补偿器内工质的状态随充装量和传热量的变化及充装量对环路热管传热性能的影响.研究发现,容积为51.4 mL的环路热管最佳充装量约为19.7 g.充装量小于最佳充装量的各工况下,能观察到对应补偿器内工质液面高度低于引流管,蒸发器和补偿器之间相变换热强烈,引流管外壁面明显有工质的冷凝及流动,且工质冷凝和流动的速度随着传热量的增加而加快;随着充装量增加,环路热管传热热阻减小,280 K工作温度以下的传热量增大.最佳充装量对应的补偿器内液面高度浸没引流管而接近蒸发器核心通道顶端,得到280 K以下最大传热量为40 W,对应的最优传热热阻为2 K/W.充装量大于最佳充装量的工况下,补偿器内液面高度超过蒸发器核心顶端,随着充装量增加,环路热管传热热阻增大,280 K以下的传热量减小.补偿器和蒸发器核心通道内的工质分布能影响蒸发器向补偿器的漏热量,这是充装量影响环路热管性能的重要原因.

借鉴轴向槽道热管结构在工作时良好的气、液分离工作特性,本文提出了一种带蒸汽腔的复合微通道热沉,用以解决大面积或高热流能量收集时热沉通道内部由于排气不畅易导致气塞和返流现象,进而出现流动沸腾不稳定性问题和传热恶化的问题.热沉底板包含20个Ω形平行通道,肋顶端与盖板下表面间形成连通的蒸汽腔作为两相流时的气体流道.实验以无水乙醇、Novec HFE 7100为工质,并结合可视化观测对热沉性能进行了研究,可以观察到随加热热流密度逐步增加,热沉内部工质依次经强制对流到过冷沸腾、核态沸腾,并最终达到过渡沸腾,可视化实验结果与温度测量结果相吻合.当使用乙醇为工质,在入口质量流速qm=280.37kg/(m2·s)、加热热流密度qeff =30.32W/cm2时,最大传热系数为9494W/(m.℃).此种结构在有效地保证了热沉换热效果的同时,通过分离气、液流道对抑制流动沸腾不稳定性有明显效果.

设计并测试了一台金属隔膜泵,该泵通过磁致伸缩致动器驱动隔膜往复振动,配合单向阀门实现流体的单方向运输.以该泵为压力源,搭载微通道换热器,并以斯特林制冷机为冷源,搭建了两相流体回路换热系统,对系统进行了漏热标定以及性能测试,结果表明,以氨为工质在-30℃设计工作点下,系统能实现最高150W的热量传输.

A gas-liquid separation device for cooling circuit based on the flow characteristics through porous media was designed.On the theory of fluid pressure drop and gas hold-up within porous media,combining CFD simulation,the optimized parameter of separation equipment porous zone was evaluated,and phase separation effects were predicted.By high speed imaging device and specifically designed quartz container,visualization was realized on fluid circuit,and separation results were verified.

To enhance the optical recognition and wavelength filtering of an infrared cold optical system, some lens need to be maintained within a certain temperature range, which requires specific thermal management of the aperture. A 250K liquid cooling circuit designed for this purpose is introduced, and the experimental results established and operated in a vacuum environmental simulation chamber is carried out and analyzed. A practical cooling power source of radiation cooling equipment is adopted and the sun exposure heat load is imitated by array of planar membrane heaters attached on the specific designed structure of the aperture. Controlling the aperture temperature and improving the optical system performance are proved effective. Numerical optimization of the cooling circuit and simulation of the aperture are performed , and the factors affect the optical system performance in the mean time are also investigated.

A metal membrane pump driven by a magnetostrictive actuator was presented.Parametric design of solenoid was conducted with finite element analysis method,which indicated the lowest copper loss occurs when the inner and outer diameter were 20 mm and 50 mm respectively to sustain the same magnetic field.Magnetostrictive strain under different current was measured and the maximum strain reaches 1 100 ppm.The pump has a flow rate of 2 mL/s when driven by the actuator and reaches the design target of fluid loop.

针对天基红外凝视与扫描观测系统的载荷冷却需求,具有流体传输和热传输能力强、扬程大以及可调节性较强等优点的泵流体回路可用作长距离、大面阵、分布性载荷的冷却回路.在单相流体回路中,对气相分数的控制非常重要.介绍了一种基于多孔介质中两相流体的流动机理实现气液两相分离的装置及其设计思路和试验验证方法.通过数值计算及仿真得到了优化参数,测量了回路中的流动参数,并验证了此装置的气液分离效果.