空间膜式水蒸发散热理论分析与试验研究

Theoretical and Experimental Analysis on Heat Rejection of Space Water Membrane Evaporation

针对空间膜式水蒸发器(SWME)中水工质蒸发过程的散热问题,应用管内对流换热和努森扩散-泊肃叶流动混合传质模型对该过程进行了数学描述。通过开展地面试验与数值计算,对工作参数与膜式水蒸发原理试样件稳态散热量之间的作用机理进行了研究,结果表明:流体入口温度和环境压力通过影响膜式水蒸发过程的压差驱动力,对该过程的稳态散热量产生显著影响,稳态散热量随流体入口温度线性增加,而与环境压力呈现负相关性。在小功率散热情况下,膜式水蒸发原理试样件散热量的单管数学模型计算值与试验结果之间的偏差更小。研究结果可为后续空间膜式水蒸发器的设计提供参考。

Using the convection hest transfer for flow in pipes and Knudsen diffusion-Poiseuille flow mass transfer model, the water’ s transmembrane evaporation process,which acts as a working fluid for the space water membrane evaporator （SWME） is described mathematically. Through the experiments and the numerical calculations, the influential mechanism between the operation parameters and the steady-state heat rejection of the principle test article is studied. The study shows that fluid inlet temperature and ambient pressure act on the differential pressure driving force directly, and then have a significant effect on the steady-state heat rejection of the transmembrane evaporation of water, steady-state heat rejection increases linearly with the inlet temperature, but negatively correlates with the ambient pressure. Under the condition of low heat rejection,the membrane evaporation single pipe mathematical model＇s numerical calculations are more corresponding to the experimental results. The analysis of this paper can provide a reference for the subsequent design of the space water membrane evaporator.