本文以太阳能热利用和蓄能技术为研究背景,提出了一种基于膜蒸馏的太阳能溶液蓄能模式.采用疏水性聚偏氟乙烯中空纤维膜为膜蒸馏材料,基于膜蒸馏常温操作、小温差大传热面积的特点,利用膜材料微观上的高比表面积和单位体积的高接触面积为载体,选取50％溴化锂溶液为工质,以减压膜蒸馏的方式进行溶液浓缩和潜能存储,浓缩后的溶液可作为吸收式热力系统的工质.为此,针对50％的溴化锂溶液进行了减压膜蒸馏实验,对不同溶液温度、溶液流量在不同真空度下进行减压膜蒸馏实验,得到了3组实验数据.根据实验结果,对膜蒸馏式溶液蓄能系统进行分析,结果表明:蓄能密度可以达到245 kJ/kg,单位面积的膜组件可以产生0.27～0.40 kW的蓄能量,膜蒸馏式溶液蓄能为太阳能利用、吸收式热力系统和蓄能技术提供了一种新的应用方法和途径.%With respect to solar energy utilization of buildings, a solution chemical energy storage mode is proposed based on membrane distillation technology focusing on the low density of solar radiation distribution and the imbalance between energy supply and demand, the purpose of which is to convert solar energy into solution chemical energy. A hydrophobic polyvinylidene fluoride ( PVDF) hollow fiber membrane with operational characteristics of a normal temperature region and low temperature difference is adopted as the membrane mate-rial, and the PVDF membrane material has a highly specific surface area microscopically and a huge contact area per unit volume;as a re-sult, a lithium bromide solution can be concentrated and stored using the vacuum membrane distillation mode, and the concentrated solu-tion can be used as the working medium of the absorption thermal system. Therefore, experimental tests of the vacuum membrane distil-lation of a lithium bromide solution were carried out under different operating temperatures, solution flow rates, and vacuum degrees. Ac-cording to the experimental results, a solar-driven solution energy storage system based on membrane distillation is described. The results show that the energy storage intensity can reach 245 kJ/kg, and the hollow fiber module can produce 0. 27-0. 40 kW of energy storage per square meter. Thus, membrane distillation solution storage provides a new approach to absorption thermodynamic systems and storage technology.
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