逆电渗析法热-电转换系统匹配工质对的溶解与电导特性研究

Taking the technology exploration of converting low grade thermal energy to electricity as the research background, authors of this project focus on the unsolved problems of a new proposed closed cycle of heat to electricity system with Reverse Electro-dialysis (RED) method, and proposing an available solution by using ternary working fluids, named inorganic salt-solvent-modifier, to replace the previous brine. Further more, the research subject has been extracted to the key physical properties of working fluids as solubility and electroconductibility, and which are also relational to each other. Throughout studying on effective intersectionality among the multi parameters, as well as the improving the solution’s thermodynamics theory and testing methodology, this project would explore out the dynamic characteristics during the process of dissolution and ionization between the inorganic salt and solvent-modifier mixture. Besides, the critical properties of solutions when achieving the maximal conductivity as well as its influence factors would also be discussed, which is benefit to develop the optimization strategies of the RED generating efficiency, and also to the improvement of thermodynamical perfectness. The expected results can be regarded as the data foundation and theoretical references for evaluating the heat and mass transfer characteristics of working fluids that match the heat sources feature closely. Finally, this project plays a foundational and scientific role in the aspects of low grade thermal energy usage field harmoniously between the energy comsumption and ecology environment.

本项目以低品位热能的动力转换为技术背景，针对闭式逆电渗析法热-电转换循环系统匹配性工质对亟待挖掘的问题，提出无机盐-溶解剂-调节剂三元工质对解决方案，并以三元工质对的溶解性和电导性两大相互关联的基础物性为核心切入点，理论和试验相结合地探索三元工质对在系统匹配条件下的关键热力学性质和电化学性质。通过多维度和多参数的关联与交叉，以及对溶液热力学理论的完善和实验方法的改进，从微观和宏观双向地推进三元工质对的溶解和电离动态过程的研究，并揭示三元体系电导率极值临界条件及影响因素的作用机理，为发展RED热-电转化效率优化策略、提高系统热力学完善度提供科学依据。所获成果是完善系统匹配性三元工质对筛选准则理论的有力支撑，为深入探索三元工质对在复杂热-电转换条件下的传热、传质过程机理的奠定数据基础和理论参考，对高效梯级利用低品位热能、协调生态环境和能源发展间关系具有基础性科学价值。

以无机盐-溶解剂-调节剂三元溶液体系与闭式逆电渗析法热-电转换系统的匹配性为技术背景，面对提升系统能量转换效率的发展亟需，本项目以理论和实验相结合的方法，从溶液溶解性和电导性两大核心物性切入，再辅以电转换性和活度物性研究，收获了多项成果。通过多参数的关联与交叉，以及对溶液热力学理论的完善和实验方法的改进，有效地深化了对于二元和三元溶液体系的溶解和电离过程的认识。揭示了溶液电导率极大值临界特性及其重要影响性，在多种溶液中都发现了随着溶质质量分数的增加，溶液的电导率呈现先迅速增大，而后增速减缓，当达到峰值后，会转而逐渐减小的现象。确定了溶液的溶解度、电导率与电转换性之间存在一定的联系。为发展逆电渗析法热-电转换效率优化策略、提高系统热力学完善度奠定科学依据。