聚光太阳能电站中氯盐作为传热流体的研究进展

Research progress of chloride salt as heat transfer fluidin concentrating solar power plant

太阳能是地球表面最丰富的清洁可再生能源,太阳能利用是全球可再生能源发展战略最重要的组成部分,将聚光太阳能发电(CSP)与热能储存(TES)耦合产生可调度的清洁电力是实现能源低碳转型的重要途径之一。太阳能光热电站的能量转换效率和功率成本是上述技术的制约因素。以熔融盐为代表,开发具有更高工作温度(>565℃)的热能储存(TES)/传热流体(HTFs)系统是提升太阳能光热发电效率的重要技术途径。其中,氯盐被认为是下一代最有希望实现更高效率和更低成本的TES/HTF体系之一。基于目前氯盐的研究现状,本文探讨了氯盐的基础研究和当前的发展策略,主要包括氯盐的热性能、腐蚀机理和缓解腐蚀的策略。分析结果表明,熔盐的最大工作温度是决定TES系统效率的关键。然而,金属结构材料在熔盐中的腐蚀限制了氯盐的发展。在高温熔盐中,抑制金属结构材料腐蚀的主要手段为氯盐提纯和加入缓蚀剂。

Solar energy is the most abundant clean renewable energy on the surface of earth.Solar energy utilization is the most important part of the global renewable energy development strategy.Coupling concentrating solar power(CSP)with thermal energy storage(TES)to produce schedulable clean power is one of the important ways to achieve low-carbon transition of energy.Energy conversion efficiency and power costs hold the key to solar thermal power plants.Taking molten salt as an example,the development of thermal energy storage(TES)/heat transfer fluids(HTFs)systems with higher operating temperature(>565℃)is of great importance to improving the efficiency of solar thermal power generation.Chloride salt is considered to be one of the most promising TES/HTF systems for the next generation to achieve higher efficiency and lower cost.Based on the current research status of chloride salt,this paper discusses the basic research and development strategy of chloride salt,including the thermal properties,corrosion mechanism and corrosion mitigation strategy.The results show that the maximum operating temperature of molten salt is the key to determining the efficiency of TES system.However,the corrosion of metal structural materials in molten salts limits the development of chloride salt.In high temperature molten salt,the main means to inhibit the corrosion of metal structural materials are purification of chloride salt and addition of corrosion inhibitor.