中文摘要：

以斜温层蓄热单罐设计理念为基础,采用硝酸熔融盐作为传热蓄热介质,锆质蓄热球与泡沫碳化硅陶瓷2种代表性的多孔介质填料作为固体蓄热体,构建了多尺度结构斜温层混合蓄热方法及系统,实验研究了多尺度结构中熔融盐的流动与蓄热特性。研究结果表明,由于斜温层的存在,系统理论蓄热效率小于80%;相对于熔融盐单相流体蓄热,采用锆质蓄热球与泡沫碳化硅的斜温层混合蓄热方式会导致系统的有效蓄热容量有所降低,但多孔介质填料的加入有利于保持熔融盐流体为理想的重力流或活塞流,并部分替代价格较高的熔融盐,需要结合蓄热容量以及经济性进行最优化设计。

英文摘要：

According to the design idea of thermocline heat storage in single tank,a kind of hybrid thermocline heat storage method in multi-scale structure and relevant experimental systems were built by using the mixed molten nitrate salt as the heat storage medium and two representative porous fillers,i.e.zirconium ball and silicon carbide（SiC） foam,as the solid heat storage materials.The fluid flow and heat storage performances of molten salt in multi-scale structure were experimentally investigated.The results show that the theoretical heat storage efficiencies among the three heat storage manners are less than 80% because of the existence of thermocline layers.Comparing to the heat storage manner of single-phase molten salt thermocline,the two hybrid thermocline heat storage manners using zirconium ball and SiC foam as porous fillers lead to a certain decrease in the effective heat storage capacity.On the other hand,the presence of porous fillers can help to maintain the molten salt fluid as ideal gravity flow or piston flow and partially replace expensive molten salt.Therefore,it requires a combination of heat storage capacity and economical consideration for optimization design when similar spherical particles or foam ceramics are employed as the porous fillers.