A single tank solar heat storage system is selected as the model in this paper, with a new ternary molten salt KNO3-NaNO3-NaNO2 as the heat transfer and storage medium, and Fluent software is used for numerical simulation of the flow rule and heat transfer characteristics of molten salt in a heat storage single tank with thermocline. The result shows:thermocline thickness increases and heat storage efficiency decreased gradually with increasing inflow velocity of molten salt, and heat storage cycle will increase with the lower inflow velocity;in the winter and summer conditions, heat storage tank should be insulated and heat-storaging process should avoid being shut down, these will reduce heat loss and improve the efficiency of the heat storage single tank. This study gives a new idea for the single tank heat storage system to improve the thermal efficiency, serves a certain foundation for the improvement and study of the complex single tank heat transfer and storage model.%文章以太阳能单罐蓄热系统为研究模型,以新型三元熔融盐KNO3-NaNO3-NaNO2为传热、蓄热介质,利用Fluent软件对熔融盐在斜温层蓄热单罐中的流动规律和传热特性进行数值模拟研究.研究结果表明:随着熔融盐入口流速的增大,斜温层厚度逐渐增加,蓄热效率逐渐降低,但过低的入口流速会延长蓄热周期;冬季、夏季工况下,应对罐体进行保温,并减少蓄热进程的中断,以降低热损失,提高蓄热单罐的蓄热效率.研究结果为单罐蓄热系统蓄热效率的提高指明了一条新思路,并为更加复杂的单罐传热以及蓄热模型的改进与研究奠定基础.
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