熔盐自然循环回路热损失功率实验及计算

熔盐自然循环回路是为研究熔盐的自然循环特性,支持先进熔盐堆非能动安全系统设计而建造的实验装置。熔盐在回路中的热量损失对于自然循环的建立和保持具有重要的影响。本文以熔盐储罐为代表部件,通过实验得到了其热量损失的数据,并利用数值模拟的方法,计算了不同温度下储罐各部分的热损失,分析了储罐热损失规律,拟合得到了热损失随温度及时间的变化关系。对比熔盐在不同温度下热损失的实验值和计算值,发现两者吻合良好,相对误差均小于10%。分析结果表明,内插式电加热器是储罐主要热损失途径之一,并导致了熔盐的温度分层。

Experiment and calculation of the heat loss power of molten salt natural circulation loop

Background:A molten salt natural circulation experimental loop was developed to study characteristics of the molten salt natural circulation and support the design of passive safety systems of advanced molten salt reactors. Purpose:The heat loss of the loop may affect the molten-salt natural circulation profoundly, thus, it is necessary to quantify the heat loss. Methods: A series of heat loss experiments were conducted on the salt storage tank of the natural circulation loop and the heat losses were also calculated using numerical methods. Based on the measured and calculated results, we obtained the relations between the power of the heat loss and the temperature and the cooling time. Results:It was found that the calculated values of the power of the heat loss were in good agreement with the measured ones. The difference is within 10% for all temperatures concerned. Conclusion: The thermal insulation design of the molten salt natural circulation experimental loop limits the heat loss successfully. An intrusive heating device, though widely adopted, may become a major heat loss channel when not in use, and lead to the molten salt temperature stratification.