为使混合熔盐能在更低温度下使用,扩宽混合熔盐的工作温度范围,以KNO3-NaNO2-KNO2-Ca（NO3）2四元系混合硝酸盐为研究对象,采用DSC、TG测试分析方法,筛选出一种新型低熔点四元硝酸盐。对新型四元盐在不同温度下恒温失重情况进行研究,并对其比热容、密度、导热系数等进行测试分析。研究结果表明：新型四元盐熔点为94.8 ℃,分解温度达到622.3 ℃,储热密度达到696.43 kJ/kg,在550 ℃工况下恒温48 h后样品失重率仅为2.71%,表现出良好的热稳定性。
Abstract
To lower the minimum operating temperature and broaden the working temperature range of mixed molten salts, a quaternary nitrate mixture of KNO3-NaNO2-KNO2-Ca（NO3）2 was studied. Using DSC and TG analysis methods, a new low-melting-point quaternary nitrate was identified. The thermal stability of the new quaternary salt was investigated through isothermal weight loss measurements at various temperatures. Furthermore, its thermal properties such as specific heat, density, and thermal conductivity were tested and analyzed. The research findings indicate that the new quaternary salt has a melting point of 94.8 ℃, a decomposition temperature of 622.3 ℃, and an energy storage density of 696.43 kJ/kg. After maintaining a constant temperature of 550 ℃ for 48 hours, the sample exhibits a low weight loss rate of only 2.71%, demonstrating excellent thermal stability.
关键词
太阳能热发电 /
低熔点 /
宽温域 /
四元硝酸/亚硝酸盐 /
热物性 /
储热材料
Key words
solar thermal power generation /
low melting point /
wide temperature range /
quaternary nitrate/nitrite salts /
thermal properties /
heat storage material
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基金
国家重点研发计划（2022YFB4202402）; 国家自然科学基金（52076006）
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