三元体系LiNO_3-NaNO_3-KNO_3相图预测及其热性能研究

Phase diagram prediction of the LiNO_3-NaNO_3-KNO_3 ternary system and its thermodynamic performance

采用对称的 Kohler 模型对 LiNO 3-NaNO 3-KNO 3三元体系的相图进行预测,得到三元共晶点为395．50 K,摩尔分数组成为（LiNO 3）＝0．388,（NaNO 3）＝0．102,（KNO 3）＝0．510.对该共晶点组成材料进行 DSC 实验测定,其熔点为397．32 K,而热重 TG 测试表明热稳定温度为868．62 K,表明该材料有可能作为高温蓄热传热材料应用于太阳能热电厂及核能发电厂,工作温度范围为397．32~868．62 K.

The symmetric Kohler model was applied to predict phase diagram of the LiNO 3 -NaNO 3 -KNO 3 terna-ry system,in which one ternary eutectic point （its molar fractions composition： （LiNO 3 ）=0.388, （NaNO 3 ）=0.102, （KNO 3 ）=0.5 10）with low melting temperature was found to be 395.50 K.The DSC and TG curves of the predicted eutectic point were measured and the results showed that the melting temperature was 397.32 K and the thermal stability temperature was 868.62 K,and the predicted molten salts mixture was expected to be used in concentrating solar power and nuclear energy power plants.