This study calculated the optimal formula (sample A) of ternary carbonate based melting salt using a phase diagram firstly and other four sets of ternary carbonates with different ratios were prepared by changing the content of sodium carbonate and lithium carbonate. The results showed that sample A had better comprehensive thermophysical properties, the melting point, phase change enthalpy, upper limit temperature of thermal stability and stability were the optimal. Whose melting point and phase change enthalpy were 395.57 °C and 322.06 J/g, respectively. The specific heat capacity in the solid phase (330–380 °C) enhanced slightly from 1.38 J/(g·K) to 1.84 J/(g·K) with the increase of temperature, while in the liquid phase, the specific heat capacity was maintained at 1.5 J/(g·K). The ternary carbonate only underwent simple physical mixing without chemical reactions, the decomposition temperature and thermal conductivity of sample A were 885.73 °C and 1.325 W/(m·K), respectively. The ternary carbonates exhibited good thermal stability when continuously heating and heating-cooling cycles.

本研究首先利用相图计算出三元碳酸盐基熔盐的最佳配方（样品A），并通过改变碳酸钠和碳酸锂的含量制备了另外四组不同配比的三元碳酸盐。结果表明，样品A具有较好的综合热物理性能，熔点、相变焓、热稳定性上限温度和稳定性最优。其熔点和相变焓分别为395.57℃和322.06J/g。随着温度的升高，固相（330~380℃）的比热容从1.38 J/（g·K）略有增加到1.84 J/（g·K），而在液相中，比热容则略有增加。容量保持在1.5 J/(g·K)。三元碳酸盐仅进行简单的物理混合，未发生化学反应，样品A的分解温度和导热系数分别为885.73℃和1.325W/(m·K)。三元碳酸酯在连续加热和加热-冷却循环时表现出良好的热稳定性。