改进三水醋酸钠蓄热性能的实验研究

Experimental researches for improving the heat storage performance of sodium acetate trihydrate

无机水合盐三水醋酸钠(CH3COONa.3H2O)具有58℃的熔点和较大的融解热(264 J/g),但作为相变蓄热材料有析出和过冷两大缺点,极大地影响了它的贮热容量和释热温度.在分析三水醋酸钠理化特性的基础上,实验研究了添加抗沉淀剂以及添加PCM晶粒对三水醋酸钠析出和过冷的抑制效果,对实验现象和结果进行了详细的分析研究,并对抑制机理作了分析讨论.研究结果显示增稠剂CMC具有良好的析出抑制效果,添加PCM晶粒是一种有效的过冷抑制方法.

The sodium acetate trihydrate （CH3COONa· 3H2O） has a melting point of 58 ℃ and the fairly large heat energy of thaw（264 J/g）. As a phase change material for heat energy storage, however, it is characterized by the unfavorable phase separation and super-cooling, which drastically influence its thermal energy storage capacity and solidification temperature. Base on the analysis to the characteristics of the sodium acetate trihydrate, experimental investigations were carried out to testify the effect on restraining the super-cooling and the phase separation of the sodium acetate trihydrate added with suspension mediums and PCM crystal seeding. It is concluded that the phenomenon of separating phase is significantly inhibited by CMC used as a thickening agent and the apparent control of super-cooling is achieved by the appending crystal seeding of sodium acetate trihydrate.