空气浴条件下三水醋酸钠相变材料的储热性能实验

Sodium acetate trihydrate (SAT), which has high energy storage density and high thermal conductivity, is an important phase change material (PCM) for thermal storage. But it suffers from serious supercooling during the solidification process, which constrains its application. In this study, seven kinds of nucleating agents (Na₂HPO₄•12H₂O, Na₂CO₃•10H₂O, Na₄P₂O₇•10H₂O, Na₃PO₄•12H₂O, Na₂SiO₃•9H₂O, Na₂S₂O₃•9H₂O and Na₂B₄O₇•10H₂O) were proposed to reduce the degree of supercooling of SAT. With the help of the high-low temperature test chamber, the experiments were performed to investigate the degree of supercoiling, and to validate the thermal stability of composite PCM by using the curve law of step. As a result, the composite PCM with the mass fraction of 96%CH₃COONa•3H₂O+2%Na₂HPO₄•12H₂O+2%carboxymethycellulose presents the smallest the degree of supercooling, which is 5.6℃. Moreover, the phase transformation point of the composite PCM varies a little with 25, 50 and 75 thermal cycles. While its latent heat would decrease and the degree of supercooling would increase with the number of thermal cycles increasing. Therefore, this study enriches the adjustment program of the degree of supercooling of SAT, and will be evaluated for engineering application in future offerings.