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用步冷曲线法研究室温冷却环境下成核剂-Na2HPO4·12H2O复合体系的过冷性能,分析成核剂的添加量和晶体结构对过冷度的影响.结果表明:Na2SiO3·9H2O、NaF、CH3COONa·3H2O和Na2B4O7·10H2O这4种成核剂对Na2HPO4·12H2O的过冷现象有不同程度的改善.为有效改善过冷,成核剂的添加量有一个合适的范围.在10g的Na2HPO4·12H2O中,分别添加0.30g的Na2SiO3·9H2O、0.15g的CH3COONa·3H2O、0.05g的NaF和0.05g的Na2B4O7·10H2O时,抑制过冷的效果最好.同时发现,与Na2HPO4·12H2O晶体结构不同的成核剂Na2SiO3·9H2O改善过冷的效果最显著;与Na2HPO4·12H2O晶体结构相同的成核剂中,Na2B4O7·10H2O改善过冷的效果优于CH3COONa·3H2O.
The supercooling performance of the nucleating agent-Na 2 HPO 4 · 12H 2 O under room temperature cooling was studied by a step-cooling curve method. The effects of nucleating agent addition amount and crystal structure on the undercooling were analyzed. The results showed that Na2SiO3 · 9H2O, The three nucleating agents, CH3COONa · 3H2O and Na2B4O7 · 10H2O, improved the undercooling of Na2HPO4 · 12H2O to a certain extent.In order to effectively improve the supercooling, there was a suitable range of nucleating agent addition.After 10g of Na2HPO4 · 12H2O, 0.30g of Na2SiO3 · 9H2O, 0.15g of CH3COONa · 3H2O, 0.05g of NaF and 0.05g of Na2B4O7 · 10H2O, respectively, the effect of inhibiting supercooling is the best.At the same time, it is found that the crystal structure is different from that of Na2HPO4 · 12H2O Of the nucleating agent Na2SiO3 · 9H2O to improve the cooling effect of the most significant; and Na2HPO4 · 12H2O crystal structure of the same nucleating agent, Na2B4O7 · 10H2O improve overcooling effect better than CH3COONa · 3H2O.