成核添加剂对低温相变蓄冷材料过冷度的影响研究

Impact of nucleating agent on supercooling of low temperature phase changed material

实验研究了成核剂对低温相变材料过冷度的影响.以冷藏工业中常用的-6^-7℃为目标相变温度,NaCl,KCl,NH4Cl三种盐溶液为实验对象.首先查找相图确定了它们在目标相变温度发生相变时的浓度,然后以此浓度为对象,进行了成核剂添加实验.结果表明添加0.02%硅藻土的10%NH4Cl溶液,添加0.1%CuS的12%KCl溶液和添加1%硼砂的12%KCl溶液,以及添加0.02%硅藻土的10%NaCl溶液和添加1%硼砂的10%NaCl溶液可以较好降低过冷度.实验还发现,在连续实验中KCl溶液较易出现环状结冰,环状结冰的相变时间比普通结冰方式要长近一个小时.

Impact of nucleating agent on supercooling of low temperature phase changed materials （PCMs） were experimentally studied in this paper. The objective temperature of phase changed materials is -6--7 ℃, which often used in refrigeration industry. The concentration of salt solutions of NaCl,KCl and NH4Cl which used as PCMs in experiment are determined by looking up phase diagram. The result shows that 12%KCl with 0.1% CuS,12%KCl with 1% borax, 10% NaCl with 0.02% diatomite, 10% NaCl with 1%borax and 10% NH4Cl with 0.02% diatomite can effectively release supercooling of salt solutions. In addition, 12 % KCl is more likely to occur annulus solid ice phenomena in successive experiment, with which phasing time is prolonged by 1 hour.