十水硫酸钠相变蓄冷材料的制备及性能研究

Preparation and Characteristics of Sodium Sulfate Decahydrate as a Phase Change Cold Storage Material

针对果蔬保鲜冷链运输对温度的要求,制备出一种具有适宜相变温度和潜热值的十水硫酸钠相变蓄冷材料。本研究考察了成核剂硼砂的含量对材料过冷度的影响,分析了增稠剂聚丙烯酸钠的含量对材料相分离问题的改善效果,探究了氯化铵和氯化钾的配比对材料蓄冷温度的调节效果,并进行了冷热循环测试。结果表明,十水硫酸钠水合盐体系的最优配比为:4%硼砂+0.75%聚丙烯酸钠+15%氯化铵+5%氯化钾,此时相变体系基本无过冷和相分离,相变温度为11.42℃,相变焓为97.99J/g,经过30次冷热循环后相变温度和焓值基本没有发生变化。

To meet the temperature requirements of cold chain transportation for fruit and vegetable preservation,a sodium sulfate decahydrate with suitable phase change temperature and latent heat was prepared as a cold storage material.This study investigated the effect of nucleating agent(Borax)content on the supercooling degree of materials.The improvement effect of the content of thickener(Sodium polyacrylate)on the phase separation problem was analyzed.The effect of the ratio of ammonium chloride and potassium chloride on the regulation of phase transition temperature was investigated.In addition,the heating-cooling cycle tests were conducted.The results indicated that the optimal ratio for the hydrated salt system of sodium sulfate decahydrate was:4% Borax+0.75% Sodium polyacrylate+15% NH_(4)Cl+5% KCl.The obtained material had basically no supercooling degree or phase separation phenomenon,with a phase change temperature of 11.42℃ and a latent heat of 97.99 J/g.After experiencing 30 heating-cooling cycles,the phase change temperature and latent heat of materials remained largely unchanged.