摘要
随着矿井开采深度的增加,热害已成为影响矿井安全生产的主要灾害之一,大面积的机械制冷降温能耗高且投资大。穿着冷却服是除机械降温手段外一种高温高湿环境下保证人体免受热害的一种有效个体的防护措施。冷却服中填充的相变蓄冷材料对冷却服的性能有着重要影响。实验研究了冷却服中填充的相变蓄冷材料的降温剂、防过冷剂、成核剂、基液的特性及凝胶形成的方法。结果表明:氯化钠(NaCl)可作为相变点在-2~-5℃时的降温剂,氯化钾(KCl)可作为相变点在-5~-10℃时的降温剂;质量浓度为0.5%的四硼酸钠(Na_2B_4O_7·10H_2O)可降低NaC溶液的过冷,质量浓度为1.0%的Na_2B_4O_7·10H_2O可降低KCl溶液的过冷;在柠檬酸的催化作用下,聚乙烯醇和戊二醛发生化学交联而形成的凝胶性能稳定、且具有较高的潜热;聚乙烯醇、戊二醛、柠檬酸浓度分别为7%、10%及2%的溶液以质量为20∶1.1∶1的比例配制的混合溶液可作为冷却服填充相变蓄冷材料的理想基液。
With the increase of mining depth,thermal damage has become one of the main disasters affecting the safety of mine production.Wearing a cooling suit is an effective individual protective measure to protect the human body from heat damage in high temperature and high humidity environment.The phase-change material filled in the cooling suit has an important influence on the performance of the cooling suit.In this paper,the cooling agent,anti-supercooling agent,nucleating agent,characteristic of base liquid and formation method of gel were studied experimentally.Results show that NaCl can be used as a phase change point in-2℃to-5℃cooling agent and KCl can be used as a phase change point in-5℃to-10℃;Na_2B_4O_7·10H_2O with a mass concentration of 0.5%can reduce supercooling of NaCl solution,while Na_2B_4O_7·10H_2O with a mass concentration of 1.0%can reduce supercooling of KCl solution.Under the catalysis of citric acid,the gel formed by chemical crosslinking of polyvinyl alcohol and glutaraldehyde are stable and have high latent heat.The mixed solutions of pva,glutaraldehyde and citric acid with the concentration of 7%,10% and 2%,with a mass of 20∶1.1∶1,can be used as the ideal base solution for the phase change cold storage material filled with the cooling suit.
引文
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