新一代替代制冷剂燃爆惰化机理及实验

Mechanism and Experiment of Flammability and Inert Effect of New Alternative Refrigerant

二甲醚(DME)以其较好的热力学、传热学和环境特性决定了其有可能成为环境友好型制冷剂或混合工质的组元.不足的是DME具有可燃性,需要对其可燃性及可惰化性进行评估.通过基团贡献法和燃烧学相关理论对含有DME的二元混合工质阻燃剂的抑制系数进行了分析,提出了阻燃制冷剂最小惰化浓度的理论估算公式.对以一定体积配比的A/DME和B/DME混合制冷剂的可燃性进行了实验研究,得到了混合制冷剂的临界爆炸曲线图.结果表明:A和B对DME的惰化体积分数分别为7.04%和9.97%,理论估算值和实验值基本吻合;并得到了三元混合工质A/C/DME和B/D/DME的爆炸浓度分数图.实验结果对新一代替代制冷剂燃爆惰化及安全使用具有现实指导意义.

The dimethyl ether （DME） is potentially developed as an alternative refrigerant or a group member of mixture refrigerants because of its high thermodynamic efficiency and good environmental protection features. The flammability and inert effect of DEM need to be evaluated due to its flammability. The inhibition coefficient of nonflammable refrigerants was analyzed and a novel equation for predicting the minimum inert concentration of nonflammable refrigerant was proposed by analyzing the group contribution method and the theory of combustion in binary mixtures. At the same time, the explosive experiments of the mixture refrigerants A/DME and B/DME in different volume ratios were studied and the explosion limit curves were plotted. Analysis result shows that the inert concentrations of nonflammable A and B are 7.04% and 9.97% respectively, and the theoretical results were basically in agreement with experimental data. Furthermore, based on the results of binary mixture, the explosion ranges of ternary mixtures of A/C/DME and B/D/DME were obtained. The results have practical significance on the safety utilization of the mixture refrigerant.