| 摘要: |
| 卤代烷烃和卤代烯烃等氟为代表的工质是当前使用最广泛的人工合成制冷剂，随着环保要求不断提高，可选的氟代物多具有一定可燃性。制冷剂的可燃性限制了其在家用和商用等场景下的使用范围。根据可燃工质的燃烧特性寻找阻燃方法，其中重要的手段是从研究燃烧反应机理及反应路径出发对单一或混合制冷工质进行燃烧过程反应研究。本文研究了R1234yf为代表的低碳氟代烯烃燃烧点火延迟、温度压力变化、典型组元燃烧过程；并对比了R32和R1234yf燃烧机理与反应路径。研究结果表明：R32和R1234yf与烷烃和烯烃燃烧模型吻合，R1234yf点火延迟更高，加成和夺取反应更加复杂；通过反应路径的研究发现，两种可燃性工质中间稳定产物存在较多重合，在R32中仅添加体积分数为10%R1234yf时，当量比为1时的燃烧平衡温度可下降87.5 ℃；添加体积分数5%的R32混合物的燃烧平衡温度可下降21.0 ℃，混合物可燃性可低于两者任意组分；添加少量R32后点火时间提前，放热反应的自由基生成峰值明显降低。 |
| 关键词: 制冷剂 可燃性 阻燃 反应路径 混合抑制 |
| DOI： |
| 投稿时间：2021-01-20 修订日期：2021-04-11
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| 基金项目:国家自然科学基金 (51936007) 和中国制冷学会课题(CAR20190701)资助。 |
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| Flammability Comparison and Flame Retardancy Research on R32 and R1234yf |
| Shi Yuqi,Yang Zhao,Lü Zijian |
| (Key Laboratory of Efficient Utilization of Low and Medium Grade Energy, Tianjin University, MOE) |
| Abstract: |
| Halogenated alkanes and halogenated olefins, especially fluorine substitutes, are currently the most widely used synthetic refrigerants. With the implementation of a series of increasingly stringent environmental regulations, most optional fluorinated substances are flammable, thus limiting their scope of use in domestic and commercial scenarios. Novel flame-retardant methods need to be developed based on the combustion mechanism. An important method is to study the combustion process of pure or mixed refrigerants through the reaction mechanism and reaction path. In this study, the ignition delay, temperature and pressure changes, and typical component combustion processes of low-carbon fluoroolefins represented by R1234yf were studied, and the combustion mechanisms of R32 and R1234yf were compared. These results are consistent with the combustion models of alkanes and olefins. R1234yf’s ignition delay is higher, and the addition and capture reactions are complicated; through the study of the reaction path, it was found that the intermediate stable products of the two flammable working fluids have many overlaps. When R1234yf is 10%, at an equivalent ratio of 1.0, the combustion equilibrium temperature can be reduced by 87.5 ℃ compared to that for pure R32; when R32 is 5%, the combustion equilibrium temperature can be reduced by 21.0 ℃ compared to that for pure R1234yf. The flammability of the mixture was lower than that of any of the two components. With the addition of a small amount of R32, the ignition time was increased, and the peak of free radicals boosting the exothermic reaction was significantly reduced |
| Key words: refrigerant flammability flame retardant reaction path mixing inhibition |
