三氟甲烷灭火过程中HF生成量的研究

三氟甲烷（CF3H, HFC-23）是全氟烷烃的一种，在目前的卤烃气体灭火介质市场占据了主导地位；然而，在三氟甲烷和火焰作用的过程中产生的HF不仅对火灾现场设备具有严重的腐蚀，而且对灭火现场人员具有严重的伤害，故氟化氢（HF）的生成量是其工程应用需要考虑的重要问题之一；然而，对三氟甲烷在灭火过程中HF生成量的研究，目前尚缺乏深入有效的理论计算方法；本文应用量子化学从头算方法，在B3LYP/6-311++G(d,p)水平上，对三氟甲烷在火场作用下热分解动力学特性进行研究，建立三氟甲烷灭火生成HF量的计算模型；其次，采用原位光谱诊断方法，对在Cup-Burner中，CF3H熄灭酒精火焰作用过程中HF的浓度变化进行在线测量；通过HF理论预测值与实验值对比分析，验证了预测模型的可靠性；此外，CF3H灭火过程中产生HF主要产生路径是为CF3H+?H反应；理论分析和实验表明，CF3H在100℃到400℃之间，HF产生量最快；超过400℃时，HF量基本保持不变。该研究为优化三氟甲烷的系统设计，减少腐蚀性气体的生成量和拓宽三氟甲烷工程应用范围提供指导。

Amount and Mechanism of HF Production in Fire Extinguishing Process Using CF3H

Trifluoromethane (CF3H, HFC-23), as one of important perfluoroalkanes, is used commonly in now fire extinguishing agent market. However, when CF3H is discharged into the fire protection place, HF will be produced by the interaction between the flame and CF3H. HF not only has severe erosion to the metal apparatus, but also makes serious harm to the people in fire scene, so the production amount of HF in fire extinguishing protection is an important problem when CF3H is applied. At present, there is lacking of in-depth insight of HF production in fire extinguishing process with CF3H. So the amount and mechanism of HF production in fire extinguishing process using CF3H is studied in this paper. Firstly, the decomposition of CF3H under different temperature is calculated by Ab initio method at B3LYP/6-311 + + G (d, p) level. And then, the model for predicting HF amount is proposed on the base of calculation. Thirdly, the production amount of HF is measured real-timely by in-situ spectral diagnostics method when CF3H is discharged into Cup-burner with steady alcohol flame. Conclusion: By comparing the calculated results with experimental results, it shows that the HF production predicting theory model was reliable; When the temperature is lower than 100℃, there little HF；The fastest HF production rate between 100℃ and 400℃；after 400℃, it has nearly no change; The main pathway for HF production is CF3H+?H reaction.