多元混合气体爆炸特性及惰化防爆研究

为了完善常见多元混合气体爆炸特性参数数据库,为安全工程师开展城镇燃气防爆管理、安全操作规程的制定及对废弃管道进行改造、拆除提供依据,采用理论和试验方法对CO2与N2两种惰性气体对液化石油气(LPG)爆炸特性参数的影响规律进行了研究,对比分析了两种惰化剂对LPG的抑爆效果。结果表明:LPG体积分数为4.0%、CO2体积分数为22%时,LPG可燃气退出爆炸区间,此时极限氧体积分数为15.54%;LPG体积分数为3.5%、N2体积分数为32%时,LPG可燃气退出爆炸区间,此时极限氧体积分数为13.545%;两种惰化剂对LPG爆炸特性的抑制规律基本相似,但CO2的抑制效果明显优于N2。当CO2和N2充入的体积分数均为20%时,最大爆炸压力到达时间分别由166 ms延长到1 222 ms和826.30 ms;两种惰化剂用量在体积分数大于10%之前,对最大爆炸压力到达时间的影响均较小,因此在工程应用中采用惰化方式抑爆,惰化剂充入的体积分数需高于10%。

On the bursting and explosion characteristic features and inert inhibition of the mixed gas

This article intends to make an exploration of two kinds of inert gases,i.e.the carbon dioxide and nitrogen,to identify and determine their characteristic features for explosion suppression through a careful comparison and their influence on the suppression of explosion risks through a theoretical and experimental practice.For this purpose,we have worked out the explosive characteristic parameters of the common mixed gas to provide the engineering safety evidences for the safety engineers of the urban and suburban anti-explosion to manage and implement the fuelgas safety application along with the renovation and dismantlement of the forsaken gas pipes.The results of our investigation and tests prove that there exit the explosion range and the limit of the oxygen concentration,which stands at about 15.54％.And,on the condition when the LPG' s volume fraction is 4.0％ and the volume fraction of carbon dioxide is 22％,it would be possible to improve the database of the explosive characteristic parameters of the ordinary mixed gas.On the other hand,there also exits the explosion range and the limit oxygen concentration for the LPG gas,which stands about 13.545％ with the LPG' s volume fraction being 3.5％ and that of nitrogen being 32％.Although the two kinds of inert agents are working with similar function for LPG' s explosion suppression,the suppression effect of the carbon dioxide proves obviously more advantageous than that of nitrogen.With the inflated volume fraction of the carbon dioxide and nitrogen at a percentage rate of 20％,their maximum explosion pressure (tmn) can further be extended from 166 ms to 1 222 ms and 826.30 ms,respectively.The maximum explosion pressure tmn,known as the "momentus to arrive at the LPG' s maximum explosion pressure" can be regarded as the most important parameter representing the delayed effect of the inertagent for explosive environment.Therefore,the aforementioned conclusion can help the safety engineers to work out more scientific and reasonable emergency plans and fire-control measures.Nevertheless,the delay of the bursting moment of the maximum explosive pressure wouldn' t be apparent or can be controlled if the volume fraction of the two inert agents can be made to reach merely 10％ or below.Thus,there will be the moment for the volume fraction of the inert agent to increase accordingly still higher than or beyond 10％ for their engineering application to the explosion suppression.