二元可燃烃类混合气体的爆炸下限实验及理论预测

Experiments and theoretical prediction of lower explosion limit for binary flammable hydrocarbon gas mixtures

利用FRTA爆炸极限测试仪对二元可燃烃类混合气体爆炸下限(LEL)进行测试,共获得16组144个二元可燃混合气体的爆炸下限值,并对混合气体随其组分及配比变化的规律进行研究。基于Chemkin软件的绝热燃烧相平衡模型模拟了二元可燃烃类混合气体的绝热燃烧过程,以绝热压升达到324. 24 kPa为依据判断此时可燃混合气体已达爆炸下限。结果表明:模拟规律与实验规律相类似,且两者间曲线变化幅度差距不大;样本中二元可燃混合气体爆炸下限预测值与实验值平均绝对误差为0. 22%,平均相对误差为9. 41%,预测误差在实验误差允许范围之内,可见预测方法具有较强的可靠性。本文的研究为工程上预测二元可燃混合气体的爆炸下限提供了一种新的有效方法。

The explosion limit are an important parameter to evaluate explosive characteristic of combustible,and is applied in the combustible gas monitoring and early warning and risk assessment.16 group with 144 lower explosion limit( LEL) values of binary flammable hydrocarbon gas mixtures were tested by FRTA explosion limit tester and its variation with the gas mixture compositions and ratios were investigated. Based on the adiabatic combustion phase equilibrium of Chemkin model,the adiabatic combustion process of binary combustible hydrocarbon gas mixtures was simulated. The combustible gas mixtures reached their lower explosive limits at the time when adiabatic pressure increased to 324. 24 kPa.It was found that the simulation values were similar to the experimental results,and the curve variation between gap was not obvious,average absolute error was 0. 22%( volume fraction),and the average relative error was 9. 41% with the prediction error in the acceptable range.The prediction was reliable by Chemkin for lower explosion limit of binary combustible gas mixtures,and it provided a new effective way for the engineering prediction of lower explosive limit for binary flammable hydrocarbon gas mixtures.