长径比对管道油气爆炸特性与火焰传播规律影响研究*

为了探究长径比对油气爆炸传播特性与火焰传播规律的影响，为复杂管道受限空间油气爆炸防控提供理论参考，结合油气爆炸与爆炸抑制工程实际需要，构建不同长径比管道油气爆炸模拟实验系统,在此基础上开展不同初始浓度的预混油气-空气混合气爆炸实验。研究结果表明:管道内部的预混油气爆炸超压信号呈先上升后下降的趋势，由于耗散以及憋压效应导致超压下降平稳后仍大于初始压力；同时长径比增加会导致达到最大爆炸超压的油气浓度增加，油气爆炸超压峰值随着长径比的增加呈现上升→下降→上升的规律，小长径比管道的油气爆炸超压峰值高于大长径比管道，但同为小长径比管道或大长径比管道工况的实验结果对比显示爆炸超压峰值随着长径比增加而提升；而超压上升速率则会随着长径比的增加而上升；长径比的增加同时也会促进火焰的加速传播并减小火焰持续时间。

Study on influence of length diameter ratio on explosion characteristics and flame propagation laws of gasoline air mixture in pipeline

In order to explore the influence of length diameter ratio on the explosion characteristics and flame propagation laws of gasoline air mixture,and provide theoretical reference for the prevention and control of gasoline air mixture explosion in the confined space of complex pipelines,combined with the actual requirements of gasoline air mixture explosion and explosion suppression engineering,a simulation experimental system of the gasoline air mixture explosion in the pipelines with different length diameter ratios was established,and on this basis,the explosion experiments of premixed gasoline air mixture with different initial concentrations were conducted.The results showed that the overpressure signals of premixed gasoline air mixture explosion inside the pipeline increased first and then decreased,and the overpressure was still greater than the initial pressure after decreasing to be stable due to the dissipation and pressure holding effect.At the same time,the increase of length diameter ratio led to an increase in the concentration of gasoline air mixture that reached the maximum explosion overpressure.The peak overpressure of gasoline air mixture explosion presented the trend of rising decreasing rising with the increase of length diameter ratio,and the peak overpressure of the pipeline with small length diameter ratio was greater than that of the pipeline with large length diameter ratio,but the comparison of experimental results for the conditions of pipeline with small length diameter ratio or pipeline with large length diameter ratio showed that the explosion peak overpressure increased with the increase of length diameter ratio.The rising rate of overpressure increased with the increase of length diameter ratio,and the increase of length diameter ratio would also promote the accelerated propagation of flame and reduce the flame duration.