市政污水检查井可燃气体组分及分布影响因素研究

Study on Influence Factors of Flammable Gas Composition and Distribution in Municipal Sewage Manhole

为研究市政污水管网内主要可燃气体成分与分布,以实现其燃爆灾害的精准防控,本文采用现场检测的方法采集污水检查井内甲烷、氢气等5种可燃气体以及总的可燃气体浓度,统计分析污水管网各可燃气体的浓度范围,研究检查井深度和季节对甲烷浓度分布的影响。研究结果表明:污水检查井内甲烷浓度占比较大,一氧化碳、硫化氢、氢气和氨气所占比例较小;沿检查井深度方向,甲烷分布规律不尽相同,大部分检查井内甲烷随着与井口距离的增大呈逐渐增大变化趋势;季节对甲烷浓度变化影响较大,夏秋两季甲烷浓度较高,春季次之,冬季未检出甲烷。

In order to make clear the composition and distribution of the main combustible gas and realize the accurate prevention and control of fire blast disaster,five kinds of combustible gases,such as methane and hydrogen,as well as the total flammable gas concentration,were collected by means of field testing,and the change laws of methane concentration along the depth of the inspection well and the influence of season on methane concentration were analyzed.The results show that methane accounts for a large proportion in the sewage manhole,and carbon monoxide,hydrogen sulfide and hydrogen and ammonia gas accounted for a smaller proportion.The distribution of methane is not the same along the depth of the manholes.Methane in most of the manholes increases gradually with the increase of distance from the ground.Seasons have a great influence on the change of methane concentration.The concentration of methane in summer and autumn is higher,followed by spring and there is no methane in winter.