城市燃气泄漏检测新方法及其应用

A new method for urban gas leak detection and its application

在城市燃气泄漏检测中,常用甲烷检测仪很容易受到CO、CO2、H2O等气体和现场实际条件(如潮湿度、覆盖物和风向等)的干扰影响,导致误检和判断失效。为此,优选了利用红外吸收原理的光学甲烷检测仪替代传统可燃气体探测器,分析了光学甲烷检测仪的5个优点:①气体选择性好;②检测仪表不易受有害气体的影响而老化;③响应速度快,稳定性好;④防爆性好,信噪比高,使用寿命长,测量精度高;⑤应用范围广。为了提高燃气泄漏检测的精度和效率,还提出了车载式OMDTM光学甲烷探测仪和便携式RMLDTM激光甲烷遥距检测仪互补使用的燃气泄漏检测新方法,即在巡检过程中,若车载式OMDTM光学甲烷探测仪出现报警,则用RMLDTM在报警范围内进行遥测,确定泄漏源。该方法可有效排除沼气等其他可燃气体对泄漏检测的干扰影响,不仅能够覆盖城市的整个燃气管网,主动预防泄漏事故的发生,而且在泄漏抢险工作中,检测车能够迅速到达现场参与漏点查找工作,有助于尽快处理泄漏事故。现场实际应用效果表明,该燃气泄漏检测方法准确率较高,误报率低,响应速度快,符合现代城市燃气泄漏检测的需要。

The frequently used methane detector for gas leak is vulnerable to gases like CO,CO2 and H2O,as well as on-site conditions,such as humidity degree,coverings,and wind direction,which will lead to failure diagnosis or false detection.The optical methane detector based upon the infrared absorption principle is accordingly used instead of the traditional one and its five advantages are summarized herein:(1)good performance in differentiating the mixed gases;(2)being anti-ageing and invulnerable to harmful gases;(3)quick response and good stability;(4)a wide range of application;and(5)other advantages like a good explosion-proof quality,a high signal-to-noise ratio,a long service life,and a high accuracy of measurement.To increase the accuracy and efficiency of gas leak detection,a new method is introduced combining the vehicle-mounted OMDTM optical methane detector and the portable RMLDTM laser methane remote detector.If the former detector alarms,the latter one will be used within the alarming range to ascertain the leakage source.This detection method can not only effectively help get rid of the interference caused by some other combustible gases,such as biogas,but cover the whole urban gas grids to actively prevent accidents,the most important of all,the vehicle with the detector will arrive and participate in dealing with such accidents as early as possible.Field application results show that this gas leak detection method is characterized by a high accuracy,a low rate of false alarm,and a high response speed,and can meet the current demand of urban gas leak detection.