基于TDLAS的天然气泄漏空间动态分布监测技术及应用研究

Research on space dynamic distribution monitoring technology and application of natural gas leak based on TDLAS

天然气泄漏污染空气,易造成爆炸事故,危害人身安全,长期泄漏造成资源浪费,因此天然气泄漏监测成为天然气站亟待解决的问题。相较于其他各种测量原理,可调谐激光二极管吸收光谱(TDLAS)技术因其响应迅速、非接触式测量等优点,广泛应用于开放环境下天然气泄漏监测。目前天然气站一般采用多点多线布置多个开放式激光气体遥测仪监测或采用多个扫描式激光气体遥测仪巡航监测的方案,监测区域范围小、漏洞大。本文基于TDLAS的奇次谐波信号建立吸收率函数在线重构算法,提出了一种天然气泄漏空间监测方法及系统,该系统基于GIS平台对天然气站进行三维建模,将监测数据融合处理,采用空间浓度场反演算法,在动态扫描后生成整个场站的浓度动态分布图。该系统实施后的试验结果表明,天然气泄漏监测系统响应迅速、灵敏度高、报警联动及时,三维场景及浓度动态分布图显示直观,泄漏点判断准确。

Natural gas leakage pollutes the air,which is easy to cause explosion accidents and endanger personal safety.The long-term leakage results in waste of resources.Therefore,natural gas leak monitoring has become an urgent problem to be solved in natural gas stations.Compared with other measurement principles,tunable laser diode absorption spectroscopy(TDLAS)technology has been widely used in natural gas leak monitoring in open environments due to its rapid response and non-contact measurements.At present,natural gas stations generally adopt a multi-point and multi-line arrangement of multiple open laser gas telemeters for monitoring or use multiple scanning laser gas telemeters for cruise monitoring.These programs have small monitoring scopes and large loopholes.Based on the odd harmonic signal of TDLAS,the online reconstruction algorithm of recover absorption shape is established,and a space monitoring method and system for natural gas leakage is proposed.The system is based on a GIS platform to perform three-dimensional modeling of natural gas stations.The monitoring data is fused and processed.The spatial concentration field inversion algorithm is used to obtain the concentration dynamic distribution map of the entire station after each dynamic scan.The test results show that the natural gas leakage monitoring has rapid response,high sensitivity and timely alarm linkage.In addition,the monitoring system also provides a clear three-dimensional scene and a concentration dynamic distribution map with the leakage points accurately observed.