天然气管道泄漏对周围土壤温度的影响

Effect of natural gas pipeline leakage on surrounding soil temperature

分布式光纤测温技术应用于天然气管道泄漏检测时,测温光缆一般敷设在管道上方。随着国内长输管道管径的增大,当微小泄漏发生在管道正下方时,现有光纤测温系统及其敷设位置的适用性有待研究。分析了天然气发生泄漏后,由于天然气发生节流膨胀引起的温度变化,建立了恒温气团模型,研究了气体温度变化对周围土壤温度的影响,并给出了稳态时周围土壤温度分布的计算公式。在实际应用上,该计算公式可为选择相应适用范围的分布式光纤测温技术和光缆的合理布置提供参考,也可为其他测温技术应用于天然气管道泄漏检测提供指导。

When the distributed optical fiber temperature measurement technique is applied to detect natural gas pipeline leakage,the optical cable for temperature measurement is laid above the pipeline.With the increase of the diameter of the domestic long-distance pipelines,the applicability of the existing optical fiber temperature measurement system and its laying position remains to be studied,when the micro-leakage occurs directly below the pipeline.This paper analyzes the temperature change caused by throttling expansion of natural gas after gas leakage,and further studies the influence of gas temperature change on the surrounding soil temperature by establishing a constant temperature air mass model,and obtains the calculation formula of the surrounding soil temperature distribution in steady state.In practical application,it can provide reference for the selection of suitable distributed optical fiber temperature measurement technique and the reasonable arrangement of optical cable,and also provide guidance for the application of other temperature measurement techniques in gas pipeline leakage detection.