基于主动瞬变流的天然气管道泄漏检测研究

Study on natural gas pipelines leak detection based on active transient flow

潮湿复杂的土壤环境会导致天然气管道发生腐蚀泄漏,研究准确可靠的天然气管道泄漏定位方法对保障管道安全运行具有重要意义。采用主动控制方法建立了瞬变流泄漏定位模型。以现场数据为基础,通过模拟分析评价了泄漏定位模型的预测精度。研究了阀门动作时间、泄漏孔径对泄漏定位精度的影响。结果表明:随着阀门动作时间的增加,压力信号波动幅度降低。相比1 s关闭阀门,20 s关闭阀门产生的压力信号无明显的周期变化,加大了泄漏定位的计算误差。随着阀门关闭时间的增加,定位误差随之变大,阀门动作时间应根据实际管道长度及压力波传播速率进行确定。随着泄漏孔径的增大,泄漏定位误差先降低后升高,模型对中孔泄漏定位较为准确。

The humid and complex soil environment can cause corrosion and leakage of natural gas pipelines.It is of great significance to study accurate and reliable natural gas pipelines leakage location methods to ensure the safe operation of pipelines.An active control method is used to establish a transient flow leakage location model.Based on the field data,the prediction accuracy of the leak location model is evaluated through simulation analysis.The effect of valve action time and leakage aperture on the accuracy of leakage location is studied.The results show that with the valve action time increasing,the fluctuation range of the pressure signal decreases.Compared with closing the valve in 1 s,the pressure signal generated by closing the valve in 20 s has no obvious periodic change,which increases the calculation error of leakage location.With the valve closing time increasing,the location error becomes larger.The valve action time should be determined according to the actual pipelines length and pressure wave propagation speed.With the increase of the leakage aperture,the leakage location error first decreases and then increases,and the model is the most accurate for the leakage location of the middle hole.