基于稳态模型的井下抽采主管道泄漏检测方法研究*

为准确检测煤矿井下瓦斯抽采主管道泄漏位置，提出基于稳态模型的管道泄漏检测与定位方法，采用Comsol数值模拟及地面相似实验研究压力梯度法对煤矿井下抽采管道泄漏检测与定位的可行性及准确性。研究结果表明:管道未泄漏时，管内沿线压力呈均匀分布，当管道突发泄漏时，管内压力分布呈现明显弯折现象，弯折处即为管道漏点位置，并对管道阻力计算公式进行修正，提高了检测准确性；随着管道泄漏程度的加大，湍流效应显著增强，漏点处速度、压力产生明显突变，且当其他条件恒定时，随着管道泄漏孔径的扩大，管道的漏入量越大，定位的相对误差越小；在宏岩矿开展地面相似实验，实验结果绝对误差为4.5 m，相对误差为6%；在阳煤五矿井下8421抽采巷进行现场应用，绝对误差134 m，相对误差约7.95%。

Research on leakage detection method of underground extraction main pipeline based on steady state model

In order to accurately detect the leakage location of gas extraction main pipeline in the underground coal mine,a method of pipeline leakage detection and location based on the steady state model was proposed.The Comsol numerical simulation and the ground similar experiments were used to study the feasibility and accuracy of adopting the pressure gradient method to detect and locate the leakage of extraction pipeline in the underground coal mine.The results showed that when the pipeline was not leaking,the pressure along the pipeline distributed evenly.However,when the pipeline suddenly leaked,the pressure distribution inside the pipeline presented the obvious bending phenomenon,and the bending position was the pipeline leakage point.The calculation formula of the pipeline resistance was also modified to improve the detection accuracy.As the leakage degree of pipeline increased,the turbulence effect enhanced significantly,and the velocity and pressure at the leakage point changed sharply.When the other conditions were constant,the leakage amount of the pipeline became larger,while the relative error of locating became smaller with the expansion of the leakage aperture of the pipeline.In the ground similar experiments carried out in Hongyan mine,the absolute error of the experimental results was 4.5 m and the relative error was 6%.According to the field application in 8421 extraction roadway of Yangmei No.5 coal mine,the absolute error was 134 m and the relative error was about 7.95%.