Abstract:

To provide boundary conditions for the analysis of the consequences of the accident, a self designed loop device was adopted. Air was used as experimental medium. The buried pipeline gas leakage experiment was carried out under different soil depths (0—60 cm), leak hole diameter (1—4 mm) and leakage pressure (10—50 kPa). The variation of gas leakage amount, dynamic pressure and pressure drop before leak point under different conditions were studied. The results showed that when other conditions remained the same, dynamic pressure peak increased as the leakage pressure increased, increased as the leak hole diameter incresed and decreased as the soil depth increased. In the process of leakage, the gasflow rate increased before the leak point and decreased after the leak point, then, the pressure and gas flow rate in the pipeline remained stable quickly. The gas leakage amount decreased as the soil depth increased, but the influence was small. The gas leakage amount increased approximately exponentially with the increases of leak hole diameter, the gas leakage amount increased linearly with the increases of leakage pressure. The larger the dynamic pressure peak, the larger the gas leakage amount. The larger the gas leakage amount, the larger the pressure drop before the leak point. The quantitative relation formula between gas leakage amount with soil depth, leak hole diameter and leakage pressure, quantitative relation formula between gas leakage amount with dynamic pressure peak, quantitative relation formula between gas leakage amount with pressure drop before leak point were fitted by Matlab program. To generalize the formula, the calculation results were compared with the theoretical model for calculating gas leakage amount of overhead pipelines. By adding the coefficient \alpha , three quantitative relations of gas leakage amount of buried gas pipeline under the condition of small hole leakage (d ≤ 20 mm) and subsonic flow (P≤ 90 kPa) were obtained.

Key words: buried pipeline, leakage amount, dynamic pressure, pressure drop, fitting

摘要：

为给埋地输气管道发生泄漏事故的后果分析提供边界条件，采用自行设计的环道装置，以空气作为实验介质，在不同土壤埋深（0~60 cm）、泄漏孔径（1~4 mm）和泄漏压力（10~50 kPa）条件下进行埋地管道气体泄漏实验，研究不同条件下气体泄漏量、动态压力、泄漏点前压力降的变化规律。对实验数据进行拟合，得到泄漏量与土壤埋深、泄漏孔径、泄漏压力的定量关系式，泄漏量与动态压力幅值的定量关系式，泄漏量与泄漏点前压力降的定量关系式。将计算结果与架空管道气体泄漏量计算的理论模型做对比，通过引入系数 \alpha ，得出适用于小孔泄漏（d ≤ 20 mm）、亚音速流动（P≤ 90 kPa）条件下埋地输气管道泄漏量预测的定量关系式。

关键词: 埋地管道, 泄漏量, 动态压力, 压力降, 拟合