Experimental study on leakage characteristics of buried gas pipelines

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 α, 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. © All Right Reserved.