Research on Pipeline Leakage Calculation and Correction Method Based on Numerical Calculation Method

The hazard coefficient for leakage diffusion of gas transmission pipeline is extremely high, which can easily lead to explosive accidents. The amount of gas leakage is an important factor in the safety assessment of pipeline leakage. Therefore, this paper considers the influence of gas interactions inside and outside the pipeline on pipeline leakage and establishes a three-dimensional leakage diffusion model that is coupled with the pipeline and air domain. Through the use of theoretical, experimental, and numerical simulation methods, this paper investigates the effects of leak hole diameter, leak hole shape, and changes in transport pressure on pipeline leakage. Finally, based on simulated leakage data, we analyze the sources of error and propose a high-precision formula for calculating leakage from small holes in pipelines. The results show that an increase in the diameter of the leak hole leads to a decrease in the central velocity of the leak hole and a sharp increase in leakage volume. The leakage volume of different leak hole shapes is ranked in the following order: rectangle > diamond > circle. When the leak holes are rectangle and diamond, the leakage velocity distribution range of the leak hole is larger and more regular than that of the circular leak hole. Also, the volume of gas leakage increases with the increase in delivery pressure, while the central velocity of the leak hole remains relatively unchanged. Based on the proposed pipeline leakage correction formula, it is calculated that under the same working condition, the relative error range between the numerical simulated leakage rate and the theoretically corrected leakage rate is significantly reduced from -8.40%similar to 18.03% to -1.58%similar to 2.60%, and the calculation accuracy is significantly improved.