Numerical Simulation Of Leakage And Diffusion Of Buried Natural Gas

Natural gas pipeline transportation is an important way of energy transportation.However,pipeline leakage accidents occur frequently,which seriously threaten the safety of energy transmission.In recent years,distributed optical fiber temperature measurement system has been widely used in pipeline monitoring.When the gas pipeline leaks,the high-pressure gas in the pipeline leaks into the soil pores,and the gas goes through a large pressure drop from the high-pressure state to the low-pressure state.When the pressure decreases and the gas expands,the temperature of the gas will change,resulting in the change of the ambient temperature near the leakage point.The distributed optical fiber temperature measurement system realizes the detection of pipeline leakage based on the monitoring of the surrounding temperature of the gas transmission pipeline.The study of the temperature field around the leakage of natural gas pipeline is helpful to guide the reasonable installation of optical cable in the distributed optical fiber temperature measurement system and provide help for the monitoring of pipeline leakage.This paper analyzes the research status of leakage and diffusion of oil and gas transmission pipeline at home and abroad,and based on the previous research results,the research of leakage and diffusion of buried natural gas pipeline is carried out;The physical and mathematical models of the leakage of buried gas pipeline are established.By analyzing the characteristics of natural gas flow in soil,and based on the related knowledge of fluid mechanics,the control equations of natural gas flow in soil,namely the mathematical model,are established.This model can basically describe the flow of natural gas in soil;The leakage of buried natural gas pipeline is simulated by computer.Establish the watershed model for numerical simulation.Natural gas leaks from the pipeline and flows through the soil.A region of natural gas flowing in the soil around the leakage is selected as the numerical simulation region,i.e.watershed model.The ICEM is used to divide the basin into grids,which is ready for the following solver.In the solver ANSYS fluent,the reasonable flow model,the physical parameters of the fluid and the flow medium,and the boundary conditions of the basin are set to solve the problem iteratively.To achieve the real simulation of the leakage of buried natural gas pipeline.Through the numerical simulation results,the temperature distributioncharacteristics of the leakage of buried natural gas pipeline are analyzed.In order to verify the correctness of the numerical simulation,the field simulation of the leakage of gas pipeline is carried out.In a gas transmission pipeline in Northern Shaanxi Province,the leakage condition is simulated,and the experimental data of the leakage place is detected by the distributed optical fiber temperature measurement system.The experimental data are processed and analyzed to verify the correctness of the numerical simulation of the leakage of the buried natural gas pipeline.Through the combination of theoretical analysis and experimental research,the temperature distribution characteristics of the leakage of buried natural gas pipeline are further understood,which provides a strong support for the monitoring of gas transmission pipeline.