Research On Experiment And Numerical Simulation Of Indoor Natural Gas Pipeline Leakage

With the vigorous promotion and use of gas,safety accidents such as gas explosions have gradually increased,which has aroused widespread concern.Although the LPG long-distance pipeline leak detection technology has made great progress,the indoor gas pipeline leak detection is still in the initial stage of development,and the relevant detection theory is still lacking.Especially for the leakage research of gas bellows,there are still many shortcomings to solve.In this paper,the stainless steel bellows for indoor gas is taken as the research object,and the analysis conditions of bellows leakage in the indoor gas pipeline system are discussed and determined.Under this analysis condition,based on the hydraulic theory involved in the pipeline flow and leakage process,the hydraulic relationship of the fluid in the conduit is pushed.The theoretical calculations are made on the steady-state pressure and leakage rate of the leakage point respectively.The relationship between the change of the pressure at the end of the pipe and the physical flow of the pipe flow,leakage flow and pipe inlet pressure before and after the leakage of the stainless steel bellows is analyzed.Set up an indoor gas pipeline leak detection test bench,using the typical control variable method,set the experimental conditions under the same conditions of different leakage holes,pipe flow,pipe shape and pipe diameter specifications to test the flow in the pipeline system.Relevant parameters such as pressure,especially the pressure at the end of the pipe before and after the leak.The difference in pressure at the end of the pipe is analyzed under different pipe flow,pipe diameter,leak rate and pipe shape.The physical model and mathematical model of indoor gas pipeline leakage are established,and the process of solving the leakage of indoor gas bellows by CFD software is introduced.Based on the determined set parameters,the five geometric models that have been established and completed the meshing are numerically simulated,and the change values of the end pressure of each pipe flow before and after the pipe leakage are obtained under the five models.Pipeline leakage value.The simulation results are compared with the experimental data to obtain the change trend and the data result which are consistent with the experimental data.In the 1stOpt software,the genetic algorithm,the Macquay method,the standard simple face climbing method and the self-organizing fusion algorithm were used to fit the data,and the fitting result of the best self-organizing fusion method was selected.Therefore,the correlation between the change value of the end pressure of the pipe and the pipe flow and leakage flow before and after the leakage of the bellows is obtained,and the effect of this correlation on the leak detection of the indoor gas pipe is explained.In this study,the quantitative relationship between the change of the end pressure of the pipeline before and after the leakage of the indoor gas pipeline and the pipeline flow and leakage flow is given.The qualitative analysis of different diameters,leaks and pipe flow is equivalent.The influence of the pressure change value at the end of the pipe has certain guidance and reference significance for the development of leak detection technology for indoor gas pipelines.