Study On The Safety Impact Assessment Of A Parallel Gas Pipeline Depositing

Natural gas is a kind of clean energy.In the future,China's demand for natural gas will continue to increase.Pipeline is the main carrier of natural gas transportation.Due to the need for pipeline construction,more and more pipelines adopt the construction method of parallel laying in close distance.The parallel laying of pipelines will have an impact on pipeline construction,maintenance,and operational safety.The parallel pipeline spacing is a key factor that affects the size of pipeline failure damage.In this paper,the TNT equivalent method is used to simulate the failure explosion of two pipeline laying methods(clear and buried),and the deformation and failure process of the pipeline is analyzed.The explosion damages of parallel pipelines with different spacings are studied,and the safe parallel distance between pipelines is obtained.Firstly,an appropriate explosion model for pipe laying and buried laying is established,and the TNT equivalent method is used to calculate the initial explosion equivalent of the pipeline explosion model.Based on this,ANSYS-Autodyn software was used to establish the explosion models for the open and buried pipelines respectively,to determine the pressure and displacement changes at each observation point during the explosion process,and the impact was calculated with empirical methods.Comparison of overpressure and deformation to verify the reliability of the model.The deformation process of the buried pipeline under the influence of the adjacent pipeline explosion under different parallel spacings and the variation of pressure,displacement,and other related factors were simulated.On the basis of fully understanding the explosion impact damage,we can guide the process of pipeline construction and maintenance,and detennine the parallel safety distance of the open and buried ground conditions respectively.The research and calculations show that the overpressure damage in the early stage of blast impact is the primary cause of the large deformation of the pipeline.Afterwards,the pipeline deformation is also affected by overpressure and impulse damage.Explosive impacts are more damaging to buried pipelines,and the requirements for parallel safety spacing of pipelines are even more stringent.According to the pipe's ellipticity design criteria and the destructive effect of the post-explosion combustion effect,it is recommended that the parallel safe operation distance of the pipeline:the clear pipe laying spacing S>4m,and the buried laying spacing S>8m.