Research On The Spatial And Temporal Evolution Law Of Gas Pipeline Network Leakage Effect Under Coupling Conditions

With the popularization of gas,it further promotes the economic development of cities and improves the quality of people’s lives.However,the flammability and explosiveness of gas have made safety issues increasingly prominent.When gas leaks occur,they can easily spread to adjacent underground spaces,leading to coupled accidents.In particular,due to reasons such as short circuits,overloads,and poor contacts in power cables,anomalies such as abnormal discharge and high temperature overheating may occur in pipeline networks,and the explosion risk of cable channels is relatively high compared to other underground networks.Therefore,it is necessary to conduct targeted identification and prevention of areas where high-risk gas pipelines are combined with power channels.Conducting research on the leakage and diffusion of urban buried gas pipelines to adjacent underground spaces can provide technical references for monitoring and planning municipal pipeline networks,which is of great significance for maintaining the safety of urban underground spaces.Based on typical gas accidents,this paper conducts risk assessment on multiple scenarios of gas-electricity coupling in urban areas by considering the spatial relationship between urban underground gas pipelines and adjacent power cables,as well as the information parameters of the gas network.Different mathematical models are established based on the above-mentioned risk areas under different conditions to explain relevant laws and solve the fluid control equations.The process of gas leakage and accumulation under restricted conditions under different factors is studied,and the spatial and temporal evolution laws of gas leakage from municipal gas pipelines infiltrating into adjacent power cable channels are obtained.Based on risk assessment and system theory methods,an analysis was conducted on the occurrence process of coupled power accidents in gas and power pipelines,clarifying the connotation of urban gas and power pipeline coupling accidents.It is concluded that urban gas coupling accidents have characteristics such as dynamism,uncertainty,complexity,and coupling.Based on GIS,a train of thought for identifying high-risk areas of gas and power coupling accidents is proposed,and the various indicator factors are analyzed to clarify their roles in accidents.Studying the diffusion law of gas leakage under the obstruction of power pipeline and manhole wall,it was found that due to the obstruction effect of the power pipeline,a low gas concentration area will be formed directly above the leakage point,and the gas will spread outward along the power pipeline.In low and medium pressure gas pipelines,the lateral diffusion distance of gas concentration is related to the pipeline pressure.As the pressure increases,the lateral diffusion increment of gas will decrease.Most of the gas will be driven by pressure gradient and concentration gradient to diffuse in the vertical direction,while lower pipeline pressure will make the gas easy to accumulate in other underground spaces.The various properties of the soil will affect the distribution and diffusion speed of gas quality score.Methane diffusion is arranged according to the degree of danger,with sand,loam,and clay in order.Research on the aggregation pattern of gas in the event of gas leakage at transformer stations and electric vehicle charging stations has been conducted.The conclusion is as follows: when the distance between buildings is small,gas is prone to accumulate in the cavity of the building,and the gas will flow upward along the wall of the building,entering the atmosphere.With the increase in building height,the downwind diffusion will shorten.When gas leakage occurs between two buildings and the atmospheric wind speed is zero,due to the lack of lateral force,gas will rapidly disperse in the vertical direction.At low wind speeds,the gas will gather towards the wall of the downwind building and form a vortex at the bottom of the building,leading to gas accumulation.At high wind speeds,the gas will mix rapidly with the atmosphere,filling the entire cavity of the building.The research results can provide a reference basis for the risk assessment and monitoring program of the composite laying area of urban cable ducts and gas pipelines.At the same time,it has a certain degree of engineering significance for the site selection of urban substations and community electric vehicle charging stations,as well as emergency decision-making for leakage accidents.Figure 38 table 15 reference 93...