Numerical Simulation Of Gas Pipeline Accident Damage Based On GIS And Research On Emergency Rescue

In recent years due to economic growth and social development,natural gas as one of the pillars of life and industrial production of energy is playing an increasingly important role.However,natural gas pipeline system frequent accidents seriously threaten people's life and property safety.In order to reduce the occurrence of gas accidents and lower the hazards caused by the accidents,it is necessary to carry out the natural gas system accidents risk assessment investigations to strengthen the natural gas rescue system and safety construction.GIS system can record,store,calculate and describe the geographic information materials,and its combination with the occurrence of gas accidents can greatly improve the efficiency of natural gas accidents rescue system.First,natural gas leak is the main gas pipeline accident.Gas leakage will cause fire and explosion after meet with open fire.This paper firstly analyzes the model for different types of gas leakage accidents,determine the scope of its use,analyses the calculation methods of gas leakage diffusion,involved in the process of the calculation and the corresponding method of choosing parameters.The analysis of related influence factors of gas leakage shows that when the leakage distance is greater than 20 m,lower speed slow leakage of gas concentration in the air.And the wind speed is greater than 8 m/s,the gas concentration changes small er.Second,fire will be formed after leaked natural gas meet open fire.This article firstly generalizes the basic theory of fire from the perspective of theory.Then CFD numerical simulation method is adopt for the occurrence of gas fire.Based on the simulation,compared with the results of theoretical calculation,the correction of the theoretical calculation model makes it more convenient to combine with GIS system.Analysis the influence factors of fire,when the wind speed is less than 8 m/s and leak mouth diameter less than 0.003 m,the damage radius change is more obvious.Third,Explosion is another serious damage caused by the gas leakage.This article is based on the common explosion model of TNT equivalent method and multi-energy method.Analysis of gas explosion consequences with the comparison of the two methodes,it is found that multi-energy method is more appropriate to calculate the gas explosion accidents damage.But the calculation of multi-energy method is based on the method of check figures,it is not conducive to the application in GIS system.This article adopts the method of data fitting to form formula of the hazard scope of the multi-energy method.Analyze the influence factors of gas explosion accidents,it can be got that when the pipeline pressure is less than 1 MPa,the damage radius change is more obvious.On the basis of injury caused by leak,fire and explosion accidents,this article establishes the gas accident rescue system and determines the content and structure.Based on the GIS system,D-J tesla optimization algorithm is adopting to optimize the emergency rescue route and valve closed calculation is also processed.