Numerical Simulation Of Natural Gas Pipeline Leakage

Natural gas plays a more and more important role in our country’s clean energy.However,natural gas has some potential dangerous characteristics,is a typical flammable and explosive.The transportation of natural gas is relatively simple,and pipeline transportation is the main mode of transportation.The transportation safety of natural gas is required to be extremely high,because natural gas will explode in case of fire,which is very easy to cause panic and cause great losses of people,property and things.Moreover,natural gas leakage will also cause air pollution and water pollution,affecting people’s normal life.In order to reduce the occurrence of natural gas pipeline leakage explosion accident and reduce the harm consequences of the accident,it is necessary to take effective means to control.Therefore,numerical simulation can be used to study the diffusion law of natural gas pipeline leakage,so as to provide a plan for rescue and relief of such accidents.Based on the city’s regional pressure pipelines as the research object,according to the theory of jet,the gas flow control equation and pipeline leakage model as the foundation,applying GAMBIT software builds the geometric model of natural pipeline leakage diffusion,change of wind speed and leak hole size,change the height of the barriers and obstacles to the leakage source center distance conditions,such as using FLUENT software is obtained under different conditions of natural gas pipeline leakage diffusion rule.The results show that: at the beginning of the natural gas pipeline leakage,the air flow from the leakage outlet to the atmosphere at a high speed jet,and constantly to the upper air diffusion,the concentration near the leakage outlet is the highest.With the increase of the leakage pore size,the gas diffusion area will increase with the increase of the pore size,that is,the wider the gas diffusion range.Wind speed promotes the leakage natural airflow and makes it spread along downwind direction near the ground,which can change the spatial distribution of natural gas leakage diffusion.Wind speed is proportional to the horizontal diffusion distance of natural gas and inversely proportional to the diffusion height.The higher the height of obstacles is,the shorter the horizontal diffusion distance of natural gas diffusion in the downwind direction will be,but the lifting effect will increase the diffusion height of natural gas.On the windward side of the obstacle,the concentration of natural gas accumulation is high,and its distribution range is proportional to the distance from the obstacle to the center of the leakage source.It can be seen from the simulation results that,in case of a natural gas pipeline leakage accident,emergency rescue personnel should quickly demobilize the personnel near the leakage outlet and block the area downwind.If there is an obstacle in the downwind direction of the leakage source,the concentration of natural gas gathered in the downwind side of the obstacle is very high.The rescue in the windward side of the obstacle should be increased and the upper air ventilation should be strengthened to reduce the harm of poisoning and asphyxiation of other personnel and prevent the occurrence of leakage and explosion.Fig[21]table[9]reference[63]...