Numerical Simulation And Consequence Analysis Of Indoor Gas Leakage And Diffusion In Residential Building

With the state's increasing emphasis on environmental protection,natural gas has attracted much attention due to its clean advantages,and more and more favored by human beings,not only going into the production but also into life.Whereas,its flammability can provide convenience for people,meanwhile it is still dangerous.When the natural gas leaks in the process of utilization and reaches a certain concentration range,the explosion will occur in case of open fire,which will do harm to people's life and property security seriously.Therefore,after the gas leaks in residential rooms,studying the law of its diffusion and assessing the risks is important for advising people how to use the natural gas safely.Through a large number of literature research,we learn about the status of research,and make the analysis and comparison of the advantages and disadvantages of various models.Based on the existing research,this paper takes the residential building of two rooms and one hall as the research object,verifies the correctness of the model by using the tracer gas CO₂,and makes use of CFD numerical simulation method to emphatically analyze and compare the laws of gas diffusion concentration distribution with time change,kitchen structure change,leakage quantity change,wind or no wind change and working medium type change.Then according to the simulation results,the paper divides the gas distribution area under different working conditions,taking 2%of the mass concentration as the limit of explosion risk area,and 4%of the mass concentration as the limit of the respiratory asphyxiation risk area.Besides,we rely on TNT equivalent method which is usually applied to engineering theory to evaluate the explosion effect of the leaked gas.The results show that the concentration of indoor gas increases with the increase of leakage time,the longer the time,the greater the risk area,the more serious the consequences of explosion,so,if we can find the leak earlier,the risk will be lower;Under the condition of large leakage,the concentration of gas diffusion is higher,the dangerous region grows faster,and the flow doubled and the concentration nearly doubled,so the explosion is more likely to occur.Compared with the closed kitchen,the gas diffusion range under the open kitchen structure is wider,and the explosion hazard area at the same time is the largest.The natural ventilation has a good dilution effect on indoor gas,which can speed up the gas diffusion rate,thus effectively reduce the concentration of indoor gas and improve the safety factor;The law of gas diffusion is also related to the diffusion working medium.The heavy gas and light gas gather in the opposite way.The heavy gas accumulates from bottom to top,while the natural gas accumulates from top to bottom.The research results of this paper have important guiding significance for the safety of residents,and can provide scientific basis for the revision of relevant gas regulations.