| Since the reform and opening up,China’s national economy has achieved rapid development.Cars that were not common before have gradually entered the lives of ordinary people,and the number of civilian vehicles has been significantly improved.Due to the tight space in the city and the inability to provide a large number of ground parking spaces to meet parking needs,the underground garage has become a good choice.However,the underground garage meets people’s living needs,but also brings a major hidden danger of garage fires.Large underground garages are often built underground in high-rise civil buildings or large shopping and entertainment venues,mainly to facilitate people’s travel.However,these are places where people are highly concentrated.There are a large number of cars parked in the garage.In case of fire,it is very likely to cause serious casualties and property losses.Therefore,in order to effectively control the fire,this paper will conduct an in-depth study on underground garage fire control measures.In the theoretical research part,aiming at the special environment of large underground garage,the research on the gas state equation theory of underground garage fire smoke,the calculation model of smoke diffusion in underground garage fire is established.Through the research on the theory of heat radiation spread,the underground is established.A calculation model for the spread of garage fires.Taking the second fire compartment of an underground garage in Nanjing as an application example,the FDS fire dynamics simulation software was used to simulate the fire smoke diffusion and fire spread in the underground garage,and the data processing software such as Origin and Tecplot 360 was used to simulate The result is processed.After analyzing and studying the simulation results,the following conclusions are obtained:(1)In the case of the same parking density of the garage,the mechanical exhaust system alone has played a negative role in controlling the temperature and fire of the fire field,and even in the initial stage will accelerate the rise of the fire temperature and the spread of the fire.However,the mechanical smoke exhaust system can effectively discharge the smoke generated by the fire,improve the visibility of the escape exit,and provide time for the emergency escape of the personnel.(2)In the case of the same parking density of the garage,the separate opening of the sprinkler system can effectively control the rise of the fire temperature and limit the spread of the fire.But it is possible to reduce the visibility of the fire.(3)When the parking density of the garage is constant,when the mechanical smoke exhaust system and the sprinkler system are combined,the mechanical exhaust system should not be turned on or the amount of smoke exhausted should be reduced in the early stage of the fire.The water sprinkler system is mainly used for fire extinguishing.In the later period,the two should work together to maximize the effectiveness of fire protection.Mechanical exhaust systems and sprinkler systems are essential fire control measures in underground garages.(4)Under the condition that the mechanical exhaust system and the water sprinkler system are working normally,it is recommended to set the distance between the vehicles in a parking space to 0.8m,and the distance between the vehicle and the wall or column is 0.4m.Even if there is a fire in the underground garage,the fire can be controlled within a limited range under the control of the fire protection system,so that personnel can have sufficient time to evacuate the fire site,protect the property from fire damage,and facilitate fire fighting operations of firefighters.An optimized design scheme for the defects of the original design scheme of an underground garage in Nanjing is proposed.After comparison of the two design schemes,the optimization scheme is better than the original scheme in terms of fire temperature control,smoke diffusion and fire spread in the underground garage.Figure [47] table [33] reference [63]... |
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