Research And Application Of High Pressure Water Mist Fire Extinguishing System For Metro Vehicle

The high-pressure water mist fire extinguishing system has the advantages of low water consumption,low loss of malfunction,extinguishment of electrical fire and liquid fire,and harmlessness to the environment.With the change of people's concept of environmental protection and fire prevention and extinguishing,the high-pressure water mist fire extinguishing system has gained the attention of the fire protection industry and became a research hotspot.Domestic and foreign scholars have made remarkable achievements in the research of high pressure water mist fire extinguishing systems: The first is that the nozzle protection radius can reach 2m and can produce about 200?m fog drops;The second is to deepen its understanding and research and establish local norms,which lays a foundation for its application research.At present,the layout of high-pressure water mist fire extinguishing system is not perfect.Therefore,the effectiveness of fire extinguishing and the ability to block heat radiation under different flow coefficients or spacings are studied through experiments and simulations,which have guiding significance for the optimal design of the installation.This article takes the high-pressure water mist fire extinguishing system inside of the Subway car carriage as the research object,and uses a combination of experiments,simulations and theoretical analysis to conduct a systematic study.Through the experiment of a series of fire extinguishing basins in the whole submerged and open space,the effectiveness of the high pressure water mist in the whole submerged and open space was verified.Analysis of the extinguishing oil basin fire is based on the mechanism of high pressure fine water mist using evaporative heat absorption,asphyxiation and cooling.Experimental results show that the factors that influence the fire extinguishing effect are the closure of the fire place,the flow coefficient of the sprinkler head and the height of the nozzle layout.The same simulation model is established to verify the reliability of the simulation.Through the FDS simulation of water mist in different conditions put out the oil basin fire inside of the Subway car carriage,and monitor the temperature changes in the space field under different conditions,optimal spacing of sprinklers with different discharge coefficients in the carriage is obtained.The main factors affecting the effect of high pressure water mist fire extinguishing are the sprinkler spacing and the discharge coefficient K of the sprinkler.The data from experiment and simulation are designed for high pressure water mist fire extinguishing system.The research results of this paper have certain engineering practicability,which can be helpful for the selection and optimization design of high pressure fine water mist in the carriage.