Experimental Study On Performance Of Water Mist Fire Extinguishing System In Confined Space

In this paper,the water mist fire-extinguishing system in confined space is the research object,Through literature review,theoretical analysis model,cold state experiment,confined space fire-fighting experiment and numerical simulation,etc.The research results of this project are applicable to the study,kitchen,underground garage and other confined spaces,and can provide theoretical support for the installation of water mist fire extinguishing system.The research results of this paper mainly include the following aspects:(1)This paper analyzes the importance of water mist fire extinguishing system in confined space by consulting literature and data,puts forward relevant introduction to water mist fire extinguishing system,and summarizes the research status of water mist fire extinguishing system.By coMParing the previous research status,the research content of this paper is proposed,which mainly includes the influence of fire source model,nozzle type and space filling quantity on water mist fire extinguishing system.Finally,the overall technical route of the article is made.(2)The water mist fire extinguishing system is briefly introduced and classified,and its characteristics and fire extinguishing mechanism are analyzed.In order to ensure the practicability of the water mist fire extinguishing system,this paper designs the experimental platform and selects the experimental materials according to the actual life.The sprinkler coefficient and the pressure range of the pump set shall be set according to the specifications for water mist fire extinguishing.And in order to better explore the experimental research content,according to the existing experimental conditions,designed the experimental measurement system.(3)Firstly,this paper introduces PIV and its working principle.Then,PIV was used to measure the characteristics of water mist particles and fog field in the confined space.Finally,the influence of water mist nozzle coefficient and pipe network pressure on the movement characteristics of water mist particles is analyzed by consulting literature theory,and a new standard of space filling for fire extinguishing is proposed,which is only applicable to confined space.(4)A confined space test-bed was set up and a water mist fire-extinguishing experiment was carried out.By changing the nozzle coefficient and pipe network pressure of water mist,the particle characteristics and space filling amount of water mist can be changed,verify the performance of the water mist fire extinguishing system in the confined space.The experimental results show that the water mist will cause some disturbance to the fire source,and the larger the sprinkler coefficient,the worse the fire extinguishing performance.For the fire source model,the effect of water mist on extinguishing gasoline fire is better.The larger the space filling is,the better the fire extinguishing effect is.(5)FDS is used to verify the experimental results.Firstly,the confined space is established,and the calculation model and fire source are defined.The results show that the water mist has a great disturbance on the flow field in the space,resulting in a relatively large temperature fluctuation in the space,and the simulation results are consistent with the experimental results.