Research On The Reaction Between Water Mist And Obstacle Blocked Oil Pool Fire

Due to the rapid economic development and great progress of science and technology, people have much higher requirements on the method of fire suppression.However,traditional halongen-based agents makes series destruction of the ozone layer,hence,United Nations Convention on Environmental Protection clearly requires all of the countries to full fill a specific objection of replacing Halongen-based agents in the early twenty-first century,which makes a new environmentally-friendly and highly efficient fire extinguishing agent become the focus of global research.As a new,environmentally-friendly fir-fighting technology,water mist is not only with the feature of no environmental pollution,low water consumption and small destructive to protected object but also the advantage of both gas and water fir-fight technology.Therefore,it has great significance to do research on water mist fire suppression Technology.Currently those researches are being done by many people,however numerical simulation studies on water mist fire suppression Technology used under conditions of obstacles blocking are not deep enough on content,which requires a further improve during the research.To make it,the studies which this article is about are focused on the following points:(1)In this paper,the author makes analysis of the numerical simulation of the interaction between the water mist and oil pool obscured by the barrier in the room.The simulation software used in the study is computational fluid dynamics software FDS(Fire Dynamics Simulator).Based on taking large Eddy Simulation(LES) as turbulence,the combustion reaction is simulated by mixture fraction combustion model.The nature of droplet radiation is calculated according to Mie theory while the nature of the radiation of the hot flue gas is assumed according to gray body radiation.According to second-order finite differences and staggered mesh system,the numerical methods used here discriminates the filtered control equations.Time variable is in form of indicating the forecast and amend while space variable is in form of second-order finite difference scheme.(2)The temperature field and velocity field in the room is get by making numerical simulation of the interaction between water mist and the fire plume under the condition of that the fire source is completely blocked by obstructions in the room on fire.The author analyze the effect of fire-fighting role by change the particle size of water mist,operating pressure water mist nozzle and point of view of the jet nozzle to find out the regularity of fire-fighting under this condition and discuss the mechanism of water mist fire-fighting. (3)The author also makes numerical simulation of the interaction between water mist and the fire plume under the condition of that the fire source is partially blocked by obstructions in the room on fire.By partially blocked by obstructions,it means both the condition that the oil pool deviates from the centerline or and obstacles deviates from the centerline.The impacts from different factors to the effect of fire-fighting is researched by changing the droplet size of water mist,water mist,nozzle operating pressure as well as the size of ethanol during the process of simulation.The article determine the conditions for water mist to successfully extinguish the fire by analyses the simulation results and compare the data and graphics under both condition of completely and partially block the fire source.