Experimental Research And Numerical Simulation Of Sprinkler System At High Clearance Building

At present,Chinese heavy fires are in a high incidence stage,and the sprinkler system is the most effective system to extinguish the fire in the initial stage of fires.However,most of the design parameters of the sprinkler system in China adopt directly foreign design parameters,rarely based on the actual fire load density,fire hazard,especially at high clearance building.In addition,it is cost and expensive to carry out such large-scale fire tests.Based on the full-scale fire test,this paper explores the effects of different densities and response time index on fire extinguishment in a large space building with a clearance of 18 m through numerical simulation.This study will provide technical support for the design parameters of the sprinkler system and make the sprinkler system more scientific.Physical fire extinguishing tests were carried out at two heights of 16 m and 18 m.When the clearance is 16 m and the density is 20 L /(min?m2),when the fast response sprinkler is used,the sprinkler will appear "jump opening".When the clearance is 18 m and the density is 40 L /(min?m2),the sprinkler system can protect the object well after the action.Numerical simulation of standard burning items using Fire dynamics simulator.From the comparison of the three parameters of the peak heat release rate,its arrival time,and fire load,it is concluded that the established model of standard burning items can replace standard burning items,and the relative error is controlled at 10%.In order to verify the model built,the standard burning item was stacked to obtain the standard burning item combinatorial model,and its numerical simulation results also agree well with the heat release rate curve of the physical fire test.Taking the physical fire test with a clearance height of 18 m as an example,a numerical simulation model of sprinkler systerm was established.Through a comprehensive analysis of various extinguishing parameters of the sprinkler action time,the number of sprinkler action,the heat release rate of the fire during the sprinkler action,the temperature of the smoke during the sprinkler action,and the temperature curve,the final conclusion is that the numerical simulation of sprinkler systerm can replace the physical fire test,the numerical simulation of sprinkler systerm can be used for the research and analysis of engineering parameters.The effect of different densities and RTI on fire extinguishment in a large space with a clearance of 18 m was explored.The results show that when the density is 30 L /(min? m2),the sprinkler system can suppress the fire quickly.When the density is 20 L /(min?m2),the sprinkler actives in time or more sprinklers opened to control the fire.When the density is 15 L /(min?m2),due to the low density,the water droplets cannot directly reach the fuel surface,but when more sprinklers are opened,wetting combustibles can also control the fire.By comparing the extinguishing time,the number of sprinkler,the fire area,and the loss of fire,the final determination of the density of a high space with a clearance of 18 m is 20 L /(min.m2).