Study On The Fire Extinguishing Performance Of Self- Absorption Air Spraying

Due to the phasing out of Halon extinguishing agent, water mist is being taken increasingly seriously as environmental protection, high efficiency and an wide scope application of new fire extinguishing agent.Many scientific research units and individuals have studied the water mist fire extinguishing around the globe. While the traditional method of water mist with defects and limitations of different degrees,therefore a lot of research units and individuals proceed to the study of new spray equipment. The suction spray has good atomization effect compared with ordinary single nozzle and puts forward an application of dust removal with good results. But there is still no application in the field of fire extinguishing field.This paper design the suction sprayer and analyze the suction spray atomization mechanism and fire extinguishing mechanism theoretically,based on the summarizing forefathers’ research results.And velocity field under different parameters are analyzed on the suction sprayer through the numerical simulation on the spray characteristics of Fluent software.Through simulation, compared with ordinary spray the suction spray velocity attenuation is relatively weak and have very good atomization effect.In order to predict the size of water mist on the influence of fire extinguishing effect, this article use FDS fire simulation software make numerical simulation for different size of water mist under the suppression of fire.Through the above theory and simulation research, different size of water mist fire extinguishing experiment is analyzed and the ISO9705 standard fire extinguishing is established. In the experiments the temperature is measured by thermocouple and the flue gas is analyzed though flue gas analyzer. Comparing the extinguishing time of the suction spray and ordinary spray under different pressure and the nozzle aperture,The fire extinguishing effect of the suction spray improve significantly with the decrease of the pressure and extinguishing time gap increase under the same conditions.Based on the analysis of droplets size under the same pressure and the nozzle aperture, it can be found that the suction of the spray particle diameter can be reduced by 15% under the same conditions, On the same time the suction spray have better inhibitory effect on flame temperature in the process of extinguishing temperature changes.When the nozzle aperture is 1.8 mm, the two kinds of spray can effectively extinguish the fire, but the self-sucking air spray is more rapid.When the nozzle aperture is 1.0 mm, the average extinguishing time can be reduced by about 20%. With the decrease of the pressure, the time difference is bigger. When the nozzle aperture is 0.8 mm, two kinds of spray cannot be effectively put out when the pressure is 1MPa and 2MPa.When the pressure is increased to 3MPa, the self-absorption of the spray can extinguish the fire, ordinary spray cannot fire, 5MPa, 4MPa, the time to reduce the fire by about 30%. By comparing the different parameters of the self-suction air sprayer, the fire performance is obtained, with the increase of pressure and the time of fire suppression is decreased. When the nozzle aperture 1.8 mm, when the pressure increases to 3MPa, the time of fire suppression is very little, from the economic point of view,3MPa when the ability to fire more desirable.Through the research on the characteristics of self- sucking air spray, it is found that the self- sucking air sprayer is superior to the ordinary one-nozzle spray in both the atomization effect and the fire- extinguishing performance. Therefore, the self-absorption air spray has a very wide application prospect in the new environment protection fire extinguishing system.