Study On Momentum Characteristics And Fire Suppression Efficiency Of Low-pressure Two-fluid Water Mist

In the airborne furnace extinguishing system,water mist has step by step come into people’s sight with its gorgeous hearth extinguishing effectivity and cleanliness.For studying how the momentum parameters of the water mist affect the fire extinguishing efficiency,research experiments on the momentum characteristics of the low-pressure two-fluid water mist and its effectiveness in extinguishing oil pool fires were carried out.Based on the water-based verification system for large-scale civil aircraft cargo hold fire suppression,an independent water mist fire-extinguishing effectiveness experimental platform was built.Set gas flow rates of 250,275,300,325 and 350 lpm,liquid flow rates of 0.5,0.75 and 1.0 lpm and obstacles with different inclination angles.Studied the effectiveness of water mist fire extinguishing from parameters.Finally,this paper used the PyroSim software to simulate the experiment under the same working conditions.It was once observed that the droplet dimension of low-pressure two-fluid water mist was once positively correlated with liquid float charge and negatively correlated with the gas flow rate.The alternate regulation of droplet pace satisfies the momentum conservation equation.When droplet measurement was once decreasing,droplet mass used to be lowered and droplet pace was once increased accordingly,and the droplet pace was once increased.The momentum of the fog is related to the third power of the particle size and the product of the droplet velocity,where it was positively related to the third power of the particle size of the droplet.Through experimental research on suppression of fire extinguishing efficiency,it used to be decided that the fine end result was once when the droplet dimension used to be 95 μm,the gasoline go with the flow fee was once 350 lpm,the liquid drift charge was once 0.5 lpm,the droplet velocity was 16.4 m/s,and the fog momentum was 7.4×10-9 kg·ms-1 and the fire extinguishing time was 290 s.When a fine water mist was applied at 100 s,the peak of the flame plume decreased,and the temperature close to the oil floor confirmed an upward style contrary to the flame temperature trade trend,and the most temperature reached 610℃.The existence of obstacles with different inclination angles would affect the water mist fire extinguishing efficiency.The fireplace extinguishing time expanded with the expand of the inclination attitude.Tilting the obstacle to the right combined with the water mist would increase the oxygen consumption,reduce the CO release,and accelerate the flame extinguished,extinguishing time was 176 s.Numerical simulation software program was once used to set up a 3-dimensional model,set the same parameters,the simulation consequences had been constant with the proper statistics consequences.The simulation and analysis of the space turbulence velocity could reach 2.0 m/s and 1.5 m/s and the real-time changed trend of the space visibility during empty fire and fire extinguishing,which provides a certain reference basis for subsequent experiments.