Simulation Research on Interaction Rules between Superfine Powder Extinguishing Agent and Fire Plume

When the nozzle of release device directly faces the protected object, it is necessary for the superfine powder extinguishing agents (SPEA) to penetrate fire plume, so that SPEA can reach the fire source to extinguish fire effectively. Numerical simulation was used to make a comparative study on SPEA motion released at different driving pressures in fire. The simulation results indicate that the converging nozzle will enhance the capacity of extinguishing agent particles to penetrate fire plume, and its penetration capacity is directly proportional to the driving pressure value. When interacting with particles, the flame height decreases and flame width increases. The larger the driving pressure, the shorter time for particles to enter into fire source area. Particle concentration value in fire source area is relatively higher at 1.2 MPa and it less changes at 1.0 MPa. Larger driving pressure can accelerate the motion of particles to fill the extinguishing room. Eddies, which appear more easily at lower driving pressure, can also drive particles to fill the extinguishing room quickly, but with uneven distribution.