Abstract: In order to study the atomization performance of halon substitute extinguishing agent to guide fire control design, the atomization characteristics of water mist and perfluorohexanone under different injection pressures were studied by combining experiment and numerical simulation. The results show that there are differences in the shape of fog field between the two groups due to the physical characteristics of the fluid itself. Under the same working condition, the atomization cone angle of the fine water mist is larger than that of perfluorohexanone, and the coverage area is wider. In terms of velocity field, both velocities increased with the increase of injection pressure, but the average velocity of water mist at the distance of 100 mm from the nozzle at 2.5 MPa was 47.3% higher. In terms of particle size distribution, droplet particle size D32 at the same section decreased with the increase of injection pressure, and the D32 value of perfluorohexanone increased by 39.0% compared with that of water mist droplet at 2.5 MPa. The droplet breaking process and the variation trend of D32 were further analyzed by numerical simulation. Therefore, it is recommended to apply more injection pressure when using perfluorohexanone fire extinguishing agent in fire fighting design to achieve good atomization effect.

Key words: water mist, perfluorohexanone, injection pressure, atomization characteristic