Abstract: According to the atomization and fire extinguishing mechanism of the liquid, analyze the droplet formation and breaking process of the water mist, the factors that affect the atomization of the liquid, and the advantages and disadvantages of various marine water mist nozzle structures to obtain the basic requirements of water mist atomization for nozzles. The design of marine sprinklers uses spiral internal flow channels to make the liquid rotate strongly at indoors to increase the kinetic energy of the water mist, enhance the centrifugal atomization effect, and enhance the fire extinguishing capability. Using STARCCM+to compare and analyze the direct jet nozzle and the improved centrifugal nozzle, the flow field and the pressure, velocity, flow trace and the volume fraction of liquid water on the relevant surface in the flow field are obtained. The results show that the nozzles with a centrifugal structure with spiral flow channel can increase the spray radius, expand the protection
range, and enhance the fire extinguishing effect.

Key words: marine water mist nozzle, atomized fire extinguishing, centrifugal structure, STAR-CCM+ simulation