Abstract: Taking the local application fire extinguishing technology of perfluoro- 2-methyl- 3- pentanone as the research object, based on the characteristics of low-pressure and large-flow atomization of the rotary core nozzle, used Fluent to carry out the simulation of the external flow field of this nozzle, and completed the simulation analysis of the distribution characteristics of atomized fire extinguishing agent, and determined concentration cut-off points. Combined with Gilliland semi-empirical formula, derived the calculation formula of nozzle flow for different atomizing half angles, and established the calculation method of local application of fire extinguishing.Combined with the experiment, verified the accuracy of local application of fire extinguishing technology. The results show that higher height, larger atomizing half Angle, higher temperature, and smaller particle size all lead to the increase of the required fire extinguishing flow, among which the atomizing half angle has the greatest influence on the fire extinguishing flow. The local applied fire extinguishing calculation method established by combining the concentration distribution characteristics and the calculation formula of nozzle flow can realize the reliable fire extinguishing. 

Key words: perfluoro-2-methyl-3-pentanone; local application, Fire suppression technology