Numerical Simulation of Gas-particle Two-phase Flow of the Solid Particulate Aerosol Fire Suppressants in Confined Spaces
The solid particulate aerosol fire suppressant, with a good capacity for preventing the explosion of the mixture of gas and dust in the mine as well as suppressing the Class B and C fires is a newly developed substitute in application for the Halon. Fire suppression of aerosol is achieved mainly by removing and recombining flame propagation radicals to restrain the combustion chain reactions and reducing the fire temperatures by absorbing heat through the produced fine solid particles. Therefore, the properties of the particles in the air such as the flow velocity, the concentration distribution, the suspended time and the sedimentation rate are important factors affecting the extinguishing effect. In this paper, the algebraic-slip method (ASM) for the modeling of multi-phase flows was utilized to simulate the flow process and distribution characteristics of the gas-particle two-phase flow of aerosol fire suppressants in confined spaces. The sliding force and resistant force for the particles in the flow space were taken into consideration. The influence of the particle diameters and spouting positions of the aerosol products on the flow processes and particle concentration distributions in the space was simulated and explored. The results demonstrate that the produced particles with relative large diameters mainly deposit near the spout, while the small particles have the better distribution characteristics and can spread to the far positions of the space. The solid particles with the diameter reducing to 10μm can pervade into the wee rounding the obstacles. When the particle diameter reduces further to 1.0μm, the flow and distribution properties are similar to those of gases, and the deposition rate becomes relatively slowly, which is beneficial to fire suppression. When the spouting position is close to the open door, the deposited particles are easier to flow outside the room with the continuous mediums, while the device is placed in the inner region, the solid particulates mainly deposit internally, by which most of the aerosol acts on the protected space and better fire suppression efficiency can be obtained. The study is helpful to understand the dispersing process of the aerosols in confined spaces and can provide a reference for the design and installation of aerosol fire suppressant device.
aerosol fire suppressant gas-particle two-phase flow numerical simulation distribution characteristic
CHEN Changkun YOU Fei
Institute of Disaster Prevention Science & Safety Technology, Central South University, Changsha, Hu State Key Laboratory of Fire Science, Univ. of Sci. & Tech. of China, Anhui, Hefei, 230026, China
国际会议
The 2007 International Symposium on Safety Science and Technology(2007采矿科学与安全技术国际学术会议)
河南焦作
英文
1896-1901
2007-04-17（万方平台首次上网日期，不代表论文的发表时间）