细水雾控制高层住宅烟道火灾的有效性及参数优化

Effectiveness and parameter optimization of water mist control system for exhaust duct fire in high-rise residential

为了有效控制高层住宅厨房烟道火灾,构建细水雾控制厨房食用油火和带分支烟道的高层住宅厨房烟道油垢火的FDS数值模型,分析高层住宅厨房烟道细水雾灭火系统有效性的影响因素及最佳设计参数。结果表明,如果未能即时扑灭高层住宅底层厨房食用油火,在强烈的烟囱效应作用下,高温火焰和烟气会引燃烟道内油垢,造成火势的迅速蔓延。本文所建的30 m高厨房烟道火模型中,最佳细水雾灭火系统运行模式为关闭厨房抽油烟机,即时开启厨房灶台上方和主烟道内分段设置的细水雾喷头,雾流量分别为0.6,10 L/min,细水雾最佳参数为喷射流速10m/s、喷射角度60°、水雾粒径500μm。

In order to effectively control the kitchen flue fire in high-rise residential buildings, the water mist fire control simulation models for cooking oil fire and cooking grease fire of flue with branches in kitchen in high-rise residential buildings were established based on FDS. The effectiveness and the optimum parameters of the water mist fire suppression system were analyzed. The results show that once a cooking oil fire in the kitchen on the ground floor of a high-rise residential buildings was not suppressed in time, the hot flame and smoke will ignite the cooking grease in the flue under the effect of the strong chimney effect, and the exhaust duct fire will spread immediately. In the fire simulation model of the 30 m height kitchen flue with branches established in this paper, the optimum operation mode of the water mist fire suppression system is to shut down the exhaust fan in the kitchen, start the water mist spray nozzles of 0.6 L/min which are arranged directly above the oil pan and nozzles of 10 L/min at different positions of the main flue of the high-rise residential buildings. The best spray velocity should be 10 m/s with spray angle 60° and 500 μm diameter of water mist particle size.