高大空间火灾烟气蔓延影响因素研究——以广州某大型机库维修库为例

Study on Influence Factors of Fire Smoke Spread in Large Space Taking a Large Maintenance Hangar in Guangzhou as an Example

为研究高大空间火灾时的烟气蔓延情况,选用PyroSim对广州某大型机库的维修机库进行数值模拟,研究不同火源功率、排烟方式及挡烟垂壁尺寸对烟气蔓延的影响。结果如下:中心火源下,自然顶侧结合的排烟方式优于顶部排烟;机械排烟且排烟速率为10 m/s的设计虽然可以更好地降低烟气层的浓度和温度,但由于火灾初期的薄烟层会造成吸穿现象,扰动烟羽流导致烟气层加速下降;挡烟垂壁的设计可以降低建筑内部烟气蔓延的速率和单位消光率。因此,在进行高大型建筑防排烟设计优化时,应优先设计顶侧结合排烟系统,并根据防排烟规范及相关规范设计挡烟垂壁。

In order to study the smoke spread when a fire occurs in a large space,PyroSim was used to simulate the maintenance hangar of a large hangar in Guangzhou.The effects of different fire source power,smoke exhaust mode and smoke barrier size on smoke spread were studied.The results show that the natural top-side combined smoke exhaust method is better than the top smoke exhaust method under the central fire source;that although the mechanical smoke exhaust and smoke exhaust rate of 10 m/s can better reduce the concentration and temperature of the smoke layer,the thin smoke layer in the early stage of the fire causes the aspiration phenomenon,and the disturbance of the smoke plume leads to the accelerated decline of the smoke layer;and that the smoke barrier can reduce the smoke spread rate in the building and the unit extinction rate.Therefore,when the smoke control and extraction design is optimized in large buildings,the top-side combined smoke exhaust system should be selected preferentially,and the smoke barrier should be designed according to the related building fire protection design standards.