建筑火灾中的火源多为固体可燃物。该文基于固体可燃物热解动力学模型,对多室内聚氨酯泡沫(PUF)板热解与空间火蔓延及烟气运动的相互作用进行了大涡数值模拟。计算得到的PUF板质量变化速率和各房间内烟气温度及CO2与O2浓度随时间的变化与实验基本相符合。CO2浓度随时间变化达到的峰值在着火房间最高,在邻近房间较低。O2浓度随时间变化达到的谷值在着火房间最低,在邻近房间较高。烟气温度和浓度峰值与谷值的出现与PUF板质量变化速率的峰值有关。
The sources in building fire are mainly solid combustibles. Based on the pyrolysis kinetics model of solid combustibles, a large eddy simulation (LES) is applied to the study of the interactions between the pyrolysis of the polyurethane foam (PUF) slab and the space fire spread and smoke flow in a multi-room building. The calculated mass variation rate of the PUF slab with time and the evolutions of the smoke temperature and CO2 and O2 concentrations in each room agree generally with the measured test data. The peak in the evolution of the CO2 concentration is high in the burn room and low in the neighboring rooms, while the valley in the evolution of O2 concentration is low in the burn room and high in the neighboring rooms. The peaks and valleys found in the evolutions of the smoke temperature and concentrations are relevant to the peak in the mass variation rate of the PUF slab with time.