室内火灾烟气层高度的理论与模拟研究

通过对室内火灾中烟气层质量守恒方程的求解，得出了烟气层稳定高度的数学表达式，分析了影响烟气层下降速度和稳定高度的因素，并运用CFAST区域模型进行了数值模拟。结果表明，室内火灾烟气层下降到一定高度将达到稳定，下降速度和稳定高度与火源大小、房间几何尺寸等因素有关；火源功率越大、房间面积越小、通风口越小，烟气层下降速度越快；房间面积和房间高度越大、通风口越小，烟气层的稳定高度越小，改变火源如果引起烟气净累积量增加则稳定高度减小，反之，稳定高度将增大。

Theoretical Study and Simulation on Smoke Layer Height in Enclosure Fires

Through solving the mass conservation equation of the smoke in enclosure fires, the mathematical formulas of the steady smoke layer height are obtained, the factors influencing the descent speed and steady height of the smoke layer are analysed, and CFAST zone model is used to simulate the smoke descending process. Results show that the smoke layer will reach a steady state when descends to a certain height, the descent speed and steady height is related to the fire source power , the size of the room; the larger fire source power and the smaller area and vent of the room will increase the descend speed; the larger area and height, the smaller vent of the room will decrease the steady height of the smoke layer, and the steady smoke layer height will decrease if the net smoke accumulation amount increases when changing the fire source power, otherwise the steady height will increase.