基于沉积理论的碳黑痕迹数值方法

Numerical Method for Carbon Black Trace Based on Particle Deposition Theory

将颗粒沉积理论中的经验公式法应用到烟气颗粒的沉积计算中,推导建立了壁面单位面积上沉积的碳黑颗粒质量与时间等因素关系的数学模型.将该模型嵌入FDS软件,实现烟气流过壁面时形成的可视化痕迹的数值模拟.在数值模拟环境中,设定测点,记录任意时刻壁面单位面积颗粒的沉积总量,对碳黑痕迹进行定量分析.与实际火灾事故进行模拟比对,验证了数值模拟结果与实际火灾情况具有较高的吻合度.该方法可以根据不同的火灾场景、壁面粗糙情况、火源位置等现场情况计算研究壁面碳黑痕迹的形成规律,对火灾调查具有理论指导意义和实用价值.

Some traces of carbon black particles will be left on the wall surfaces when smoke flows over in a room fire, which are very useful for fire investigators to judge fire point, fire cause, and fire responsibili- ty. According to the particle deposition theory, a mathematical model for these traces was built and em- bedded in the FDS software. The new FDS software with carbon black trace model can not only quantita- tively calculate the mass of soot left on the wall surfaces but also make these simulation values visible. Then a room fire was simulated to verify the validity of the model. Based on these simulations, the develo- ping characteristics of the carbon black trace was analyzed.