基于多组分热解气体的炭化可燃物燃烧模拟

Simulation of charring solid combustion based on multiple pyrolysis gases

为弥补现有火灾数值模拟在热解气体和气固边界耦合方面的不足,将真实燃烧往往包含的多组分热解气体直接应用于炭化可燃物燃烧模拟过程,提高数值模拟的预测精度。首先,针对多组分热解气体更新热解模型、燃烧模型、烟模型、边界条件等;然后,基于OpenFOAM平台建立新的求解器—multiFireFOAM进行数值模拟,并通过热重、红外光谱、火蔓延仪(FPA)、锥形量热仪等仪器进行试验,从而提供必要的模拟输入参数和验证数据。结果表明:新建求解器的模拟结果与试验数据取得较好的一致性;对比基于多组分和单组分热解气体的锥形量热仪模拟结果,虽然多组分比单组分多用时3%,但质量损失速率和热释放速率模拟精确度显著提升。

In order to make up for deficiencies of current fire numerical simulation in pyrolysis gas and gas-solid boundary coupling,multiple pyrolysis gases,existing in actual fire,were applied to combustion simulation of charring fuels for more accurate prediction.Firstly,pyrolysis model,combustion model,smoke model and boundary conditions,etc.were updated for multiple pyrolysis gases.Then a new solver called multiFireFOAM was built based on OpenFOAM,and a series of experiments were conducted with thermogravimetry,infrared spectroscopy,fire propagation apparatus(FPA)and cone calorimeter to provide necessary input parameters and verification data for numerical simulation.The research shows that simulation results of newly built solver reach a good agreement with experimental data.And according to a comparison of simulation results of cone calorimeter separately for single and multiple pyrolysis gases,though it takes 3%more time for the latter,yet its accuracy of mass loss rate and heat release rate significantly improves.