摘要
对燃油锅炉的燃烧过程进行了数值模拟,燃油采用癸烷作为模型分子式,雾化采用压力旋流雾化,燃烧采用一步统观模型,燃烧与湍流耦合采用Finite-rate/Eddy-dissipation模型。计算表明:当网格数目较少时,数值模拟的残差随迭代次数增大不断减小,可以通过残差小于某一小的阈值判定收敛;当网格数目足够大时,数值模拟的残差不再随迭代次数的增大单调递减,而是出现振荡或者稳定在一定范围内。在分析产生这种结果原因的基础上,针对大网格的多相湍流燃烧数值模拟收敛性判定出现的困难,通过大量反复的计算,发现当炉膛内部最高温度、炉膛出口平均温度和氧气平均浓度等随迭代步数变化100步,其相对值的变化都小于10^(-2)时,炉膛内的温度场、速度场、组分场等趋于稳定,以此可以作为判定大网格下多相湍流燃烧数值模拟收敛的判据。
Combustion is simulated of oil boiler,and decane is oil model molecular,and atomizer is adapted pressure swirl spray.Combustion model is one pace global reaction.Turbulent combustion coupled is Finite-rate/Eddy-dissipation model.Results show that simulation residuals are less along with iteration when mesh amount is less,convergence criterion are that all residuals are less than small threshold values,and when mesh amount is large number,simulation residuals are not monotone decreasing along with iteration,and they are oscillation or stabilized in range of 10-2~10-3 because of smaller simulation dissipation.For problem to decide convergence of great mesh model,it is found that temperature,velocity and compositional field are stable when relative change are less than 10-2 of maximum temperature,outlet average temperature and oxygen mass fraction in 100 paces iteration.Their three parameters can be as convergence criterions of Multi-phase Turbulence Combustion Simulation.
作者
张瑞
安恩科
韩益帆
刘栋
ZHANG Rui;AN Enke;HAN Yifan;LIU Dong(Thermal and Environmental Engineering Institute of Tongji University,Shanghai 201804,China)
出处
《锅炉技术》
北大核心
2018年第5期46-50,72,共6页
Boiler Technology
基金
上海市科委项目(16dz1206305)
关键词
多相湍流
燃油燃烧
数值模拟
收敛性分析
multi-phase turbulence
oil combustion
numerical simulation
convergence analysis
