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基于涡耗散概念燃烧模型思想,考虑小涡上的化学反应建立亚格子反应模型。分析了流化床内煤颗粒的流动与燃烧过程。模拟了出口处气体组分,采用亚格子反应模型的模拟结果更接近实验值。对于挥发分均相反应,给出了亚格子反应速率与总反应速率随颗粒浓度的分布特性,亚格子反应速率与总反应速率分布趋势基本一致,随着浓度的增加也有上升的趋势。亚格子反应速率占总反应速率的22%左右。对于碳燃烧异相反应,给出了采用亚格子反应模型与未采用亚格子反应模型模拟的反应速率随浓度的分布特性,考虑亚格子反应模型与未考虑亚格子反应模型的模拟结果趋势一致,随着浓度的增加反而有所降低,未考虑亚格子反应模型模拟的反应速率大约为采用亚格子反应模型模拟的80%。
Based on the concept of vortex dissipation concept combustion model, a subgrid response model was established considering the chemical reaction on the small vortex. The flow and combustion of coal particles in a fluidized bed are analyzed. The gas composition at the outlet was modeled, and the simulation results using the sub-lattice reaction model were closer to the experimental values. For the homogeneous reaction of volatiles, the distribution characteristics of the subgrain reaction rate and the total reaction rate with the particle concentration are given. The trend of the subgrain reaction rate and the total reaction rate are basically the same, and also increase with the increase of the concentration. Sub-grid reaction rate of about 22% of the total reaction rate. For the heterogeneous reaction of carbon combustion, the distribution characteristics of the reaction rate with concentration using the sub-lattice reaction model and the non-sub-lattice reaction model are given. The trend of the simulation results considering the sub-lattice reaction model and the sub-lattice reaction model is the same, But decreased with the increase of concentration. The response rate of the model without considering the subgrid response model was approximately 80% of that simulated by the subgrid response model.