流化床内B类颗粒介尺度流动特征及其对煤气化过程影响

This project is aiming at the clean gasification technology of low rank coal, such as lignite and long-flame coal. By using the method of theory analysis, experimental investigation and numerical simulation, the meso-scale cluster structures of Geldart B type mono-particle systems and Geldart A/B mixtures with mainly B particles are investigated in 2D and 3D fluidized beds, and the effect of cluster characteristic on the macro-scale hydrodynamics is taking into more consideration. The micro-scale intrinsic kinetics, particle-scale global kinetics and meso-scale effective kinetics of low rank coal are explored in the thermogravimetric analyzer, fixed-bed differential reactor and small-sized fluidized beds, respectively, and the effect of meso-scale structure of particle clusters on the effective kinetics is highlighten. Coupling with the meso-scale drag force model and the effective kinetics model validated by the above experiments, a comprehensive CFD model for describing the fluid dynamics and chemical reaction is established for high-flux circulating-fluidized-bed coal gasification. The influence of the complex meso-scale structure of particle cluster on the process transfer phenomenon and gasification reaction performance is revealed in detailed, and some of important optimization methods and regulation measures are proposed in this project. These results should provide some necessary information of theoretical guidance and fundamental data for the process development and industrial application of the “low-rank coal gasification in high-flux circulating-fluidized-bed”, which is also useful for the other related processes in the fluidized beds.

以洁净煤气化技术为背景，采用理论分析、实验研究和数值模拟相结合的研究思路，研究二维和三维流化床内Geldart B类单一颗粒体系和以B类为主的A/B类混合体系的介尺度颗粒团聚特性及其对宏观流场的影响；在热分析天平、小型固定床和流化床内，分别研究褐煤和长焰煤等低阶煤在微观和介观尺度上的本征、宏观和有效反应动力学，重点探索聚团结构对有效反应动力学的影响行为；基于实验验证的介尺度曳力模型和有效动力学模型，建立描述高通量循环流化床煤气化炉内气固流动和反应耦合的综合数学模型，重点揭示流化床内复杂介尺度聚团结构与传递现象和气化性能的耦合机制，提出气化炉流动反应过程的优化和调控方法。为“高通量循环流化床低阶煤气化技术”的工程化应用提供理论指导和基础数据，其结果对类似过程也有一定的指导作用。

以洁净煤气化技术为背景，采用理论分析、实验研究和数值模拟相结合的研究思路，研究循环流化床内Geldart B类单一颗粒体系介尺度颗粒团聚特性及其对宏观流场的影响；在热分析天平、小型固定床和流化床内，分别研究了褐煤和长焰煤等低阶煤在微观和介尺度上的本征、宏观和有效反应动力学，重点探索聚团结构对有效反应动力学的影响行为；基于实验验证的介尺度曳力模型和有效动力学模型，建立了描述高通量循环流化床煤气化炉内气固流动和反应耦合的综合数学模型，重点揭示了流化床内复杂介尺度聚团结构与传递现象和气化性能的耦合机制，提出了气化炉流动反应过程的优化和调控方法。为“高通量循环流化床低阶煤气化技术”的工程化应用提供理论指导和基础数据，其结果对类似过程也有一定的指导作用。