上吸式固定床生物质气化炉氧化层和还原层设计的热态数值模拟

Thermal Numerical Simulation of Oxidation Layer and Reduction Layer Design of Updraft Fixed Bed Biomass Gasifier

生物质气化炉氧化层和还原层的设计是否合理直接决定了气化效率的高低。先建立生物质气化炉氧化层和还原层的几何模型,再采用计算流体动力学(Computational Fluid Dynamics,CFD)方法对气化炉氧化层和还原层内的氧气和二氧化碳浓度分布情况进行数值计算,结果发现生物质原料破碎后粒径取140 mm左右为宜,氧化层和还原层高度均取500 mm为宜。与传统生物质气化炉相比,整个气化炉高度降低1 m,证明数值模拟的结果合理,可为生物质气化炉的优化设计提供理论依据。

Whether the design of oxidation layer and reduction layer of biomass gasifier is reasonable directly determines the gasification efficiency. In this paper, the geometric models of the oxidation layer and reduction layer of the biomass gasifier are first established, and then the Computational Fluid Dynamics(CFD) method is used to calculate the concentration distribution of oxygen and carbon dioxide in the oxidation layer and reduction layer of the gasifier. According to the calculation results, it is found that the particle size of the biomass raw material after crushing is about 140 mm, and the height of the oxidation layer and reduction layer is 500 mm. Compared with the traditional biomass gasifier, the height of the entire gasifier is reduced by 1 m, It is proved that the results of numerical simulation are reasonable and can provide a theoretical basis for the optimal design of biomass gasifier.