低直径比柱状颗粒固定床化学链燃烧的数值分析

随机固定床化学链燃烧氧化反应非常复杂，固定床中载氧体结构对床层内的流场和化学反应均有较大的影响，而流场与化学反应之间又相互影响。利用数值方法对低直径比实心圆柱和开孔圆柱两种载氧体颗粒的固定床的径向孔隙率、流动压降、传质传热以及反应特性进行分析。结果表明，采用开孔圆柱载氧体的固定床，由于其径向孔隙率较大，流动压降更小，组分以及反应产生的热量能够在整个床层内迅速传递。开孔圆柱结构载氧体能够显著地改善颗粒的内扩散现象，使得床层达到最大温升和Cu转化为CuO的时间大大缩短。

Numerical analysis of chemical looping combustion in a fixed bed with low diameter ratio column particles

Complicated oxidation reaction of chemical looping combustion occurred in random fixed bed. The structure of oxygen carriers had great influence on the flow field and chemical reaction in the bed, and mutual interaction between flow field and chemical reaction existed. In this paper, numerical analysis of radial porosity, flow and pressure drop, mass transfer and heat transfer, and reaction characteristics in a fixed bed containing solid column and opening column with low diameter ratio was conducted respectively. The results show that the fixed bed with opening column oxygen carriers has smaller flow pressure drop due to larger radial porosity, and the heat generating by the components and reaction can be transferred rapidly throughout the bed. The opening column oxygen carriers can significantly improve the internal diffusion of particles and shorten the duration for the bed to reach the maximum temperature rise and the conversion of metal copper to cupric oxides.