基于能量平衡,推导出计算中心气升式气固环流反应器中不同区域内气固混合物流动能耗的理论模型,测量了不同区域内固相颗粒速度、气固混合物密度及床层压降,并根据实验数据确定出相应的模型参数,模型计算与实验结果吻合较好.模型计算表明,中心气升式气固环流反应器内环隙区和气固分离区的能耗分别占反应器总能耗的近40%和30%,颗粒环流受到的阻力主要集中在这2个区域;而导流简区及分布器影响区能耗较小,共占总能耗的近30%.随导流筒区表观气速增加,环隙区能耗占总能耗的比重减小,气固分离区能耗所占比重增大,导流筒区和分布器影响区能耗基本保持不变.气体分布器的安装位置对反应器内能量消耗的分布影响较大,中心气升式气固环流反应器内流动阻力更小.
Based on the energy balance, an energy dissipation rate model of different regions of a draft tube-lifted gas-solid air loop reactor (GSALR) was established. The local particle velocity, bed density and pressure drop were measured in a cold model GSALR and the model parameters were obtained based on the experimental data. The predictions agree with experimental data. The predicted results show that nearly 40% and 30% of the energy dissipation rate occur in the annulus and gas-solid separation regions, while that in the draft tube and gas distributors region is relatively small, reaching a sum of nearly 30%. With increasing of the draft tube gas velocity, the ratio of individual region to global reactor energy dissipation rate decreases for the annulus region, increases for the gas-solid separation region, and basically remains constant for the draft tube and gas distributor affecting regions. Compared with that obtained in an annulus-lifted GSALR, the location of gas distributor has a significant influence on energy dissipation, the flow resistance is smaller in the draft tube-lifted GSALR.