化工学报2024，Vol.75Issue(6)：2201-2213,13.DOI:10.11949/0438-1157.20231386
气固微型流化床反应分析仪的理想流型判据分析
Analysis of criteria for ideal flow patterns in gas-solid micro fluidized bed reaction analyzer
摘要
Abstract
Micro fluidized bed(MFB)has received much attention in the reaction kinetics measurement due to its unique features like small gas back-mixing and good operability.Only by obtaining the change pattern of flow pattern with operating parameters we can achieve effective control of the ideal flow pattern of the micro fluidized bed.In this study,the combination of two-fluid model(TFM)and the structure-dependent drag model(namely multiscale CFD)is used to simulate a series of fluidization behaviors of Class A particles and Class B particles in MFBs.Then the effects of gas velocity Ug,bed diameter Dt and initial bed height Hs on the gas back-mixing behaviors are investigated by analyzing the characteristics of the solid concentration distribution and the gas residence time distribution(RTD).It is shown that the ideal flow pattern only appears when the MFB is operated between incipient bubbling fluidization and incipient turbulent fluidization.The RTD curves are further analyzed and a new criterion,that is,the skewness S<0.6,which takes into account the features of RTD curve(e.g.,trailing,multiple peaks),is proposed,thus avoiding the misjudgment by using the original criterion[the variance σt2<0.25 and peak height E(t)h>1].In the future,the effects of material properties and extreme operating conditions will be further investigated to establish an operating standard for MFB used in reaction kinetics measurement.关键词
气固微型流化床/平推流/停留时间分布/气体返混/多尺度/数值模拟Key words
gas-solid micro fluidized bed/plug flow/residence time distribution/gas back-mixing/multiscale/numerical simulation分类
化学化工引用本文复制引用
卢飞,鲁波娜,许光文..气固微型流化床反应分析仪的理想流型判据分析[J].化工学报,2024,75(6):2201-2213,13.基金项目
国家重点研发计划项目(2022YFF0705104) （2022YFF0705104）
国家自然科学基金项目(22078331) （22078331）
