煤间接液化费托合成浆态床反应器的研究进展

随着煤炭间接液化技术在百万吨级商业示范装置上的成功应用，作为其核心设备的费托合成浆态床反应器，涉及气液固三相湍流流动、传热传质及反应，其随反应器直径放大及内构件结构布局的变化而发生改变，进而影响反应器性能的多个复杂过程，导致在反应器设计、放大及操作优化上面临巨大挑战，科研及工业界仍然持续重视。本综述分析了影响浆态床反应器流体力学性能的主要因素，对浆态床反应器的流型、气含率、气泡行为、传热等研究进行了总结。介绍了浆态床反应器核心内构件的结构特点及发展状况，回顾了浆态床在费托合成反应过程中的工业应用历程，并展望了费托合成浆态床的研究趋势。     

浆态床反应器气含率研究进展

介绍了浆态床反应器应用现状和对浆态床反应器进行气含率研究的重要性,详细介绍了浆态床反应器气含率的研究方法,重点讨论了对气含率生产影响的各种因素,对浆态床反应器流体力学研究具有指导意义和参考价值.     

微型气液固三相等温微分浆态床反应器的优化

针对气液固三相浆态床催化反应中,传递、反应、催化剂的原位表征均比较复杂的问题,为了有利于气、固相均匀分散于液相和反应温度在反应器中实现等温,通过对气液固三相反应工艺特性和反应器性能要求的分析,对微型气液固三相浆态床反应器进行了优化。根据微型浆态床对气液固三相反应分析的要求,采用图像法研究了分布器为G1、G2、G3,砂板直径为2、2.5、3 cm反应器中的流体力学性能特征,考察了气体流速、温度、反应器直径及气体分布器对气含率、气泡尺寸、气泡上升速率以及气泡分布的影响,并进行流体动力学模拟计算,确定了微型浆态床反应器的直径为2 cm,气体分布器为G3砂板的反应器结构,该反应器可以应用于反应过程中间态及液体产物生成过程的测试。     

浆态床反应器流体力学行为研究及工业应用

浆态床是一种重要的气-液-固三相反应器,具有结构简单,传热、传质性能好以及催化剂可在线补加和更换等优点,在学术研究和工业应用上备受关注。对浆态床反应器的流型、气含率、气泡行为、传质、传热等研究进行了总结,并对温度、压力、液体性质等参数对于流体力学性质的影响进行了分析。介绍了多级浆态床和构件式浆态床新型反应器,对浆态床在大化工、精细化工及环保等重要过程中的工业应用进行了总结,并对浆态床反应器的应用前景和研究趋势进行了展望。     

浆态床反应器流体力学行为研究及工业应用

浆态床是一种重要的气-液-固三相反应器,具有结构简单,传热、传质性能好以及催化剂可在线补加和更换等优点,在学术研究和工业应用上备受关注。对浆态床反应器的流型、气含率、气泡行为、传质、传热等研究进行了总结,并对温度、压力、液体性质等参数对于流体力学性质的影响进行了分析。介绍了多级浆态床和构件式浆态床新型反应器,对浆态床在大化工、精细化工及环保等重要过程中的工业应用进行了总结,并对浆态床反应器的应用前景和研究趋势进行了展望。     

操作变量对大型浆态床反应器流体力学特性的影响

研究了系统压力、表观气速和固体颗粒体积分数对浆态床反应器气含率、气泡直径及气液接触面积的影响 ,通过试验得出了气含率和操作变量之间的统计关联式 ,给出了在湍流条件下浆态床反应器中气含率和气体动量之间的关系     

浆态床鼓泡反应器中气含率的分布

为了解浆态床鼓泡反应器中气含率的分布规律,在浆态床鼓泡反应器冷模试验装置中,以空气-液体石蜡-氧化铝微球为试验介质对装置内部的气含率进行研究。利用压差法研究了表观气速、浆液固含量等操作条件对反应器床层总体气含率的影响,利用光纤探针法研究了浆态床反应器不同操作条件对局部气含率的影响,总结了反应器内部气含率的分布规律,并由此对工业浆态床鼓泡反应器的设计进行了研究。结果表明:浆态床反应器的总体气含率随表观气速的增大而增大,固体细颗粒的加入能适当降低总体气含率;在反应器底部,分布器对气体的均布作用明显,但表观气速的增大能够弱化分布器的作用;在反应器的中上部气含率不受分布器的影响,沿反应器径向呈现"中间高,边缘低"的分布趋势;在工业费托浆态床中,表观气速不宜低于0.12 m/s,内过滤系统适宜设置于反应器中上部靠近器壁的位置。     

鼓泡床反应器内流动与传质行为的研究进展

总结了有关浆态鼓泡床反应器内流动、混合用气液传质特性的研究成果,详细地介绍了鼓泡床反应器内气含率、液速、液体轴向扩散系数、传质系数的测量方法,阐述了鼓泡床反应器性能的主要影响因素,如系统压力、温度、气体表观气速、液体性质及固含率等对流动、液相混合和传质特性的影响,并对鼓泡床反应器的应用前景进行了详述.     

湍动浆态床流体力学研究（Ⅱ）轴向浆料速度的径向分布

对高气速、大塔径条件下的湍动浆态床轴向速度进行了实验测定,提出了简化的一维流体力学模型。实验结果表明：固含率对浆料速度的径向分布影响不明显;采用中心速度和塔径作为参考量,则不同条件下的量纲1流速分布相似;高气速下中心速度随塔径的变化可近似用Nottenkamper关联式描述。提出了一维流体力学模型预测浆态床液速分布,模型计算结果与实验数据符合较好,模型较好地反映了浆态床反应器内液速分布随表观气速、固含率及塔径变化的规律。     

液体燃料合成浆态反应器内部过滤的研究

在液体燃料合成浆态搅拌反应器中设置了以金属烧结板为过滤介质的内过滤器,实现固液分离。研究了压降、温度、搅拌转速、固含率、过滤介质孔径及颗粒粒径对过滤速率的影响。实验结果表明:在浆态反应器中进行内过滤可以得到澄清稳定的滤液;随着操作进行,滤饼厚度达到动态平衡,过滤速率最终趋于稳定;过滤速率随着压降、温度、过滤介质孔径、颗粒粒径的增大及搅拌转速、固含率的减小而增大。应用因次分析法建立过滤模型,通过麦夸特算法对实验数据进行最优拟合得到模型的参数值,统计检验以及模型计算值与实验值的比较表明该模型可靠。     

Influences of top clearance and liquid throughput on the performances of an external loop airlift slurry reactor integrated mixing and separation

A new developed external loop airlift slurry reactor, which was integrated with gas–liquid–solid three-phase mixing, mass transfer, and liquid–solid separation simultaneously, was deemed to be a promising slurry reactor due to its prominent advantages such as achieving continuous separation of clear liquid from slurry and cyclic utilization of solid particles without any extra energy, energy-saving, and intrinsic safety design. The principal operating parameters, including gas separator volume, handling capacity, and superficial gas velocity, are systematically investigated here to promote the capabilities of mixing, mass transfer, and yield in the pilot external loop airlift slurry reactor. The influences of top clearance and throughput of the clear liquid on flow regime and gas holdup in the riser, liquid circulating velocity, and volumetric mass transfer coefficient with a typical high solid holdup and free of particles are examined experimentally. It was found that increasing the gas separator volume could promote the liquid circulating velocity by about 14.0% at most. Increasing the handling capacity of the clear liquid from 0.9 m~3·h~(-1) to 3.0 m~3·h~(-1) not only could increase the output without any adverse consequences, but also could enhance the liquid circulating velocity as much as 97.3%. Typical operating conditions investigated here can provide some necessary data and guidelines for this new external loop airlift slurry reactor to upgrade its performances.     

变径鼓泡浆液反应器的气含率特性

本文研究了变径鼓泡浆液反应器的平均气含率特性,考察了气体速度、静液床高、固体颗粒浓度以及颗粒直径的影响,并提出了变径鼓泡浆液反应器平均气含率的计算方法。     

Flow behavior of wakes in a three-phase slurry bubble column with viscous liquid medium

Flow behavior of wakes has been investigated in a three-phase slurry bubble column of 0.102 m ID and 1.5 m in height. The dependence of wake characteristics such as rising velocity, frequency, holdup and equivalent size on the operating variables was examined by employing an electric resistivity probe method. The gas velocity, liquid viscosity and solid content in the slurry phase were chosen as independent parameters. The rising velocity of wake region increased with an increase in the gas velocity (4.0–12.0 cm/s), liquid viscosity (1.0–50.0 mPa·s) or solid content (0–25 wt%) in the slurry phase. The frequency and holdup of wake phase increased with increasing gas velocity, but decreased with increasing liquid viscosity or solid content in the slurry phase. The equivalent size of wake phase increased with increasing gas velocity, liquid viscosity or solid content in the slurry phase. The wake properties and holdup were well correlated with operation variables within these experimental conditions.     

LOCAL HYDRODYNAMICS IN AN EXTERNAL LOOP AIRLIFT SLURRY REACTOR WITH AND WITHOUT A RESISTANCE-REGULATING ELEMENT

The hydrodynamic behavior of an external loop airlift slurry reactor (ALSR) with and without a resistance-regulating element was studied with a fiber optic probe and ultrasound Doppler velocimetry. The influences of the superficial gas velocity and solid holdup on the global gas holdup and radial profiles of the suspension circulation velocity in the downer and of gas holdup, bubble size, and bubble rise velocity in the riser were studied. Local measurements allow a better understanding of the flow behavior in the reactor and can be used for CFD modeling and validation. Experimental results show that the resistance-regulating element increases the gas holdup and decreases the suspension circulation velocity, indicating that an optimum design of the flow resistance is needed to obtain the maximum gas-liquid volumetric mass transfer coefficient for a specific superficial gas velocity. A high superficial gas velocity and low solid holdup are favorable for increased uniformity of the radial profile of the gas holdup and bubble rise velocity. Hydrodynamic models that predict the gas holdup and suspension circulation velocity were developed for an ALSR with and without a resistance-regulating element. Good agreement was obtained between measured and predicted values.     

Effect of pressure fluctuations on the heat transfer characteristics in a pressurized slurry bubble column

The hydrodynamics and heat transfer characteristics were investigated in a slurry bubble column reactor whose diameter was 0.0508 m (ID) and 1.5 m in height. Effects of gas velocity (0.025–0.1 m/s), pressure (0.1–0.7MPa), solid concentration (0–20 vol%) and liquid viscosity (1.0–38.0 mPa s) on the hydrodynamics and heat transfer characteristics were examined. The pressure difference fluctuations were analyzed by means of attractor trajectories and correlation dimension to characterize the hydrodynamic behavior in the column. The gas holdup increased with increasing gas velocity or pressure, but decreased with increasing solid concentration or liquid viscosity. It was found that the attractor trajectories and correlation dimension of pressure fluctuations were effective tools to describe the hydrodynamic behaviors in the slurry bubble column. The heat transfer coefficient increased with increasing pressure or gas velocity, but decreased with increasing solid concentration or viscosity of slurry phase in the slurry bubble column. The heat transfer coefficient value was well correlated in terms of operating variables and correlation dimension of pressure fluctuations in the slurry bubble column.     

LOCAL HYDRODYNAMICS IN AN EXTERNAL LOOP AIRLIFT SLURRY REACTOR WITH AND WITHOUT A RESISTANCE-REGULATING ELEMENT

The hydrodynamic behavior of an external loop airlift slurry reactor (ALSR) with and without a resistance-regulating element was studied with a fiber optic probe and ultrasound Doppler velocimetry. The influences of the superficial gas velocity and solid holdup on the global gas holdup and radial profiles of the suspension circulation velocity in the downer and of gas holdup, bubble size, and bubble rise velocity in the riser were studied. Local measurements allow a better understanding of the flow behavior in the reactor and can be used for CFD modeling and validation. Experimental results show that the resistance-regulating element increases the gas holdup and decreases the suspension circulation velocity, indicating that an optimum design of the flow resistance is needed to obtain the maximum gas-liquid volumetric mass transfer coefficient for a specific superficial gas velocity. A high superficial gas velocity and low solid holdup are favorable for increased uniformity of the radial profile of the gas holdup and bubble rise velocity. Hydrodynamic models that predict the gas holdup and suspension circulation velocity were developed for an ALSR with and without a resistance-regulating element. Good agreement was obtained between measured and predicted values.     

湍动浆态床流体力学研究（Ⅰ）气含率及其分布规律

对高气速、高固含率、大塔径条件下的湍动浆态床平均气含率和气含率径向分布进行了实验测定,结合工业实验数据,归纳出可用于工业条件的气含率计算关联式,给出了简化的流体力学模型用于气含率分布的模拟。结果表明,浆态床气含率将随塔径增加而降低,固含率与塔径之间存在交互影响;同时,气含率的径向分布也随气速和塔径的增大而改变,存在明显的放大效应,简化模型能够较好地模拟实验结果。     

锥形鼓泡床内气含率特性的研究

本文分析了锥形鼓泡床内流型过渡、平均气含率及气含率轴向分布特性，考察了入口气体速度、静止液体（或淤浆）高度及淤浆浓度的影响，比较了与圆柱床的差异，结果表明对于鼓泡床内气体体积收缩的反应，用锥形床的冷态试验可以较精确地模拟其实际结果。