复杂反应中的非催化气—固均相模型研究

探讨了复杂反应体系单个球形颗粒非催化气－固均相一级非可逆反应的情况。根据以稳态假设，建立了两种不同类型串联反应的质量传递和热量传递模型，在忽略气体主体与颗粒表面的传质阻力，并假定某些参数，用数值法对方程进行求解，得到了反应物浓试、产物浓度、温度、有效系数、反应选择性、反应时间等分布曲线，并对各种情况作了分析和讨论。     

颗粒流的动力学模型在催化裂化中的应用（Ⅱ）：催化剂？…

运用已经建立的催化裂化反应的数学模型和模型边界条件及求解方法,结合炼油厂工业提升管的实际操作参数,模拟预测了催化裂化提升管反应器内催化剂颗粒的流场特征和原料油反应产物的浓度及气粒两相平均温度的沿程分布特征。模拟结果表明,由于原料油射流的影响,提升管反应器内催化剂颗粒的流动特征非常复杂,在喷嘴附近的催化剂颗粒存在明显的滑返混,裂化产物浓度沿提升管存在非均匀分布,气粒两相间温差在喷嘴附近显著,在中上部     

微观-介观双尺度模型下循环流化床内宏观流动

基于气体分子运动论和颗粒动理学,建立微观-介观尺度双尺度的稠密气固两相流流动模型.微观尺度考虑气体与单颗粒以及单颗粒间相互作用造成的能量和动量传递和耗散,介尺度考虑气体与颗粒团聚物以及团聚物间相互作用形成的能量和动量传递和耗散,同时考虑微观尺度与介观尺度间相互作用导致动量和能量的传递.模拟计算颗粒相浓度、速度等参数与实测值相吻合.     

颗粒流的动力学模型在催化裂化中的应用(Ⅱ)--催化剂的流动特征及产品浓度沿程分布

运用已经建立的催化裂化反应的数学模型和模型边界条件及求解方法,结合炼油厂工业提升管的实际操作参数,模拟预测了催化裂化提升管反应器内催化剂颗粒的流场特征和原料油反应产物的浓度及气粒两相平均温度的沿程分布特征。模拟结果表明,由于原料油射流的影响,提升管反应器内催化剂颗粒的流动特征非常复杂,在喷嘴附近的催化剂颗粒存在明显的滑落返混;裂化产物浓度沿提升管存在非均匀分布;气粒两相间温差在喷嘴附近显著,在中上部气粒两相温度几乎相等     

非等温催化剂颗粒上活性组分的最佳分布Ⅰ──连串反应体系

讨论了一维多孔性催化剂颗粒在非等温情况下活性组分的最佳分布。活性组分集中在离颗粒中心某一距离的无限薄层上可得到最大的选择性Ｓ＿（ｍａｘ）．该最佳位置决定于非等温效应、传质阻力以及反应速率的相对大小．文中针对连串反应体系，运用数学方法证明了颗粒催化剂活性组分非均匀分布时的最大反应选择性。结果表明，当分布函数为δ－ｄｉｒａｃ时，连串反应的选择性最大，并讨论了活性组分位置对选择性的影响和体系的多重态．     

燃烧模型对多孔介质内预混燃烧的影响

采用二维非稳态数学模型研究燃烧模型多孔介质内预混燃烧影响.燃烧模型分别为单步和多步化学反应动力机理（17种组分,58个反应）,CH4/空气当量比的范围为0.55～1.0.对比分析两种燃烧模型下燃烧器中心处的温度、组分浓度分布曲线.结果表明,多步燃烧模型对燃烧器内温度、组分浓度分布有更准确的预测,并与文献结果比较,证实了二维非稳态数学模型的正确性.此外,将二维的温度场进行比较,结果表明单步化学机理的反应区域小,温度梯度大,而多步化学反应由于各反应步骤存在时间尺度的差异,反应区域大,温度梯度相对较小,与实际燃烧情况能很好的吻合.     

高交联木薯淀粉的非糊化特性

以三氯氧磷为交联制备非糊化的高交联木薯淀粉，并测定了反应的取代度和布拉班德粘度曲线，研究了在沸水中受热后非糊化淀粉的颗粒形貌及粒度分布等特性。提出高交联非糊化木薯淀粉存在着不同原淀粉颗粒的在沸水中只发生轻度有限溶胀的非糊化颗粒态。     

新型粉尘浓度测定仪的开发研究

本文介绍了一种作者新研制的悬浮态颗粒浓度测量仪器。该仪器采用红外光源，利用通过含尘气体产生的光强衰减现象测量颗粒点浓度，可广泛用于研究各种悬浮床的粉体浓度分布情况，该仪器探头尺寸小，灵敏度和精度均比较高，性能稳定，能迅速可靠地测定较宽浓度范围的颗粒点浓度，本文还在特制的标定系统上利用抽气采样法对仪器进行了标定，并测定了Smidth F.L.型预分解炉的浓度场，发现了一些有价值的现象和规律。     

非稳态下井巷瓦斯浓度弥散模型及其求解

根据紊流传质理论建立了非稳态下井巷瓦斯浓度的弥散模型，对其进行了分析，确定出弥散系数的计算公式，应用有限差分方法对该瓦斯浓度弥散模型进行了求解．并给出了利用该方法计算循环通风系统内瓦斯浓度的非稳态显现规律的实例．     

固/液界面上腐殖酸吸附机理的探讨

运用SS表面络合模型研究了腐殖酸分子在赤铁矿颗粒/水界面上的吸附情况。主要研究了pH值和离子强度2个重要影响因素,通过分析反应前后溶液的ζ电势和赤铁矿颗粒表面的吸附量,从而得出赤铁矿颗粒/水界面吸附配位反应的程度和腐殖酸分子的吸附机理。     

环柱状银催化剂内反应-传质-传热耦合过程数学模型

建立了乙烯氧化制环氧乙烷环柱状银催化剂内复合反应－传质－传热耦合过程的二维数学模型模型中未引入人为的假定,所需参数均由实验确定     

可逆反应过程耦合强化策略研究

介绍了化工过程强化中的反应过程耦合强化技术,从反应、传热、传质等方面研究探讨了可逆反应过程耦合共性特征,着重从理论上分析单产品可逆反应过程与多产品可逆反应过程的耦合强化途径及其强化机理,提出解决可逆反应过程受动力学、热力学平衡限制的有效途径,同时结合实例进行论证。所提出的过程强化策略对发展现有系统节能方法和策略以及实现传统过程工业的节能降耗、增进效益有着一定的理论和实际意义。     

气-固流化床内射流矩的混合特性

实验测试了矩内颗粒的线速度，空隙率分布和颗粒卷吸量。结果表明颗粒瞬时速度高达10m/s且与射流气速有一个数量级的滑移，由此证实了良好的混合与反应机理。     

A New Method for Computing Radiation Heat Flow of In-Cylinder Soot of Diesel Engines

A concise formula for computing radiation heat flow of in-cylinder soot is presented,based on the assumptions that in-cylinder heat transfer of diesel engines is a quasi-equilibrium process and in-cylinder soot particles are spherical. That in this formula there consist neither constants needing adjustments nor variables related to engine types or operating conditions makes it universal and easy to use. Also it can be seen from the formula that radiation heat transfer is proportional to the quotient of in-cylinder soot mass over the average radius of primary particles. Besides, with the help of different algorithms it can be used for predicting cylinders' global as well as local radiation heat flows. As a demonstrative application on its global facet, a three-dimension simulation study about the soot-radiation-related heat flow in the combustion chamber of a diesel engine is carried out. Results show that the range of the soot-radiation-related heat flow computed by this formula agrees well with other researcher's earlier theoretic reasoning and experimental measurements.     

微波辐照球形煤焦间的电场强化效应

微波等离子体在材料处理及能源环境等领域有着广泛的应用,但微波辐照球形煤焦颗粒影响电场强化效应的因素目前并不明确。通过建立电磁波频域-固体传热耦合模型,研究了2个球形煤焦颗粒间的电场强化效应。结果表明:当2个颗粒接触点处的表面法线和电场方向之间的夹角从40°增加到50°时,微波的入射角达到了煤焦界面的临界入射角,电场强化效应出现骤降;微波在球形煤焦颗粒内的穿透深度对电场强化效应起决定性作用;球形煤焦颗粒间的电场强化效应最佳条件是小间距而不是无间距。     

螺旋肋片管与气固多相流传热特性研究

本文在试验的基础上对气固多相流横向冲刷螺旋肋片管的传热特性进行了研究。试验所用物料为平均粒径ｄｐ＾－＝４４μｍ电厂灰和ｄｐ＾－＝１２０μｍ细石英砂。颗粒重量浓度Ｍｓ在０￣４．５ｋｇ／ｋｇ范围内。结果表明,螺旋肋片管与气固多相流传热与气流Ｒｅ数,颗粒浓度以及颗粒尺寸均有关,在较细颗粒和较低Ｒｅ数下,气固多相流强化传热程度随颗粒浓度的增加而增加。     

Numerical Modeling of NO Formation during Packed-bed Combustion of Coke Granules

A comprehensive kinetic model of NO formation during coke combustion in packed-bed in presence of noncombustible particles was developed. The detailed homogeneous gas-phase chemistry (including 102 chemical reactions), heterogeneous gas-solid chemistry (including 11 reactions) of coke combustion and NO formation, and the heat and mass transfer were taken into account in the present model. The governing equations which are strongly coupled, non-linear and unsteady with 26 unknowns in total, were dispersed into differential equations with the finite differential method. Meanwhile, all the differential equations were numerically solved to give the time-histories and space-distributions oftemperatures of the bed and gas phase as well as the concentrations of all the gaseous species. By comparison, the experimental data were explained well by the calculated results. Based on the kinetic and mathematical model, the effects of O2 content of inlet gas, the initial chemical analysis of coke, bed-temperature and local reductive atmosphere (CO/O2) on NO formation during packed-bed coke combustion were numerically discussed. It was found that coke samples with a higher initial content of [N] and volatile matters, combusted under a suitable O2-containing atmosphere produced less NO emission. The reactions between CO and NO, catalyzed by high temperature surface of coke particles may be responsible for efficient reduction of NO.     

Mathematical model for coupled reactive flow and solute transport during heap bioleaching of copper sulfide

Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 °C. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process.     

气流干燥器设计中的加速区分段公式

本文分析了用分段积分法设计气流干燥器时要试差分段的原因,从气固两相热交换工作方程式出发,通过适当地近似处理、推导出了气流干燥器加速运动区的分段公式。在一般气流干燥条件下的恒速干燥带,可用本文提出的分段公式直接计算出每一小段的终点气体温度 ti,从而实现了加速区的分段,避免了分段过程的试差计算,且在允许的误差范围内,本法所分得的段数最少,从而减少了计算量,使分段积分法变得更为简捷,宜于手算。     

球面弓形折流板换热器壳程流体流动与传热的数值模拟

为了改善普通弓形折流板换热器换热性能,提出了一种新型折流板换热器-球面弓形折流板换热器。建立曲率半径为0.75 D的球面弓形折流板换热器和普通弓形折流板换热器数值分析模型,得到了壳程流体流场分布情况以及壳程压力降和传热系数。结果表明,在相同结构参数和进口流速条件下,球面弓形折流板换热器壳程压力降比普通弓形折流板换热器降低8%~11%,壳程传热系数比普通弓形折流板换热器降低1%~5%。