DYNAMIC MATRIX CONTROL FOR PROCESS SYSTEMS WITH TIME VARYING PARAMETERS

The industrially successful Dynamic Matrix Control technique (Cutler and Ramaker, 1979; Cutler, 1983) was originally developed for time invariant systems. The expansion of its scope to single variable systems with time-varying time delays and steady state gains is shown to be surprisingly simple. Realistic examples with substantial industrial flavor are used to illustrate the ease of application, and to demonstrate the usefulness of these results.     

丙烯腈连续水相聚合的过程分析及控制

简要介绍丙烯腈水相聚合过程的机理及其数学模型，从而导出过程的参变数及对聚合过程目标值的影响。在此基础上，提出丙烯腈水相连续（共）聚合过程的控制方案。     

CLOSED-LOOP DATA RECONCILIATION FOR THE CONTROL OF A BINARY DISTILLATION COLUMN

Data reconciliation is a procedure that makes use of process models along with process measurements to give more precise and consistent estimates for process variables. Data reconciliation has been traditionally used to provide a more representative set of data to calculate steady-state inventories and process yields. For dynamic systems, the use of data reconciliation is relatively nascent. This article examines the potential use of data reconciliation in closed-loop control as a filter to attenuate the noise in measurements of the controlled variables so that the controllers can access more accurate sets of data. Data reconciliation filters were implemented in simulations of a PID control system for a binary distillation column. Results showed that data reconciliation could efficiently reduce the propagation of measurement noise in control loops, so that the overall performance of the controller is enhanced.     

CLOSED-LOOP DATA RECONCILIATION FOR THE CONTROL OF A BINARY DISTILLATION COLUMN

Data reconciliation is a procedure that makes use of process models along with process measurements to give more precise and consistent estimates for process variables. Data reconciliation has been traditionally used to provide a more representative set of data to calculate steady-state inventories and process yields. For dynamic systems, the use of data reconciliation is relatively nascent. This article examines the potential use of data reconciliation in closed-loop control as a filter to attenuate the noise in measurements of the controlled variables so that the controllers can access more accurate sets of data. Data reconciliation filters were implemented in simulations of a PID control system for a binary distillation column. Results showed that data reconciliation could efficiently reduce the propagation of measurement noise in control loops, so that the overall performance of the controller is enhanced.     

模糊非线性内模控制算法及其在pH值控制中的应用

pH值控制过程具有较强的非线性,历来是过程控制研究的一大热点,本文针对pH值控制系统提出了一种基于模糊推理网的非线性内模控制算法（FNIMC）。模糊推理网用于辨识对象的模糊模型;FNIMC由一个逆模控制器和具有一个可调参数的鲁棒滤波器组成。仿真结果表明该算法优于非线性PID调节器,且计算效率高。     

A MODEL-BASED DIRECT ADAPTIVE PI CONTROLLER FOR NONLINEAR PROCESS CONTROL

This article proposes a model-based direct adaptive proportional-integral (PI) controller for a class of nonlinear processes whose nominal model is input-output linearizable but may not be accurate enough to represent the actual process. The proposed direct adaptive PI controller is composed of two parts: the first is a linearizing feedback control law that is synthesized directly based on the process's nominal model and the second is an adaptive PI controller used to compensate for the model errors. An effective parameter-tuning algorithm is devised such that the proposed direct adaptive PI controller is able to achieve stable and robust control performance under uncertainties. To show the robust stability and performance of the direct adaptive PI control system, a rigorous analysis involving the use of a Lyapunov-based approach is presented. The effectiveness and applicability of the proposed PI control strategy are demonstrated by considering the time-dependent temperature trajectory tracking control of a batch reactor in the presence of plant/model mismatch, unanticipated periodic disturbances, and measurement noises. Furthermore, for use in an environment that lacks full-state measurements, the integration of a sliding observer with the proposed control scheme is suggested and investigated. Extensive simulation results reveal that the proposed model-based direct adaptive PI control strategy enables a highly nonlinear process to achieve robust control performance despite the existence of plant/model mismatch and diversified process uncertainties.     

系统性观念在工艺过程控制中的应用

工艺过程的异常状态事前都有一个演变发展过程,如果监控方法得当,事故苗头就能及时被发现,事故发展有可能得到有效遏制。通过具体实例,说明系统性观念在工艺过程控制中的具体应用。     

实现电渗析淡化过程微机自控的理论与实践

提出了一种符合电渗析淡化过程控制需要的、特定的前馈－反馈联合控制法，据此方法设计的微机自动控制系统应用于实际工程，使电渗析淡化水厂操作更加方便，且能降低运行成本和日常维护费用、保持稳定的出水水质。     

基于数值模拟的气体辅助注射成型工艺控制研究

基于广叉Hele-Shaw流动模型描述了气体辅助注射成型时气体的穿透过程。采用有限元／有限差分／控制体积法计算充填阶段的压力场、温度场,确定熔体前沿和气熔界面,并以实际产品为例分析工艺参数对气体辅助注射成型产品质量的影响。     

百万吨级乙烯装置裂解炉先进控制系统设计与应用

以恒力石化(大连)化工有限公司1500 kt/a乙烯装置裂解炉为例,详细描述裂解炉的工艺流程,分析常规控制方案存在的问题,进而重新设计控制系统,该系统包括平均COT控制、支路温度平衡控制、支路温度“高控”“低控”和总进料流量提/降量控制。并且还介绍控制系统的工程实施,其中包括先进控制系统硬软件平台、先进控制与常规控制的切换逻辑、先进控制系统操作界面等。本系统的投用提高了裂解炉控制的平稳度,延长了裂解炉的运行周期,带来了显著的经济效益。     

小波网络在陶瓷工业过程控制中的应用

针对陶瓷工业过程控制问题，介绍了一种新的控制方案，即基于小波网络的控制。论述了小波网络结构、学习算法以及其优良逼近性能，探讨了小波网络对陶瓷工业过程的辨识与建模问题。最后介绍了基于小波网、网络的几种控制方案并讨论了其在陶瓷工业过程控制中的应用可行性。     

等离子体煤裂解测控方案的探讨

对既有工业生产基本要素,又具备典型科研特征的煤在富氢的高温等离子体裂解直接生产乙炔中试,提出采用硬件配置先进且价格相对低廉的工控机为基本控制装置,利用高级语言开发适合该工艺的应用软件,最终形成以IPC为核心的集监、控、管为一体的等离子煤转化微机监控系统,并对实施过程中出现的主要问题进行探讨和提出相应对策。     

膜生物反应器强化脱氮除磷工艺优化与控制

随着城镇污水排放标准对氮、磷等营养元素的进一步提高,对于传统污水处理工艺来讲是一种挑战.膜生物反应器工艺技术以其独特的优势备受关注,在强化脱氮除磷方面亦表现出优于传统工艺的特点.非传统脱氮除磷的观念的后置反硝化工艺(无外加碳源)在膜生物反应器中得到了应用,并取得良好的去除营养物的效果.从现有的MBR脱氮除磷工艺着手,分析探讨了MBR脱氮除磷工艺研究进展及其应用前景.     

PROCESS CONTROL PERSPECTIVE FOR PROCESS ANALYTICAL TECHNOLOGY: INTEGRATION OF CHEMICAL ENGINEERING PRACTICE INTO SEMICONDUCTOR AND PHARMACEUTICAL INDUSTRIES

FDA's Process Analytical Technology (PAT) initiative provides an unprecedented opportunity for chemical engineers to play significant roles in the pharmaceutical industry. In this article, the authors provide their perspectives on (1) the need for chemical engineering principles in pharmaceutical development for a thorough process understanding; (2) applications of chemical engineering principles to meet the challenges from the semiconductor and pharmaceutical industries; and (3) the integration of chemical engineering practice into the semiconductor and pharmaceutical industries to achieve process understanding and the desired state of quality-by-design. A real-world case study from the semiconductor industry is presented to demonstrate how a classic chemical engineering concept, mixing homogeneity, can be implemented by inducing forced flow to ensure an excellent copper electrochemical plating process performance and to improve product quality substantially. Further, a case study of brake system design is discussed with the concept of Dr. Taguchi's robust engineering design to illustrate how quality-by-design can be achieved through appropriate experimental design, in conjunction with the discussion on the concept of quality-by-design in pharmaceuticals. Third, a case study of freeze-dried sodium ethacrynate is presented to demonstrate the vital importance of controlling the processing factors to achieve the desired product stability. Finally, the problems of the current pharmaceutical manufacturing mode, the opportunities and engineering challenges during implementation of PAT in the pharmaceutical industry, and the role of chemical engineering in implementation of PAT is discussed in detail.     

PROCESS CONTROL PERSPECTIVE FOR PROCESS ANALYTICAL TECHNOLOGY: INTEGRATION OF CHEMICAL ENGINEERING PRACTICE INTO SEMICONDUCTOR AND PHARMACEUTICAL INDUSTRIES

FDA's Process Analytical Technology (PAT) initiative provides an unprecedented opportunity for chemical engineers to play significant roles in the pharmaceutical industry. In this article, the authors provide their perspectives on (1) the need for chemical engineering principles in pharmaceutical development for a thorough process understanding; (2) applications of chemical engineering principles to meet the challenges from the semiconductor and pharmaceutical industries; and (3) the integration of chemical engineering practice into the semiconductor and pharmaceutical industries to achieve process understanding and the desired state of quality-by-design. A real-world case study from the semiconductor industry is presented to demonstrate how a classic chemical engineering concept, mixing homogeneity, can be implemented by inducing forced flow to ensure an excellent copper electrochemical plating process performance and to improve product quality substantially. Further, a case study of brake system design is discussed with the concept of Dr. Taguchi's robust engineering design to illustrate how quality-by-design can be achieved through appropriate experimental design, in conjunction with the discussion on the concept of quality-by-design in pharmaceuticals. Third, a case study of freeze-dried sodium ethacrynate is presented to demonstrate the vital importance of controlling the processing factors to achieve the desired product stability. Finally, the problems of the current pharmaceutical manufacturing mode, the opportunities and engineering challenges during implementation of PAT in the pharmaceutical industry, and the role of chemical engineering in implementation of PAT is discussed in detail.     

化工过程模拟优化的演变优化方法

研究了化工过程模拟优化的一类新方法——过程演变优化方法,提出基于ＤＮＮ（动态人工神经网络）的动态算法的统一框架,阐明其并行分布计算特性,并给出一些基于过程规划的计算动力学模型。     

卧式层状燃煤锅炉炉内消烟除尘技术

引　言我国煤炭产量的 80 %左右用于锅炉等燃烧设备的直接燃烧 ,它是“煤烟型”污染的主要来源 .工业锅炉的消烟除尘问题虽然一直受到人们的重视 ,但又是一直没能很好解决的问题 .在综合考虑我国工业锅炉燃烧特性、锅炉结构形式 ,结合国内外在消烟除尘方面所取得的成功经验 ,作     

FAST AND SLOW GENERATION OF A MULTILEVEL CONTROL FOR THE WOOD DRYING PROCESS

ABSTRACT

The dynamic characteristics of the wood drying process were represented by an actuator network and an internal model. These two subsystems are composed of a set of ordinary differential, partial differential and algebraic equations with adjusting operating functions. The formulation of the operating functions is based on interaction between air and the lumber board in a semi-industrial drying kiln. Using this internal model, it was possible to establish a state observer, a state predictor, and a reference model for which the boundary conditions were generated by the actuator network. Simulation results were obtained with a C++ software package. In order to implement the optimization techniques to the wood drying process, the two-level control structure was proposed and tested for a minimum drying time as a performance criterion. Numerical results confirm that the internal model and its operating functions were properly chosen.     

A comparison of nonlinear control performance assessment techniques for nonlinear processes

Assessing the quality of industrial control loops is an important auditing task for the control engineer. However, there are complications when considering the ubiquitous nonlinearities present in many industrial control loops. If one simply ignores these nonlinearities, there is the danger of over‐estimating the performance of the control loop in rejecting disturbances and thereby possibly overlooking loops that need attention. To address this problem, several techniques have been recently developed to extend the control performance assessment (CPA) of single input/single output linear systems to nonlinear systems. This article surveys these nonlinear CPA techniques and compares their performances using three case studies. These results can be used to guide control engineers to select the most suitable CPA techniques for their particular applications. © 2012 Canadian Society for Chemical Engineering