Chemical Process Control An Introduction to Theory and PracticePDF电子书下载

Part Ⅰ The Control of a Chemical Process：Its Characteristics and Associated Problems 1

1.Incentives for Chemical Process Control 2

1.1 Suppress the Influence of External Disturbances 4

1.2 Ensure the Stability of a Process 7

1.3 Optimize the Performance of a Chemical Process 10

2.Design Aspects of a Process Control System 12

2.1 Classification of the Variables in a Chemical Process 12

2.2 Design Elements of a Control System 14

2.3 Control Aspects of a Complete Chemical Plant 25

3.Hardware for a Process Control System 28

3.1 Hardware Elements of a Control System 28

3.2 Use of Digital Computers in Process Control 30

Concluding Remarks on Part Ⅰ 33

Things to Think About for Part Ⅰ 33

References for Part Ⅰ 35

Problems for Part Ⅰ 36

Part Ⅱ Modeling the Dynamic and Static Behavior of Chemical Processes 43

4.Development of a Mathematical Model 45

4.1 Why Do We Need Mathematical Modeling for Process Control？ 46

4.2 State Variables and State Equations for a Chemical Process 48

4.3 Additional Elements of the Mathematical Models 55

4.4 Dead Time 58

4.5 Additional Examples of Mathematical Modeling 59

4.6 Modeling Difficulties 74

Things to Think About 78

5.Modeling Considerations for Control Purposes 80

5.1 The Input-Output Model 81

5.2 Degrees of Freedom 86

5.3 Degrees of Freedom and Process Controllers 89

5.4 Formulating the Scope of Modeling for Frocess Control 93

Things to Think About 97

References for Part Ⅱ 98

Problems for Part Ⅱ 100

Part Ⅲ Analysis of the Dynamic Behavior of Chemical Processes 111

6.Computer Simulation and the Linearization of Nonlinear Systems 113

6.1 Computer Simulation of Process Dynamics 114

6.2 Linearization of Systems with One Variable 116

6.3 Deviation Variables 119

6.4 Linearization of Systems with Many Variables 121

Things to Think About 126

7.Laplace Transforms 128

7.1 Definition of the Laplace Transform 128

7.2 Laplace Transforms of Some Basic Functions 130

7.3 Laplace Transforms of Derivatives 139

7.4 Laplace Transforms of Integrals 139

7.5 Final-V？lue Theorem 140

7.6 Initial-Value Theorem 141

Things to Think About 141

8.Solution of Linear Differential Equations Using Laplace Transforms 143

8.1 A Characteristic Example and the Solution Procedure 143

8.2 Inversion of Laplace Transforms.Heaviside Expansion 145

8.3 Examples on the Solution of Linear Differential Equations Using Laplace Transforms 152

Things to Think About 157

9.Transfer Functions and the Input-Output Models 159

9.1 Transfer Function of a Process with a Single Output 159

9.2 Transfer Function Matrix of a Process with Multiple Outputs 163

9.3 Poles and Zeros of a Transfer Function 167

9.4 Qualitative Analysis of the Response of a System 168

Things to Think About 172

10.Dynamic Behavior of First-Order Systems 173

10.1 What Is a First-Order System？ 173

10.2 Processes Modeled as First-Order Systems 174

10.3 Dynamic Response of a Pure Capacitive Process 178

10.4 Dynamic Response of a First-Order Lag System 179

10.5 First-Order Systems with Variable Time Constant and Gain 183

Things to Think About 184

11.Dynamic Behavior of Second-Order Systems 186

11.1 What Is a Second-Order System？ 186

11.2 Dynamic Response of a Second-Order System 187

11.3 Multicapacity Processes as Second-Order Systems 193

11.4 Inherently Second-Order Processes 201

11.5 Second-Order Systems Caused by the Presence of Controllers 201

Things to Think About 204

Appendix 11A Examples of Physical Systems with Inherent Second-Order Dynamics 205

12.Dynamic Behavior of Higher-Order Systems 212

12.1 N Capacities in Series 212

12.2 Dynamic Systems with Dead Time 214

12.3 Dynamic Systems with Inverse Response 216

Things to Think About 220

References for Part Ⅲ 220

Problems for Part Ⅲ 223

Part Ⅳ Analysis and Design of Feedback Control Systems 239

13.Introduction to Feedback Control 241

13.1 Concept of Feedback Control 241

13.2 Types of Feedback Controllers 245

13.3 Measuring Devices（Sensors） 248

13.4 Transmission Lines 253

13.5 Final Control Elements 253

Things to Think About 256

14.Dynamic Behavior of Feedback-Controlled Processes 258

14.1 Block Diagram and the Closed-Loop Response 258

14.2 Effect of Proportional Control on the Response of a Controlled Process 265

14.3 Effect of Integral Control Action 273

14.4 Effect of Derivative Control Action 276

14.5 Effect of Composite Control Actions 277

Things to Think About 279

15.Stability Analysis of Feedback Systems 281

15.1 Notion of Stability 281

15.2 The Characteristic Equation 285

15.3 Routh-Hurwitz Criterion for Stability 287

15.4 Root-Locus Analysis 290

Things to Think About 295

16.Design of Feedback Controllers 297

16.1 Outline of the Design Problems 297

16.2 Simple Performance Criteria 299

16.3 Time-Integral Performance Criteria 302

16.4 Select the Type of Feedback Controller 306

16.5 Controller Tuning 310

Things to Think About 316

17.Frequency Response Analysis of Linear Processes 317

17.1 Response of a First-Order System to a Sinusoidal Input 317

17.2 Frequency Response Characteristics of a General Linear System 321

17.3 Bode Diagrams 326

17.4 Nyquist Plots 338

Things to Think About 341

18.Design of Feedback Control Systems Using Frequency Response Techniques 344

18.1 Bode Stability Criterion 344

18.2 Gain and Phase Margins 349

18.3 Ziegler-Nichols Tuning Technique 352

18.4 Nyquist Stability Criterion 355

Things to Think About 358

References for Part Ⅳ 360

Problems for Part Ⅳ 363

Part Ⅴ Analysis and Design of Advanced Control Systems 381

19.Feedback Control of Systems with Large Dead Time or Inverse Response 383

19.1 Processes with Large Dead Time 383

19.2 Dead Time Compensation 385

19.3 Control of Systems with Inverse Response 390

Things to Think About 393

20.Control Systems with Multiple Loops 394

20.1 Cascade Control 395

20.2 Selective Control Systems 402

20.3 Split-Range Control 407

Things to Think About 409

21.Feedforward and Ratio Control 411

21.1 Logic of Feedforward Control 411

21.2 Problem of Designing Feedforward Controllers 414

21.3 Practical Aspects on the Design of Feedforward Controllers 420

21.4 Feedforward-Feedback Control 423

21.5 Ratio Control 427

Things to Think About 429

22.Adaptive and Inferential Control Systems 431

22.1 Adaptive Control 431

22.2 Inferential Control 438

Things to Think About 443

References for Part Ⅴ 444

Problems for Part Ⅴ 447

Part Ⅵ Design of Control Systems for Multivariable Processes：Introduction to Plant Control 459

23.Synthesis of Alternative Control Configurations for Multiple-Input，Multiple-Output Processes 461

23.1 Design Questions for MIMO Control Systems 461

23.2 Degrees of Freedom and the Number of Controlled and Manipulated Variables 462

23.3 Generation ofAlternative Loop Configurations 467

23.4 Extensions to Systems with Interacting Units 469

Things to Think About 484

24.Interaction and Decoupling of Control Loops 486

24.1 Interaction of Control Loops 487

24.2 Relative-Gain Array and the Selection of Loops 494

24.3 Design of Noninteracting Control Loops 504

Things to Think About 508

25.Design of Control Systems for Complete Plants 510

25.1 Process Design and Process Control 510

25.2 Hydrodealkylation of Toluene Plant to Produce Benzene：A Case Study 516

25.3 Material Balance Control for the Hydrodealkylation Plant 519

25.4 Product Quality Control for the Hydrodealkylation Plant 524

25.5 Some Comments on the Control Design for Complete Plants 529

Things to Think About 534

References for Part Ⅵ 537

Problems for Part Ⅵ 540

Part Ⅶ Process Control Using Digital Computers 549

26.Digital Computer Control Loops 551

26.1 The Digital Computer 552

26.2 Computer-Process Interface for Data Acquisition and Control 557

26.3 Computer Control Loops 561

26.4 New Control Design Problems 566

Things to Think About 568

27.From Continuous to Discrete-Time Systems 570

27.1 Sampling Continuous Signals 571

27.2 Reconstruction of Continuous Signals from Their Discrete-Time Values 576

27.3 Conversion of Continuous to Discrete-Time Models 581

Things to Think About 587

28.z-Transforms 589

28.1 Definition of z-Transforms 589

28.2 z-Transforms of Some Basic Functions 591

28.3 Properties of z-Transforms 595

28.4 Inversion of z-Transforms 599

Things to Think About 604

Appendix 28A：The Modified z-Transform 606

29.Discrete-Time Response of Dynamic Systems 608

29.1 Response of Discrete Dynamic Systems 609

29.2 Discrete-Time Analysis of Continuous Systems.The Pulse Transfer Function 613

29.3 Discrete-Time Analysis of Closed-Loop Systems 621

29.4 Stability Analysis of Discrete-Time Systems 626

Things to Think About 631

30.Design of Digital Feedback Controllers 634

30.1 Digital Approximation of Classical Controllers 635

30.2 Effect of Sampling 638

30.3 A Different Class of Digital Controllers 640

30.4 “Ringing” and the Placement of Poles 647

30.5 Design of Optimal Regulatory Control Systems 650

Things to Think About 654

31.Process Identification and Adaptive Control 656

31.1 Process Identification 657

31.2 Process Identification and Adaptive Control 662

Things to Think About 667

References for Part Ⅶ 670

Problems for Part Ⅶ 674

Index 685