Process Control Fundamentals-Analysis, Design, Assessment, and Diagnosis

✍ Scribed by Raghunathan Rengaswamy (Author); Babji Srinivasan (Author); Nirav Pravinbhai Bhatt (Author)

• Publisher: CRC Press
• Year: 2020
• Leaves: 349
• Edition: 1
• Category: Library

✦ Synopsis

The field of process control has evolved gradually over the years, with emphasis on key aspects including designing and tuning of controllers. This textbook covers fundamental concepts of basic and multivariable process control, and important monitoring and diagnosis techniques.

It discusses topics including state-space models, Laplace transform to convert state-space models to transfer function models, linearity and linearization, inversion formulae, conversion of output to time domain, stability analysis through partial fraction expansion, and stability analysis using Routh table and Nyquits plots. The text also covers basics of relative gain array, multivariable controller design and model predictive control. The text comprehensively covers minimum variable controller (MVC) and minimum variance benchmark with the help of solved examples for better understanding. Fundamentals of diagnosis of control loop problems are also explained and explanations are bolstered through solved examples. Pedagogical features including solved problems and unsolved exercises are interspersed throughout the text for better understanding.

The textbook is primarily written for senior undergraduate and graduate students in the field of chemical engineering and biochemical engineering for a course on process control.

The textbook will be accompanied by teaching resource such a collection of slides for the course material and a includsolution manual for the instructors.

✦ Table of Contents

List of Figures

List of Tables

1 Introduction

1.1 Single-input-single-output and Multi-input-Multi-output Controllers

1.2 Regulator and Servo Control Problems

1.3 Dynamic Behaviour of Processes

2 Models for Control

2.1 Linearization

2.2 State-space representation of dynamic models

2.3 Transfer function models

2.4 Problems and Solutions

2.5 Exercises

3 Process Identification

3.1 Identification of First-order Processes

3.2 Identification of Second-order Processes

3.3 Identification of First-order with Dead Time

3.3.1 Identification of overdamped second-order systems

3.4 Problems and Solutions

4 Analysis of Transfer Function models

4.1 Introduction

4.2 Partial Fractions Approach for Solving Transfer Functions

4.3 Stability of Transfer function

4.4 Problems and Solutions

4.5 Exercises

5 Controllers and analysis of closed loop transfer functions

5.1 PID Controllers

5.2 Analysis of Block Diagram

5.3 Routh Test

5.4 Problems and Solutions

5.5 Exercises

6 Controller tuning

6.1 Stability based on Zeigler Nichols tuning

6.2 Tuning based on direct synthesis

6.2.1 Inverse response systems

6.2.2 Systems with delay element

6.2.3 Unstable Systems

6.3 Internal Model Control Method

6.4 Problems and solutions

6.5 Exercises

7 Multi-loop and multivariable control

7.1 Relative gain array

7.2 Cascade control

7.3 Static decoupler

7.4 Dynamic decoupling

7.5 Multivariable PID control

7.6 Problems and Solutions

8 Model Predictive Control

8.1 Introduction to MPC

8.1.1 Key aspects of MPC

8.2 Development of discrete models

8.3 MPC Formulation

8.3.1 MPC demonstration through a simple example

8.4 Bias removal in MPC

8.5 Problems and Solutions

9 Fundamentals of controller performance assessment

9.1 Performance assessment of control loops

9.2 Control loop performance assessment for step type changes in load

9.2.1 Model based approach - DS/IMC tuning rule based Indices

9.3 Algorithm for development of SIMC based performance indices

9.4 Idle index technique for identification of sluggish control loops

9.5 Detecting Oscillations

9.5.1 Introduction to ACF

9.6 Regularity of zero-crossings of the auto-correlation function

9.7 Control loop performance assessment based on variability in the process output

9.8 Minimum Variance Index

9.9 Scaling exponent based measure for controller performance assessment

9.9.1 Implications of the scaling exponent to control loop performance assessment

9.10 Problems and Solutions

10 Fundamentals of controller performance diagnosis

10.1 Control Valve and Stiction

10.2 Modeling of Stiction

10.2.1 One parameter model for valve stiction

10.3 Identification of stiction in control valves

10.3.1 Shape based formalism for stiction detection

10.3.2 Issues in stiction detection

10.3.3 Hammerstein model based approach to Stiction detection

10.3.4 Least Squares approach for model parameter identification

10.4 Oscillations due to improper controller tuning

11 Case Studies

11.1 Introduction

11.2 2x2 Distillation Column

11.2.1 RGA Analysis

11.2.2 Decoupler

11.2.3 PI Controller Tuning

11.2.4 Model Predictive Controller

11.3 3x3 Distillation Column

11.3.1 RGA Analysis

11.3.2 Decoupler

11.3.3 PID Controller Tuning

11.3.4 Model Predictive Controller

11.4 CSTR

11.4.1 Model Predictive Controller

Bibliography