Advanced Process Control Beyond Single Loop Control [Hardcover]

This book fills the gap between basic control configurations (Practical Process Control) and model predictive control (MPC). For those loops whose performance has a direct impact on plant economics or product quality, going beyond simple feedback or cascade can improve control performance, or specifically, reduce the variance about the target. However, the effort required to implement such control technology must be offset by increased economic returns from production operations. The economic aspects of the application of the various advanced control technologies are stressed throughout the book.

Preface ix

1 Introduction 1

1.1. Implementing Control Logic 2

1.2. Control Blocks for Process Control 12

1.3. PID Controller 16

1.4. Integrator or Totalizer 23

1.5. Lead-Lag Element 26

1.6. Dead Time 29

1.7. Selector Block 34

1.8. Cutoff Block 35

1.9. Hand Station 36

2 Cascade Control 38

2.1. Jacketed Reactor 38

2.2. Block Diagrams 43

2.3. Problem Element 45

2.4. Cooling Media Disturbances 49

2.5. Effect of Varying Heat Transfer Rate 51

2.6. Cascade Control Modes 55

2.7. Remote Set Point 58

2.8. Output Tracking 60

2.9. Control Modes 62

2.10. Interacting Stages 64

2.11. Tuning Cascades 69

2.12. Windup in Cascade Controls 74

2.13. Integral Tracking 78

2.14. External Reset 81

2.15. Inhibit Increase Inhibit Decrease 83

3 Split-Range Control 86

3.1. Storage Tank Pressure Control 87

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