过程控制仪表技术 第8版PDF电子书下载

INTRODUCTION TO PROCESS CONTROL 1 1

Instructional Objectives 1 1

1 Introduction 1 1

2 Control Systems 2 1

2.1　Process-Control Principles 1

2.2　Servomechanisms 1

2.3　Discrete-State Control Systems 1

3　Process-Control Block Diagram 6 1

3.1 Identification of Elements 1

3.2 Block Diagram 1

4 Control System Evaluation 10 1

4.1　Stability 1

4.2　Steady-State Regulation 1

4.3　Transient Regulation 1

4.4 Evaluation Criteria 1

5 Analog and Digital Processing 14 1

5.1　Data Representation 1

5.2 ON/OFF Control 1

5.3 Analog Control 1

5.4　Digital Control 1

5.5　Programmable Logic Controllers 1

6 Units,Standards,And Definitions 22 1

6.1 Units 1

6.2　Analog Data Representation 1

6.3　Definitions 1

6.4　Process-Control Drawings 1

7 Sensor Time Response 36 1

7.1 First-Order Response 1

7.2　Second-Order Response 1

8 Significance and Statistics 40 1

8.1 Significant Figures 1

8.2 Statistics 1

Summary 2

Problems 2

Supplementary Problems 2

ANALOG SIGNAL CONDITIONING 53 2

Instructional Objectives 53 2

1 Introduction 53 2

2　Principles of Analog Signal Conditioning 54 2

2.1 Signal-Level and Bias Changes 2

2.2　Linearization 2

2.3 Conversions 2

2.4　Filtering and Impedance Matching 2

2.5　Concept of Loading 2

3　Passive Circuits 58 2

3.1　Divider Circuits 2

3.2 Bridge Circuits 2

3.3 RC Filters 2

4 Operational Amplifiers　83 2

4.1 Op Amp Characteristics 2

4.2　Op Amp Specifications 2

5 OP Amp Circuits in Instrumentation 89 2

5.1　Voltage Follower 2

5.2　Inverting Amplifier 2

5.3　Noninverting Amplifier 2

5.4　Differential Instrumentation Amplifier 2

5.5　Voltage-to-Current Converter 2

5.6　Current-to-Voltage Converter 2

5.7 Integrator 2

5.8　Differentiator 2

5.9　Linearization 2

6　Design Guidelines 102 2

Summary 3

Problems 3

Supplementary Problems 3

DIGITAL SIGNAL CONDITIONING 115 3

Instructional Objectives 115 3

1 Introduction 115 3

2 Review of Digital Fundamentals 116 3

2.1　Digital Information 3

2.2　Fractional Binary Numbers 3

2.3　Boolean Algebra 3

2.4　Digital Electronics 3

2.5　Programmable Logic Controllers 3

2.6 Computer Interface 3

3 Converters 125 3

3.1　Comparators 3

3.2　Digital-to-Analog Converters(DACs) 3

3.3 Analog-to-Digital Converters(ADCs) 3

3.4 Frequency-Based Converters 3

4 Data-Acquisition Systems 155 3

4.1 DAS Hardware 3

4.2 DAS Software 3

5 Characteristics of Digital Data 160 3

5.1 Digitized Value 3

5.2 Sampled Data Systems 3

5.3 Linearization 3

Summary 4

Problems 4

Supplementary Problems 4

THERMAL SENSORS 175 4

Instructional Objectives 175 4

1 Introduction 175 4

2 Definition of Temperature 176 4

2.1 Thermal Energy 4

2.2 Temperature 4

3 Metal Resistance versus Temperature Devices 180 4

3.1 Metal Resistance versus Temperature 4

3.2 Resistance versus Temperature Approximations 4

3.3 Resistance-Temperature Detectors 4

4 Thermistors 189 4

4.1 Semiconductor Resistance versus Temperature 4

4.2 Thermistor Characteristics 4

5 Thermocouples 193 4

5.1 Thermoelectric Effects 4

5.2 Thermocouple Characteristics 4

5.3 Thermocouple Sensors 4

6 Other Thermal Sensors 204 4

6.1 Bimetal Strips 4

6.2 Gas Thermometers 4

6.3 Vapor-Pressure Thermometers 4

6.4 Liquid-Expansion Thermometers 4

6.5 Solid-State Temperature Sensors 4

7 Design Considerations 211 4

Summary 5

Problems 5

Supplementary Problems 5

MECHANICAL SENSORS 223 5

Instructional Objectives 223 5

1 Introduction 223 5

2 Displacement,Location,or Position Sensors 224 5

2.1 Potentiometric Sensors 5

2.2 Capacitive and Inductive Sensors 5

2.3 Vairiable-Reluctance Sensors 5

2.4 Level Sensors 5

3 Strain Sensors 232 5

3.1 Strain and Stress 5

3.2 Strain Gauge Principles 5

3.3 Metal Strain Gauges 5

3.4 Semiconductor Strain Gauges(SGs) 5

3.5 Load Cells 5

4 Motion Sensors 246 5

4.1 Types of Motion 5

4.2 Accelerometer Principles 5

4.3 Types of Accelerometers 5

4.4 Applications 5

5 Pressure Sensors 258 5

5.1 Pressure Principles 5

5.2 Pressure Sensors(p＞1 atmosphere) 5

5.3 Pressure Sensors(p＞1 atmosphere) 5

6 Flow Sensors 267 5

6.1 Solid-Flow Measurement 5

6.2 Liquid Flow 5

Summary 6

Problems 6

Supplementary Problems 6

OPTICAL SENSORS 285 6

Instructional Objectives 285 6

1 Introduction 285 6

2 Fundamentals of EM Radiation 286 6

2.1 Nature of EM Radiation 6

2.2 Characteristics of Light 6

2.3 Photometry 6

3 Photodetectors 296 6

3.1 Photodetector Characteristics 6

3.2 Photoconductive Detectors 6

3.3 Photovoltaic Detectors 6

3.4 Photodiode Detectors 6

3.5 Photoemissive Detectors 6

4 Pyrometry 311 6

4.1 Thermal Radiation 6

4.2 Broadband Pyrometers 6

4.3 Narrowband Pyrometers 6

5 Optical Sources 316 6

5.1 Conventional Light Sources 6

5.2 Laser Principles 6

6 Applications 322 6

6.1 Label Inspection 6

6.2 Turbidity 6

6.3 Ranging 6

Summary 7

Problems 7

Supplementary Problems 7

FINAL CONTROL 333 7

Instructional Objectives 333 7

1 Introduction 333 7

2 Final Control Operation 334 7

2.1 Signal Conversions 7

2.2 Actuators 7

2.3 Control Element 7

3 Signal Conversions 336 7

3.1 Analog Electrical Signals 7

3.2 Digital Electrical Signals 7

3.3 Pneumatic Signals 7

4 Power Electronics 342 7

4.1 Switching Devices 7

4.2 Controlling Devices 7

5 Actuators 358 7

5.1 Electrical Actuators 7

5.2 Pneumatic Actuators 7

5.3 Hydraulic Actuators 7

6 Control Elements 371 7

6.1 Mechanical 7

6.2 Electrical 7

6.3 Fluid Valves 7

Summary 8

Problems 8

Supplementary Problems 8

DISCRETE-STATE PROCESS CONTROL 387 8

Instructional Objectives 387 8

1 Introduction 387 8

2 Definition of Discrete-State Process Control 388 8

3 Characteristics of the System 389 8

3.1 Discrete-State Variables 8

3.2 Process Specifications 8

3.3 Event Sequence Description 8

4 Relay Controllers and Ladder Diagrams 403 8

4.1 Background 8

4.2 Ladder Diagram Elements 8

4.3 Ladder Diagram Examples 8

5 Programmable Logic Controllers(PLCs) 413 8

5.1 Relay Sequencers 8

5.2 Programmable Logic Controller Design 8

5.3 PLC Operation 8

5.4 Programming 8

5.5 PLC Software Functions 8

Summary 9

Problems 9

Supplementary Problems 9

CONTROLLER PRINCIPLES 439 9

Instructional Objectives 439 9

1 Introduction 439 9

2 Process Characteristics 440 9

2.1 Process Equation 9

2.2 Process Load 9

2.3 Process Lag 9

2.4 Self-Regulation 9

3 Control System Parameters 442 9

3.1 Error 9

3.2 Variable Range 9

3.3 Control Parameter Range 9

3.4 Control Lag 9

3.5 Dead Time 9

3.6 Cycling 9

3.7 Controller Modes 9

4 Discontinuous Controller Modes 448 9

4.1 Two-Position Mode 9

4.2 Multiposition Mode 9

4.3 Floating-Control Mode 9

5 Continuous Controller Modes 457 9

5.1 Proportional Control Mode 9

5.2 Integral-Control Mode 9

5.3 Derivative-Control Mode 9

6 Composite Control Modes 466 9

6.1 Proportional-Integral Control(PI) 9

6.2 Proportional-Derivative Control Mode(PD) 9

6.3 Three-Mode Controller(PID) 9

6.4 Special Terminology 9

Summary 10

Problems 10

Supplementary Problems 10

ANALOG CONTROLLERS 481 10

Instructional Objectives 481 10

1 Introduction 481 10

2 General Features 482 10

2.1 Typical Physical Layout 10

2.2 Front Panel 10

2.3 Side Panel 10

3 Electronic Controllers 483 10

3.1 Error Detector 10

3.2 Single Mode 10

3.3 Composite Controller Modes 10

4 Pneumatic Controllers 500 10

4.1 General Features 10

4.2 Mode Implementation 10

5 Design Considerations 504 10

Summary 11

Problems 11

Supplementary Problems 11

COMPUTER-BASED CONTROL 513 11

Instructional Objectives 513 11

1 Introduction 513 11

2 Digital Applications 514 11

2.1 Alarms 11

2.2 Two-Position Control 11

3 Computer-Based Controller 519 11

3.1 Hardware Configurations 11

3.2 Software Requirements 11

4 Other Computer Applications 533 11

4.1 Data Logging 11

4.2 Supervisory Control 11

5 Control System Networks 540 11

5.1 Development 11

5.2 General Characteristics 11

5.3 Fieldbus Types 11

6 Computer Controller Examples 550 11

Summary 12

Problems 12

Supplementary Problems 12

CONTROL-LOOP CHARACTERISTICS 559 12

Instructional Objectives 559 12

1 Introduction 559 12

2 Control System Configurations 560 12

2.1 Single Variable 12

2.2 Cascade Control 12

3 Multivariable Control Systems 564 12

3.1 Analog Control 12

3.2 Supervisory and Direct Digital Control 12

4 Control System Quality 568 12

4.1 Definition of Quality 12

4.2 Measure of Quality 12

5 Stability 575 12

5.1 Transfer Function Frequency Dependence 12

5.2 Stability Criteria 12

6 Process-Loop Tuning 580 12

6.1 Open-Loop Transient Response Method 12

6.2 Ziegler-Nichols Method 12

6.3 Frequency Response Methods 12