Boiler Instrumentation Toc

Table of Contents Introduction to the Workshop 1 Introduction to Boiler Controls 1.1 Objectives of boiler controls 1.2 Boiler processes 1.3 Process dynamics in boilers 1.4 Overview of boiler types 1.5 Hazards of boiler operations 1.6 Boiler control functions 1.7 Safety control functions 1.8 Practical Exercise No. 1 1.9 Summary

ix 1 1 3 7 8 16 18 23 23 24

2

Process Controls and Instrumentation 2.1 Overview of sensors, controllers and actuators 2.2 Sensor types 2.3 Final control elements or actuators 2.4 Control system equipment 2.5 Risk reduction by safety instrumented systems 2.6 Process modeling 2.8 Introduction to process control 2.9 Summary of this chapter

25 26 28 32 33 34 54 63 79

3

Feedwater and drum level control 3.1 Steam and water processes in the boiler 3.2 Drum level measurement systems 3.3 Safety systems for drum level protection 3.4 Measurement of steam flow 3.5 Water quality 3.6 Conclusions

81 82 90 96 97 100 101

4

Furnace and air draft controls 4.1 Furnace draft processes 4.2 Balanced draft boilers 4.3 Measurement of furnace draft 4.4 Draft control schemes

103 103 106 109 113

5

Combustion Control Systems 5.1 Introduction 5.2 Combustion Processes 5.3 Control Strategies

117 117 118 128

6

Burner Management Systems 6.1 Functions of Burner Management Systems 6.2 Safety Integrity Requirements of BMS 6.3 Ignition Systems 6.4 Flame Monitoring

149 150 159 163 165

7 8

Slide Presentations Steam pressure and load control Steam temperature control

164 164 171

Appendix A

182

Practical Exercises

188

Appendix B

202

Answers to Practical Exercises

210