Basu / Debnath Power Plant Instrumentation and Control Handbook

A Guide to Thermal Power Plants
1. Auflage 2014
ISBN: 978-0-12-801173-7
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 942 Seiten

The book discusses instrumentation and control in modern fossil fuel power plants, with an emphasis on selecting the most appropriate systems subject to constraints engineers have for their projects. It provides all the plant process and design details, including specification sheets and standards currently followed in the plant. Among the unique features of the book are the inclusion of control loop strategies and BMS/FSSS step by step logic, coverage of analytical instruments and technologies for pollution and energy savings, and coverage of the trends toward filed bus systems and integration of subsystems into one network with the help of embedded controllers and OPC interfaces. The book includes comprehensive listings of operating values and ranges of parameters for temperature, pressure, flow, level, etc of a typical 250/500 MW thermal power plant. Appropriate for project engineers as well as instrumentation/control engineers, the book also includes tables, charts, and figures from real-life projects around the world. - Covers systems in use in a wide range of power plants: conventional thermal power plants, combined/cogen plants, supercritical plants, and once through boilers - Presents practical design aspects and current trends in instrumentation - Discusses why and how to change control strategies when systems are updated/changed - Provides instrumentation selection techniques based on operating parameters. Spec sheets are included for each type of instrument - Consistent with current professional practice in North America, Europe, and India

Swapan Basu is founder member & Chief Executive, Systems & Controls Kolkata India. Basu is a member of Institute of Electrical and Electronics Engineers (IEEE) and IEEE Instrumentation and measurement society. He brings over 40 years of international professional engineering experience in instrumentation and controls systems for subcritical, super critical thermal power plants including combined cycle projects, and other process plants. Since 1979, he has been leading teams of engineers in India, Jordan, Singapore, South Korea, Syria, and USA. He has a number of national and international technical papers to his credit. He has published two editions of Power Plant Instrumentation and Control Handbook, Plant Hazard Analysis and Safety Instrumentation Systems and Plant Flow Metering and Control Handbook

Autoren/Hrsg.

Basu, Swapan

Debnath, Ajay Kumar

Inhaltsverzeichnis

1;Front
Cover;1
2;Power Plant Instrumentation
and Control Handbook;4
3;Copyright;5
4;Dedication;6
5;Contents;8
6;Foreword;10
7;Preface;12
8;Acknowledgments;14
9;Chapter I - Introduction;16
9.1;1. INTRODUCTION;16
9.2;2. FUNDAMENTAL KNOWLEDGE ABOUT BASIC PROCESS;16
9.3;3. PROCESS PARAMETERS AND RANGES;47
9.4;BIBLIOGRAPHY;52
10;Chapter II - Main Equipment;54
10.1;1. OVERVIEW OF TYPES, FUNCTIONS, AND DESCRIPTION OF MAIN EQUIPMENT;54
10.2;2. STEAM GENERATOR: BOILER;57
10.3;2.4 BOILER DRUM: ITS PRESSURE PARTS WITH LOCATIONS;82
10.4;2.5 MISCELLANEOUS BOILER EQUIPMENT;88
10.5;3. TURBINE TYPES;90
10.6;4. GENERATOR;118
10.7;5. BOILER FEED PUMP AND CONDENSATE EXTRACTION PUMP WITH ASSOCIATED MEASUREMENTS;124
10.8;6. DEAERATORS AND HEATERS;128
10.9;7. FUNCTION AND DESCRIPTION OF CW AND ACW SYSTEMS;132
10.10;8. DEMINERALIZING PLANT'S FUNCTION AND DESCRIPTION;137
10.11;9. BASIC SYSTEM FUNCTIONS AND DESCRIPTION OF COAL HANDLING;147
10.12;10. BASIC SYSTEM FUNCTIONS AND DESCRIPTION OF ASH HANDLING;153
10.13;10.1 PROPERTIES OF ASH;154
10.14;BIBLIOGRAPHY;161
11;Chapter III - Plant P&ID Discussions;162
11.1;1. INTRODUCTION (P&ID);162
11.2;2. MAIN STEAM (P&ID);166
11.3;3. REHEAT STEAM (P&IDS): COLD AND HOT REHEAT;171
11.4;4. EXTRACTION STEAM (P&IDS): BLEED STEAM;177
11.5;5. AUXILIARY STEAM (P&IDS);180
11.6;6. FEED WATER SYSTEM (P&ID);185
11.7;7. CONDENSATE SYSTEM (P&IDS);195
11.8;8. HEATER DRAIN AND VENT (P&IDS);203
11.9;9. AIR AND FLUE GAS SYSTEM (P&IDS);208
11.10;10. COGENERATION P&ID;221
11.11;11. MISCELLANEOUS OTHER SYSTEMS (P&ID);228
11.12;BIBLIOGRAPHY;243
12;Chapter IV - General Instruments;244
12.1;1. INTRODUCTION;244
12.2;2. PRESSURE MEASUREMENT: VARIOUS MEASURING POINTS AND RANGE SELECTION;247
12.3;3. TEMPERATURE MEASUREMENT: VARIOUS MEASURING POINTS AND RANGE SELECTION;255
12.4;4. FLOW MEASUREMENT, VARIOUS MEASURING POINTS, VARIOUS TYPES, AND RANGE SELECTION;271
12.5;5. LEVEL MEASUREMENT;298
12.6;BIBLIOGRAPHY;310
13;Chapter V - Special Instrument;312
13.1;1. SPECIAL INSTRUMENTS;312
13.2;2. VIBRATION AND TURBOVISORY INSTRUMENTS;313
13.3;3. GAS ANALYZERS;340
13.4;4. STEAM AND WATER ANALYSIS SYSTEM;363
13.5;5. SAMPLE CONDITIONING SYSTEM;389
13.6;6. BLOW DOWN AND DOSING CONTROL;395
13.7;7. ANALYZERS FOR AIR POLLUTION MONITORING AND CONTROL (NOX CONTROL);399
13.8;BIBLIOGRAPHY;400
14;Chapter VI - Final Control Element;402
14.1;1. VALVES AND ACTUATORS;402
14.2;2. CONTROL VALVE TYPES;420
14.3;3. DAMPERS AND MISCELLANEOUS OTHER FCES;429
14.4;4. ACTUATORS;434
14.5;5. ACCESSORIES;442
14.6;BIBLIOGRAPHY;455
15;Chapter VII - Intelligent Control System;458
15.1;1. BASICS (DISCUSSION ON INTELLIGENT NETWORK SYSTEM);458
15.2;2. PLC SYSTEM: INTRODUCTION;491
15.3;3. ANNUNCIATION AND SEQUENCE OF EVENT: PREAMBLE;526
15.4;4. INTEGRATED DCS-DDC MIS: PREAMBLE;531
15.5;5. MMI AND RECORDING: INTRODUCTION;555
15.6;6. MIS: INTRODUCTION;587
15.7;BIBLIOGRAPHY;598
16;Chapter VIII - Boiler Control System;600
16.1;1. BASIC CONTROL REQUIREMENTS;600
16.2;2. STEAM PRESSURE CONTROL WITH LOAD INDEX;601
16.3;3. AIR FLOW CONTROL;604
16.4;4. FUEL FLOW CONTROL;610
16.5;5. COAL MILL CONTROL-MILL AIR FLOW FOR TT BOILER;619
16.6;6. FURNACE DRAFT CONTROL;633
16.7;7. DRUM-LEVEL AND FEEDWATER CONTROLS;637
16.8;8. SUPERHEATER TEMPERATURE CONTROL;643
16.9;9. REHEAT TEMPERATURE CONTROL;649
16.10;10. MISCELLANEOUS BOILER CONTROLS, INCLUDING OVERFIRE AIR DAMPERS;657
16.11;11. HP-LP BYPASS SYSTEM;679
16.12;12.0 BOILER OLCS: INTRODUCTION TO INTERLOCK AND PROTECTION OF BOILER BMS, SADC, AND SB CONTROL;688
16.13;BIBLIOGRAPHY;708
17;Chapter IX - Turbo Generator Control System;710
17.1;1. INTRODUCTION;710
17.2;2. ELECTRO HYDRAULIC GOVERNOR CONTROL SYSTEM;711
17.3;3. TURBINE PROTECTION SYSTEM;720
17.4;4. ATRS;723
17.5;5. ATT SYSTEM;728
17.6;6. THERMAL STRESS EVALUATOR;734
17.7;7. LPBP SYSTEM;736
17.8;8. TURBINE CONTROLS: SEAL STEAM PRESSURE CONTROL SYSTEM;739
17.9;9. HYDROGEN SEAL OIL SYSTEM AND DIFFERENTIAL PRESSURE CONTROL;741
17.10;10. GENERATOR CONTROL SYSTEM;747
17.11;11. CONDENSER LEVEL AND DEAERATOR LEVEL CONTROL SYSTEM;751
17.12;12. VARIOUS TG OPTIONS AND MISCELLENIOUS TG CONTROLS;754
17.13;BIBLIOGRAPHY;761
18;Chapter X - Coordinated Control System;764
18.1;1. INTRODUCTION;764
18.2;2. COORDINATE CONTROL MODE;766
18.3;3. TURBINE FOLLOW MODE;773
18.4;4. BOILER FOLLOW MODE;773
18.5;5. RUN BACK SYSTEM;774
18.6;6. DISCUSSIONS AND EXPLANATIONS;776
18.7;BIBLIOGRAPHY;781
19;Chapter XI - Balance of Plant Control System;782
19.1;1. BALANCE OF PLANT: INTRODUCTION;782
19.2;2. BFP RECIRCULATION CONTROL;782
19.3;3. CEP RECIRCULATION CONTROL;785
19.4;4. GSC MINIMUM FLOW CONTROL;789
19.5;5. DEAERATOR (PRESSURE) CONTROL;790
19.6;6. LP HEATER LEVEL CONTROL;793
19.7;7. HP HEATER LEVEL CONTROL;796
19.8;8. EJECTOR CONTROL AND TAS;798
19.9;BIBLIOGRAPHY;800
20;Chapter XII - Installation Practices;802
20.1;1. INTRODUCTION;802
20.2;2. PIPE VALVE FITTING MATERIAL SPECIFICATION AND RATING;811
20.3;3. MECHANICAL INSTALLATION OF INSTRUMENTS;814
20.4;4. ELECRICAL INSTALLATION OF INSTRUMENTS;830
20.5;BIBLIOGRAPHY;849
21;Appendix I - Process and Mechanical Standard Table;852
21.1;STANDARD PREFIXES;852
21.2;STANDARD UNITS;852
21.3;FLANGE DIMENSIONS;855
21.4;. VISCOSITY;859
21.5;DYNAMIC VISCOSITY;860
21.6;KINEMATIC VISCOSITY;861
21.7;BIBLIOGRAPHY;862
22;Appendix II - Electrical Data and Tables;864
22.1;MULTIPAIR INSTRUMENTATION CABLES: SIZE, RESISTANCE, AND OTHER PHYSICAL DATA;864
22.2;BIBLIOGRAPHY;873
23;Appendix III - ISA Standard, Materials, Human Engineering, and Control Room;874
23.1;1.0 ISA STANDARDS;874
23.2;2.0 MATERIAL COMPOSITIONS;875
23.3;3.0 ERGONOMIC CONTROL ROOM DESIGN CONCEPTS;877
23.4;BIBLIOGRAPHY;880
24;Appendix IV - Network Control and Communication;882
24.1;1.0 NETWORK CONTROL AND COMMUNICATIONS;882
24.2;2.0 FIBER OPTIC AND ASSOCIATED NETWORKS;882
24.3;3.0 ELECTROMAGNETIC SPECTRUM;882
24.4;4.0 LARGE INTEGRATED COMPUTER NETWORK;882
24.5;5.0 FIREWALLS;884
24.6;6.0 FAULT TOLERANT ETHERNET-AN APPROACH;885
24.7;BIBLIOGRAPHY;888
25;Appendix V - Super/Ultra Super Critical Power Plants;890
25.1;1.0 POWER PLANTS WITH SUPERCRITCAL AND ULTRA CRITICAL STEAM GENERATORS;890
25.2;2.0 SUPER AND ULTRA CRITICAL STEAM GENERATORS;892
25.3;BIBLIOGRAPHY;902
26;Appendix VI - Integrated Gasifier and Combined Cycle Plant (Pollution Control);904
26.1;1.0 INTRODUCTION;904
26.2;2.0 BASIC PROCESS;904
26.3;3.0 CONTROL SYSTEM;909
26.4;BIBLIOGRAPHY;910
27;Appendix VII - A Few Operational Features of the Unit;912
27.1;1.0 INTRODUCTION;912
27.2;2.0 UNIT PROTECTION SYSTEM;912
27.3;3.0 HOUSE LOAD OPERATION;915
27.4;4.0 BUS TRANSFER SYSTEM (BTS);916
27.5;BIBLIOGRAPHY;920
28;Index;922

Leseproben

Chapter II

Main Equipment

Abstract

The power plant is conceived as a “basic heat engine” comprising a boiler, turbine, condenser, boiler feed pump (BFP), generator, heaters, water treatment, coal/ash/oil-handling plant, condensate polishing unit (CPU), CW and ACW system, cooling towers, etc. Boilers incorporate subsystems like fuel, air/draft/feed water with auxiliaries such as pulverizers (solid fuels), fuel oil, FD/PA/ID fans, BFPs, etc. A turbine drives the generator with subsystems like turbine oil, turning gear, HP/LP bypass, gland sealing systems, governor and isolation valves, condenser, ejectors, electro hydraulic governing control, protection and testing, supervisory instrumentation, CPU, and CEPs. Generators are based on two major parts: the rotor working as a DC magnetic field rotating inside hollow stator. Generators are cooled with almost pure hydrogen gas with a sealing system by oil. Hollow stator conductors are cooled with ultra pure water.

Keywords

basic heat engine; EHG; fuel/air/water system; mill/pulverizers; offsite plants; pump and heating unit; regenerative heating cycle; thermal stress evaluation

1. Overview of Types, Functions, and Description of Main Equipment

Modern large thermal power plants have evolved as a result of years of research work, experience, and state-of-the-art technologies; however, the basic equipment and/or subsystems are more or less the same, of course, with a lot of sophistication and technological development to increase efficiencies.

There are five (5) fundamental elements, as shown in Figure I/2.1, that may be referred to for an overall idea at a glance; they are the following:

• Boiler

• Turbine

• Condenser

• Boiler feed pump

• Generator

Some other subsystems are, namely, the regenerative heating cycle or offsite packages such as a water treatment plant (demineralization and pretreatment), a coal-handling plant (CHP), an ash-handling plant (AHP), an oil-handling plant (OHP), circulating water (CW) and auxiliary circulating water (ACW) systems, a condensate polishing unit (CPU), and others. This clause briefly describes the functions of the preceding elements vis-à-vis the main equipment with important auxiliaries.

1.1. Boiler

A boiler is a combination of several items that is a means for combustion to provide energy to be transferred to water until it becomes heated steam that is then used for transferring the heat to the turbine. Water is used as the working fluid to transfer the heat to a process because it is not expensive. As a result of the tremendous volume change after the water is converted to steam, it needs careful handling. The main subsystems or system auxiliaries are divided into three (3) principal categories: fuel and air/draft system, feedwater (FW) system, and steam system; each has various supplementary items or equipment to make them suitable for use in large and modern power plants.

1.1.1. Fuel and Air/Draft System

The fuel and air/draft system includes all necessary auxiliary equipment required to make fuel available to create the necessary heat. The equipment needed for the fuel system depends on the type of fuel used in the system. The amount of fuel and air required for steam generation is automatically controlled per steam demand. Mills/pulverizes are used for solid fuels, pumping and heating units are required for liquid fuels, and compressor/boosters are required for gaseous fuels, of course with a suitable type of burner and air supply arrangements. Supplementary equipment and/or items are comprised of the following:

Mills/pulverizers: For solid fuels, mills and pulverizers are supplied with the main equipment so as to achieve higher thermal efficiencies and for spontaneous ignition through burning of finely powdered fuel. The type of mills and pulverizers depends on the type of fuels. Associated feeders and so forth are also a part of this subsystem.

Pumps and heating units: For liquid types of fuels, supply pumps are needed and heating units are also required for a viscous type of fuel such as heavy fuel oil (HFO)/heavy sulfur heavy stock (LSHS) and others.

Fuel burners: This category covers both oil and solid fuel with various designs—for example. low NOx burners. Burner type also varies with type of atomizer, etc.

Air flow control elements: These are, for example, forced draft (FD) air fans, primary air (PA) fans, air dampers or registers for fuel air, auxiliary/secondary air, overfire air, etc.

Draft system or flue gas system: These include induced draft (ID) air fans and various flue gas dampers for evacuating the product of combustion from the furnace.

Soot blowing system: Periodic cleaning of soot buildup, which damages boiler metals and causes inefficient operation, on the radiant furnace surfaces, boiler tube banks, economizers, and air heaters is accomplished using a soot blowing system that blows hot steam on a regular basis.

1.1.2. Feedwater System

The feedwater system provides necessary piping, heat exchangers to preheat water, a recirculation system (if so designed), and feed control valves to control the required amount to meet the steam demand.

Pressurized and preheated water supplied to the boiler as the working fluid to be converted into steam is popularly called feedwater in a normal running condition. There are two sources of feedwater: the major part is condensate that is nothing but condensed steam from the condenser and many other heat exchangers used in the processes; the minor part (3~5%) is the continuous and/or intermittent makeup water (demineralized, DM water) that must come from outside of the boiler.

It also includes blowdown and chemical dosing systems to drain a part of the feedwater when it contains dissolved solids unacceptable to boiler metal, or a reason for scale formation that resists heat transfer causing localized overheating vis-à-vis boiler tube failure, foaming causing carryover to turbine, and so on.

Chemical dosing: This is done to clean the feedwater to avoid blowdown causing both heat and water loss making it slightly alkaline to minimize metal loss due to a chemical reaction.

Boiler circulating water system: In some plants, a boiler circulating water pump (BCWP) is deployed for better circulation of feedwater in the boiler with its suction connected to a steam drum and a discharge connected to a boiler water wall header. Furnace height may be reduced by having BCWP.

1.1.3. Steam System

The steam system includes evaporation of water up to superheating, reheating of cold steam (for a hot reheat system), collection and transfer of the steam through a piping system to the turbine. Throughout the system, excess steam pressure is regulated and/or vented through suitable valves automatically.

1.2. Turbine

The turbine accepts steam from the boiler at a high temperature and pressure, and converts the heat energy into mechanical energy for driving the generator. The following are the associated subsystems:

• Turbine oil system (lubricating, control, and power oil)

• Turning gear/barring gear

• HP/LP bypass system

• Governor and isolation valves

• Gland sealing systems

1.2.1. Turbine Oil System

This subsystem is one of the most important items; it supplies the lube oil to all the bearings, hydraulic control oil, jacking oil, and actuator power oil through individual oil coolers, strainers, redundant pumps, etc.

1.2.2. Turning Gear/Barring Gear

The turning gear (or barring gear) is basically a gear arrangement provided to rotate the turbine generator (TG) rotor shaft at a very low speed before turbine startup and after unit shutdown at low speed (~1% of rated speed) by the turning the gear until the temperature comes down sufficiently.

1.2.3. HP/LP Bypass System

These subsystems are supplied to protect the boiler reheater from a burnout when no steam is passing through the turbine with the boiler generating steam during start up or running or tripped condition.

1.2.4. Governor and Isolation Valves

These valves are provided for both high- and intermediate-pressure turbines. Both are hydraulically operated and are special valves with high controllability and isolating capability, respectively.

1.2.5. Gland Sealing Systems

Turbine glands are a part of the turbine so that steam cannot escape from the higher pressure parts of it and air cannot enter the lower parts of the turbine. However, many parts of the turbine operate at such a high pressure that it cannot prevent leakage to the full extent. On the other hand, the lower pressure parts operate at a subatmospheric region so air ingress cannot be totally eliminated. This subsystem is provided to seal the glands in such a way that leakage of steam from the high side is controlled at a certain pressure and extra steam from the control valve outlet is diverted to the low-pressure (LP) side glands to arrest air ingress by maintaining a certain pressure.

1.3. Condenser

The function of condenser is to condense the steam coming from the turbine exhaust. High vacuum is maintained to extract steam and...