Centrifugal Compressors
SECTION ONE - ANTI-SURGE PROTECTION AND THROUGHPUT REGULATION
0 INTRODUCTION
1 SCOPE
2 MACHINE CHARACTERISTICS
2.1 Characteristics of a Single Compressor Stage
2.2 Characteristic of a Multiple Stage Having More
Than One Impeller
2.3 Use of Compressor Characteristics in Throughput
Regulation Schemes
3 MECHANISM AND EFFECTS OF SURGE
3.1 Basic Flow Instabilities
3.2 Occurrence of Surge
3.3 Intensity of Surge
3.4 Effects of Surge
3.5 Avoidance of Surge
3.6 Recovery from Surge
4 CONTROL SCHEMES INCLUDING SURGE PROTECTION
4.1 Output Control
4.2 Surge Protection
4.3 Surge Detection and Recovery
5 DYNAMIC CONSIDERATIONS
5.1 Interaction
5.2 Speed of Response of Antisurge Control System
6 SYSTEM EQUIPMENT SPECIFICATIONS
6.1 The Antisurge Control Valve
6.2 Non-return Valve
6.3 Pressure and flow measurement
6.4 Signal transmission
6.5 Controllers
7 TESTING
7.1 Determination of the Surge Line
7.2 Records
8 INLET GUIDE VANE UNITS
8.1 Application
8.2 Effect on Power Consumption of the Compressor
8.3 Effect of Gas Conditions, Properties and Contaminants
8.4 Aerodynamic Considerations
8.5 Control System Linearity
8.6 Actuator Specification
8.7 Avoidance of Surge
8.8 Features of Link Mechanisms
8.9 Limit Stops and Shear Links
APPENDICES
A LIST OF SYMBOLS AND PREFERRED UNITS
B WORKED EXAMPLE 1 COMPRESSOR WITH VARIABLE INLET PRESSURE AND VARIABLE GAS COMPOSITION
C WORKED EXAMPLE 2 A CONSTANT SPEED ~ STAGE COMPRESSOR WITH INTER-COOLING
D WORKED EXAMPLE 3 DYNAMIC RESPONSE OF THE ANTISURGE PROTECTION SYSTEM FOR A SERVICE AIR COMPRESSOR RUNNING AT CONSTANT SPEED
E EXAMPLE OF INLET GUIDE VANE REGULATION
FIGURES
2.1 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT DISCHARGE CONDITIONS
2.2 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT INLET CONDITIONS
2.3 PERFORMANCE CHARACTERISTICS OF A COMPRESSOR STAGE AT VARYING SPEEDS
2.4 SYSTEM WORKING POINT DEFINED BY INTERSECTION OF PROCESS AND COMPRESSOR CHARACTERISTICS
2.5 DISCHARGE THROTTLE REGULATION
2.6 BYPASS REGULATION
2.7 INLET THROTTLE REGULATION
2.8 INLET GUIDE VANE REGULATION
2.9 VARIABLE SPEED REGULATION
3.1 GAS PULSATION LEVELS FOR A CENTRIFUGAL COMPRESSOR
3.2 REPRESENTATION OF CYCLIC FLOW DURING SURGE OF LONG PERIOD
3.3 TYPICAL WAVEFORM OF DISCHARGE PRESSURE DURING SURGE
3.4 MULTIPLE SURGE LINE FOR A MULTISTAGE CENTRIFUGAL COMPRESSOR
3.5 TYPICAL MULTIPLE SURGE LINES FOR SINGLE STAGE AXIAL-FLOW COMPRESSOR
4.1 GENERAL SCHEMATIC FOR COMPRESSORS OPERATING IN PARALLEL TO FEED MULTIPLE USER PLANTS
4.2 ILLUSTRATION OF SAFETY MARGIN BETWEEN SURGE POINT AND SURGE PROTECTION POINT AT WHICH ANTISURGE SYSTEM IS ACTIVATED
4.3 ANTISURGE SYSTEM FOR COMPRESSOR WITH FLAT PERFO ..........
Centrifugal Compressors
SECTION ONE - ANTI-SURGE PROTECTION AND THROUGHPUT REGULATION
0 INTRODUCTION
1 SCOPE
2 MACHINE CHARACTERISTICS
2.1 Characteristics of a Single Compressor Stage
2.2 Characteristic of a Multiple Stage Having More
Than One Impeller
2.3 Use of Compressor Characteristics in Throughput
Regulation Schemes
3 MECHANISM AND EFFECTS OF SURGE
3.1 Basic Flow Instabilities
3.2 Occurrence of Surge
3.3 Intensity of Surge
3.4 Effects of Surge
3.5 Avoidance of Surge
3.6 Recovery from Surge
4 CONTROL SCHEMES INCLUDING SURGE PROTECTION
4.1 Output Control
4.2 Surge Protection
4.3 Surge Detection and Recovery
5 DYNAMIC CONSIDERATIONS
5.1 Interaction
5.2 Speed of Response of Antisurge Control System
6 SYSTEM EQUIPMENT SPECIFICATIONS
6.1 The Antisurge Control Valve
6.2 Non-return Valve
6.3 Pressure and flow measurement
6.4 Signal transmission
6.5 Controllers
7 TESTING
7.1 Determination of the Surge Line
7.2 Records
8 INLET GUIDE VANE UNITS
8.1 Application
8.2 Effect on Power Consumption of the Compressor
8.3 Effect of Gas Conditions, Properties and Contaminants
8.4 Aerodynamic Considerations
8.5 Control System Linearity
8.6 Actuator Specification
8.7 Avoidance of Surge
8.8 Features of Link Mechanisms
8.9 Limit Stops and Shear Links
APPENDICES
A LIST OF SYMBOLS AND PREFERRED UNITS
B WORKED EXAMPLE 1 COMPRESSOR WITH VARIABLE INLET PRESSURE AND VARIABLE GAS COMPOSITION
C WORKED EXAMPLE 2 A CONSTANT SPEED ~ STAGE COMPRESSOR WITH INTER-COOLING
D WORKED EXAMPLE 3 DYNAMIC RESPONSE OF THE ANTISURGE PROTECTION SYSTEM FOR A SERVICE AIR COMPRESSOR RUNNING AT CONSTANT SPEED
E EXAMPLE OF INLET GUIDE VANE REGULATION
FIGURES
2.1 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT DISCHARGE CONDITIONS
2.2 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT INLET CONDITIONS
2.3 PERFORMANCE CHARACTERISTICS OF A COMPRESSOR STAGE AT VARYING SPEEDS
2.4 SYSTEM WORKING POINT DEFINED BY INTERSECTION OF PROCESS AND COMPRESSOR CHARACTERISTICS
2.5 DISCHARGE THROTTLE REGULATION
2.6 BYPASS REGULATION
2.7 INLET THROTTLE REGULATION
2.8 INLET GUIDE VANE REGULATION
2.9 VARIABLE SPEED REGULATION
3.1 GAS PULSATION LEVELS FOR A CENTRIFUGAL COMPRESSOR
3.2 REPRESENTATION OF CYCLIC FLOW DURING SURGE OF LONG PERIOD
3.3 TYPICAL WAVEFORM OF DISCHARGE PRESSURE DURING SURGE
3.4 MULTIPLE SURGE LINE FOR A MULTISTAGE CENTRIFUGAL COMPRESSOR
3.5 TYPICAL MULTIPLE SURGE LINES FOR SINGLE STAGE AXIAL-FLOW COMPRESSOR
4.1 GENERAL SCHEMATIC FOR COMPRESSORS OPERATING IN PARALLEL TO FEED MULTIPLE USER PLANTS
4.2 ILLUSTRATION OF SAFETY MARGIN BETWEEN SURGE POINT AND SURGE PROTECTION POINT AT WHICH ANTISURGE SYSTEM IS ACTIVATED
4.3 ANTISURGE SYSTEM FOR COMPRESSOR WITH FLAT PERFO ..........