Emerson Compressor Control Process Control Made Easy with SmartProcess ™ Compressor
Agenda Problems to Solve Compressor Control from Bottom to Top SmartProcess ™ Compressor Additional Information
Problems to Solve
Compressor Operating Objectives Operate Safely Avoid Compressor Keep Compressor Highest Possible Reduce Cost of Surge On-line Efficiency Ownership Get rid of “black Do not recycle Automatically follow A surge event can Handle process boxes” that require already compressed procedures to safely damage the demand swings and gas start, operate and compressor and avoid trips from third party contractor shut down the raise the potential hitting limits. Quickly to support compressor for catastrophic troubleshoot and consequences return to service when something happens
Compressor Operating Challenges Speed Of Basic Compressor Poorly Performing Parallel and Serial Black Box Problem Response Control Control Operation Control loops Manual operation Profit loss due to Surge events Highly-specialized interaction, and significantly inefficiencies: require very high hardware, software inefficiency, potential reduced operating reduced operating scan rate to and expertise for surging range and range, higher efficiently prevent compression ratio compression ratios instability unavailable Lack of recorded Potential for surging data
Compressor Control From Bottom to Top
What is surge? ~ P Load P s P d R c Vol 1 Vol 2 R c Flow
What is surge? ~ P Load P s P d R c Vol 1 Vol 2 R c • Motor started, compressor unloaded Flow
What is surge? ~ P Load P s P d R c Vol 1 Vol 2 R c • Antisurge valve is closing • Discharge pressure is raising Flow
What is surge? ~ P Load P s P d R c Vol 1 Vol 2 R c • Antisurge valve is closing • Discharge pressure is raising • Check valve opens Flow
What is surge? • Compressor reaches surge point A • Max R C and Min Flow cause rotating stall ~ P Load • Compressor surges P s P d R c • P Load becomes bigger than Р d Vol 1 Vol 2 R c Surge Line A Flow
What is surge? • Reverse flow ~ • Operating Point reaches point B P Load P s P d • Check valve closes R c • Flow drops from А to В within 20-60 ms Vol 1 Vol 2 R c Surge Line A B Flow
What is surge? • Reverse flow makes R C drop ~ • Operating Point reaches point C P Load P s P d • Transition from B to C is 200 to 1000 ms R c Vol 1 Vol 2 R c Surge Line A B C Flow
What is surge? • Compressor can maintain the R C • Operating Point reaches point D ~ P Load • Check valve opens P s P d R c Vol 1 Vol 2 R c Surge Line A B D C Flow
What is surge? • From A to B (surge): 20 ÷ 60 ms ~ • From C to D (recovering): 20 ÷ 120 ms P Load P s P d • A-B-C-D-A (full surge cycle): 0,4 ÷ 2,0 sec R c Vol 1 Vol 2 R c Surge Line A B D C Flow Surge phenomena applies to only centrifugal and axial compressors.
Antisurge Control: Key Elements Key Antisurge Control Features − R 1 = c h p red • Calculate Operating Point value • Main PI control loop Operating Point N max • Derivative Control N min • Open-loop step response ( ) q = dPo f h q = 2 p red P • Limiting Loops 1 T • Adaptive tuning parameters 2 ln 2 q T 1 = = OP OP 100 % 2 P q • Automated load/unload/ESD/purge 2 ln SL P 1
Basic Antisurge Control Strategy Valve After Surge Loop Decoupling Input Loop Decoupling Output Flow Calculation Manual Output to the Pressure of the OP Operation and Antisurge Valve > PID Control and other Automatic Temperature Antisurge Valve parameters Sequencing Balancing Output Antisurge Safety Open Valve Step Balancing Input
Load Control: Key Elements Key Load Control Features Surge line Pressure Network (process) resistance ratio Pressure limit • Main PI control loop Power limit 2 3 Pressure РТ setpoint • Limiting Loops 1 N 3 • Automated load/unload/ESD/purge N 2 Recycle Choke N 1 Flow N 3 Power N 2 Savings N 1 Flow
Load Sharing: Key Elements Key Load Sharing Features • Optimized overall efficiency • Operating Points reach control lines simultaneously • Antisurge Valve Balancing • Automated load/unload • No Master Controller – no single point of failure
Single Compressor • Most of the time it looks like this: Load Control Main Control Parameter Anti-Surge Valve
Parallel Compressors • Or like this: Main Control Parameter Load Control Anti-Surge Valve
Parallel and Serial Compressors • Or like this:
SmartProcess ™ Compressor
Emerson SmartProcess™ Compressor Solution Pre-Engineered Module Experts Libraries Smart Devices DeltaV Controls Special Anti-Surge Valves
Emerson SmartProcess ™ Compressor Solution • Pre-engineered DeltaV compressor control libraries • Standard DeltaV graphical objects • Fast Historian software • Compressor control expertise • Customer training • Worldwide engineering centers • Global support
Main Control Functions • SmartProcess ™ Compressor DeltaV Control libraries: – Antisurge Control – Load Control – Load Sharing Control – Automatic load, unload, ESD and purge sequencing – Demo system simulator • Documentation
Example Screen from Real Project
DeltaV Template Libraries • Standard template libraries • Sample graphics • Custom faceplates • Documentation – Installation Manual – Configuration Guide – User Guide
Fast Data Recording
Fast Data Recording
Compressor Consulting Services • Project Services – FEED – Control Strategy Consulting – Instrumentation and Control Performance Review – Configuration – Commissioning • Global Worldwide Support • On-site troubleshooting and Support – Surge testing – Tuning and modifications assistance
Compressor Controls Engineers
SmartProcess™ Compressor Benefits • No black boxes • High-quality Antisurge Control • Increased efficiency • Standard solution supported worldwide
Additional Information • SmartProcess ™ Compressor Product Data Sheet – Web Link: http://www.emerson.com/documents/automation/1510338.pdf • Emerson Turbo Machinery Control Solutions Brochure – Web Link: http://www.emerson.com/documents/automation/587900.pdf
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