Prognostic Health Management PHM System for Monitoring Blade Vibrations in Turbo Machinery

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Prognostic Health Management (PHM) System for
Monitoring Blade Vibrations in Turbo Machinery

• Agilis Measurement Systems, Inc.
• Ben Roorda

Propulsion - Safety and Affordable Readiness
Conference 2009
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Content

• NSMS fundamentals
• Current capability experience
• Deployed system pictures
• System configuration
• Sensors and signal triggering
• Blade health monitoring outputs
• System support
• Current development

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NSMS Fundamentals

• The Non-intrusive Stress Measurement System
  (NSMS) is an alternative to strain gage
  instrumentation for measurement of blade dynamic
  stresses.

Blade passing time measurement
Deflection conversion
Frequency calculation
Stress conversion
FEA model
Blade passings
t
T
1/rev
X Vt2pR(t/T)
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Blade Health Monitoring Capability

• Every Blade, Every Probe, Every Revolution
• Blade Event Detection
• FOD damage detection
• Flutter detection
• Crack detection
• Resonant response measurement and cycle counting
• Blade Event Trending
• Trends for Prognostic Forecasting
• Knowledge based inspection / maintenance interval
• Data for root cause determination of HCF problems

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Blade Health Monitoring Experience

• Utilized Blade Crack Detection Capability
• The Agilis PHM system recently completed a series
  of crack propagation studies.  The system
  consistently detected cracks near the limit of
  manual die penetrant methods.
• Current Operations
• A system is currently in operation monitoring an
  industrial centrifugal compressor.
• Several long duration industrial gas turbine
  compressor and steam turbine test applications
  have been completed with the AMS 8000PHM system
  and the AMS Realtime software.

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Deployed System Pictures
Sensors
Eddy current sensors installed with counter bore
Counter bore filled with epoxy
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Deployed System Pictures
Signal Conditioners
Remote DAQ Cabinet
Digitizers
BNC cables
Ethernet connection
Digital Link (laptop PCMCIA card)
Conditioners are mounted over the compressor in a
NEMA box
Laptop
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System Configuration Overview
Sensing (Conditioning) Processing
Every Probe sensing Every Blade on Every
Revolution
Data Collection Event Deflection Event Trending
AMS 8000 PHM Signal Conditioning Module

• 8 Sensors, up to 4 stages
• Weatherproof hardware

Ethernet /Internet Communications
Control Room
Machine Enclosure
Machine Case
Conditioned Signal
Sensor Length 6 Meters Max
UL Class I Division 2 ATEX Category 2 Class 3
DAQ Computer with AMS Software
Purge Air Input
Power Input
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Probe Types and Quantity
Probe types
Eddy Current- low cost, low maintenance, low
resolution, larger case hole Capacitive- low
maintenance, high temperature, greater
cost Optical / RF- small case hole, high
resolution, greater cost, maintenance
Probe quantity
Synchronous Non-Sync 1 Knowledge of
engine order Knowledge of frequency range 2
Knowledge of engine order Knowledge of frequency
range 3 Knowledge of engine order Improved
frequency solution Less Assumptions 4
Single frequency solution Frequency Nodal
diameter calculation gt4 Multiple Frequency
Solution Frequency Nodal diameter calculation
Capability Requirements
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Probe Signal Triggering
Optical
1
2
Typical AMS 8 point Falling and Rising Edge
triggers
Eddy Current
2
1
1
2
Area Average trigger
Analog output is directly digitized and triggered
in software. Available triggers
voltage level, area averaging, clearance, and
of pulse.
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Health Monitoring System Outputs
Steady State Blade Position
Static changes can be caused by -Cracks -FOD
impact -Rubs
Red and Yellow limit checking

• Real-time checking for limit excursions
• Limit violations automatically launch predefined
  actions -Alert control system -Disable
  hardware -Record data -Send email or text
• Record trending data for prognostic analysis

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Non-Synchronous Vibrations
Health Monitoring System Outputs
Traveling Wave Analysis
System response characterization and monitoring
Individual Blade Analysis
Steady state frequency and amplitude monitoring
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Non-Synchronous Vibrations, Flutter Monitor
Health Monitoring System Outputs
Red and Yellow limit checking

• Real-time checking for limit violations
• Limit violations automatically launch
  predefined actions -Alert control system
  -Disable hardware -Record data -Send email or
  text
• Record trending data for prognostic analysis

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Synchronous Vibration Raw Data
Health Monitoring System Outputs
Time Domain Deflections
RPM Mapped Resonant Responses
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Health Monitoring System Outputs
Synchronous Vibrations,
Resonant Frequency Shift
Analysis
Adjust speed to align
Current Data
Baseline
Compare current data against a baseline to detect
small resonant frequency changes
lt 0.05 Frequency Shift
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Synchronous Vibration Analysis (4 or more probes)
Health Monitoring System Outputs
All blades Amplitude and Phase measurement

• Real-time checking for limit violations
• Limit violations automatically launch
  predefined actions
• -Cycle counting -Alert control system
  -Disable hardware -Record data -Send email
  or text
• Record trending data for prognostic analysis

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Health Monitoring System Support
Remote System Support

• Internet Connection Required
• System checks from AMS Headquarters in Florida
• Download of data for further analysis
• Software advancements uploaded
• Monthly report creation

Remote site monitoring via satellite Internet
connection
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Health Monitoring System Development

• Fully Automated System

• Arrival Time Analysis Health Monitor (ATAHM)
• Data in, raw or triggered
• Trending out static deflection, non-sync
  responses, frequency changes, cycle counting,
  etc.
• No GUI required
• Self system monitoring
• Simplified setup
• Multiplex with other sensors
• Utilize existing data systems
• What would you want in a PHM system?

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Agilis Measurement Systems, Inc.
Question time
Providing accurate and complete blade vibration
analysis
Providing Prognostic Blade Health Management
Systems
Agilis Measurement Systems, Inc. 3930 RCA
Boulevard, Suite 3000 Palm Beach Gardens, FL.
U.S.A. 33410
AgilisMeasurementSystems.com Phone (USA)
561-626-8900 Fax (USA) 561-472-3101