VSD Bearings - James Neale - Public

Monitoring Variable Speed
Bearings Using Ultrasound
Dr James Neale
BE ME PhD
CMRP
Energy Research Group
University of Waikato
Hamilton
New Zealand
Where is Hamilton?
Energy Research Group Overview
• Research into improving Industrial Energy Efficiency
Compressed Air
Steam
Utility Loop Optimisation
Heat Recovery and Heat Integration
Pinch Analysis
Industrial Fluid Flow Optimisation
Renewable Energy Solutions
Distributed Generation
Energy Audit Methodology Development
Energy Efficiency Policy Development
Applications of Ultrasound
Airborne
Structure Borne
Energy Research Group Overview
• Numerical Modelling
Computational Fluid Dynamics Modelling
Proprietary Software Development
• Economic Modelling
Capital Project Assessment
Energy Future Scenario Modelling
• Experimental Investigation & Analysis
Laboratory Scale
Plant Scale
• Capital Project Implementation
System Analysis
System Design
Verification
Presentation Overview
1.
Project Rationale
a. Site: Fonterra Te Rapa
b. Applications
2.
Project Definition
a. Variable Speed Applications
b. Test Variables
3.
Laboratory Testing
a. Applications
b. Results
4. In-Plant Implementation
5.
Conclusions
a. Implementation in Your Plant?
Project Definition
1. Variable Speed Applications
a. Q: How does speed impact condition monitoring of
bearings?
b. Q: What is our acceptance standard?
2.
Test Variables
a.
b.
c.
d.
Speed
Test Frequency
Alarm levels?
How does the acoustic response vary with speed
for different applications/equipment?
Laboratory Testing
The following equipment was used to test
the effect of varying frequency and speed on
the ultrasound level recorded.
•Smart Pump
•Pulp Screen
•Water Flume
•Air Heater Fan
Smart Pump
Smart Pump
Bearing noise was measured in dB
at 4 points:
•Motor
•1 - Outboard Bearing
•2 - Inboard Bearing
•Pump
•3 - Inboard Bearing
•4 - Outboard Bearing
1
2
3
Motor Specifications:
• 25 kW
• 1475 rpm max.
4
Speed v dB Results – 30kHz
Pulp Screen
Pulp Screen
4
1
3
Bearing noise was measured in dB
at 4 points:
•Motor
•1 - Outboard Bearing
•2 - Inboard Bearing
•Pump
•3 - Inboard Bearing
•4 - Outboard Bearing
2
Motor Specifications
• 15 kW
• 2935 rpm max.
Speed v dB Results – 30kHz
Water Flume
Water Flume
1
Motor Specifications
•4 kW
•960 rpm max.
3
2
Bearing noise was measured in dB at 3 points:
• Motor
• 1 - Outboard Bearing
• 2 - Inboard Bearing
• Pump
• 3 - Single Bearing
Speed v dB Results – 30kHz
Air Heater Fan
Air Heater Fan
Bearing noise was measured in
dB at 2 points:
• Motor
• 1 - Outboard Bearing
• 2 - Inboard Bearing
1
2
Motor Specifications
•4 kW
•1445 rpm max.
Speed v dB Results – 30kHz
Summary - Speed v dB
@ 30 kHz
• Variation in speed had little effect on dB level of
motor bearings tested at this frequency (less than 5
dB).
• Variation in speed had marginally greater effect on
dB level of the application (driven end) bearings (5
to 25 dB). Very application Specific.
• Potential for actual in-plant usage bands to be quite
narrow, resulting in a lower dB band in practice.
Smart Pump – Frequency Variation
Pulp Screen – Frequency Variation
Water Flume – Frequency Variation
Air Heater – Frequency Variation
Summary - Varying Test Frequency
• Ultrasound level trends higher at lower test
frequency for most speed ranges.
• dB level relatively stable with varying motor
speed at all frequencies on motor bearings.
• dB level increased on some pump/prop bearings
as speed increased, for all frequencies.
In-Plant Implementation
• Condition Monitoring Implemented across a range of critical
variable speed equipment
–
–
–
–
–
Water Pumps
Main Inlet & Exhaust Fans to Drier
Chilled Water Compressors (Ammonia)
Plate Freezer Compressors
VSD Air Compressor
• Will be carried out over an extended period to allow long term
trending of results.
In-Plant Implementation
• Measurements
– dB level (using ultraprobe 10000) – UP15000 (Please Gary!)
– motor speed (using displayed speed or a hand held strobe)
– Sound Files
• Ultimate Objectives
– Traffic Light Assessment
• Green – good
• Red – Bad
• Amber – recheck etc
– Avoid Measuring Speed
• Keep life simple
– Sound File Primary Measure of “Bad” bearing
– Capture Lubrication Fault in timely manner
Implementation
in Your Plant
• Establish baselines
– What are the speed limits?
• High
• Low
– How does the dB Vary?
• Motor
• Driven End (Application)
• What is your acceptance Standard?
– Degrees of criticality
– False alarms?
– Modified Alarm Levels
• Lower level => dB driven
• Upper level => Sound File driven
Acknowledgements
Energy Research Group – University of Waikato
UE Systems Inc
New Zealand Foundation for Research Science and
Technology
Research Contract UOWX0302
New Zealand National Energy Research Institute (NERI)
Further information:
jamesn@waikato.ac.nz