Risk mitigation: Investigation and analysis of gas turbine exhaust ducts.

1. Lloyd’s Register services to the energy industry
Lloyd’s Register ODS
Gas turbine exhaust duct failures
Johan Gullman-Strand, Ph.D.
Senior consultant
Lloyd’s Register ODS

2. Lloyd’s Register services to the energy industry
Gas turbine exhaust ducts
Immediate problems
• Damage on duct walls,
cracks, missing insulation,
• WHRU* failure, exhaust
gas leaks , silencer
degradation
• Emergency shutdown,
loss of production
* Waste Heat Recovery Unit

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The main problems
•Structural integrity compromised by pressure
fluctuations in the highly separated flow
•Start-up and shutdown causing excessive thermal
stresses.

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Lloyd’s Register ODS
services and solutions
•Failure investigation
•Coupled analysis of complete system
(FSI)
•Fluid Dynamics (CFD)
•Structural analysis (FEA)
•Analytical evaluation of old and new
designs
•Verification by on-site measurements
•Pressure, vibration, temperature, strain

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Pressure, vibration, temperature, strain

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FSI Response

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Summary
Typical solutions:
• Benefits: Guide vane design
• Capture complex interactions.
Valve re-design
• Better understanding of failure mechanics.
Flange improvement
• Provide knowledge and tools for re-design.
Duct insulation changes
• The ODS advantage:
• Extensive experience
• Combination of analyses and
measurements
• Computational resources for coupled
analyses.
• Experts in each field

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Turbulence
Immediate problems
• Damagage on duct walls,
cracks, missing insulation,
• WHRU* failure, exhaust gas
leaks , silencer degradation
• Emergency shutdown, loss of
production

9. For more information, please contact:
Johan Gullman-Strand M.Sc, Ph.d.
Senior Consultant, Lloyd’s Register ODS
Lloyd’s Register group entity
71 Fenchurch Street
London, EC3M 4BS
T +46 733 298 330
E johan.gullman-strand@lr-ods.com
w www.lr-ods.com
Services are provided by members of the Lloyd's Register Group.
For further information visit www.lr.org/entities