HRSG-09 Wholistic Approach to HRSG Inspections - Turner

A Wholistic Approach to HRSG Inspections Charles Turner, P.Eng. Charles G. Turner & Associates Ltd. Consulting Engineers Presented at the 2014 Canadian HRSG Forum October 21, 2014

Charles G. Turner & Associates Ltd.

Charles G. Turner and Associates Ltd. (CGTA)  Consulting

Engineers specializing in Power

& Utilities  Founded

 Located

in 1973

in Toronto, Ontario, Canada


Charles G. Turner and Associates Ltd. (CGTA)  Consulting

Engineers specializing in Power

& Utilities  Founded

 Located

in 1973

in Toronto, Ontario, Canada


CGTA Areas of Expertise  Simple 

Cycle and Combined Cycle Power Plants

Thermal Power Stations (Coal, Gas & Oil Fired)

 Cogeneration

(Steam Turbines, Gas Turbines & Reciprocating Engines)

 Central

Heating Plants (Steam Boilers, Thermal Fluid Heaters & Vaporizers, Glycol & Hot Water, Plant Auxiliaries, buried steam & HW distribution piping)

 Central

Cooling Plants (Chilled Water, Refrigerant, Steam Absorption & Ammonia, buried chilled water distribution piping) Charles G. Turner & Associates Ltd.

CGTA Areas of Expertise Continued  Burners

& Combustion (Natural Gas, Fuel Oil, Liquid and Gaseous Process Fuels, Biomass)

 Water

Treatment Systems

 Compressed

Gas Plants (Air, Digester Gas, Landfill Gas and Carbon Dioxide)

 Industrial

Plant Processes

 Industrial

HVAC

 Cooling

Tower Systems

 Instrumentation  Electrical

& Controls (PLC & DCS)

Generation (High and Low Voltage) Charles G. Turner & Associates Ltd.

Putting “Wholistic” into HRSG Inspections 

Wholistic refers to the approach and execution of the HRSG inspection, where the HRSG is inspected from an asset integrity and management approach.



The approach integrates the HRSG inspection and boundary limits into the Company’s long term maintenance plan that includes; – Integrity Plans – SAMP’s – Long Term Maintenance Plan Charles G. Turner & Associates Ltd.

Aligning Inspection Deliverables within the Asset Management Plans •

What is a Corporate Asset Management Plan? 

Defines the organizational goals and objectives of the plant components.



Defines performance targets.



Provides future demand forecasts.



Specifies regulatory requirements.



Identifies site specific maintenance intervals, capital and operating improvement projects.



Records equipment condition.



Provides a summary location for the performance history and operating strategy to maintain performance requirements. Charles G. Turner & Associates Ltd.

HRSG Integrity Plans •

HRSG Integrity Plans are developed to support the Asset Management Plans: 

Defines the life cycle wholistic view of the specific equipment.



Incorporates Operations and Maintenance strategies.



Develops Risk Assessment including analysis and consequences.



Defines Provincial and State compliance requirements.



Assurance of Insurance compliance requirements.



Provides a basis for the lessons learned.


Critical Pre-Inspection Key Parameters 





HRSG Superstructure Design 

Bottom supported components



Top hung from casing superstructure

Waste Heat Source: 

Gas Turbine - Size/Make/Model



Duct Firing – Location and rating

Operating Parameters 

Number of Pressure Levels



Pressure/Temperature



Operating Hours



Number of Cold Iron Starts, Cold/Warm/Hot Starts, Forced Cooling Events, and EOH’s. Charles G. Turner & Associates Ltd.

Critical Pre-Inspection Key Parameters Continued 

High Temperature Materials 

P91/T23



Hardened Low Temperature Regions for FAC



In-Cycle water treatment program 

HP & IP Phosphate / LP – SALP or FFLP?



Once Through requirements.



Cascading Blowdown.


Typical F Technology Triple Pressure HRSG


Once Through Steam Generator


Enhanced Oil Recovery Once Through Wet Steam Generator


External Casing Inspection


Casing Expansion Joint Limited Flexibility


Casing Hot Spots


External Casing Liquid Refractory Injection Locations


Thermography Analysis Transition Duct Liner Issue

Casing Hotspot


Thermography Analysis Sidewall Bellows Failure

Door Seal Leak


External Piping Supports


HEP BEP Supports


HEP BEP Supports


HRSG Superstructure Supports


Duct Burner Blowers


Duct Burner Manifolds


Preheater Recirculation Pump


Pump Inlet Expansion Joint


Preheater Expansion Joint Misalignment


Preheater Expansion Joint Failure


Lower Vestibules


Chemical Clean Connections


Gasket Leaks


Small Bore Drain Line Pinhole Leaks


OTSG Side Vestibules


OTSG Sidewall Bundle Restraint


Lower Vestibule and Outlet Header


Swaged Fitting Tube Plugs


EOR OTSG Vestibule


EOR OTSG Return Bend Inspection


Drain Lines Inspection


Corrosion Under Insulation


Internally Insulated Gas Tight Expansion Joint


Removed Drain Line


Corroded Drain Line


Distorted Vestibule Upper Tubesheet Limit Guide


Tubesheet to Fin Tube Lockup


Upper Vestibule Vent Line Distortion


Tube Support Module Splay


HRSG Inlet Transition Section


OTSG Steam Outlet Header


Tubesheet Distortion


Tubesheet Witness Marks


Fin Tube to Tubesheet Ratcheting Effect


Tube Collar Installation


Tube Collar Migration


Tube to Tubesheet Ratcheting and Collar Movement


OTSG End Gas Seal Plates


OTSG Tube Return Bends


Return Bend Indentation


OTSG Return Bend Indentation


Exhaust Gas Distributor


Exhaust Gas Perforated Plate


Duct Burners


Vertical Duct Burner


Horizontal Configuration Duct Burner


Duct Burner Fixed Igniter End


Bat Wing Bluff Body Configurations


Duct Burner Floating Element End


Duct Burner Element Wall Liner Distortion


Duct Burner Pinning


Duct Burner Cavity Liner Distortion


Duct Burner Cavity Wall Liner Distortion


Duct Burner Cavity Liner Replacement


Inlet Duct Insulation Block


Superheater & Reheater Modules


HRSG Bottom Supported Superheater


Sliding Floor Seal Distortion


Floor Seal Plate Failure


Tube Distortion and Migration


Plug Weld Failures


Scallop Bar Failure & Distortion


Scallop Bar Tube Impingement


Robust Scallop Bar Design


OTSG HP Superheater Tubes


Swollen HP SH Tube


OTSG Tube Rupture


OTSG Circuit Plugging


OTSG SH Ruptured Tube


Freeze Damage


Superheater & Reheater Upper Vestibule Floor Seal Plates


Upper Header Supports


Top Hung Module Saddle Supports


Support Saddle Crack


Tube to Header Inspections


Superheater Toe Welds


Lower HP SH & RH Links


Lower SH Drains & Penetrations


Evaporator & Feedwater Modules


Exfoliated Fin Deposits


Feedwater Heater Vents & Supports


Top Support Systems


Evaporator Support Fixtures


Exhaust Duct and Stack


Heavy Exfoliation and Sulphur Deposition


Preheater Tube UT Wall Thickness Monitoring


Exhaust Transition Expansion Joint


Exhaust Duct/Stack Inlet Expansion Joint


Sulphur Deposits


Sulphur On Stack Floor


Rectangular Duct Damper Blades


Typical Circular Stack Butterfly Damper


Closed Butterfly Dampers


Stack Silencers


Drum Inspections


Primary Separators, Secondary Mesh Demisters and Chevrons


Drum Wall Wash Effect


HP Drum Primary Separators and Demister/Chevron Assemblies


Underside of HP Primary Separator


HP Drum Floor Deposits


Chevron Separator Failure


Demister Pad Blow Out


Demister Pad/Chevron Assembly at Saturated Steam Lead


Steam Water Level Line


HP Downcomer Passivation


IP Drum


IP Demister Pads


LP Drum


LP Drum Water Line


LP Feedwater and Evaporator Riser Distributors


LP Drum Deposits


LP Demister Pads


Door Castellation Seals


Don’t Forget the Blowdown Tank


And Remember the Interstage Attemperators


Tig Weld Cracks


And Borescope Liner Upstream & Downstream


Now On To Pigging


Cleaning Pig & Before/After Foam Dewatering Pigs


Feedwater Inlet & Steam Outlet Borescopes


Pig Launcher


Pig Launchers/Receivers


Borescope Inspection


Pigged Steam Lines


Pigged Gasket Results


Incorporating the Inspection Results into the LONG TERM MAINTENANCE PLAN 

The Long Term Maintenance Plan (LTMP) will define the scope, frequency and estimated cost of equipment maintenance required to attain expected plant availability.



The LTMP will be built based on the outputs of the equipment Integrity Plans and the System Asset Management Plans (SAMP). Integrity Plans Objective: Develop equipment specific plans defining maintenance intervals, related projects and applicable operating procedures.

SAMP’s Objective: Develop specific plans utilizing operating assumptions and performance history


LTMP Objective: Develop wholistic plant view on scope, frequency and cost of outages over 5 and 20 year horizons

LTMP & Business Plan LTMP Linkage with the Annual Business Plan •

•

The LTMP will include the following; 

Discussion on Integrity Plans and SAMP content as it relates to the long term maintenance requirements.



Short term view showing major outage work scopes, durations and cost estimates.



Long term view showing major outage work scopes, durations and cost estimates.

With the combination of Integrity Plans and SAMP’s in the LTMP, which should be reviewed and updated on an annual basis, the annual Business Plan will contain an accurate maintenance scope, duration and cost estimates for the coming year.


Incorporating the Inspection Findings into a Risk Registry 





The Risk Registry is a tool used to document risks known to Management and associated mitigation activities. As a group the management team distributes risks appropriately to team members, who become the “risk manager”. The Risk Manager is responsible for documenting current mitigation activities or developing strategies for further mitigation when appropriate.


Calculate Risk Value •

A Risk Value is calculated using the probability, frequency and impact values.


A Wholistic Approach to HRSG Inspections  Concluding

remarks:

– Know what you are up against. – Begin the inspection with the end in mind. – Understand the deliverables of the inspection. – Hope for the best, prepare for the worst. Charles G. Turner & Associates Ltd.

HRSG-09 Wholistic Approach to HRSG Inspections - Turner

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