El Paso MarriottEl Paso, TX

July 26-27, 2016

Plant Management, Engineering & Operations Conference and Roundtable

Instructed by:Mike Preston, Chemical Engineering Section Leader, Black & Veatch Corp.

Benjamin Franklin, Director, Technical Services, Headwaters Resources Anthony Tipton, Sr. Engineer, Thielsch Engineering, Inc.

Chad Kline, Superintendent, Generation Projects, El Paso Electric Company James Nyenhuis, Performance Consultant, Emerson Process Management

Power & Water SolutionsJohn Michael Harris, Consultant, R-Levels Power Partner LLC

Jackie Liu, Director, R-Levels Power Partner LLCAnthony “Tony” Carrino, Manager, Power Studies, Solomon Associates

Aubrey Johnson, VP, New Mexico Operations, PNM Resources

Brent Gifford, Manager, Major Project and New Generation, Arizona Public Service

RMEL ~ 6855 S. Havana, Ste 430 ~ Centennial, CO 80112 ~ (303) 865-5544 ~ FAX: (303) 865-5548 ~ www.RMEL.org

Tuesday, July 26, 20168:30 a.m. – 9:15 a.m.ELG ComplianceMike Preston, Chemical Engineering Section Leader, Black & VeatchThe CCR and ELG rules have been finalized and compliance plans are being prepared. These rules have profound effects on some power generating stations residuals management and water man-agement approaches. Now that the rules are final, it is helpful to reconsider compli-ance options in light of the established requirements and review holistic compliance approaches to reduce cost for affected power generators. This presentation will provide an overview of rules as they stand, integrated CCR and ELG compliance solutions with examples of implementa-tion, and impacts to operating philosophies.

9:15 a.m. – 10:00 a.m.The Effect of Sorbents on Flyash Quality and the Impacts to MarketingBenjamin Franklin, Director, Technical Services, Headwaters ResourcesThe presentation will cover, dry sorbent injection products and their potential impacts to fly ash quality and issues regarding marketing to the concrete industry and the various State Department of Transportation requirements.

10:00 a.m. - 10:15 a.m.Networking Break

10:15 a.m. - 11:00 a.m.Root Cause Analysis Collapse of 10th Stage Ip Diaphragm Steam Turbine Generator, Unit No. 2 Omaha Public Power DistrictAnthony Tipton, Sr. Engineer, Thielsch Engineering, Inc.On November 28th 2014 the Steam Turbine Generator for Unit #2 at Omaha Public Power District’s Nebraska City facility experienced a catastrophic failure in the HP/IP section while operating at full load. A root cause analysis revealed that the event was precipitated by the collapse of the 10th stage diaphragm into the 10th stage disk and rotating blades. The primary causal factor responsible for the collapse of the 10th stage diaphragm was identified as weld cracking at the vanes to outer and inner ring circum-ferential weldments which likely occurred during manu-facturing. The diaphragm integrity was therefore dependent on the remaining tack/seal welds between the vanes and outer/inner rings which eventually fractured due to creep or creep/fatigue during operation. The detailed results of the root cause investigation are presented.

11:00 a.m. - 11:45 a.m.Common Problems En-countered with Commis-sioning an LMS 100 PlantChad Kline, El Paso Electric Company

Noon – 1:00 p.m. Networking Lunch

1:00 p.m. – 4:00 p.m.Generation Vital Issues RoundtableRoundtable registration is limited to the first 40 members.Roundtables offer a unique forum for peer-to-peer shar-ing of experiences, critical issues and expertise. The roundtable is a discussion group, open only to RMEL members. Discussion is based on topics brought by attendees. Roundtables are focused on the open discus-sion period and provide each attendee the oppor-tunity for participation and dialogue on their particular issue. Roundtables are held in conjunction with a conference and many topics presented at the conference are discussed further in the roundtable setting. The roundtable is a good oppor-tunity to share experiences, troubleshoot problems and network with peers in a smaller, informal setting. Each participant is offered a chance to pose questions and share information. All attendees are encouraged to bring issues for discussion and materials for sharing.

Wednesday, July 27, 20168:30 a.m. – 9:15 a.m.Advanced Automation Strategies for Combined Cycle PlantsJames Nyenhuis, Performance Consultant, EmersonMarket and regulatory forces continue to change the op-erational profile of combined cycle plants. Plant owners and operators are constantly looking for ways to increase unit operational flexibility while maintaining plant reli-ability in an environment of

CONFERENCE AgENdAconsistent pressure on O&M costs. This environment is driving many plants to seek additional capabilities from their automation systems. This session will review some of the advanced technolo-gies and control strategies currently being deployed and how these applications have impacted dynamic plant performance capabilities.

9:15 a.m. – 10:00 a.m.New Generation Boiler Drum Water Level Instruments for Improved Boiler SafetyJohn Michael Harris, Consultant, R-Levels Power Partner LLCJackie Liu, Director, R-Levels Power Partner LLCTraditional boiler drum water level instruments simply do not work correctly. But don’t take our word for it ask your operators and instrument technicians three questions when you get back to your plant: 1) do the different theory drum water level in-struments (e.g. conductivity probe and DP transmitter) agree even when the level deviates from “zero”? 2) do the different theory instruments agree with one another during startup, shutdown, or large pressure changes? 3) when the drum is open during an outage, does the water mark inside match what the instruments have been reading?

10:00 a.m. - 10:15 a.m.Networking Break

10:15 a.m. - 11:00 a.m.Maintaining Reliability in Low Margin MarketsAnthony “Tony” Carrino, Manager, Power Studies, Solomon AssociatesLow margins and lower capacity factors don’t allow for the same level

Thank You RMEL Generation Committee

CHAIRJeff Karloff

Division Manager, Production Engineering & FuelsOmaha Public Power District

VICE CHAIRCurt Brown

Project Manager, Power Generation ServicesBlack & Veatch Corp.

David ArandaNewman Plant Manager

El Paso Electric Company

Ben CluffArizona Public ServiceEngineering Manager

Matt FergusonVP, Power & Energy Section Manager

HDR, Inc.

Darrel HensleySr. Director, Generation

Kansas City Power & Light

Richard ThreetDirector, Power Generation

PNM Resources

Kellen WaltersRegional Sales Director

Mitsubishi Hitachi Power Systems Americas, Inc.

Tom WosRegulatory Program Administrator

Tri-State Generation and Transmission Assn.

The RMEL Generation Committee plans all RMEL Generation events. If you’d like to send

information to the committee, email James Sakamoto at jamessakamoto@rmel.org.

of maintenance spending as ‘the good old days’. Prioritization of scarce financial and human resources requires some better perspectives. A time-based and value-based spending framework is necessary to make better decisions around maintenance and reliability programs.

11:00 a.m. - 11:45 a.m.Engineering Resources/Workforce Management Panel

PNM’s Rotational Engi-neering ProgramPanelist #1: Aubrey Johnson, VP, New Mexico Operations, PNM ResourcesHow we developed the Program; how we admin-ister the program; results that we’re seeing.

Training Entry Level Engineers for a Career in Fossil GenerationPanelist #2: Brent Gifford, Manager, Major Project and New Generation, Arizona Public ServiceA solid foundation in operations makes for a better engineer and a solid foundation in engineer-ing makes for a better operator. APS’s New Engineering in Operations (NEO) program puts every new engineer through a set of rotations totaling 21 monthsin each of the vari-ous functions of an opera-tions crew. The 21 month rotations are followed by a 12 month assignment as a shift supervisor. After the 12 month assignment the engineer is free to choose to stay in operations or come to engineering. Regardless a more techni-cal, operations aware work force is created in Fossil.

11:45 a.m. - 1:00 p.m. Grab & Go Lunch and Transportation to Montana Power Station Montana Power Station is about 18 miles from the hotel. A shuttle will take you to the plant tour and return you back to the hotel.

1:00 p.m. - 3:00 p.m.Montana Power Station Plant Tour

PLANT MANAGEMENT, ENGINEERING AND OPERATIONS CONFERENCEConference, Roundtable and Montana

Power Station Plant Tour

ELG Compliance

Mike Preston Chemical Engineer Section Leader

Black & Veatch Corp.

26 Ju

ly, 2

016

CHEMICAL ENGINEERING SECTION LEADER MIKE PRESTON, PE

ELG COMPLIANCE

AGENDA • Regulatory Overview • Solutions • Getting Started

2

REGULATIONS

3

Regulation 2011 2012 2013 2014 2015 2016 2017 2018

EGU MACT

Cross State Air Pollution

Coal Combustion Residuals

Water 316 (b) & Effluent

Guidelines

Greenhouse Gases (GHGs)

Comment Period

Final Rule

MACT Rule Pre-compliance Period for existing sources

MACT Rule Compliance for existing sources

Current Clean Air Interstate Rule (CAIR)

CSAPR Phase I Compliance

Cross State Air Pollution Rule (CSAPR) Phase II Compliance

EPA Developing Final Rule

Final Rule

CCR Rule Pre-compliance Period CCR Rule Compliance

Develop Final 316(b) Rules

Develop New Effluent Guidelines

Rules

Final Rule 316(b) Rule Compliance

Final Rule Effluent Guidelines Compliance

EPA GHG Reporting Rule Compliance Best Available Control Technology for Modified/New Sources (PSD/NSR/BACT) Smaller Sources Included by EPA

Proposed GHG Regulation for New Sources

Develop GHG Regulation for Existing Plants Possible Compliance with New GHG Rules

Proposed Rule

Proposed Rule

Develop Final Rule

Impacts: • Elimination of Non Compliant

CCR Impoundments and Landfills • Revised Ash Handling Systems • Monitoring and Reporting • Public Exposure Due to

Enforcement Mechanism • Plant Wastewater Treatment

COAL COMBUSTION RESIDUALS

4

STEAM ELECTRIC POWER GENERATING EFFLUENT LIMITATIONS GUIDELINES 40 CFR 423

5

Waste Stream BPT BAT NSPS PSES & PSNS

All Waste Streams pH 6.5-9 PCBs: Zero discharge PCBs: Zero discharge pH 6.5-9

PCBs: Zero discharge PCBs: Zero discharge

Low Volume Wastes TSS 100/30 Oil and Grease 20/15 No Limitation = BPT No Limitation

Fly Ash Handling TSS 100/30 Oil and Grease 20/15 No Limitation Zero Discharge

Zero Discharge (PSNS only) No limitation in PSES

Bottom Ash Handling TSS 100/30 Oil and Grease 20/15 No Limitation TSS 100/30 Oil and

Grease 20/15 No Limitation

Chemical Metal Cleaning TSS 100/30 Oil and Grease 20/15 Cu 1.0/1.0 Fe 1.0/1.0

Cu 1.0/1.0 Fe 1.0/1.0 TSS 100/30 Oil and Grease 20/15 Cu 1.0/1.0 Fe 1.0/1.0

Cu 1.0 max

Once Through Cooling FAC 0.5/0.2 TRC 0.20 max or = BPT if <25 MW

TRC 0.20 max or = BPT if <25 MW No Limitation

Cooling Tower Blowdown FAC 0.5/0.2 FAC 0.5/0.2 126 Pr. Pol. No. Detect Cr 0.2/0.2 ZN 1.0/1.0

FAC 0.5/0.2 126 Pr. Pol. No. Detect Cr 0.2/0.2 ZN 1.0/1.0

126 Pr. Pol. No Detect Cr 0.2 max Zn 1.0 max

Coal Pile Runoff TSS 50 max No Limitation TSS 50 max No Limitation

Concentrations are in mg/l. If daily maximum and 30-day average concentrations apply, they are given as “maximum/average”.

BCT is reserved for all waste streams.

Low Volume Wastes include: clarifier blowdown, makeup water filter backwash, lime softener blowdown, ion exchange softener regeneration, demineralizer regeneration, powdered resin demineralizer back flush, reverse osmosis brine, boiler blowdown, evaporator blowdown, laboratory drains, FGD bleed stream, and diesel engine cooling system discharge.

• FGD wastewater

• Ash impoundments

• Wet ash handling systems • Metal cleaning wastewaters

• Landfill leachate

FOCUS OF UPDATED GUIDELINES

6

BASIS OF ELG

7

Waste Stream Technology Regulatory Option BAT NSPS PSES PSNS

FGD Wastewater

Chemical Precipitation x x x x

Biological Treatment x x x x

Evaporation x x

Fly Ash Dry Handling x x x x

Bottom Ash Dry Handling Closed Loop x x x

Leachate Chemical Precipitation Impoundment

x x

x x

Gasification Wastewater Evaporation x x x x

Flue Gas Mercury Control Wastes Dry Handling x x x x

PREFERRED TECHNOLOGIES

NEW FEDERAL REQUIREMENTS

8 Technology based limits

Waste Stream BAT Limits, Avg/Max NSPS, PSES, PSNS Limits, Avg / Max

FGD Blowdown

As – 8/11 ppb Hg – 356/788 ppt NO2-NO3 – 4.4/17 ppm Se – 12/23 ppb

As – -/4 ppb Hg – 24/39 ppt Se – -/5 ppb TDS – 24/50 mg/l

Non-Chemical Metal Cleaning No New Limits No New Limits

Ash Transport No Discharge No Discharge

Leachate Impoundment TSS - 30/100 ppm Oil and Grease - 15/20 ppm

As – 8/11 ppb Hg – 356/788 ppt

Anti Circumvention Provision (ACP)

• Requires a particular waste stream for which a zero discharge limitation has been established not be used in another plant process that results in a surface water discharge. The exception to this provision is use of ash transport water as FGD makeup water.

Legacy Provisions

• Ash transport water generated prior to the date established by the ELG as the control date (earliest November 2018; latest December 2023) would be treated under current BPT (settling ponds)

Combined Waste Streams

• Factored approach to limits where waste streams of different categories are combined for discharge

Removal Credits

• POTW’s may grant qualifying removal credits to indirect discharges. POTW must apply and receive authorization to offer credits.

ADDITIONAL PROVISIONS

9

TIME FRAME

10

Latest Compliance Deadline

4

Earliest Compliance Deadline

3 Final Regulations

2

Draft Regulations Published

1

2013 2014 2015 2016 2017 2018 2019 2020 2023

Takes effect upon next permit issuance or renewal

• More Stringent Effluent Limits to Existing Wastewater Discharge

• Less Flexible Water Management

• Segregation of Some Wastewaters

• Additional Internal Monitoring Points (IMP’s) • Additional Analytical Work and Reporting • Additional Treatment of Non-Compliant Streams

IMPACT OF UPDATED EFFLUENT LIMITATION GUIDELINES

11

EFFLUENT GUIDELINE SOLUTIONS

12

• Isolate and address water issues individually

• Take a holistic approach to water management

WATER MANAGEMENT APPROACH

13

Water management can greatly reduce the capital required to comply

Every 1 gpm of FGD wastewater discharge may cost as much as

$90,000+ to comply with regulations

COST OF TREATMENT

14

• Holistic water review

• Opportunities for reuse

• Minimize treatment

• New water management paradigm

• Understand • Regulatory impact • Treatment options • Cost of treatment ($, MW)

WATER MANAGEMENT GOALS

15

WATER BALANCE

16

CCR AND ELG INTERSECTION

17

Ash Impoundment

(Pond)

Ash Handling Systems

Low volume wastewater

FGD wastewater

Coal pile runoff

Metal cleaning wastewater Other wastewater

ASH SYSTEM SOLUTIONS

18

Replace non-compliant

impoundment with compliant

impoundment

Dewatering Bin System

Dewatering Basins System

Submerged Scraper Conveyor

Dry Ash Conveyor System

Remote Submerged Scraper Conveyor

WASTEWATER SOLUTIONS – LOW VOLUME WASTEWATER (LVW)

19

• Considering future regulatory changes

• Cataloging all the flows

• Understanding plant water balance

• Data collection and analysis

• Flexibility • Understand variable

water quality

• Sizing treatment systems

• Solids handling

• Oily water

• Schedule • Coordination with ash

system modifications • Permitting

CHALLENGES

20

Chemical Precipitation • TSS Reduction • Metals

Reduction

Biological Treatment • Denitrification • Selenium

Reduction

OR

Evaporation • Falling Film • Crystallizer • Solidification • Spray Drier

FGD WASTEWATER TREATMENT

21

FGD WASTEWATER TREATMENT

22

PHYSICAL-CHEMICAL TREATMENT

23

Equalization

Tank

Primary Clarifier

Desaturation

Tank

Sulfide Rxn Tank

Secondary Clarifier

Neut Tank (Optional)

Dewatering

Lime Sulfide

Polymer

FGD

Wastewater

Treated

Wastewater

Cake

To Landfill

Effluent Tank (and possibly

filters)

Filtrate

Sludge Tank

Sludge Recycle

Coagulation

Tank

Ferric Chloride Acid

BIOLOGICAL SELENIUM REDUCTION

• Create conditions that allow microbes to use selenate and selenite as an oxygen source, precipitating elemental selenium.

• Same bio-mechanism as denitrification or perchlorate reduction.

24

SeO42- + organic carbon → SeO3

2- + organic carbon → Se0 + CO2 + H2O

BIOLOGICAL TREATMENT

25

GE’s ABMet® Process

Source: General Electric

ZERO LIQUID DISCHARGE (ZLD)

26

Source: General Electric

SPRAY DRYER

27

Source: Advatech

• Oasys Water

• Membrane Brine Concentrator (80 – 90 Percent Recovery)

• Process using Draw Solution

• Draw Solution is Regenerated

• Capable of Efficiently Concentrating High TDS Brine Solutions

• Unit In Service – Changxing Power Station

• Test Unit being Prepared for WRC

FORWARD OSMOSIS

28

• Blending Wastewater with Power Plant Residuals for Disposal

• Typically Fly Ash Blending

• GE Proposed Improved Process

SOLIDIFICATION

29

PIRONOX™ - EVOQUA • Zero valent iron (ZVI), Fe0, iron

filings

• Past results inconsistent

• Removal mechanism is complex

• 3 or 4 different pathways

• Iron passivates

• New method for maintaining reactive oxide coating developed at Texas A&M

• Evoqua + Texas A&M licensing agreement

Latest development in ZVI arena 30

ZERO VALENT IRON - EVOQUA

31

THE BENEFITS OF GETTING STARTED

32

• Make the best of difficult requirements

• Understand the potential scenarios

• Understand schedule issues • Prepare for possible outcomes

• Select best solution for your facility

• Prepare for regulatory discussions

LOOKING AHEAD

33

High Level Study

• Evaluate current water usage

• Determine options

• 3-6 months

Detailed Study / Permitting Engineering

• Determine optimal solution

• 6-12 months

Capital Project

• 2-3 years

ELG COMPLIANCE PROGRAM DEVELOPMENT

34 Don’t overlook permitting and regulatory approval

www.bv.com

The Effect of Sorbents on Flyash Quality and the Impacts to

Marketing

Benjamin Franklin Director, Technical Services

Headwaters Resources

Dry Sorbent Injection A marketers perspective.

RMEL workshop, El Paso TX 7/26/ 2016

Dry Sorbent Technologies

Dry Sorbent Injection (Trona) 40-75% reduction in SO2: Lime, hydrated lime, Sodium bi-carbonate

Selective Non Catalytic Reduction (SNCR) 35% reduction in NOx (Ammonia)

Selective Catalytic Reduction (SCR) 90% reduction in NOx

Powdered Activated Carbon (PAC) 90% mercury removal

DOT Specifications Alkali Content

Department of Transportation: ◦ AASHTO M295: 1.5% available alkali ◦ ASTM: optional on request 1.5

Fly ashes in the US:~1.5% or greater available alkalis.

DOT total alkali allowances:3.0 Proper QA/QC is key to marketing ash

with Trona.

Powdered Activated Carbon

PAC creating many air issues in the fly ash market, which creates a tight supply chain.

Many in the specifying agencies and ready mix/related industry do not understand PAC.

Will create entrained air issues, effect dependent on PAC utilized.

Does not effect specification at DOT.

Impacts to Concrete Quality

Trona: Raises alkalis. May effect set times.

Ammonia: May be a health concern in confined spaces, no issue with concrete performance.

All sorbents create marketing issues and may cause the material to be removed from the market.

Currently many utilities still trialing different PACs, as results differed during peak vs, off peak generation.

Fuel change, wet scrubber w/ additives and other options might be available.

Mercury and Air Toxics Standards (MATS) final rule went into effect in December 2011 requiring coal fired power plants to control mercury emissions within 3 years (April 2015):

− States may grant 4th year (2016) −USEPA administrative order would allow 5th year (2017) for critical units.

Activated Carbon Injection Post Fly Ash Collection

Fly Ash

Flue Gas

Electrostatic Precipitator Boiler

Stack Carbon Injected after ESP

Fly Ash Only

C + Hg

Baghouse

Activated carbon

9

Sorbent Vendors Top players vying for this $10 billion /year market

Mercury Control: • Cabot (Norit) – DARCO-Hg family of sorbents • Calgon – Flue PAC family of sorbents • ADA carbon Solution: Power PAC, Fast Pac • Albemarle: B-PAC, C-PAC, H-PAC, • BASF – Mercury Sorbent HX – Brominated mineral sorbent • Novinda: Amended Silicates • EM2C: Additive & PAC • ADA ES: coal additive, engineering solutions and consulting • Others: Shaw, Nalco (scrubber additives)

10

Foam Index/ Carbon Reactivity Testing

Foam Index

200ml: water 40gms: fly ash AEA, company standard or most prevalent 4:1 for C ashes/low LOI Full strength for high LOI/highly reactive.

12

Foam Index/Windows/Carbon not mitigated.

13

Foam Index/No Windows/Carbon mitigated

Cement or fly ash

AEA

Air Bubble

Activated Carbon

Chemical mitigation saturates the activated carbon surfaces with a sacrificial agent to prevent the adsorption of AEA’s.

Air Entrainment Agents (AEA’s) prefer powdered activated carbon.

Activated carbon in concrete attracts the AEA hydrophobic end and prevent it from entraining air.

15

0%

5%

10%

15%

20%

25%

30%

35%

1 1.3 1.6 1.9 2.2 2.5 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 5.8 6.1 6.4 6.7 7

Perc

en

t o

f ti

me a

t in

ject

ion

ra

te

ACI Rate lb per million acf of flue gas

1st Generation Less Consistent

Current Generation

More Consistent

Lower PAC injection rates and a tighter control range =

less PAC in ash + Improved consistency (AEA demand)

Improvements in Activated Carbon Technology

16

PAC Adsorption Capacity varies…….

The slope of the linear regression line indicates the foam index variability relative to changes in PAC % concentration in ash.

In this example, C-PAC is less adsorptive of MBVR than B-PAC.

0

5

10

15

20

25

30

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

Fo

am

In

dex (

MB

VR

Co

nc.

)

RA 2.2 Dosage lb/ton of ash

Chemical Treatment 2.2 Tamed Dose-Response

Class C ash samples containing variable levels of PAC treated to acceptable foam index level.

Sample Description Control C-Ash C-Ash with PAC

Cement No PAC Untreated Treated

Foam Index (conc MBVR) 3 18 5 AEA dosage (oz/cw) 1.2 1.4 4.2 1.7

Air Content (6%+1%) 7.0% 7.0% 6.25% 5.75% Bulk Density, lb/ft3 144.8 145.6 147.2 148.0

Slump, inches (6+1) 6.25 6.0 6.25 5.75 3 day, psi 2814 2858 3039 2907 7 day, psi 3433 3689 3592 3918 28 day, psi 4594 4802 4764 4908

Beneficiated ash with chemical treatment

Ash treatment restored the AEA dosage to same level expected with ash containing NO activated carbon.

Sorbent Sensor

•New State of the Art Patented technology. •Provides definitive data as opposed to Foam Index. •Significant cost to develop and produce. •Produced and used by one marketer

Plants in Service Meeting current Regulations.

Port Neal: Ammonia, PAC and Trona

Newton: PAC Baldwin: PAC Jeffrey's and Tecumseh: PAC

THANKS

Benjamin J. Franklin Director of Technical Services Mobile: 314-974-5095 Email: bfranklin@headwaters.com www.flyash.com

Root Cause Analysis Collapse of 10th Stage Ip Diaphragm Steam Turbine Generator, Unit No. 2 Omaha Public Power District

Anthony Tipton Sr. Engineer

Thielsch Engineering, Inc.

Anthony Tipton Thielsch Engineering, Inc.

July 2016

Tandem Compound Train Combined HP-IP Two Double Flow LP’s

Design Rated Conditions 720MW 2460 psig 1050⁰F/1050⁰F Speed-3600 RPM

Began Operation-July 2009

Unit Operating at 720MW for 2 ½ Hours Was Ramped from

500MW High-High Vibration

Levels at #1 and #2 Bearings Instantaneous No Warning Unit Tripped

30 Minutes to Coast Down

0

5

10

15

20

25

30

35

40

3500

3520

3540

3560

3580

3600

3620

4:19:12 AM 4:33:36 AM 4:48:00 AM 5:02:24 AM 5:16:48 AM 5:31:12 AM 5:45:36 AM 6:00:00 AM 6:14:24 AM

Vibr

atio

n (m

ils),

Trus

t Bea

ring

Posi

iton

(in)

Spee

d (R

PM)

Time

Turbine Speed

#2 Bearing Vibration

#1 Bearing Vibration

Thrust Bearing

Majority of Damage Centered in IP Turbine at 9th-11th Stages

Damage to 8th, 9th ,11th Stage and 12th Stage Rotating

Blades and Diaphragms Deemed Secondary

Rub and Impact Damage

8th and 9th Stage Diaphragms were Dished

10th Stage Blade Airfoils Missing Blade Roots “Proud”

on Exit Side of Disk 10th Stage Disk

Rubbed on Inlet Side Thickness Reduced

50%

10th Stage Diaphragm All Vanes Liberated

from Inner/Outer Rings Fractured at Vane to

Inner/Outer Ring Weld Joints

Severe Rub Damage on Exhaust Side of Inner Ring

Primary Failure Identified as 10th Stage Diaphragm

Fracture of Vane at the Outer Ring and Inner Ring Weld Joints Allowed Diaphragm to Deflect Downstream

Severe Wear to 10th Stage Disk and Blades Eventual Liberation of All 10th Stage Diaphragm Vanes

Diaphragm Components Outer and Inner

Spacer Rings Profiled Vane Slots

Vanes Outer and Inner

Rings

Vanes are “Tack Welded to Outer and Inner Spacers Follows Vane Profile

Multipass Circumferential Welds Join Outer and Inner

Ring to Vane and Outer and Inner Spacers

All Vanes Separated at Outer Ring to Vane Weldments Leading and Trailing

Edges

Outer Ring to Vane Weldment at Leading Edge Weld Passes Evident Surface Heavily

Oxidized Fracture Morphology

Exhibits Melted Appearance Weld Directionality

Apparent

OUTER RING LEADING EDGE SECTION

METALLOGRAPHIC SAMPLE

Circumferential Weld Fracture (100X) Transgranular

Fracture Path Lack of Deformation

at and Adjacent to Fracture

Oxidation app. 0.003” Thick

No Evidence of Creep Damage

Outer Ring to Vane Weldment at Trailing Edge Weld Passes Not

Evident Surface Heavily

Oxidized No Fracture Features Melted Appearance

Lack of Fusion

Vane to Outer Ring

Weldment at Leading Edge Fracture Morphology

Mimics Mating Fracture on Outer Ring

“Tack Weld” Evident Rub Damage Consumed

Most Fracture Features Shear Evident in Select

Areas

Circumferential Weld Fracture (500X) Fracture Progressed

Through Weld Metal Oxidation Present on

Fracture Weld Metal on Vane

Surface App. 0.008” Thick

Small Areas Exhibit Lack of Fusion

Transgranular Fracture Path

All Vanes Separated from Inner Ring

Severe Rub Damage on Exhaust Side of Inner Ring Vane Trailing Edge

Weldment Consumed

Inner Ring to Vane Weldment at Leading Edge Fracture Morphology

Similar to Outer Ring Fracture

Oxidation on surface Rub Debris on

Surface

INNER RING LEADING EDGE SECTION

METALLOGRAPHIC SAMPLE

Circumferential Weld Fracture (100X) Transgranular

Fracture Path No Evidence of Gross

Deformation No Evidence of Creep

Damage

Vane to Inner Ring Weldments Rub Damage

Consumed Trailing Edge Weldment

Majority of Leading Edge Weldment Fracture Damaged by Rubbing

Circumferential Weld Fracture at LE (500X) Fracture Progressed

Through Weld Metal Oxidation Present on

Fracture Transgranular

Fracture Path No Evidence of Gross

Plastic Deformation No Evidence of Creep

Damage

Fracture Through Vane to Outer Ring Weldment at Leading Edge Likely Occurred During Manufacturing

Weld Metal had Limited Ductility Prior to PWHT Significant Shrinkage and Transformational Stresses Highly Restrained Weld Joint

Fracture Through Vane to Outer Ring Weldment at Trailing Edge Could Not be Determined Due to Secondary Damage

Significant Lack of Fusion/Penetration Evident

Some Fractures Through Vane to Inner Ring Weldment at Leading Edge Likely Occurred During Manufacturing

Similar to Vane to Outer Ring at Leading Edge Fractures

Some Fractures Through Vane to Inner Ring Weldment at Leading Edge Were Due to Tensile Overload

Probably Occurred During Turbine Incident

Cause of Vane to Inner Ring Separation at Trailing Edges Could Not be Determined from Evidence Available.

Vane to Outer Ring Joint Strength was Reliant on the “Tack Welds” (Seal Weld)

Component Materials are Typical Materials of

Construction for High Temperature Steam Turbines Hardness of Components and Weldments Indicates

they were Properly Heat Treated and/or PWHT’d

Reported Excursions 30 minutes at 1148°F 130 minutes at 1182°F 10 minutes at 1142°F

IP Inlet Temps Not Affected Reduced Effectiveness of IP Rotor Cooling

Lower Creep Rupture Life of Diaphragm Minor Effect at Diaphragm Outer Rings

Primarily to Cool Disks and Blades Will Cool Diaphragm

Inner Ring Much Less Effective at

Cooling Vanes and Outer Ring

Erratic Operation of Cooling Steam Valve Reported Diaphragm will

Experience Higher Temps Lower Creep Rupture

Life

IP Diaphragm Collapse at Major Southern Utility Same Turbine Manufacturer Similar Design

Attributed to “Cold Cracking” of Vane to Outer/Inner Ring Weld Joints

Fracture Characteristics Similar to OPPD Failure

Lack of Penetration/Fusion Evident No Evidence of Global Creep

Primary-Manufacturing Reduced Weld Joint Strength Welds Joining Vanes to Outer Ring at Leading Edge

Appear to Have Cracked During Fabrication Welds Joining Vane to Outer Ring Trailing Edge

Exhibited Significant Areas of Lack of Fusion/Penetration

Secondary-Operation

Erratic Operation of IP Rotor Cooling Steam Valve High Main Steam Temps Reduced Effectiveness of IP Rotor

Cooling Steam

10th Stage IP Diaphragm Inner Ring Deflected Downstream and Contacted the 10th Stage Disc and Blades

Severe Rubbing Separation of Vanes from Diaphragm Damage to 10th Stage Disc and Blades Secondary Downstream Damage

Imbalance Resulted in High Vibration Unit Tripped

Deflection of Inner Ring Occurred When The Vanes Fractured at the Outer Ring and Inner Ring Weldments

Likely Occurred at the Outer Ring Leading Edge and Inner Ring Trailing Edge First

Circumferential Welds between Vane and Outer

Ring/Inner Ring Cracked During Diaphragm Fabrication

Weld Joint Integrity/Strength Compromised

Common Problems Encountered with Commissioning an

LMS 100 Plant

Chad Kline Superintendent, Generation Projects

El Paso Electric Company