USING THE ERC TOSOLVE POWER PLANT PROBLEMS

(a) Research Scientist Arlan Benscoter(left) examines a failed boiler tube foran Energy Liaison Program membercompany.

(b) ERC researcher conducts fieldevaluation of air preheater cold end

fouling.

(Continued on Page 2)

(Continued on Page 3)

November 2001, Vol. 19, No. 3

Steve M arbaise, an engineer atPSE&G’s Hudson Station, needed help indetermining boiler control settings to useat Unit 2 to achieve lower NO x emissions.Greg Schmidt of PPL Generation had anupcoming maintenance outage and neededto determine what vertical sag to expect inthe tube supports of an economizer duringinstallation of the new tube bundle. KalMerimets of Ontario Power Generation wasconsidering removal of a steam air heaterat Nanticoke Station and needed to knowthe impact on air preheater fouling. BrianWarnaka of FirstEnergy had to solve aboiler tube wastage problem, possiblybrought about by cofiring petroleum cokewith coal, and needed to determine if thepetroleum coke was a contributing factor.Alex Huhmann of PSE&G asked for acritical assessment of the issues related to

cofiring biomass in pulverized coal boilers.His company wanted to learn more aboutperformance impacts, necessary plantmodifications and conversion costs. LarryKielasa of Detroit Edison neededinformation on recommended practices foron-line cleaning of Selective CatalyticReduction (SCR) catalyst beds. CONECTIVwas experiencing weld cracking in one of itsHeat Recovery Steam Generators (HRSG)and Steve Reid of CONECTIV wanted toknow the magnitude of the transientstresses in those weld during cold start-up

Inside this Issue:Solving Power Plant Problems Energy Liaison ProgramRecently Initiated Projects

ENERGY LIAISONPROGRAM PROVIDES

EASY ACCESS TOCENTER CAPABILITIES

Lehigh’s Energy Liaison Program (ELP)was organized in the late 1970's to make iteasy for the Energy Research Center towork with industry in solving energyrelated problems. Twenty years later, theELP has become the “window” throughwhich the Center’s faculty and staff workwith comp any engineers to utilize thelatest in techniques and results in solvingday-to-day technical problems. “Over theyears, as more and more people in industryhave become aware of our research andproblem solving activities, our reputationhas grown. We have become quite wellknown for the quality, timeliness, andimpartiality of our work,” says John Sale,Director of the Energy Liaison Program.

ELP activities include feasibilitystudies, equipment design modifications,third party design reviews, failureanalyses, computer software development,l i tera ture searches , environmentalassessments, problems dealing witheconomic and social issues, and specialeducational programs, including on-sitetraining. These activities involve theCenter’s professional staff and facultyrepresenting academic disciplines such asmechanical engineering, metallurgy, civilengineering, geology, biology, andeconomics.

Companies participate in the ELP undera letter of agreement that is renewable on ayearly basis. An annual participation feecovers consulting, laboratory tests,computer use, participation in educationalprograms, and other services.

Typically, each interaction with Lehighthrough ELP utilizes from one to threeman-days of faculty or staff assistance.

(“Problems,” Continued from P. 1)

PROBLEM-SOLVING AT THE ENERGY RESEARCH CENTER

Listed below are examples of areas in which ERC staff provide problem-solving assistance. Typical investigationsinclude state-of-the-art assessments, field tests, laboratory studies, theoretical analyses, and/or computer simulations.

! NOx CONTROL AND HEAT RATE IMPROVEMENTTHROUGH COMBUSTION OPTIMIZATION

The Center staff performs field tests to determine the effects ofboiler control settings on heat rate and emissions. The resultsare used to identify the combustion control settings which meetthe station's NOx and heat rate goals. The results are providedto the operators in the form of a new set of control curves.

! DIAGNOSING THE CAUSES OF OPACITYEXCURSIONS

Center staff conduct field tests to identify the causes of opacityexcursions. The test results are used to develop new operatingstrategies for minimizing opacity problems.

! FURNACE SLAGGING CONTROLLaboratory analyses and field tests are performed to identifyfactors contributing to severe boiler slagging episodes.Recommendations typically involve some combination of newinstrument ation, changes to furnace operating conditions, andchanges to furnace sootblowing practice.

! SOOTBLOWING OPTIMIZATIONField tests and analyses are performed to develop plant-specificsolutions to optimized sootblowing. The results can beimplemented as written inst ructions for the operators or can beused as input to automatic sootblowing systems.

! SNCR SYSTEM OPTIMIZATIONField tests and computer analyses are performed to identifyboiler control settings and SNCR reagent injection patternswhich minimize reagent consumption and reduce by-productemissions.

! COAL PIPE BALANCINGComputer analyses are performed to determine orifice sizesneeded to achieve balanced primary air (dirty air) flows in

coal pipes, and recommendations are made on techniques forobtaining more accurate coal flow measurements.

! AIR PREHEATER PERFORMANCEIMPROVEMENTS/COLD END FOULING

Analyses are performed to diagnose reasons for heat transferperformance problems with regenerative air preheaters. Fieldtests and analyses are performed to determine how air preheatercold end fouling rate varies with boiler and air preheateroperating conditions and with SCR and SNCR operations.

! CEM FLOW MEASUREMENT ACCURACY ISSUESField tests and analyses are performed to determine themagnitude of the CEM flow bias and identify the factors whichcontribute to the error. The results are used to develop the beststrategy for reducing bias error.

! COMPONENT FAILURE ANALYSESLaboratory analyses and computer simulations are performed todetermine the cause(s) of mechanical failures of power plantcomponents. Recommendations for corrective action areprovided.

! COMPONENT LIFE PREDICTIONSComputer simulations are performed to determine the remaininglife in components subject to high temperature creep, creep-fatigue, or low-cycle fatigue damage.

! EQUIPMENT DESIGN IMPROVEMENTSAnalyses are performed to develop improved designs of powerplant components. Design changes often include a modifiedconfiguration, change in materials of construction and/ormodified welding procedures. The design improvements aretypically carried out to increase component life, reduce pressuredrop, reduce emissions or improve heat rate.

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conditions. All seven engineers turned toLehigh’s Energy Research Center forassistance.

According to John Sale, “The EnergyResearch Center has been helping industrywith its problems for more than 20 years.Our people are specialists in disciplinessuch as mechanical engineering, chemicalengineering, metallurgy, and civilengineering; and the work they perform forour industrial clients includes laboratoryinvestigations, field studies, computersimulations, theoretical analyses, andstate-of-the-art assessments.”

“For example, both the CONECTIVHRSG study and the PPL Generationeconomizer tube bundle study requiredfinite element stress analyses. ERC

p e r s o n n e l p e r f o r m e d c o m b u s t i o noptimization tests at Hudson Station todetermine how NOx, CO and opacityrespond to different boiler control settings.They then used software we’d developed todetermine the optimal control settings. Thesteam air heater study at Nanticokeinvolved predictions of dew pointconditions within the air preheater. The SCRcatalyst bed investigation was performedby contacting catalyst vendors, consultantsand power plant engineering staff on thecleaning options and on the advantagesand disadvantages of each. The biomasscofiring assessment involved a review oftechnical papers and reports , anddiscussions with specialists in biomasscofiring. The petroleum coke evaluation

involved laboratory analyses of the petcoke used by FirstEnergy and a literaturereview and a utility survey on industryexperience on operational problems withpet coke cofiring.”

Although experienced researchers arethe key to the ERC’s success, its successis also due in no small part to Lehigh’sunique collection of research equipmentthat can be applied to practical problemsolving. The Center maintains laboratoriesin several buildings on campus, withaccess to the latest and most sophisticatedinstruments and computers.

“Sometimes utilities seek assistance atLehigh because other consultants haven’thelped,” Sale says. “We have the expertsand equipment to do what many others

ENERGYLIAISON PROGRAM

MEMBER

LaboratoryFacilities

Faculty & StaffExpertise

Computer Facilities& Software

EducationalPrograms

University Libraries

(“Problems,” Continued from P. 2)

(“Capabilities,” Continued from P. 1)

ELP PROGRAM SCOPE

Projects requiring more than three or fourman-days are arranged on a case-by-casebasis.

The ELP Director serves as the primarycontact for each member company. Hisfamiliarity with the faculty and staff andwith equipment resources allows him tofind the right combination of experts andequipment to solve a company’s problems.

According to Sale, “Some of thecompanies that belong to ELP participatein the program, in part, because of theirneeds for quick response when an urgentplant situation arises. To thesecompanies, the ability to have access to anexpert who can provide immediateassistance, without need for a specialpurchase order, is the key. Othercompanies value the ability to draw uponan organization with a wide range oftechnical skills. This contact is handledthrough the ELP Director, who uses hisknowledge of the faculty and staff skills toselect the appropriate consultant or teamof consultants for a particular problem.Perhaps most important, membership inELP gives the company convenient accessto the latest in new technology and ideas.ELP member companies are invited to allworkshops, seminars and short coursesheld at the ERC. We find that some peopleattend these events because they have aspecific problem to solve, while othersattend just to keep up with what is goingon.” ê

For more information about theproblem-solving capabilities of theCenter or about the Energy LiaisonProgram, contact:

John W. SaleManager, Research Program

Development andDirector, Energy Liaison Program

Telephone: (610) 758-4545Fax: (610) 758-5959

E-mail: jws3@lehigh.edu

LEHIGH ENERGY UPDATE is a publicationof the Energy Research Center at LehighUniversity. Subscriptions upon request.Address inquiries to Edward K. Levy, Director,Energy Research Center, Lehigh University,Bethlehem, PA 18015 or by visiting ourhomepage at www.lehigh.edu/~inenr/inenr.htm.Ursla Levy, editor.

Participation in the Energy LiaisonProgram covers the cost of:

! consultation with Lehigh facultyand professional staff

! use of special laboratory testingequipment

! assistance in developing researchprojects

! attendance at workshops andtechnical meetings

! receipt of research reports andpublications

Interactions with Lehigh personnelthrough the ELP are measured in man-days.Members are entitled to fifteen man-days ofservices annually. Companies typicallyrequire from one to three man-days ofassistance on any particular problem, butprojects requiring significantly moreinvolvement can be arranged on a case-by-case basis.

Considerable effort is given to problemdefinition and thorough follow-up to assuresatisfaction. A staff member from theCenter works with the company’srepresentative to provide assistance incoordinat ing activities and to keep themember company informed of newdevelopments at Lehigh.

can’t.” Sale adds, “One thing in our favoris our ability to see things that othersdon’t because of our broad experience andresearch expertise. Coupling this experi-ence and expertise with cutting edgeresearch equipment gives the Center abroad spectrum of tools to draw on toso lve our cus tomers’ day- to-dayequipment problems.”

Arnold Marder, a Professor in MaterialsScience and Engineering who has beenclosely affiliated with the Center since themid 1980's, believes that much of thesuccess of the Center also comes from ateam approach in dealing with problems.Marder recalls, “Just before a holiday wereceived a call from an ELP membercompany at a nearby plant which had acritical problem with a pressure vesselwhich was thinning to the point where itmight not sustain a load. The companyhad to report immediately on what itintended to do about the problem to avoidcomplete failure. The engineer called onthe ERC to find out what options therewere.”

“Despite the pending holiday, three ofus—a stress analyst, a welding engineer,and a corrosion specialist—droppedeverything to discuss possible approachesto the problem. Among us, we were ableto identify what stresses the vessel couldsustain, what welding repair could bedone, and where there might be potentialsources of corrosion,” Marder says. “Thisgave the company a total engineeringapproach to present as a solution.” ê

LEHIGH ENERGY UPDATEEnergy Research CenterLehigh University117 ATLSS DriveBethlehem, Pennsylvania 18015(610) 758-4090

Please notify Jodie Johnson at jlk4@lehigh.edu with any name and address changes.

__________________ NON-PROFIT ORG.

U.S. POSTAGE PAID

BETHLEHEM, PA. PERMIT NO. 230 __________________

RECENTLY INITIATED RESEARCH PROJECTSListed below are brief descriptions of some of the Center’s recently initiated research projects. For more information on any of these,

please contact John Sale at (610) 758-4545.

! R E M A I N I N G L I F E A S S E S S M E N T O FCIRCUMFERENTIALLY CRACKED WELD OVERLAYCOATINGSCertain weld overlay coatings on boiler tubes are susceptibleto circumferential cracking in low NOx combustion environ-ments. This project is estimating the remaining life of crackedcoatings as a function of coating composition, corrosionenvironment and stress level. It will use this information todevelop recommendations for extending coating life.

! DEVELOPMENT OF LOW COST WELD OVERLAYCOATINGS FOR LOW NOx WATERWALL TUBESWhile weld overlay coatings are used widely to protectwaterwall tubes from corrosion in coal-fired boilers, they canbe expensive. This project is developing low cost core wirecompositions for weld overlay coatings. It will also developa priority list of the best alloy compositions for use in boilersoperating in a low NOx combustion environment.

! IMPROVEMENTS TO AIR FLOW MEASUREMENT FORCOMBUSTION AND NOx CONTROLImproved boiler excess air monitoring capabilities and controlstrategies are being developed for combustion control andlow NOx operation. The approach being used combines directmeasurement of combustion air flow rate with economizerO2 measurements.

! DIAGNOSTICS AND CONTROL OF NATURAL GASFIRED FURNACES VIA FLAME IMAGE ANALYSISAn on-line system is being developed for extracting infor-mation from flame images using machine vision and artificialintelligence techniques. This information will be correlated tocombustion parameters, such as NOx and CO emissions, at theindividual burner level. This project is a researchcollaboration between the ERC and the University ofMissouri.

! AN INTELLIGENT SOOTBLOWING ADVISOR FORCOAL-FIRED BOILERSThe ERC is developing artificial intelligence software for useby power plant operators in scheduling sootblowing at coal-fired boilers. The advice produced by the software willindicate where and when to blow slag or soot, based on anyof several possible objectives.

! DEVELOPMENT OF AN EARLY WARNING ADVISORF O R U N C O N T R O L L A B L E F U R N A C E A N DCONVECTIVE PASS SLAGGINGThe Center is developing a methodology for identifying whenabnormally high rates of furnace slagging or slag buildup inthe convective pass are beginning to occur. The objective isto develop a method of detecting the onset of a slaggingevent while there is still time to take corrective action.

! ASSESSMENT OF METHODS OF CONTROLLING AIRPREHEATER FOULING DUE TO SCR AND SNCROPERATIONSThis project is an assessment of possible solutions to the airpreheater bisulfate fouling problem. Estimates will be made ofthe costs of each approach, and their possible advantagesand disadvantages will be summarized.

! AMMONIA REMOVAL FROM FLY ASHSome coal-fired boilers, which use NH3 injection for NOx

control or flue gas conditioning, produce fly ash which isheavily contaminated with NH3, and this limits the ability touse the ash for high volume applications. In this project, ERCinvestigators are building and testing a system which removesammonia from the fly ash in a dry process.

! SENSOR VALIDATION CODE FOR CEM SYSTEMSContinuous emission monitoring (CEM) systems rely onsignal inputs from a wide variety of instruments, anderroneous data due to a malfunction of any of the inputsensors could compromise the accuracy of the CEM outputs.A sensor validation code is being developed to monitor CEMinput and output data, compare the actual and expectedvalues, and issue a warning to plant personnel when thedifferences exceed allowed values.

! INDUSTRIAL ASSESSMENT CENTERThis DOE-supported program focuses on the improvement ofenergy use and productivity of manufacturing facilities in themiddle Atlantic states. Lehigh faculty, staff and students visitthe facilities, gather and analyze energy use data and makerecommendations to plant management on possibleimprovements and savings.