CCJ Archives: 3Q 2008

How clocking of compressor blades may impact wear in some vane rows

Have you ever thought about why people remember you, and how little what they remem­ber you for might reflect about your professional abilities?

An example: Many graying read­ers probably recall Bowzer, the gan­gly greaser of Sha Na Na, a popular rock ‘n’ roll band of the 1970s and 1980s. more

Clean heat-transfer surfaces inside and out to keep HRSGs at peak efficiency

Virtually everyone who works in a powerplant knows that clean heat-transfer surfaces are criti­cal to achieving the low­est possible heat rate. In combined-cycle plants, the heat exchangers having greatest impact on perfor­mance are the heat-recovery steam generators (HRSG) and condensers. This arti­cle is about the former. more

Learn the basics of HRSG inspection

The global economic downturn will impose new challenges on plant operations. It’s difficult to believe that you will be asked to do more with a smaller budget, but you will. However, approaching these new challenges with a positive mindset can yield significant ben­efits. One might be that your junior staff is forced to learn more about power-generation processes, equip­ment, and systems, thereby increas­ing the level of expertise onsite. more

How to verify proper operation of bypass, spray-water valves

Steam-turbine bypass sys­tems are used in combined-cycle plants during startup, shutdown, and load rejection. The most common arrangement, shown in Fig 1, allows plant opera­tors to route high-pressure (HP) superheated steam through a pres­sure control valve/desuperheat­er station to the cold-reheat line, thereby bypassing the steam tur­bine’s HP cylinder. This typically is referred to as the “HP bypass.” more

CDMS helps prevent forced outages, tune engine after overhaul

Most gas-turbine (GT) users familiar with dry low-emissions (DLE) com­bustion systems have heard the acronym CDMS, short for combustion dynamics monitor­ing system. This certainly sounds important, and it is. But the term “combus­tion dynamics” and what it means to GT owner/opera­tors often is not well under­stood at the plant level. more

‘Leave no stone unturned’ when developing O&M contracts

By Jeffrey J Fassett, PE, IEM Energy Consultants Inc

Structural changes to the elec­tric power industry over the last decade or so have made asset owners more willing to pay third parties to assume roles they themselves once held exclu­sively. The underlying reason typi­cally is risk mitigation. Some gen­erating facilities are now owned by one company (or a consortium), operated by another, managed by another, with major maintenance performed by yet another or others. more