Heat-Recovery Steam Generators: Issue #3

Take control of your SCR catalyst management
Combined- and simple-cycle gas turbine (GT) systems typically rely on SCR catalyst to reduce NOx emissions. In a combined cycle, GT exhaust gas usually flows through one or more HRSG tube banks before entering the SCR catalyst. Ammonia, a reagent, is injected ahead of the SCR, where it combines with oxides of nitrogen in the exhaust gas to form nitrogen and water vapormore 

User alert: Rare leading-edge crack found in 7FA R0 blade just above the platform

GE Power & Water has issued hundreds of technical information letters, or revisions thereof, concerning its F-class gas turbines since the first unit in this model series, Dominion Virginia Power's Chesterfield 7, began commercial operation in June 1990. One of the TILs most frequently referenced by users is 1509, "F-Class Front-End (R0, S0, and R1) Compressor Inspections," now in its third revision (R3). The goal of this advisory is to help owner/operators maximize unit availability and reliability through regular comprehensive inspections. more
TIME'S UP: Register now for the 501F, 501G Users Groups meetings, Feb 16-20
If you're an owner or operator of 501F or 501G gas turbines, the 2014 conferences of the independent, all-volunteer user organizations supporting these engines likely are the most important industry meetings for you to attend this year. The F and G users will meet concurrently at the Westin Mission Hills Resort & Spa in Rancho Mirage, Calif, February 16 - 20. more
Clean fouled HRSG tubes, increase revenue
Gas-side deposits and corrosion of HRSG heat-transfer surfaces are inevitable and are a common cause of reduced steam production, low steam temperatures, and degraded gas-turbine performance. These effects contribute to reduced electricity production and lost revenue. Thus it makes good business sense to include removal of HRSG gas-side deposits in your plant's annual maintenance program. more

New NDE tools facilitate in-service evaluation of P91 condition

The materials traditionally used in powerplant piping systems, such as P22, served well at the nominal 2400-2800-psig/1000F-1050F steam conditions that dominated in coal-fired utility generating facilities from about the late 1950s through the mid-1990s. But the trend to more efficient plants-both conventional steam and combined cycles-required materials capable of operating at higher pressures and temperatures and of accommodating the faster startups and load changes demanded by grid operators in the must-take renewables era. more 

Recommend a worthy colleague for CCUG's 2014 Individual Excellence Award
The Combined Cycle Users Group (CCUG) recognizes individuals for outstanding achievements in all areas of combined-cycle power production. The organization's Individual Excellence Award is presented annually to industry professionals who have demonstrated excellence in the design, construction, management, operation, and maintenance of CCGT facilities throughout their careers. more
Ultrasonic flowmeter differentiates between water and steam in HRSG drain lines
Improperly specified, designed, and/or installed drains continue to support welders and aftermarket suppliers of SH and RH harps, headers, and tubes despite years of discussion at user-group meeting regarding the origin of the problem and appropriate corrective action. However, ongoing work sponsored by EPRI is expected to finally help owner/operators protect their HRSGs by providing positive indication of condensate-free heat-transfer panels and drain systems prior to plant startup. more

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