Heat Recovery Steam Generator Tube Leak

[raveney]

Hello all,
Wanted to share what a "modern" steam boiler tube looks like. They are very thin compared to coal boiler tubes because they have much less heat input. The tubes pictured had failed because of u-bolts that hold gas baffle plates became loose. These tubes are midway back in the heat recovery steam generator, HRSG, which captures the waste heat or exhaust from an industrial gas turbine. It is only about 650 F where these tubes are located in the horizontal gas path, so they make intermediate pressure steam. they are 2.00" carbon steel about 0.109 thick. Note the fins that pickup and transfer the exhaust heat to the tube. The bottom one was the reason we shut down and made repairs, but one can see why we replaced the others proactively. Short sections of the tubes were cut out and replaced using TIG. Difficult time consuming process because of very limited access where this leak occurred.
Because of this leak and 24/7 repair three weeks ago, I get to take some time off this week to work on my Muncaster Joy steam engine replica

 

[olf20]

Very interesting! Thanks for sharing.
olf20 / Bob

 

[Zeb]

Very interesting, and a clever way to recover some of that lost energy. I've seen a nylon zip tie almost saw through a stainless FCU line. I would gather it didn't take long to produce that wear once the clamps came loose.