This is a composite thermographic image of a hot air duct running from an industrial Gas Turbine on the left to a heat recovery boiler on the right that I’ve just taken. At the moment a valve in the GT is closed so there should be no flow through it and the whole pipe typically 50 to 80 degC. We’re a bit stumped how the boiler end could be quite so hot, likely some kind of external heating and conduction although there are no obvious heat sources.

Not after troubleshooting advice, we’ll do an internal inspection if necessary, I just thought it was a cool visualisation of an infrared thermography survey some of you might appreciate.

I imagine that’s a similar image to my guts an hour after a phaal, rapidly cooling one end and red hot ring at the other

I imagine that’s a similar image to my guts an hour after a phaal, rapidly cooling one end and red hot ring at the other

Get yourself on Grindr looking for a snowman.

Yep, nothing like swallowing in iced cream chaser.

😮 Not quite sure what kind of replies I was expecting to my post, but I am quite sure it wasn’t that! 🤣

A literal twist.
A panoramic inside my favourite building in Oxford. Hand held and shot on a 24-70 and auto aligned in Lightroom.
The cropped original is 5,470pxx18,446px and the shot of the cobwebs shows the degree of detail available.

A detail of the painted roof structure

The cropped original is 5,470pxx18,446px

My thermography camera is 480×640 – and that’s quite a high res one!

You probably don’t get the chance to stand back and then stack a load of images.
I’m sure my camera would probably be melting doing your stuff.

My thermography camera is 480×640 – and that’s quite a high res one!

I’ve had a FLIR C2 from work for a while, it’s really interesting and/or useful for home efficiency, wiring, plumbing, all sorts of things. It overlays the IR image on a visible light image so you don’t tend to notice the resolution until you’re taking pictures in the dark, then it’s very obvious that a resolution of 80×60 is not very much 🙂

Is it possible that the GT valve has been closed for a while and the ducting, not having much mass, has cooled quite quickly? The HR boiler however, being more massive, has heated up and is releasing the heat much more slowly, and therefore is conducting heat back into the duct and warming it up, and maybe also releasing hot air backwards towards the turbines, thus also giving a heat signature.
What temperature would the boiler end usually be running at with the GT running and the valve open?

Boiler inlet temperature is 570 degC, but I don’t think that temp is right ‘there’ next to that flexible bellows. Not entirely sure how it’s constructed, but there is a second identical duct on the other side of the machine and that’s about 80 degC at the hot end.

I reckon theres a leak impinging on it internally which is conducting through, there’s a history of structural cracking in the area because it’s an old plant which suffers a lot of temperature cycling that it was never designed for. Like I say the easiest diagnosis will be getting inside for a look – once it’s cool!