Partially Burried Pipe Heat Transfer Coefficient 2

[ColourfulFigsnDiags]

Hi all,

I am trying to calculate the overall heat transfer coefficient for a PARTIALLY buried pipe ... say 1/3rd buried by sand / soil and the remainder open to the air or water.

I can find a few resources for calculating this for fully buried pipes at various depths, but what about PARTIALLY buried pipes? Any ideas?

Thanks in Advance!
CFD

Read the Eng-Tips Site Policies at FAQ731-376

 

[IRstuff]

Wouldn't the 1/3 that's buried behave like a buried pipe, and the remainder convects or conducts to whatever medium is covering it?

TTFN

FAQ731-376

 

[ione]

ColourfulFigsnDiags,

You have already received a valid answer from IRstuff.
Further to the heat transfer coefficient you can consider a weighted average of the fully buried pipe and the exposed pipe.

The attached paper could give you interesting inputs.

 

[MortenA]

IMO then for a partially buried pipe you will be fine disregarding heat loss through buried section (at least when its under water). The ehat loss thorugh the esposed pipeline will be much larger than through the soil - and the soil can therefore be disregarded.

Then all you have to do is calculate the effective free area and use whatever correlation you normally use for this.

I know that the formula normally would assume free flow around a free pipeline - and that this is not entirely the same her - but i think its OK.

Best regards

Morten