HEELP !! safety Tubes ( double wall)
HEELP !! safety Tubes ( double wall)
(OP)
Hi there !!
How can I calculate with HTRI an exchanger with double wall tubes. It's practically a safety exchanger with a OD 19.05mm ( ID 14.5 mm) 19 FPI copper tube on the outside and 1 OD 14mm tube on the inside (ID ~12 mm)?
Hoe can I simulate such a tube ? (Let's say that:
in the intermediate chamber there is compress air)
Thank You in ADVANCE
How can I calculate with HTRI an exchanger with double wall tubes. It's practically a safety exchanger with a OD 19.05mm ( ID 14.5 mm) 19 FPI copper tube on the outside and 1 OD 14mm tube on the inside (ID ~12 mm)?
Hoe can I simulate such a tube ? (Let's say that:
in the intermediate chamber there is compress air)
Thank You in ADVANCE





RE: HEELP !! safety Tubes ( double wall)
RE: HEELP !! safety Tubes ( double wall)
TTFN
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RE: HEELP !! safety Tubes ( double wall)
By considering the air a pure conductive medium, I should consider it like a tube with a thickness of 19.05-12 =3.5 mm with a resistance due to the sum of (2.5/K(copper) + 0.25/K(air) +1/Kcopper) or more simply 0.25/K(air).
RE: HEELP !! safety Tubes ( double wall)
TTFN
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RE: HEELP !! safety Tubes ( double wall)
Since the pressure will be at around 15 bar.
Since the conductivity is very low, this could be a relevant step in the right direction !!
Thank you very much for the tip !!
Do you know where I could find a table with these values ?
Thank you very much !!
RE: HEELP !! safety Tubes ( double wall)
the temperatura will be around 40°C
RE: HEELP !! safety Tubes ( double wall)
THe tube is finned with 19 FPI geometry. the conductivity value that i'm going to insert will not "interfere" with the parameters of the finns ( which are in copper). I mean it has sense simulate the air just changing the conductivity values , or it's a too rude approach ?
Thank you in advance !!
RE: HEELP !! safety Tubes ( double wall)
I don't do much with gas properties, but NIST has a database somewhere with that information:
http://www.nist.gov/srd/WebGuide/nist72/72.htm
http://srd
Engineering Toolbox might have something:
http://ww
TTFN
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RE: HEELP !! safety Tubes ( double wall)
THe question is how it will behave externally with the new fins?
Thank you very muche for the tip for the series !!
RE: HEELP !! safety Tubes ( double wall)
for fins between the two tubes, you would simply determine the thermal conductivity of the fins and add to that the thermal conductivity of the air between the fins. If there are a lot of fins between the tubes, you might be able to ignore the air altogether.
TTFN
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RE: HEELP !! safety Tubes ( double wall)