Fin Heat Transfer

[kocha]

Hello everyone,

I have I project that I am working on which involves heat transfer. I am quite conflicted and would greatly appreciate your input.

The setup is the following: There is hot water being pumped through a rectangular aluminum tube. The tube is surrounded by constant temperature cold water. Would welding aluminum rectangular thin plates (fins) inside the tube be an effective form of increasing heat transfer efficiency?

In all class exercises I ever solved, the fin was attached to a hot surface and convected heat to the atmosphere. In this case, the convection happens with the hot surrounding water and the heat is escaping through conduction.

Is this exactly the same as the usual fin problems and my brain is just fried?
Thank you!

 

[IRstuff]

Fluid is as fluid does. Heat transfer is about the movement of heat through fluid transfer, be they gases or liquids. The major difference is the convection coefficient magnitudes and whether there's any boiling involved.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[NRP99]

It would be better to understand basic concept behind using "fins".

"Fins" actually accelerate heat removal from high temperature heat source to cold temperature source in a way to attain thermal equilibrium condition - both sources at same temperature. How is this achieved? By conduction heat transfer through fin (not much) + convection heat transfer from fin to outside fluid (by increasing the surface area, the convective heat transfer (Q=h*A*ΔT) is increased from the fin surface (which gats heated due to attached to high temperature source) to low temperature source.)

Now, the amount of heat transferred from fins to low temperature source is depend on the convection coefficient of fin surrounding fluid (h) and heat transfer area (A) of fin. If the fin is attached to inside of rectangular tube, it may not be efficient way to remove heat it since fin is exposed to high temperature fluid the heat transfer coefficient might be less although the area is increased. If the fins are attached to outside surface, fin will be exposed to cold temperature and heat transfer coefficient might be high along with the increased surface area.

You can compare heat transfer rate from both cases and decide whether using fins inside or outside is effective.