Shell & Tube Heat Exchanger - With Copper / SS Tubes

In the US, using copper is starting to be a no-no for heat exchangers, I think primarily due to water quality issues with copper leaching into the water. But to answer your question, take a look at the following:

Copper k value = 400 W/m*K

316 Stainless = 13.4 W/m*K

All else being equal, the heat transfer rate will reduce appx. a factor of 30, only considering the conduction form of the system. Typically, at least in nominal sizing work that I have been involved in, the conduction term is usually ignored by the overall heat exchanger sizing as one of the convection terms in the equation dominates the heat transfer coefficient. In other words, I couldn't really answer your area question with the info provided.

Agree with betomachine.

With the assumption "all else being equal except Convective Heat Transfer Coefficient and Area", you will have to increase your surface area by a factor of approx. 30 in order to achieve same heat transfer state as copper.

factor of 30 means

if i am using 5/8" OD x 22SWG x 100Nos. of Copper Tubes in a heat exchanger having a specific heat transfer, then i have to use 130nos. of 5/8" OD x 22SWG SS316 or SS304 tubes.

is it true?

In this case, you will require to use 3000 number of SS316 tubes given by the assumptions from previous thread.

q = h_conv x (A) x (ΔT)

h_Copper / h_ss316 = A_ss316 / A_Copper

30 = A_ss316 / A_Copper

30 x A_Copper = A_ss316

Are we missing what Beto said ? Though we have agreed (and I too do)

The conductive transfer infact is much lower with reference to the convective.

In our normal sheel and tube HE, we use Admiralty Brass Tubes (of course with a much lower coefficient) with steel fins. These fins are used to break the stream line flow of the media and create better convective heat transfer.

Please note the thickness of the tubes by themself will not be able to have so much effect on the rate of transfer as the oil(insulator) or the water (coeff much less than the steel) so the effective transfer largely governed by howmuch fluid you can bring in contact with the transfer wall.

In fact in one of our case, the heat transfer was low due to much crossectional area in and outside tubes hence streamlined flow inside and outside, heat transfer was very low. Blocked some area and it dramatically improved.

Agreed..

In fact that fins also create larger surface area for heat transfer..

Hey guys I am very bad at electronics but still I am working on a project and I would really appreciate your help.Thanks
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