×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Segmented Fin Air-Cooled HEX

Segmented Fin Air-Cooled HEX

Segmented Fin Air-Cooled HEX

(OP)
Does anybody have any experience split fin or segmented fin air coolers?  It's also called High Performance or Wheelfin depending on the manufacturer.  Basically the fin is a regular L-tension wound aluminum fin with a notch cut on the outside edge to increase air turbulence and help heat transfer.  

How well does this work?  The thermal designer of a particular air-cooler has stated that use of this type of fin makes approximately 20% to 25% difference in the overall heat transfer for this particular application.

  

RE: Segmented Fin Air-Cooled HEX

Dear Aggie,

Please take what I say here with a very large block of salt.  I have been working with air-cooled exchangers for about 25 years or so, and have developed various opinions based on the mythologies of the people with whom I have worked.  Some mythologies have turned out to be much better than other in the long run.  So much for the disclaimer.

Here's what I believe.  These kinds of "enhanced" fins are little more than a smokescreen for intentionally undersizing coolers.   While there might be a slight increase in air-side performance, it would be at the cost of additional static pressure across the tube bundle.  Increased static means incresed fan horsepower.

In a "normal" air cooler, there is uaually an approximate balance between the fin-side thermal resistance and the tube-side resistance.  That is, they are approximately equal when evaluated on a similar basis (either finned or bare surface).  Therefore, in order to increase the overall heat transfer coefficient by 25%, the air-side coefficient would have to be doubled.  In my opinion, this is too fantastic to be credible.  The secondary effect of some kinds of "enhanced" fins is to make the fins really good filters by greatly increasing the places where any airborne materials will be caught in the fins.

I am told that there are some manufacturers whose normal policy is to undersized coolers by as much as 20%.  They probably work fine until the ambient air temperature gets as high as the design point.  It's only then that the end user begins to notice a problem with performance.  

Other people will have different opinions, I am sure.

Regards,

speco (www.stoneprocess.com)

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources