Contact US

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!

*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

Air Fan Coolers

Air Fan Coolers

Air Fan Coolers

API RP 521 Section3.15.7.2 This section refers air cooled exchangers in condensing service.  An alternate heat flux value of 12,000 is given to use in place of the standard value of 21,000.  Is this value only good for condensing service exchangers?  Or can it also be used in a liquid sub-cooling service.

Section 6.3.4 refers to fan power failure on an air fan exchanger.  If I have temperature switches on an air fan, which shut down the motors on high ambient air temperature, can I take credit for cooling due to natural convection, during a fire relief scenario?  This paragraph indicates that 20% - 30% cooling can be maintained when the fan is off.  Does this refer to condensing only, or could I take credit for this in liquid sub-cooling service as well?

RE: Air Fan Coolers

API RECOMMENDED PRACTICE 521 - Guide for Pressure-Relieving AND Depressuring Systems.

API Standard 661 - Air Cooled Heat Exchangers???

RE: Air Fan Coolers

Air cooler can also subcool...

In case of power failure, air cooler can do it's job by 20-30 % duty.
Now this has to be done in a new calculation, better if you have simulation package, do a new simulation with duty 25% and get outlet condition for the power fail case.

Hope your query is answered...

Samuelliu : ag92 is not wrong and you are also not wrong....

RE: Air Fan Coolers

I understand that the code gives you some credit for natural draft cooling on a fan failure.  However, I have a hard time seeing how this is applicable in a fire case, since your ambient air temperature will be much higher than normal.

RE: Air Fan Coolers

In fire case: You can consider fire upto the height og 25 ft only. So in case of fire, you will not have any cooling... and if you can let me know which case you are considering.

You cannot have two unrelated cases. So fire is one case and loss of cooling is another case.

Further to this, you need to do fire ball analysis. You cannot have all vessels under fire simultaneously. I am sorry I won't be able to help you on this issue.

Best Regards,

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close