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!

*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.

Jobs

Heat exchanger duty in upset case

Heat exchanger duty in upset case

(OP)
I have a heat exchanger with a PSV on the cold side. My scenario is control valve failure on the hot side sending more hot fluid via the exchanger than is quoted on the data sheet.

Is there a simple way for me to estimate worst case heat transfer rate to the cold side for this scenario?

Thanks.

RE: Heat exchanger duty in upset case

There are two ways I can think of:

1) Use heat exchanger software (e.g. HTRI or Aspen EDR), option "rating" for the exchanger with known geometry and fluid properties/flowrates. The software will estimate outlet temperatures for both fluids and hence the new duty point.

2) Calculate how much the overall heat transfer coefficient increases (as compared to the base case) when one side of the exchanger sees higher flow. Although the LMTD will also change in this case, the increase of the overall U should give you some estimation - a figure at least being in the same order of magnitude as the real one.

Dejan IVANOVIC
Process Engineer, MSChE

RE: Heat exchanger duty in upset case

20:22 -> 20:31 nine minutes to read the post, think about and give a detailed answer...
that' really amazing !

RE: Heat exchanger duty in upset case

I've been good with quiz and puzzles since my earliest childhood.

Dejan IVANOVIC
Process Engineer, MSChE

RE: Heat exchanger duty in upset case

When estimating the exchanger duty be aware, at least in the refinery world, that design exchanger duty uses the DIRTY service U factor. For PSV sizing the clean U must be calculated and used.

I've never seen an abnormal heat input case for an exchanger like you are describing... usually we only consider isolation of the cold side with continued heat input, which we would do a PRO/II rigorous exchanger model to estimate duty.

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


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