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

Thermal fluid flow in pipe to work out length

Thermal fluid flow in pipe to work out length

Thermal fluid flow in pipe to work out length

A pipe has outer diameter 0.142m and has ethanol vapour with mass flow rate 108kg/s entering. The temparature of the ethanol entering the pipe is 123celsius and the temperature of the furnace surrounding the pipe is 450celsius. The pipe is stainless steel 304 and thickness 0.2mm.

How do I work out the the length of tube needed for the ethanol to reach 450celsius?

Many thanks.

RE: Thermal fluid flow in pipe to work out length

Do you know any heat transfer equations? Have you attempted to solve it?

My gut feeling is: the pipe would have to be pretty long. 108kg/s and you want your outflow temperature to reach the same temperature as the furnace... as the delta T decreases, so does the energy transfer. It's asymptotic.

RE: Thermal fluid flow in pipe to work out length

No units?? What do all the numbers mean? is Do 0.142 as you stated or 0.14241??

I'm not quite sure what you've done there...

It's a flow; did you calculate Re? Mean temp? I don't see that you've used ethanol Cp nor the flow rate at all...

Most heat exchanger problems have the outflow temp lower than the system high temp. To reiterate my first post, it's gonna have to be a long pipe since the flow temp increases at a decreasing rate...

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


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