×
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

Relief rate for liquid nitrogen

Relief rate for liquid nitrogen

Relief rate for liquid nitrogen

(OP)
Would someone recommend the solution or criteria for calculation of relief flow rate to size the thermal expansion valve, fluid is liquid nitrogen in one metre of 2" stainless pipe with SIVL insulation. In case of the failure of insulation, temperature of fluid will be higher, let say 50 degC. I mean what equation shall i use to find the answer for the above mention. Please help and give advice.

RE: Relief rate for liquid nitrogen

sujins:

There are some facts that you are not stating and another that doesn't equate to what you are stating:

1) I assume you are dealing with Liquid Nitrogen (LIN) in the saturated state; if so, then you have no case for liquid thermal expansion.  What you have is is the potential for LIN vaporization once its latent heat is absorbed through the insulation.  You will probably have two phase flow through the required PSV.

2) How is it that you can have LIN at +50 oC?  Either you've made a major typo or you have a very exotic liquid Nitrogen.  Once the LIN starts to vaporize - and it will do so very, very quickly - you will have a mixed phase within the short span of pipe.  The insulation doesn't have to fail, as such.  Heat will eventually leak in to vaporize the LIN that is blocked in (you haven't said this either, but the LIN has to be blocked in, right?).   What you have on your hands is a heat leak calculation that will determine the rate of LIN evaporation.

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