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isobar on t-s diagram

isobar on t-s diagram

isobar on t-s diagram


I am trying to make a program, that is going to draw a t-s diagram with the isobars of my choosing.
i'm able to calculate the isobar for the vapour dome region and superheated region. However the subcooled liquid zone is troubling me.
First picture the isobar stops and follows the saturated liquid line down to the left?

Second picture it does not lay on-top of the saturated liquid line.

Using free online IAPWS R7-97 calculators, i am getting graphs where the isobar is on top of the saturated liquid line. I am now not sure what is exactly correct.
If it would be rather like the second picture, how can i define these points. Lets say i know the temperature and pressure, what calculation could tell me the entropy?

best regards


RE: isobar on t-s diagram


Thank you so much for this insight. I had no idea IAPWS made a new formulation 2020, or is it not from the IAPWS?
The excel AddIn(there would be no c++ or c# code for this also?, maybe it's asking to much :) ) could be very useful, do you have a list of all the functions it has etc? And possible what units it requires and gives as answers?

Anyway, thanks already!

RE: isobar on t-s diagram

Oke i get it, perfect found the .lib files, however is it possible these are not yet updated with the "steam 2020"?



RE: isobar on t-s diagram

Yes i see, but there are no .lib files in there. Anyhow it's not that important, you more than answered my question, thank you! :)

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