Drawing of the vapor-liquid phase diagram for helium and air
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This post was last edited by Hidden in on 2021-7-13 08:16. I have a question: how to draw the vapor-liquid phase diagrams for helium and air? The diagrams I created seem to have issues, and errors appear as well; I don’t know how to deal with this. This is my first time working with Aspen, and I hope the experts here can give me some advice.
Based on the hints, there is an extrapolation in EOS, and the result may be incorrect. What equation did you choose? Since it is a vapor-liquid phase diagram, at the corresponding T/P, a vapor-liquid two-phase flow must exist. At 1 atm, it should be possible to liquefy it at extremely low temperatures, but the cost is too high.
I used the PR method to simulate the two-phase diagram of helium in liquid air. Is the reason for the error that two-phase flow does not exist under this method? Thank you!
There should be a two-phase flow; are your property equations correct?
What are physical property parameters? Dew point temperature?
Property values generated automatically by the system after the phase diagram is created
It is likely due to unreasonable values of the binary parameters; this requires consulting relevant literature in order to modify those parameters.