Calculation Formulas in Hysys

[phamnhatminh]

Hi all. I am looking for some formulas to calculate the Cv, Cp, Heat Capacity(kJ/kG-C),Molar Volume,... with multicomponent in Hysys.
Please help me....

 

[EmmanuelTop]

You need to get a hold of the famous "Properties of gases and liquids" by Prausnitz, where several methods are presented and discussed. One university has the e-book available online:

https://uqu.edu.sa/files2/tiny_mce/...00270/al./Properties of Gases and Liquids.pdf

See also

http://booksite.elsevier.com/9780080966595/content/Appendices/Appendix C.pdf

Dejan IVANOVIC
Process Engineer, MSChE

 

[phamnhatminh]

Dejan IVANOVIC
Thank you... I try to find some formulas to calculate in Hysys because I dont know why does it calculte like that?

 

[EmmanuelTop]

The formulas originate from the fluid package (equations of state) you select for the model. The book I referenced to is one of the most recognized resources on the subject.
You can also look in the Hysys thermodynamics file and find the basics there - see section 2 and addendum A in

https://www.ualberta.ca/CMENG/che312/F06ChE416/HysysDocs/AspenHYSYSSimulationBasis.pdf

For any queries, you can always contact ApsenTech support team.

Dejan IVANOVIC
Process Engineer, MSChE

 

[phamnhatminh]

Dejan IVANOVIC
Thank so much.Does it difficult to calculate by hand, I mean by hand calculator? Because I think that It is so complex.
Thanks

 

[EmmanuelTop]

And based on what you have this opinion if you haven't seen the equations?

These values are definitely easy to be computed by a pocket calculator or (even better) in Excel spreadsheet.

Dejan IVANOVIC
Process Engineer, MSChE

 

[phamnhatminh]

Dejan IVANOVIC
I am a student,I study Hysys by myself, so I am looking for a formula to calculate a steam : Componetn: CH4(100%), Temperature = 500k, Pressure= 10 atm, Molar Flow =100 kgmole/h,PR Equation Of State...How can I calculate all of the others remain paraments (Cv, Cp, Heat Capacity(kJ/kG-C),Molar Volume)..? Help me!!!
Thank you

 

[EmmanuelTop]

You are a student but that doesn't mean you don't have any brains at all - see the links in my first post. You can find calculation methods there. I'm not going to read the book for you.

Dejan IVANOVIC
Process Engineer, MSChE

 

[phamnhatminh]

Dejan IVANOVIC
Thank you, I am trying with my exercise. I believe that I can do it. Thank again....

 

[georgeverghese]

All these properties you mention are generated automatically in the stream properties list by Hysys - of course you can verify it by hand calcs if you need to, but it may be very painful if you are looking for high accuracy, and you need a good handle on binary interaction parameters that influence these properties. In some very high pressure applications, believe this is done to get higher accuracy ( ethylene compressors for example). At 10bar, dont think you need to run hand calcs, the Hysis results should be good enough.

 

[MortenA]

There are two thing to what a process simulation tool like hysys does,

Theres the EOS (or in this case a selection of EOS's and then theres the flash engine, a solver that findes the equilibrium of a given mixture of components (that must be defined) at a given pressure and temperatur (or another set of defined values that makes it possible to solve for the missing).

You can replicate the calculation by hand and most college text book omn the subject (e.g. Smith and Van Ness Introduction to Chemical Engineering Thermodynamics, 7th Edition 7th Edition should be a good introduction to the subject. If you can self study this book i wont comment on but it takes some knowledge of chemistry and math up front).