How to choose this physical property method?
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A non-conventional component is mixed with water vapor, and then part of the water is separated by a separator. May I ask what physical property method is better to use in this process? At first, I used the RKS-BM method, as that was the method I employed for the entire simulation. Later, I felt it might not be the most suitable choice, given that water was involved in this scenario; so I wasn’t sure whether the RKS-BM method or the STEAM-TA method would be more appropriate for this case. Thank you very much
It is recommended to use RKS-BM; after all, STEAM-TA is only more accurate for water, and when unconventional components such as coal or biomass are involved, the accuracy of these properties can be quite low
Thank you. But when defining this unusual physical property, I specified its enthalpy. In this case, what is the difference between using RKS-BM and STEAMS? Because the entire process involves only heat exchange, and the non-conventional material properties have already been specified. The description is unclear; please forgive me
STEAM-TA is essentially a steam table; properties of incoming water and steam, among other things, need to be calculated using such a steam table. ASPEN PUS also provides several other types of steam tables, which are generally quite accurate. For unconventional components, namely the so-called Nonconventional components, if you define such components, ASPEN PLUS does not calculate their mixing enthalpy and the like for those components as well as for water components; therefore, only the STEAM-TA property method is required. There is no impact between the two methods, as the physical properties of water and steam need to be calculated using steam tables, whereas the calculation model for nonconventional components is very simple and does not involve calculations such as mixing enthalpy.
Reply to 2# laipi*ao*n: Steam tables can only be used to calculate the properties of water; they cannot be used to calculate the properties of any other components.
Reply to 3# grechenjie: There’s no difference; if you don’t believe it, you can make a comparison
I gave it a try, and there was still a difference. What I do is dry the nonconventional components using steam. If I use the STEAM-TA method, the results will be different from those obtained using the RKS-BM method. And if I use the STEAM-TA method, I won’t get a situation where some of the water is in liquid form and some is in gas form. So now it has been changed to the RKS-BM method; I’m not sure if that’s correct
By the way, if I use the STEAM-TA method, unless I specify that the nonconventional outlet should be set to LIQUID ONLY, the water at that outlet will be in liquid form; otherwise, all the water at that outlet will be in gaseous form, and it won’t be possible to achieve the goal of drying part of the water