I have noticed an (apparent) issue with the separator object.
In later versions of your software (v6.4.7 is still fine), under certain conditions, the separator's vapor stream flow is set to zero.
There are no error messages shown, but obviously, this is incorrect.
I include an example dwxml project which shows the behaviour, as well as a jpeg indicating the contents of the 'Feed to membrane' stream.
The original "Seperator_test" project was created (by a colleague) in v6.4.7 of DWSIM.
I stripped everything but the separator and it gave the error as indicated above.
Now I created a new project from scratch (v6.6.2, Windows classic UI) and added the required objects, filename "Separator_test2.dwxml".
The problem then no longer occurs. I include this second example project with this post.
Still, there might be a problem however:
Older projects, somehow, do not appear to function correctly in later versions of DWSIM.
At least, regarding to the separator object.
For me, this issue is not that important, as we are just beginning building new projects.
I will ask my colleagues to update to v6.6.1 as soon as possible and regenerate projects using the separator... (not that many)
That may be related to the "Skip Equilibrium Calculations in Well-Defined Material Streams" option which can be found in the Simulation Settings > Basis.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
It does not help.
The latest version of DWSIM (v6.6.2, checked out today) using the project created in v6.4.7 still does not operate correctly.
Switching off 'Skip Equilibrium Calculations in Well-Defined Material Streams' results in a very long flowsheet calculation (over 1 minute) and still incorrect results (zero flow in the vapor stream).
Greetings,
Auke
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi Daniel,
I have noticed an (apparent) issue with the separator object.
In later versions of your software (v6.4.7 is still fine), under certain conditions, the separator's vapor stream flow is set to zero.
There are no error messages shown, but obviously, this is incorrect.
I include an example dwxml project which shows the behaviour, as well as a jpeg indicating the contents of the 'Feed to membrane' stream.
Can you have a look at this?
Thanks and greetings,
Auke
Last edit: Auke Nauta 2021-09-08
Additional information:
The original "Seperator_test" project was created (by a colleague) in v6.4.7 of DWSIM.
I stripped everything but the separator and it gave the error as indicated above.
Now I created a new project from scratch (v6.6.2, Windows classic UI) and added the required objects, filename "Separator_test2.dwxml".
The problem then no longer occurs. I include this second example project with this post.
Still, there might be a problem however:
Older projects, somehow, do not appear to function correctly in later versions of DWSIM.
At least, regarding to the separator object.
For me, this issue is not that important, as we are just beginning building new projects.
I will ask my colleagues to update to v6.6.1 as soon as possible and regenerate projects using the separator... (not that many)
Thanks again and greetings,
Auke
Last edit: Auke Nauta 2021-09-08
That may be related to the "Skip Equilibrium Calculations in Well-Defined Material Streams" option which can be found in the Simulation Settings > Basis.
Hi Daniel,
It does not help.
The latest version of DWSIM (v6.6.2, checked out today) using the project created in v6.4.7 still does not operate correctly.
Switching off 'Skip Equilibrium Calculations in Well-Defined Material Streams' results in a very long flowsheet calculation (over 1 minute) and still incorrect results (zero flow in the vapor stream).
Greetings,
Auke
This was indeed a bug, fixed in https://github.com/DanWBR/dwsim6/commit/20ff8331061ea9cd2a97e23992a1bd66ea1dbf65
Next time you can use the github issue tracker, Auke, it is better.
Regards
Daniel
Hi Daniel,
Thanks, it works now!
I will use the issue tracker from now on (if needed).
Greetings,
Auke
Last edit: Auke Nauta 2021-09-14