Adjust function to control cooling water dT at 10C
Simulate chemical processes using advanced thermodynamic models
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Dear all,
I am trying to use the adjust function to control cooling water dT at 10 Celcius.
If I am not getting this wrong, my controlled parameter should be Cooling water Out T (which is 35 Celcius) while my controlled parameter should be cooling water mass flow.
Could you maybe have a look to see if I am missing a major point here.
Thanks in advance.
Regards,
Gökhan
Here is the attachment;
It worked just fine here.
Hi Gökhan,
it seems, you missed to set the "Adjust simultaneous" option in parameters section of the adjust object to "true".
Gregor
Dear Daniel,
Dear Gregor,
many thanks indeed for your dedication to support DWSim users.
@Gregor: Yes, you are right, I have obviously missed to adjust the object to true. I have done it and can see that the cooling water dT was achieved as 10 C (resulting in requiered flow) as desired.
@Daniel: Although my simulation achieves the dT, I cannot generate the same screen as you have posted above. Please find attached the screen of error I am facing here.
Gökhan
Here comes the print screen:
Are you running build 5905?
Daniel, I have just checked to make sure and the answer is; yes I am running DWSim 3.7 Build 5905.
Here is another little exercise around adjust and specification blocks...
Since I am introducing myself to logical functions of DWSim, I have tried to solve myself a case which was posted previously by Luca. According to this scenario steam turbine drives the pump, hence the power ratings should be equalized via controlling the steam flow into to expander. Although I have tried various setups I cannot get this working. I would appreciate if you could have a look.
Gökhan
Here is another little exercise around adjust and specification blocks...
Since I am introducing myself to logical functions of DWSim, I have tried to solve myself a case which was posted previously by Luca. According to this scenario steam turbine drives the pump, hence the power ratings should be equalized via controlling the steam flow into to expander. Although I have tried various setups I cannot get this working. I would appreciate if you could have a look.
Gökhan
Dear Gökhan, for your ref, find attached the complete simulation I did for the feedpump driven by a steam turbine.
Hope this could help you.
Luca
Dear Luca,
my sincere thanks to you=) Your support is much appreciated indeed!
Greetings,
Gökhan
Dear Luca,
after running your simulation I have noticed that adjust function also in your simulation gives the same error and the logic function cannot be calculated. Is this an issue just I am facing or are you expreiencing the same error?
Take a screenshot of your current solver settings.
Dear Daniel,
please find attached the solver settings screen.
Gökhan
Gökhan, I saw some error messages in the background of the previous screenshot (the one which shows Luca's simulation). Can you disable CPU Parallel Processing, re-run the simulation and paste the error messages here?
Dear Daniel, thanks for your attention! Here I send you the screen without CPU parallel processing.
Dear Daniel,
another minor point here: Everytime I close a simulation I am facing the following error. When installing the last version of DWsim (3.7) for some reason it was not possible to install it into C disc partition in my computer, hence I have installed into D partition.
If I remember correctly the reason was that some DWsim files could not be totally removed/replaced from previous installation on C partition.
Do you think this error would have something to do with it? If so I do not know into which disc partition to install the upcoming DWsim version once you release it.
Regards,
Gökhan
Actually I'd like to see the content of these error messages:
You don't actually need to install DWSIM in the Program Files folder. DWSIM can run on any folder, even on a USB flash drive, provided that you have full read/write access to that folder.
Maybe this is the root cause of all these errors you're having.
Dear Daniel,
this is good to hear. As next I will install the DWSim on a USB stick and see if this makes any difference.
Gökhan
Gökhan and Daniel.
I ran my simulation (that I built with rel. 3.4) with the last DWSIM 3.7 b5905 and I get the same error described above ('The manipulated variable does not seem to have effect ...') and the flowsheet does not converge. As far as I remember, this did not happen with the previous release.
One possible reason could be that the model relies on a script (to calculate the head of the pump as function of the flow) that uses a small library to parse the pump design in the annotation, In rel 3.4 in the General Setting it was possible to include customized paths for DWSIM to search the libraries. This option is now not included in the General Setting form and so the script get stopped (I saw the relevant errors in Gökhan's screenshot at lines 53 and 57).
Daniel, how it is possible to handle the personal libraries' path in DWSIM 3.7?
Thanks
Luca
http://stackoverflow.com/a/1372777/1771296