distillation bug

Discusses use of COCO, the process simulation and modelling software suite from AmsterCHEM, downloadable from www.cocosimulator.org

Moderator: jasper

Re: distillation bug

Postby jasper » 06 February 2019, 15:03

There's a unit conversion error - looking into it.
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Re: distillation bug

Postby aken » 06 February 2019, 20:33

Ok, thank you
aken
 
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Re: distillation bug

Postby jasper » 08 February 2019, 10:42

The issue is resolved, but to get it to work, you will need to
- download the new ChemSep
- edit the unit to remove the Bottoms Flowrate input variable
- then edit the unit again to add the Bottoms Flowrate input variable; now it will have units

Then hook up the controller. I am attaching the solved problem.
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BENZENE PRESSURE SWING CONTROLLED.fsd
Solved with controller
(35.75 KiB) Downloaded 33 times
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Re: distillation bug

Postby aken » 17 February 2019, 07:18

downloaded the latest chemsep, it will run individually but gives an error on coco
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error.PNG
error.PNG (6.37 KiB) Viewed 494 times
aken
 
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Re: distillation bug

Postby jasper » 17 February 2019, 09:37

I am guessing that you replied to "Do you want to overwrite registration of existing installation" you replied no, and then you uninstalled the previous version.

Either re-install (and choose yes in case it is asking to register for CAPE-OPEN interop), or use register.bat in the bin folder of the ChemSep installation folder to re-register the CAPE-OPEN binaries for interop.
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Re: distillation bug

Postby aken » 19 February 2019, 05:31

I knew the feed parameters and the required product purities, B1 and B2. l then guessed the recycle parameters of stream REC1 and carried out the simulation. after converging the simulation D2 flowrate (ultimate recycle stream) was different from REC1. I then re-guessed the REC1 flowrate, and all hell broke loose, as it wouldn't converge, l guess due estimates of the controllers, not sure. for example l put 190 kmol/h for REC1, and it wouldn't converge. is there any tricks for problems with recycle streams or any different approach from this one.




kind regards,
Akan
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BENZENE PRESSURE SWING CONTROLLED.fsd
(48.68 KiB) Downloaded 16 times
aken
 
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Re: distillation bug

Postby jasper » 19 February 2019, 06:44

I am a bit confused, as when I open this case I see again that the bottoms flow rate parameter has no unit of measure, for either of the columns. How did this happen? Did you start from the document I sent you and are you using the updated ChemSep?
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Re: distillation bug

Postby aken » 04 March 2019, 05:40

for people with same question l managed to solve it!
Attachments
BENZENE PRESSURE SWING CONTROLLED uniquac.fsd
(47.51 KiB) Downloaded 10 times
aken
 
Posts: 32
Joined: 18 December 2018, 06:02

Re: distillation bug

Postby aken » 04 March 2019, 05:40

for people with same question l managed to solve it!
Attachments
BENZENE PRESSURE SWING CONTROLLED uniquac.fsd
(47.51 KiB) Downloaded 12 times
aken
 
Posts: 32
Joined: 18 December 2018, 06:02

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