COFE Unit Operation in Aspen Plus

[CamiloC]

Hello,
I have a Matlab unit op in a COFE flowsheet, which is in turn in an Aspen Plus v8.6 flowsheet. I have connected Aspen Plus streams to the COFE UO and my Matlab unit is calculating product streams properly in the cofe environment based on the Aspen Plus feed. However, Aspen Plus isn't pulling these results for some reason. What can I do to fix this?

[jasper]

I understand the COFE flowsheet is a unit operation inside an Aspen Plus flowsheet. And if you solve the Aspen Plus flowsheet, the product streams in the COFE flowsheet are not transferred properly to the COFE unit operation's products in the Aspen Plus flowsheet. Correct?

Are there any error messages for the unit operation, or does Aspen Plus indicate that the unit operation ran ok?

[CamiloC]

Hi Jasper. Yes, you are correct. Aspen Plus does give an error message but I can't make sense of it, I'm attaching a screen cap of it.

[jasper]

It appears that COFE wants to transfer the information using a PH flash; I guess that this is a pure compounds stream (else COFE would use a TP flash); to do so, it must set enthalpy on the Aspen Plus stream and this fails. With an invalid argument.

The arguments to the enthalpy call - on my end - appear correct however. Would you be so kind to make a log of this issue to see what the traffic between COFE and Aspen Plus is like? To do so, please do not insert a COFE unit operation into Aspen Plus, but rather insert a COULIS unit operation (presuming you have installed OATS with COCO; COULIS is part of OATS). This will have you select a unit. Select a COFE Unit Operation, and proceed as before. When you quit Aspen Plus, you will be prompted for where to save the log file (*.olg).

Alternatively, you could use the CAPE-OPEN Logger and Testing Tool (COLTT), available from CO-LaN, http://sourceforge.net/projects/cape-openloggin/

Using COLTT you can log with the existing document, you just have to tell COLTT to log unit operations of the type COFE Unit Operation before starting Aspen Plus.

[CamiloC]

Yes it is a pure stream. I ran the COULIS UO but can't attach the file on the forum. It doesn't accept this extension. Is there another way I can show it to you? Thank you for your help

[jasper]

You can hit Upload Attachment (below when you write a reply), or perhaps just drop it in my e-mail. Thank you.

[jasper]

From the log you sent me, it appears the problem is on the COFE side. Would you be so kind as export the flowsheet that defines the unit operation, and send me the fsd file?

[jasper]

The problem is fixed. Please obtain the fix via COCO Update (CUP).

Also make sure to get a new copy of the Matlab CAPE-OPEN Unit Operation; a fix has been made here that prevents loading if \b characters appear in the Matlab output, which appears to be the case for Matlab 8.4 upon errors.

[CamiloC]

It all works now. Thank you, Jasper. I sincerely appreciate your help.

[jasper]

You are welcome - glad to hear that it works. Thank you for providing the logs.