4 replies to this topic

[kasiagaspar]

I have been asked to make a model simulation of a column with condenser (air cooled heat exchanger) in PRO/II. And how the ambient temperature influence on condensation (product quality of tops - we do not want heavy hydrocarbons in the top).

The question is: how to include the ambient temperature in the model?
Do i need to use Air cooled heat exchanger unit as condenser? or maybe column with "normal condenser" is enough?

[abhi_agrawa]

kasiagaspar,
The best way to go about this would be; simulate the column as a distillation column, generate a pseudo-stream from the top tray of the column (that would be stage 2 of the simulation). take this pseudo-stream and model the exchanger.

The other way would be: as the inlet temperature of air changes, the duty available for the column changes (assuming that you want to keep the air outlet temperature constant). For all you different cases, tabulate the available duties. Now develop several simulations, such that the condenser duty for the column is same as the duties you have calculated. the separation predicted by PRO-II under such a case is what you are looking for.

hope this helps,
abhishek

[kasiagaspar]

Dear abhishek!

Really thank you for your help, I hope now i will manage to solve this problem.
I do not know pro/II so well and i think i would not know that generating pseudocomponent is such a good idea :-)

Best regards,
kasiagaspar

[abhi_agrawa]

kasiagaspar
I did not suggest "generating pseudocomponent" but pseudo-streams. Pseudo-streams are (as the name suggests) ficticious streams, that can be used to get the vapor/liquid traffic in the column. Therefore for rigorous modeling of the condenser, I often generate a pseudo-stream that represents the vapor to condenser and then use it to model the condenser. Suggest you to read the PRO-II keyword manual before using this.

abhishek

[kasiagaspar]

Yes yes... i made a mistake in writing, but had this in mind what you said. I did it and it works!
Thank you one more time for your time and help!

Best regards,
kasiagaspar