Re: [dwsim-users] Shortcut Distillation: DWSIM 3 vs DWSIM 4

[Hector P. <hpe...@gm...>]

Edit: I fixed the NaN by making sure the reflux ratio is greater than the
min reflux ratio. Still don't see why DWSIM 3 and 4 don't agree.

Hector D. Perez

On Fri, Jul 29, 2016 at 9:08 AM, Hector Perez <hpe...@gm...> wrote:

> Hi Daniel,
>
> I have set up shortcut distillations for a Sulfuric Acid - Nitric Acid -
> Water system. However, I am getting very different results depending on
> which version of DWSIM I use. I have checked that my settings are the same
> in both simulations (NRTL constants and Inside-Out VLE flash algorithm).
> DWSIM 3 predicts 21 minimum stages, whereas DWSIM 4 predicts only 3 stages.
> I am running with a issue in DWSIM 3: it is not predicting the actual
> number of stages (only predicts the minimum number) or the optimal feed
> stage. Both of these values show NaN.
>
> I would appreciate any insight here.
>
> I still haven't gotten the rigorous columns to converge on these
> simulations. If you have any tips here, I'd appreciate them.
>
> I have attached 2 files, the first one (D3) is the DWSIM 3 file and the
> second one is the DWSIM 4 file.
>
> Thank you for your time,
>
> Hector D. Perez
>