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

[Daniel W. <dan...@gm...>]

This is after applying the same fix to DWSIM 3:

[image: Imagem inline 1]

A final v3.7 build will be released together with DWSIM v4.0 with some
critical bug fixes for those who prefer v3. They can be installed
side-by-side on the same machine.

Regards
Daniel

2016-07-29 10:36 GMT-04:00 Daniel Wagner <dan...@gm...>:

> Hi Hector,
>
> The IO Flash algorithm was enhanced in DWSIM 4. There are a few additional
> checks to ensure convergence. In DWSIM 3 it is converging earlier than
> expected for your case.
>
> And you're still struggling with this system in DWSIM. You really should
> use ChemSep's column and thermo models through the CAPE-OPEN interface.
>
> Daniel
>
> 2016-07-29 10:08 GMT-04:00 Hector Perez <hpe...@gm...>:
>
>> 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
>>
>
>