This is an extremely appropriate and relevant topic!
[quote author=vbakos link=topic=2454.msg5660#msg5660 date=1431358781]
.. If I have an inlet file (e.g. txt), containing different analytical data (e.g. COD, TKN, TP, etc.), I can open this file during the inlet setting, fix the parameters measured (COD, TKN, TP) and choose the appropriate model (e.g. ASM2d) and the simulator generates the fractionated inlet quality automatically (fractionation which refers to the model chosen). For me it seems to be a "rough black-box" method ..[/quote]
I don't mean to be pedantic, but, since I believe this is a key-subject, I would like to be very clear.
[list]
[li]following the modelling terminology, COD, TKN, etc. are not '[b]parameters[/b]' (which are constant by definition) but '[b]variables[/b]' (which are time-dependent)[/li]
[li]I would not call this methodology '[b]black-box[/b]', quite on the contrary! In WEST, there's absolutely nothing that may be called 'black-box' and the influent model/fractionation is no exception: you can indicate any number of measured (custom) variables; you can define a custom fractionation model, starting from the default one for that category, or starting from scratch; and you can save your modified fractionation model[/li]
[/list]
[quote author=vbakos link=topic=2454.msg5660#msg5660 date=1431358781]
.. based on I do not know what - lot of experiences?, literary ratios for municipal wastewater ww quality?) because carrying out an adequate fractionation from this "narrow spectrum" of measured parameters (i.e. COD, TKN, TP), that is quite a big challenge... [/quote]
You are very right: the influent ('[b]fractionation[/b]') model is usually the single, most crucial model in a whole-plant model.
The least measurements (COD, ..) are available, the larger is the [b]uncertainty[/b] of the fractionation model (and, as a consequence, of the overall model). Thus, the first step in the calibration of the whole-plant model will be the calibration of the fractionation model.
And yes: the default values of the default ASM- fractionation models are based on literature values.
[quote author=vbakos link=topic=2454.msg5660#msg5660 date=1431358781]
1. If I have only some measured parameters (COD, TKN, TP), the automatic fractionation may be inaccurate, my calculations may be based on data charged by huge uncertainty, so the results of the simulations may fail. Is that a right suggestion?[/quote]
Precisely!
[quote author=vbakos link=topic=2454.msg5660#msg5660 date=1431358781]
2. If I .. have a broader spectrum of measured parameters (e.g. tot COD, diss COD filtered through 1.2 micron filter, filtered-flocculated COD through 0.45 micron, ..), wide enough for an accurate fractionation, how can I deal with these data? How can I import them appropriately into the WEST fractionation panel?
[/quote]
First: you're very lucky! :)
Second: the list of four components (Water, COD, TKN, TSS) that you find in the General tab page of the Influent Tool is only a 'suggestion'.
You can add your own 'components' (i.e. measurements) to the list. As a result, the Fractionation page will be populated with all the corresponding [b]input blue blocks[/b] - that are to be connected to the relevant [b]output (green) blocks[/b].
As I mentioned above, you can start from one of the default fractionation models; or, more likely, if you have so many custom measurement, you can start from scratch and create your own, graphically (same principle as a layout in WEST main).
[quote author=vbakos link=topic=2454.msg5660#msg5660 date=1431358781]
3. Another basic technical question related to the previous: how can I / should I design the inlet file in order to be able to import the data in WEST? (is there any guideline for it? - which format (xls or txt), order of colomns, parameteres?)
[/quote]
See [b]User Guide, page 56[/b] onwards
[quote author=vbakos link=topic=2454.msg5660#msg5660 date=1431358781]
4. How can I discover what the "black-box" of WEST does with the parameters in the fractionaton step? (were are the background formules, methods?)
[/quote]
Again: no 'black-box'.
I am not sure I fully understand, but the fractionation 'step':
[list]
[li]consists in setting up of the fractionation model by graphically connecting the blue and the green blocks; optionally, defining 'work' variables ('V' blocks); and defining parameters (i.e. the 'weights' of the conversions from left- to right block along a connection)[/li]
[li]results in a [b]model [/b], written in MSL just like any other model in WEST and stored in the project folder[/li]
[/list]
Once you complete the Influent Tool (click 'Generate' in the last page), the fractionation model (the MSL file) is created and its details will be visible, like for any other model of your layout, in the Block Summary and Block Details panes.
