MEE design about biosteam HOT 7 CLOSED

Fixed! In addition to this, I also made the following corrections:

• Made sure vapor outlet of first evaporator is a gas, so now utility costs are more accurate (higher than before).
• The first effect is model by vapor-liquid equilibrium (more rigorous) and the heat exchanger network can use now integrate heat with the first effect (more savings!).

These two results balance each other out, hopefully results in your biorefinery didn't change too much.

Thanks!

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Thanks! The problem has been fixed! I did see the changes in results, couldn't recall the exact difference, but didn't seem to be large

Though I want to point out that

That's right, BioSTEAM would first test whether all 5 effects work (even if previously only 3 effects worked).

Thanks!

This doesn't seem to be the case. But I managed to work around this by resetting P to the original design (BioSTEAM changes P to match the number of effects, so the P will be different from the originally designated ones if BioSTEAM reduces the number of effects).

Thanks!!

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@yalinli2, I found the bug and fixed it:

Changed from:

if self.V_definition == 'Overall':
    P = tuple(self.P)
    self.P = list(P)
    for i in range(self._N_evap-1):
        if self._V_overall(0.) > self.V:
            self.P.pop()
            self.load_components()
        else:
            self.P = P
            break

To:

if self.V_definition == 'Overall':
    P = tuple(self.P)
    self.P = list(P)
    for i in range(self._N_evap-1):
        if self._V_overall(0.) > self.V:
            self.P.pop()
            self.load_components()
        else:
            break
    self.P = P

The code should always run self.P = P (so it resets P to the original value, as you normally do in your work around).

This should do the trick. I'll add a couple of tests eventually.

Thanks!

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That's right, BioSTEAM would first test whether all 5 effects work (even if previously only 3 effects worked).

Thanks!

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@yalinli2, if you create a test for this, feel free to post it here and I can add it to biosteam's tests (no worries if not). Thanks!

from biosteam.

That's right, BioSTEAM would first test whether all 5 effects work (even if previously only 3 effects worked).

Thanks!

This is great, thanks!

Then to my first question that

won't work if there's only one evaporator. Using a slight modified version of MEE's doc:

>>> import biosteam as bst
>>> from biorefineries.cornstover import chemicals
>>> bst.settings.set_thermo(chemicals)
>>> feed = bst.Stream('feed', Water=1000, Glucose=100, 
...                   AceticAcid=0.5, HMF=0.1, Furfural=0.1,
...                   units='kg/hr')
>>> E1 = bst.MultiEffectEvaporator('E1', ins=feed, outs=('solids', 'liquid'), 
...                                V=0.1, V_definition='Overall',
...                                P=(20000,))
>>> E1.simulate()

It will reproduce the error. Thanks!

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Yep it did the trick! Thanks!

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