[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"



I uploaded it into the problem submittals folder with this name:

PlantFlowResolver_problem_JoshK.idf

One thing I'll point out that might help you is that there are 60-some-odd
conditioned zones in this model, and there are only 6 in which I'm getting
the PlantFlowResolver warning. Of those 6, 5 are the only zones in the model
that are conditioned using PACKAGEDTERMINAL:AIRCONDITIONER objects. So
although I've looked at it and haven't been able to figure much out, I would
assume that this isn't a coincidence...

Thanks for the help,

Josh


On Feb 4, 2008 9:55 AM, Richard Raustad <RRaustad@xxxxxxxxxxxx> wrote:

>   You will have to upload your file so we can take a look.
>
>
> Josh K wrote:
> >
> > Hi Richard/Brent;
> >
> > I double checked, and the heating coils are on ACTIVE branches that are
> in
> > parallel with a demand bypass branch. Any other suggestions as to what
> > might
> > be the problem?
> >
> > Thanks,
> >
> > Josh
> >
> > On Feb 4, 2008 9:12 AM, Griffith, Brent <brent_griffith@xxxxxxxx<brent_griffith%40nrel.gov>
> > <mailto:brent_griffith%40nrel.gov>> wrote:
> >
> > > Check that the hot water coils are on a plant loop branch with
> "ACTIVE"
> > > control and that there is a bypass in parallel with them.
> > >
> > > ________________________________
> > >
> > > From: EnergyPlus_Support@xxxxxxxxxxxxxxx<EnergyPlus_Support%40yahoogroups.com>
> > <mailto:EnergyPlus_Support%40yahoogroups.com
> ><EnergyPlus_Support%40yahoogroups.com>
> > > [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx<EnergyPlus_Support%40yahoogroups.com>
> > <mailto:EnergyPlus_Support%40yahoogroups.com
> ><EnergyPlus_Support%40yahoogroups.com>]
> > > On Behalf Of josh_miarch
> > > Sent: Saturday, February 02, 2008 4:57 PM
> > > To: EnergyPlus_Support@xxxxxxxxxxxxxxx<EnergyPlus_Support%40yahoogroups.com>
> > <mailto:EnergyPlus_Support%40yahoogroups.com
> ><EnergyPlus_Support%40yahoogroups.com>
>
> > > Subject: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow
> > >
> > > rates out of bounds"
> > >
> > > I'm attempting to simulate a large, multizone building, and I'm
> > > encountering the following warning message:
> > >
> > > ** Warning ** PlantFlowResolver: Branch flow rates out of bounds, for
> > > Plant Loop=PLANT, Branch=514_COMPUTER_FC_HEATING_COIL_BRANCH
> > > ** ~~~ ** Conditions should be: 0.000 <= 1.517E-002 <= 0.000
> > >
> > > Over the course of an annual simulation, there are enough of these
> > > warnings (>30 000) to result in a fatal error that crashes the
> > > simulation.
> > >
> > > The branch in question is the heating coil branch for a
> > > PACKAGEDTERMINAL:AIRCONDITIONER object. Both the coil and the
> > > PACKAGEDTERMINAL:AIRCONDITIONER are available when these warnings are
> > > occurring.
> > >
> > > I've noticed that this error tends to occur largely in the shoulder
> > > seasons, when there is a relatively large amount of heating required
> > > in the morning (as there are relatively low external temperatures, and
> > > the zone thermostat switches from the the night set-back temperature
> > > of 16 C to 20 C), and then cooling required later in the day (as the
> > > combination of higher exterior temperatures and high internal gains
> > > adds heat to the zone). Although the load on the heating coil is
> > > relatively large in the morning and the PTAC object doesn't have a
> > > field for specifying max HW flowrates, the flow that I am seeing to
> > > coil is definitely reasonable, which makes this error more
> perplexing...
> > >
> > > Any help would be greatly appreciated.
> > >
> > > Josh
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> >
> > --
> > Josh Kjenner, EIT, LEED AP
> > Manasc Isaac Architects Ltd.
> > 10225 100 Avenue :: Edmonton, AB T5J 0A1
> > 780.429.3977
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
> --
> Richard A. Raustad
> Senior Research Engineer
> Florida Solar Energy Center
> University of Central Florida
> 1679 Clearlake Road
> Cocoa, FL 32922-5703
> Phone: (321) 638-1454
> Fax: (321) 638-1439 or 1010
> Visit our web site at: http://www.fsec.ucf.edu
>
> UCF - From Promise to Prominence: Celebrating 40 Years
>
>  
>



-- 
Josh Kjenner, EIT, LEED AP
Manasc Isaac Architects Ltd.
10225 100 Avenue :: Edmonton, AB T5J 0A1
780.429.3977


[Non-text portions of this message have been removed]



The primary EnergyPlus web site is found at:
http://www.energyplus.gov

The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/

Attachments are not allowed -- please post any files to the appropriate folder in the Files area of the Support Web Site.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/join
    (Yahoo! ID required)

<*> To change settings via email:
    mailto:EnergyPlus_Support-digest@xxxxxxxxxxxxxxx 
    mailto:EnergyPlus_Support-fullfeatured@xxxxxxxxxxxxxxx

<*> To unsubscribe from this group, send an email to:
    EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/