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

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
From: "Josh K" <jeemang@xxxxxxxxx>
Date: Tue, 5 Feb 2008 10:27:38 -0700
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Thanks Richard -- and thanks for your help. Most of those warnings stem from
the way that I created the geometry in ECOTECT; I traced a .dxf, and instead
of using a line in the middle of a partition for a zone boundary, I would
use one side of the partition as a boundary for the zone on that side of it,
and the other side of the partition for the zone boundary on the other side
of it. So, because of the unfortunate fact that buildings have corners, I
ended up with some thermally communicating heat transfer surfaces that are
of slightly different areas. I definitely won't be making this mistake
again. I plan on fixing this when we eventually submit this model to the
CaGBC.

The interzone communication errors are from the way I specified my suspended
radiant panels. I did them like this on the advice of Mike Witte, and they
seem to be working well...

Thanks again for the help,

Josh


On Feb 5, 2008 10:06 AM, Richard Raustad <RRaustad@xxxxxxxxxxxx> wrote:

>   That is correct. By the way, you did a nice job on the school layout and
>
> mechanical equipment selection. You should consider getting rid of those
> other warnings. Here is a summary in case others know these warnings
> affect the answer.
>
> *** ===== Final Error Summary =====
> *** The following error categories occurred. Consider correcting or
> noting.
> *** InterZone Surface Areas -- mismatch
> *** ..Area mismatch errors happen when the interzone surface in zone A is
> *** ..not the same size as it's companion in zone B.
> *** Interzone surfaces - different zones
> *** InterZone Surface Azimuths -- mismatch
> *** ..The azimuths (outward facing angle) of two interzone surfaces
> should not be the same.
> *** ..Normally, the absolute difference between the two azimuths will be
> 180 degrees.
> *** ..You can turn on the report: Report,Surface,Details; to inspect
> your surfaces.
> *** EnergyPlus Completed Successfully-- 75 Warning; 18 Severe Errors;
> Elapsed Time=00hr 03min 49.97sec
>
>
> Josh K wrote:
> >
> > I just finished checking the sum of the branch flowrates against the
> > sum of
> > the supply branch flowrates and found them to balance (there was
> > actually a
> > slightly varying difference on the order of 1E-20, so I'm assuming this
> is
> > essentially zero).
> >
> > So: if I understand you correctly, this is a code issue and I shouldn't
> > worry -- correct?
> >
> > Thanks,
> >
> > Josh
> >
> > On Feb 5, 2008 9:48 AM, Richard Raustad <RRaustad@xxxxxxxxxxxx<RRaustad%40fsec.ucf.edu>
> > <mailto:RRaustad%40fsec.ucf.edu>> wrote:
> >
> > > I just tested your input file by adding the pump inlet node volumetric
> > > flow rate as a report variable. Then I corrected the code to eliminate
> > > the plant flow resolver warnings. I found no differences in the
> answer.
> > >
> > >
> > > Richard Raustad wrote:
> > > >
> > > > It appears from the output (csv) file that the PTAC water heating
> coil
> > > > in zone 513_computer is operating. Please disregard these warnings
> > > > unless you find good reason to suspect it affects the simulation
> > > > results. From the report variables you selected, you did a very
> > good job
> > > > of troubleshooting the warnings. These report variables confirm
> > the unit
> > > > is operating correctly. I did not look closely at the plant loop
> > to see
> > > > if the warnings indicate a problem with the flow rate through the
> > plant.
> > > > To check the plant operation, report out all hot water coil (and
> > bypass)
> > > > outlet node flow rates and compare the sum of these to the hot water
> > > > pump flow rate. Also compare pump water flow rate with the boiler
> (and
> > > > bypass) flow rate.
> > > >
> > > > We will look into resolving this issue.
> > > >
> > > > Richard Raustad 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><brent_griffith%40nrel.gov>
> > > > <mailto: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%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>
> > > > <mailto: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>
> > > > <mailto: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
> > <http://www.fsec.ucf.edu> <http://www.fsec.ucf.edu
>
> > <http://www.fsec.ucf.edu>>
> > > >
> > > > UCF - From Promise to Prominence: Celebrating 40 Years
> > > >
> > > >
> > >
> > > --
> > > 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 <
> 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]
> >
> >
>
> --
> 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]



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References:
- [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: josh_miarch
- RE: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Griffith, Brent
- Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Josh K
- Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Richard Raustad
- Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Richard Raustad
- Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Richard Raustad
- Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Josh K
- Re: [EnergyPlus_Support] PlantFlowResolver error -- "Branch flow rates out of bounds"
  - From: Richard Raustad

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