[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[EnergyPlus_Support] Re: Electric Chiller: air cooled
Hi,
That makes sense. I had a constant volumetric flow rate, so even
though the unit was not required to do any work (the cooling coil's
operations was never requested), the system WAS requesting 7C at the
outlet of the loop year round.
I scheduled this loop to off during the winter months. This took
care of the errors however I noticed that there is still a flow
through the system!!!? Any idea why this would remain operating?
However, I still have two issues with the system.
(1) In the summer, the system is not pulling the cooling coil air
outlet node temp to 12C. It gets close, but never all the way during
peak times. The system if fully autosized..
(2) The .err file says that "Loads Initialization did not Converge
(CheckWarmupConvergence)"
I've tried increasing the warmup days to 40 but this doesn't seem to
have an effect.
Kind regards
-Elmer
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad
<RRaustad@...> wrote:
>
> The message is warning you that an "air cooled" chiller is
operating
> when outdoor temperatures are below 0C. This type of operation
could
> freeze the chiller barrel and damage the unit. Good thing it is
only a
> simulation. What type of loads are in your building that require
cooling
> when it is 0C outside? How about scheduling you chiller off in the
> winter and using an economizer.
>
>
> Elmer Morrissey wrote:
>
> > Hello all,
> >
> > I'm am getting the following error from an electric chiller (air
> > cooled) which supplies the cool water at 7C for the cooling coil
in
> > the AHU...
> >
> > ElectricChillerModel:Air Cooled Condenser Inlet Temperature
below 0C
> > continues
> >
> > Can anyone point me where I would remove this error?
> >
> > My chiller definition looks like this
> >
> > CHILLER:ELECTRIC,
> > Z1:Plant1, !- Chiller Name
> > AIR COOLED, !- Condenser Type
> > autosize, !- Nominal Capacity {W}
> > 3.2, !- COP
> > Z1:Plant1In, !- Plant_Side_Inlet_Node
> > Z1:Plant1Out, !- Plant_Side_Outlet_Node
> > ZC1:Plant1In, !- Condenser_Side_Inlet_Node
> > ZC1:Plant1Out, !- Condenser_Side_Outlet_Node
> > 0, !- Minimum Part Load Ratio
> > 1, !- Maximum Part Load Ratio
> > 0.65, !- Opt Part Load Ratio
> > 35, !- Temp Design Condenser Inlet {C}
> > 2.778, !- Temp Rise Coefficient
> > 6.67, !- Temp Design Evaporator Outlet {C}
> > autosize, !- Design Evaporator Volumetric
Water
> > Flow Rate {m3/s}
> > autosize, !- Design Condenser Volumetric Water
> > Flow Rate {m3/s}
> > 0.9949, !- Coefficient1 of the capacity
ratio
> > curve
> > -0.045954, !- Coefficient2 of the capacity
ratio
> > curve
> > -0.0013543, !- Coefficient3 of the capacity
ratio
> > curve
> > 2.333, !- Coefficient1 of the power ratio
curve
> > -1.975, !- Coefficient2 of the power ratio
curve
> > 0.6121, !- Coefficient3 of the power ratio
curve
> > 0.03303, !- Coefficient1 of the full load
ratio
> > curve
> > 0.6852, !- Coefficient2 of the full load
ratio
> > curve
> > 0.2818, !- Coefficient3 of the full load
ratio
> > curve
> > 5, !- Temp Lower Limit Evaporator
Outlet
> > {C}
> > ConstantFlow; !- Chiller Flow Mode
> >
> > I've attempted reducing the design inlet temperature into the
> > condenser but it doesn't appear to be making a difference. Also
the
> > cooling coil is not reducing the temperature of the outlet air
> > stream to the desired temp of 12C. It gets close (13C) but never
> > quite down there at peak times.
> >
> > I appreciate the help, kind regards
> >
> > -Elmer
> >
> >
> >
> >
> >
> >
> > 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.idf
and
> > press the "search" button.
> >
> >
> >
> > -----------------------------------------------------------------
-------
> > YAHOO! GROUPS LINKS
> >
> > * Visit your group "EnergyPlus_Support
> > <http://groups.yahoo.com/group/EnergyPlus_Support>" on the
web.
> >
> > * To unsubscribe from this group, send an email to:
> > EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx
> > <mailto:EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx?
subject=Unsubscribe>
> >
> > * Your use of Yahoo! Groups is subject to the Yahoo! Terms
of
> > Service <http://docs.yahoo.com/info/terms/>.
> >
> >
> > -----------------------------------------------------------------
-------
> >
>
> --
> 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
>
>
>
> [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.idf and press the "search" button.
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/EnergyPlus_Support/
<*> 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/