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Re: [EnergyPlus_Support] Re: Primary-Secondary System zero flow issue
EnergyPlus 2.0.0.025 can autosize a primary-secondary system when using the
COMMON PIPE option with a single PLANT LOOP object. See example file
CommonPipe_Pri-Sec.idf
5zoneVAV-Pri-SecLoop.idf still uses the older CONNECTION
COMPONENT:PLANTLOOP:CONTROLLED approach which uses two complete PLANT LOOP
structures to accomplish primary-secondary. When using that approach,
autosizing does not work for the primary loop.
Mike
On 13 Aug 2007 at 18:25, fernandowestphal wrote:
> Dear All,
>
> Any news about this subject?
> Is the actual version of E+ (2.0.0.025) doing the autosize for the
> primary side of primary-secondary systems?
>
> I've tried to do it in the example file "5zoneVAV-Pri-SecLoop.idf"
> and I got chiller with zero capacity and zero flows in the primary
> loop...
>
> Thanks!
> Fernando Simon Westphal
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte"
> <mjwitte@...> wrote:
> >
> > Autosizing does not currently work for the primary loop in a
> primary-secondary
> > system. In the next release (April 2007), primary-secondary
> systems will be
> > able to be modeled using a single PLANT LOOP with no connection
> component.
> > Autosizing will then flow through to the primary side. Until then,
> you must
> > specify the primary equipment capacities and flow rates.
> >
> > Mike
> >
> >
> > On 16 Jan 2007 at 3:19, miaoworld wrote:
> >
> > > Greetings,
> > >
> > > I have a primary and secondary chilled water system, and I am
> keeping
> > > having zero flow. I have specified the primary pump consumption
> and
> > > flow rate for the primary chilled water loop, but the primary
> loop and
> > > condenser loop (Autosized) is zero flow.
> > >
> > > Any suggestions will be appreciated.
> > >
> > > Thanks.
> > >
> > > Miao(Eric)
> > >
> > > ************* Beginning System Sizing Calculations
> > > ** Warning ** SizeCondDemandSide: Calculated Plant Sizing
> Design
> > > Volume Flow Rate=[0.00] is too small. Set to 0.0
> > > ** ~~~ ** ..occurs for Condenser Loop=CHILLED WATER LOOP
> > > CONDENSER WATER LOOP
> > > ** Warning ** SizeCondSupplySide: Calculated Plant Sizing
> Design
> > > Volume Flow Rate=[0.00] is too small. Set to 0.0
> > > ** ~~~ ** ..occurs for Condenser Loop=CHILLED WATER LOOP
> > > CONDENSER WATER LOOP
> > > ** Warning ** SizePump: Calculated Pump Nominal Volume Flow
> > > Rate=[0.00] is too small. Set to 0.0
> > > ** ~~~ ** ..occurs for Pump=CHILLED WATER LOOP CNDW SUPPLY
> PUMP
> > >
> > >
> > > ******Component sizing
> > >
> > > Component Sizing, CHILLER:ELECTRIC:EIR, CHILLER, Reference
> Evaporator
> > > Volumetric Water Flow Rate [m3/s], 0.0000
> > > Component Sizing, CHILLER:ELECTRIC:EIR, CHILLER, Reference
> Capacity
> > > [W], 0.0000
> > > Component Sizing, CHILLER:ELECTRIC:EIR, CHILLER, Reference
> Condenser
> > > Volumetric Water Flow Rate [m3/s], 0.0000
> > > Component Sizing, PUMP:CONSTANT SPEED, HOT WATER LOOP HW SUPPLY
> PUMP,
> > > Rated Volumetric Flow Rate [m3/s], 0.55510E-01
> > > Component Sizing, PUMP:CONSTANT SPEED, HOT WATER LOOP HW SUPPLY
> PUMP,
> > > Rated Power Consumption [W], 14182.
> > > Component Sizing, PUMP:VARIABLE SPEED, CHILLED WATER LOOP CHW SEC
> > > SUPPLY PUMP, Rated Power Consumption [W], 158.35
> > > Component Sizing, CONDENSER LOOP, CHILLED WATER LOOP CONDENSER
> WATER
> > > LOOP, Volume of the condenser loop [m3], 0.0000
> > > Component Sizing, CONDENSER LOOP, CHILLED WATER LOOP CONDENSER
> WATER
> > > LOOP, Maximum Loop Volumetric Flow Rate [m3/s], 0.0000
> > > Component Sizing, COOLING TOWER:SINGLE SPEED, MAIN TOWER,
> Autosized
> > > design water flow rate [m3/s], 0.0000
> > > Component Sizing, COOLING TOWER:SINGLE SPEED, MAIN TOWER, Fan
> power
> > > at design air flow rate [W], 0.0000
> > > Component Sizing, COOLING TOWER:SINGLE SPEED, MAIN TOWER, Design
> air
> > > flow rate [m3/s], 0.0000
> > > Component Sizing, COOLING TOWER:SINGLE SPEED, MAIN TOWER,
> Autosized
> > > tower UA value at the design air flow rate [W/C], 0.0000
> > > Component Sizing, COOLING TOWER:SINGLE SPEED, MAIN TOWER, Air
> flow
> > > rate in free convection regime [m3/s], 0.0000
> > > Component Sizing, COOLING TOWER:SINGLE SPEED, MAIN TOWER, Tower
> UA
> > > value in free convection regime [W/C], 0.0000
> > > Component Sizing, PUMP:VARIABLE SPEED, CHILLED WATER LOOP CNDW
> SUPPLY
> > > PUMP, Rated Volumetric Flow Rate [m3/s], 0.0000
> > > Component Sizing, PUMP:VARIABLE SPEED, CHILLED WATER LOOP CNDW
> SUPPLY
> > > PUMP, Rated Power Consumption [W], 0.0000
> > >
> > >
> > >
> > > 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
> > >
> > >
> > >
> > >
> > >
> >
> >
> > ========================================================
> > Michael J. Witte, GARD Analytics, Inc.
> > EnergyPlus Testing and Support
> > EnergyPlus-Support@...
> >
>
>
>
>
> 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
>
>
>
>
>
========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support
EnergyPlus-Support@xxxxxxxx
The primary EnergyPlus web site is found at:
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