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[EnergyPlus_Support] Re: Primary-Secondary System zero flow issue
Hi, Mike.
I've tried the COMMON PIPE option to simulate a primary-secondary
system, but now I got this message:
** Severe ** Current version does not support Loop pumps and branch
pumps together
** ~~~ ** Occurs in loop CHILLED WATER LOOP
I am trying to modelate a primary-secondary loop system, as specified
by ASHRAE Std 90.1 AppG - system 8, with branch pumps on supply side
(one pump for each chiller; with 3 chillers) and a loop pump in the
demand side (a variable flow pump for the cooling coils - secondary
loop).
According to this severe error message I suppose that the current
version of E+ does not support such a configuration.
Am I right, or I am missing something?
Any suggestion to modelate such a structure?
Best regards,
Fernando Westphal
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte"
<mjwitte@...> wrote:
>
> 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@...
>
The primary EnergyPlus web site is found at:
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