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Re: [EnergyPlus_Support] No Chilled or Hot water flow through coils.

Thank you so much for your help.
I have fixed the envelope problems and change the settings you mentioned in
the SYSTEM SIZING. However, there still come out no flow through the pipe.

In the error file, it has following result:
 ** Warning ** Check input. Calculated Pump Efficiency=9.97% which is less
than 50%, for pump=HW CIRC PUMP
   **   ~~~   ** Calculated Pump_Efficiency % =Total_Efficiency % [8.7] /
Motor_Efficiency % [87.0]
   **   ~~~   ** Total_Efficiency % =(Rated_Volume_Flow_Rate [9.0E-002] *
Rated_Pump_Head [250000.0] / Rated_Power_Use [259500.0]) * 100.
   ** Warning ** Check input. Calculated Pump Efficiency=3.38% which is less
than 50%, for pump=CHW CIRC PUMP
   **   ~~~   ** Calculated Pump_Efficiency % =Total_Efficiency % [2.9] /
Motor_Efficiency % [87.0]
   **   ~~~   ** Total_Efficiency % =(Rated_Volume_Flow_Rate [3.0E-002] *
Rated_Pump_Head [254072.6] / Rated_Power_Use [259500.0]) * 100.
  ** Severe  ** Temperature out of bounds (-28268019.28) for surface=SOUTH-1
   **   ~~~   ** in Zone=EXTERIOR-1
   **   ~~~   **  Occurrence info=HOUSTON TX USA TMY2-12960 WMO#=722430,
07/03 09:00 - 09:01

I really don't know what's the problem, cause the construction parameters in
my input file is based on the architecture information I got from the
building owner. Moreover, comparing with the example file, I can not find
anything wrong with my control strategy. Is there any chance that anyone can
help me? Thanks a lot.

Wenshu


On 9/14/07, Michael J. Witte <mjwitte@xxxxxxxx> wrote:
>
>   More information from the developer. This should help get you going. MJW
>
> There is a program problem. It's coming from the System Sizing input.
> Look at:
>
> SYSTEM SIZING,
> AHU1, !- name of an AIR PRIMARY LOOP object
> sensible, !- type of load to size on
> autosize, !- Design (minimum) outside air volumetric
> flow rate {m3/s}
> 0.2, !- minimum system air flow ratio
> 7.22222241354578, !- Preheat design set temperature {C}
> 12.7777781162733, !- Central cooling design supply air
> temperature {C}
> 37.7777787785472, !- Central heating design supply air
> temperature {C}
> noncoincident, !- Sizing Option
> yes, !- Cooling 100% Outside Air
> yes, !- Heating 100% Outside Air
> 0.008, !- Central cooling design supply air
> humidity ratio {kg-H2O/kg-air}
> 0.008, !- Central heating design supply air
> humidity ratio {kg-H2O/kg-air}
> design day, !- cooling design air flow method
> 5.66400071906259E-04, !- cooling design air flow rate {m3/s}
> design day, !- heating design air flow method
> 4.72000059921883E-04; !- heating design air flow rate {m3/s}
>
> The program for some reason ignores the field "cooling design air flow
> method" and looks only at
> "cooling design air flow rate {m3/s}". If the latter is > 0 it uses it
> as a user specified design flow rate.
> Since this input is tiny (the actual number should be around 10 m3/s) it
> basically zeros out the design flow rates. Ditto for heating.
> Removing these numbers results in a more normal attempt at autosizing,
> hampered by the lack of zone areas (no floors) in
> 2 of the zones. My run then aborts with temperature out of range. Some
> serious geometry problems I guess.
>
> On 12 Sep 2007 at 16:35, wenshufan1983 wrote:
>
> > I'm confused that there is no chilled or hot water flow through the
> > coils. According to Micheal's email to me, I've checked all these below
> > 1.ZONE CONTROL:THERMOSTATIC to request heating/cooling from the
> > HVAC system.
> >
> > 2.The HVAC controls must request flow in the the coil - could be a VAV
> > terminal unit with built-in controls for a reheat coil, or a
> > CONTROLLER:SIMPLE with a
> > SET POINT MANAGER:*.
> >
> > 3.The coils must be ACTIVE components on their branches.
> >
> > 4.The loop pump must be scheduled on (or the schedule omitted
> completely).
> >
> > But there is still no flow in the report. Is any one by chance can
> > help me out. My IDF file has been upload under Files:Problem
> > Submittals:Gil_5.idf. Thanks
> >
> >
> >
> > 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
> >
> >
> >
> >
> >
>
>  
>


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



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