[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[EnergyPlus_Support] Re: Sharp Increase on Air Temperature when Heating is initially on?
Thanks Richard,
Increase the air thermal capacitance at the ZoneCapacitanceMultiplier:ResearchSpecial object does help delaying the sharp increase on Air Temperature.
I set the capacity of the system, and the district heating's nominal capacity to be 6kW, one warning I am having all the time is:
** Warning ** No valid range found for Loop Demand=14990.27 in Load Range Based Operation Scheme=HW HEATING OPERATION.
** ~~~ ** All equipment will be turned off. Other cases of this condition will not be reported.
** ~~~ ** During Warmup ... ...
of which HW HEATING OPERATION has an upper limit of 6kW. I checked the result and couldn't find any load demand that is higher than 6kW. In this case, can I ignore this warning, or I need to be careful regarding to why this has happened?
Many thanks,
Denis
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad <RRaustad@...> wrote:
>
> You could:
>
> 1) reduce the capacity of the system (I don't know how you sized it)
> 2) increase the zone interior thermal mass
>
> Example:
>
> InternalMass,
> Basement Internal Mass, !- Name
> InteriorFurnishings, !- Construction Name
> Basement, !- Zone Name
> 7126.2120; !- Surface Area
>
> Construction,
> InteriorFurnishings, !- Name
> Std Wood 6inch; !- Outside Layer
>
> by changing thickness or density
>
> Material,
> Std Wood 6inch, !- Name
> MediumSmooth, !- Roughness
> 0.15, !- Thickness {m}
> 0.12, !- Conductivity {W/m-K}
> ##if #[Construction_Type[] EQS Heavy]
> 1080.0000, !- Density {kg/m3}
> ##elseif #[Construction_Type[] EQS Light]
> 540.0000, !- Density {kg/m3}
> ##endif
> 1210, !- Specific Heat {J/kg-K}
> 0.9000000, !- Thermal Absorptance
> 0.7000000, !- Solar Absorptance
> 0.7000000; !- Visible Absorptance
>
> 3) tweak the air thermal capacitance -
> ZoneCapacitanceMultiplier:ResearchSpecial
>
> On 7/14/2011 6:16 AM, Denis wrote:
> >
> > Hi everyone,
> >
> > I am new to E+, and hope if some of you can help me out on this.
> >
> > I have a simple system, district heating as the supply heat source,
> > which then connected to a radiator (currently using
> > Baseboard:Convective:Water object) for the demand side. A constant
> > flow rate pump is on the inlet side of the supply part, and the
> > remaining node connections are in Pipe:Adiabatic.
> >
> > The building is a single zone, one story house, with a setpoint
> > schedule for the room thermostat as:
> >
> > 00:00 - 07:00: 10 deg C
> > 07:00 - 23:00: 21 deg C
> > 23:00 - 24:00: 10 deg C
> >
> > Since the Air Temperature is well above the setpoint between 00:00 -
> > 07:00, and so the heating wouldn't kicked in after 07:00. What I am
> > not so sure about is the rate of temperature increase is too quick
> > (about 2 deg C per 10 minutes). I have tried adding some air
> > infiltration, but occasionally the HVAC system doesn't converge at its
> > maximum iterations. Is there any other heat source component that I
> > can use, which can simulated a more graduated increase in the air
> > temperature?
> >
> > Many thanks,
> > Denis
> >
> >
> >
>
> --
> 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
>
------------------------------------
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
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 currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/EnergyPlus_Support/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/EnergyPlus_Support/join
(Yahoo! ID required)
<*> To change settings via email:
EnergyPlus_Support-digest@xxxxxxxxxxxxxxx
EnergyPlus_Support-fullfeatured@xxxxxxxxxxxxxxx
<*> 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/