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[EnergyPlus_Support] Re: Inlet parameters for plant demand side splitter are not physically possible



Mike,i've checked the inputs for "cooling design supply air humidity 
ratio",i try to set the zone value as smaller and smaller(0.001),but 
the warnings also exit.How to set the humidity ratio in zone sizing 
and system sizing?In message 5514,you said that "These values have a 
very small impact on coil sizing. The default values can be used for 
most applications."  I'm puzzled.

I've upload a zip folder named "Hotel.zip".Appreciated your kind help 
to eliminate these warnings.

  Thanks very much.
  pch
 

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte" 
<mjwitte@g...> wrote:
>
> >  ** Warning ** SizeWaterCoil: Coil="1F_2_FPIU_CW_COIL", Cooling 
Coil 
> > has leaving humidity ratio > entering humidity ratio.
> >
> 
> For the above warning, check the inputs for "cooling design supply 
air humidity 
> ratio" in ZONE SIZING and SYSTEM SIZING objects.  If the zone value 
is too 
> high, this error can occur.
> 
> For the itereation limit warning on the hot water coil, you can 
ignore these if 
> there are only two in a full simulation.  I cannot say for sure how 
to 
> eliminate it unless I see the input file.  Please zip and send to 
energyplus-
> support@g...
> 
> Mike
> 
> 
> On 3 Nov 2005, at 16:48, hbn_pch wrote:
> 
> > Mike,thanks for your response.I check the eio ouput file and find 
> > that some zones peak heating or cooling load are zero.I don't 
know 
> > why they are sized to zero.
> > 
> > In order to eliminate the serve,i changed them to the 
uncontrolled 
> > zone,and really the serve is eliminated.But the warnings exist as 
> > described before.e.g:
> > 
> >  ** Warning ** SizeWaterCoil: Coil="1F_2_FPIU_CW_COIL", Cooling 
Coil 
> > has leaving humidity ratio > entering humidity ratio.
> >    **   ~~~   ** ..will be sized for 50% of design entering 
humidity 
> > ratio.  
> > 
> > Because there are too many zone in the model.I have to expand 
some 
> > objects in the idd.For convenience,i just upload the eio and the 
err 
> > file.Can you check the two files and give me some suggestion?
> > 
> >   thanks in advance.
> >   pch
> > 
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte" 
> > <mjwitte@g...> wrote:
> > >
> > > 1.  Check the zone peak heating and cooling loads and component 
> > sizes reported 
> > > in the eio output file.  Are these reasonable?  Are any of the 
> > coils being 
> > > sized to zero max water flow rate?
> > > 
> > > 2.  The splitter errors usually indicate that a BYPASS is 
missing 
> > or the pump 
> > > controls are invalid.  The error message means the pump is 
trying 
> > to push more 
> > > flow into the splitter than the leaving branches can take.  
This 
> > can occur if a 
> > > constant flow pump is used without a bypass.
> > > 
> > > 3.  The convection algorithms just change the zone load 
slightly, 
> > so they are 
> > > not really related to these problems.
> > > 
> > > Mike
> > > 
> > > 
> > > On 1 Nov 2005, at 16:33, hbn_pch wrote:
> > > 
> > > > I found when i input the inside convection algorithm and 
outside 
> > > > convection algorithm as simple,then the sever as description 
will 
> > > > present.If i input as detailed instead,then the severe will 
> > > > disappear,but there are much more warnings as follows:
> > > > 
> > > >     ** Warning ** Hot water coil control failed in 4 pipe 
> > induction 
> > > > unit 2F_10_FPIU
> > > >    **   ~~~   **   Iteration limit exceeded in calculating 
hot 
> > water 
> > > > mass flow rate
> > > > 
> > > >    ** Warning ** Hot water coil control failed in 4 pipe 
> > induction 
> > > > unit 2F_22_FPIU
> > > >    **   ~~~   **   Iteration limit exceeded in calculating 
hot 
> > water 
> > > > mass flow rate
> > > > 
> > > >   Apprecriated your kind help.thank you very much
> > > > 
> > > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "hbn_pch" 
> > <hbn_pch@y...> 
> > > > wrote:
> > > > >
> > > > > Hi,all
> > > > >    There is a serve and some warnings that i can't fix.As 
> > follows:
> > > > > 
> > > > >    ** Severe  ** Inlet parameters for plant demand side 
> > splitter 
> > > > > are   not physically possible
> > > > >    **   ~~~   ** Problem in input for plant demand side 
CHILLED 
> > > > WATER 
> > > > > LOOP
> > > > >    **   ~~~   ** The maximum flow out of the splitter is 
less 
> > than 
> > > > > the minimum inlet flow
> > > > >    **   ~~~   ** Flow rate inputs for the loop do not match 
> > flow 
> > > > > requirements of the various branches/components
> > > > >    **   ~~~   ** Check your flow rates and make sure that 
flow 
> > > > > balances between the splitter inlet and outlets
> > > > > 
> > > > >    ** Warning ** SizeWaterCoil: Coil="1F_9_FPIU_CW_COIL", 
> > Cooling 
> > > > > Coil has leaving humidity ratio > entering humidity ratio.
> > > > >    **   ~~~   ** ..will be sized for 50% of design entering 
> > > > humidity 
> > > > > ratio.
> > > > >    ** Warning ** For COIL:Water:Cooling 1F_9_FPIU_CW_COIL
> > > > >    **   ~~~   ** CalcCoilUAbyEffectNTU:Given Q impossible 
for 
> > given 
> > > > > inlet states,Proceeding With MaxHeat Transfer
> > > > > 
> > > > >   I check the splitter and find no problems.Meanwhile,flow 
> > rates 
> > > > are 
> > > > > all autosized.I don't know how to eliminate the serve.
> > > > > 
> > > > >   Many zones have the warning above.I don't know what do 
they 
> > mean.
> > > > > 
> > > > >   Can anybody give me some suggestion? thanks 
> > > > > 
> > > > >  pch
> > > > >
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 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@g...
> > >
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 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
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> > 
> > 
> > 
> > 
> > 
> > 
> > 
> 
> 
> 
> ========================================================
> Michael J. Witte, GARD Analytics, Inc.
> EnergyPlus Testing and Support      
> EnergyPlus-Support@g...
>






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