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[EnergyPlus_Support] Loop delta Temp




Hi, Mike:
 
As you suggested, I checked the model "VAVSingleDuctReheatBaseboard.idf".
 
But I found that the temperature of 6.67C is set for the chilled water supply temperature, not the loop DeltaT. Am I right? 
 
Could you tell me where can I set the chilled water and hot water loop DeltaT?
I guess I can set these DeltaT in the field of Plant Loop by setting Maximum and Minimum loop temperature.  But I found that in examples, these DeltaT is quite big. For chilled water loop, it is ranged from 1degree C to 98 degree C. Can I set a reasonable Delta T in this filed?
 
Thanks a lot.
 
Regards,
 
Zhen

"Michael J. Witte" <mjwitte@xxxxxxxx> wrote:
The temperature rise across the loop will depend on how you have sized the flow 
rate vs. load in the coils.  Many (all?) of the example files use a 6.67C loop 
DeltaT.

Mike


On 17 Jan 2005, at 17:17, zhen tian wrote:

> 
> Hi, Mike:
> 
> I changed the Pump cofficeints to "0, 1, 0, 0" and now the "HW PUMP OUTLET
> NODE:System Node Temp[C](Hourly) " and the "CW PUMP OUTLET NODE:System Node
> Temp[C](Hourly) " are kept at 93 degree C and 5C, and accords well to the set
> temperatures. 
> 
> But I checked the CW SUPPLY INLET NODE TEMP and CW PUMP OULET NODE TEMP, I still
> get some temperatures like these: "5, 5, 5.5, 10.9, 15.4..." which are close to
> the set temperatures, are these temperatures sound normal? 
> 
> Thanks a lot.
> 
> Regards,
> 
> Zhen
> 
> 
> 
> "Michael J. Witte" <mjwitte@xxxxxxxx> wrote:
> If the pump power remains constant and the flow varies, low flows will get hot
> because the energy must go somewhere.  You either need to let the pump power
> vary (linear power would use coefficients of 0,1,0,0) or use a constant speed
> pump so the excess flow will go through the bypass.
> 
> Mike
> 
> On 14 Jan 2005, at 16:39, zhen tian wrote:
> 
> > 
> > Hi, Mike:
> > 
> > Thanks for you reply. I have checked the pump input. Actually, I do use
> > variable flow pumps with constant pump power.  But I cannot change rated pump
> > power consumption to "autosize" as this will cause severe errors. I did not
> > use any autosize function in my model.  I have upload my model named "
> > ICT-NoRC-zt.zip " to the yahoo group. Could you check it for me? Thanks a lot.
> > The weather file is Calgary, Alberta.
> > 
> > Regards,
> > 
> > Zhen 
> 
> 
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> 






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