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Re: [EnergyPlus_Support] Re: Reformulated Electric EIR chiller
Yiqun:
The COP of chiller is a function of part load ratio. It is mainly determined
by the Energy Input to Cooling Output Ratio Function of Part Load Ratio
Curve. When a normal electric chiller is used, the curve has an independent
variable: part load ratio. For a reformulated chiller, the curve requires
two independent variables: leaving condenser water temperature and part load
ratio. Each independent variable has its min and max values. The maximum
value of leaving condenser water temperature for the chiller you used is
31.11C. The leaving water temperature you used is 35C. The curve function
uses the maximum value to calculate curve value, when the input value is
above the maximum value. After I use the leaving water temperature at 31.11,
the part load curve shows the EIRFPLR increases with part load increases.
Your statement is correct.
If you would like to compare COP for two types of chillers, you may need to
ensure the same conditions are applied. For simplicity, you may use a
spreadsheet to calculate the curve values.
Lixing
----- Original Message -----
From: "潘毅群" <yiqunpan@xxxxxxxxx>
To: <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Friday, July 18, 2008 11:23 PM
Subject: [EnergyPlus_Support] Re: Reformulated Electric EIR chiller
> The leaving chilled water temperature is 6 degree C and the leaving
> condenser water is 35 degree C.
>
> thanks.
>
> Yiqun
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Lixing Gu <gu@...> wrote:
>>
>> Yiqun:
>>
>> When a normal chiller is used, leaving chilled water temperature
> and
>> entering cooling water temperature are used to calculate COP using
> the
>> Energy Input to Cooling Output Ratio Function of Temperature Curve
> and Part
>> Load Ratio curve. When a reformulated chiller is selected, Leaving
> Chilled
>> Water Temperature and Leaving Condenser Water Temperature are used
> to
>> calculate an EIR modifier, instead of entering cooling water
> temperature.
>> Leaving Condenser Water Temperature and Part Load Ratio are used to
>> calculate part load penalty. Could you let me know what leaving
> condenser
>> water temperature and leaving chilled water temperature are?
>>
>> Thanks.
>>
>> Lixing
>> ----- Original Message -----
>> From: "潘毅群" <yiqunpan@...>
>> To: <EnergyPlus_Support@xxxxxxxxxxxxxxx>
>> Sent: Thursday, July 17, 2008 3:52 AM
>> Subject: [EnergyPlus_Support] Reformulated Electric EIR chiller
>>
>>
>> > On the Engineering Reference, it is said that the reformulated EIR
>> > chiller model can improve the accuracy of simulating a VSD chiller
>> > significantly from normal EIR chiller model. However I got some
>> > ubnormal results from the reformulated model. I selected a model
> from
>> > the chiller datasets of E+ - ReformEIRChiller Trane CVHF
>> > 2317kw/6.33COP/VSD, and tried to obtain the changing trend of COP
>> > following its part load ratio and found that its COP decreases
> with the
>> > part load ratio decreases, with the same leaving chilled water
>> > temperature and entering cooling water temperature. I also tried
> with a
>> > normal EIR chiller model from the datasets, but got different
> changing
>> > trend, which COP reaches its peak when the part load ratio is
> aroung
>> > 50%. It seems that the result from normal EIR chiller model is
> more
>> > close to the actural condition.
>> >
>> > Has anybody tried the same thing and is able to tell me something
> about
>> > it? thanks.
>> >
>> > Yiqun Pan
>> > Tongji University
>> >
>> >
>> > ------------------------------------
>> >
>> > The primary EnergyPlus web site is found at:
>> > http://www.energyplus.gov
>> >
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>> >
>> > Attachments are not allowed -- please post any files to the
> appropriate
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>> >
>> > EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf
> under the
>> > Documentation link and press the "search" button.
>> > Yahoo! Groups Links
>> >
>> >
>> >
>> >
>>
>
>
>
> ------------------------------------
>
> The primary EnergyPlus web site is found at:
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>
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>
> Attachments are not allowed -- please post any files to the appropriate
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>
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> Documentation link and press the "search" button.
> Yahoo! Groups Links
>
>
>
>
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