[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [EnergyPlus_Support] Re: The mathematical model of baseboard heater in transent period
Natasa:
Optimization problems are very difficult! What you are suggesting here
is probably impossible. There is no magic optimization procedure that
will give you perfect designs. What is your objective function?
Have you done a simple heating load calculation? If you do that you
will at lease have some reasonable starting values for an optimization,
if there really is an optimization problem present.
I suggest that you begin with one zone and one heater, and define an
objective function that makes sense. I suggest you limit the number of
parameters being optimized to three or fewer in the beginning.
Curt
On Aug 16, 2005, at 1:00 AM, natasamdj wrote:
> Fred,
> I had done the optimization for the simulation just for one winter
> design day. I had set that the outside temperature is the same whole
> day.
>
> The parameters that I have optimized are the following: insulation
> thickness (just in the outside walls), UA values for the baseboard
> heater:water:convetive (in my simulation I have 9 baseboard heaters
> and due to that I have 9 UA parameters for the optimization), sistem
> status variable (on/off or is the baseboard heaters are in use or
> no), the supply water temperature (I involved the same variable for
> the each hour), and the set value of indoor temperature.
>
> The system status parameter has been set to optimize just out of
> working period. Also, the set value of indoor temperature has been
> set to optimize out of working period.
>
> I have optimized three parameters that are defined with the schadule.
>
> I hope that I defined my problem better to you and that you can help
> me.
>
> Thank you in advance
>
> Natasa M.Djuric
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, fred buhl <wfbuhl@l...>
> wrote:
>> Natasa,
>>
>> Perhaps you could tells us what EPlus input parameters you are
> varying
>> for your optimization. Then we could comment on what
> discontinuities you
>> might expect.
>>
>> The most obvious barrier to using EPlus in an optimization process
> is the
>> variable number of warmup days. When the number of warmup days
>> changes as you vary the chosen parameters, the optimization
> process
>> encounters
>> a serious discontinuity.
>>
>> Fred Buhl
>>
>> natasamdj wrote:
>>
>>> Dear,
>>> I have used EnergyPlus for the simulation of baseboard heater.
> Also,
>>> I have used GenOpt as well. I have figured almost all
> mathematical
>>> models either from User Manual or by myself.
>>>
>>> I saw if I make the optimization of the parameters defined with
>>> Schedule Type, it impies the suddenly jump in the objective
> function
>>> each time when the parameter is changed.
>>>
>>> Also, I notice that if there is a changing in SetIndoor
> temperature
>>> (defined in Schedule Type) then the suddenly jump of HeatRate
>>> occurs. The behavoir of Baseboard Heater is defined by NTU
> method.
>>> But, in that transient moment it is not possible to connect all
>>> necessary parameters (zone temperature, water flow, specific
> heat,
>>> supply water temperature) by using the NTU method.
>>>
>>> Please, can you give some advice about that mathematical model?
>>>
>>> Thank you in advance.
>>>
>>> Natasa M.Djuric
>>>
>>>
>>>
>>>
>>>
>>> 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.
>>>
>>> Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>
>
>
>
>
> 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.
>
> Yahoo! Groups Links
>
>
>
>
>
>
------------------------ Yahoo! Groups Sponsor --------------------~-->
<font face=arial size=-1><a href="http://us.ard.yahoo.com/SIG=12h0bhhm1/M=362335.6886445.7839731.1510227/D=groups/S=1705007389:TM/Y=YAHOO/EXP=1124239323/A=2894361/R=0/SIG=13jmebhbo/*http://www.networkforgood.org/topics/education/digitaldivide/?source=YAHOO&cmpgn=GRP&RTP=http://groups.yahoo.com/";>In low income neighborhoods, 84% do not own computers. At Network for Good, help bridge the Digital Divide!</a>.</font>
--------------------------------------------------------------------~->
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.
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/EnergyPlus_Support/
<*> 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/