[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[EnergyPlus_Support] Re: primary-secondary plant loop system with different setpoint temperatures



Mike,
unfortunately, your suggestion did not work in my case. I want to 
model a system with one primary loop which serves multiple secondary 
loops. And the secondary loops have different setpoint temperatures. 
So the setpoint temerature for the primary loop is the lowest setpoint 
temperature of the secondary loops.
Thank you for your help,

Christian

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte" 
<mjwitte@g...> wrote:
>
> No.  There are two plant heat exchanger objects, HEAT EXCHANGER:
HYDRONIC:FREE 
> COOLING and HEAT EXCHANGER:PLATE:FREE COOLING, but they are designed 
to work on 
> the condenser side.
> 
> To solve your current problem, I would suggest modeling both the 
primary and 
> seconday loops at the desired secondary setpoint temperature.  
Consider what 
> would change in the actual system where the primary loop is colder 
than the 
> secondary loop.  The primary pumping power would be lower, but the 
chiller 
> power consumption would be higher.  Both of these effects can be 
modeled by 
> adjusting the inputs for the primary pump and chiller(s).  Not the 
best 
> solution, but it should give a reasonable answer.
> 
> Mike
> 
> 
> On 7 Nov 2005, at 8:17, christian1855 wrote:
> 
> > Mike,
> > is there any other E+ object which can be used to to build up a 
> > primary-secondary plant loop system with different setpoint 
> > temperatures? 
> > I have searched the documentation for a water to water heat 
exchanger 
> > to connect the plant loops, but I haven't found anything.
> > 
> > Christian
> > 
> > 
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte" 
> > <mjwitte@g...> wrote:
> > >
> > > 1.  No, the current connection component assumes that the 
secondary 
> > water 
> > > temperature will be the same as the primary.  A controllable 
> > connection 
> > > component is planned for the next major release in 2006.
> > > 
> > > 2.  This is a known bug in 1.2.3.023 which affect certain types 
of 
> > systems.  
> > > The errors occur in some of the early iterations due to a 
misplaced 
> > pump heat 
> > > adjustment.  These errors can be ignored and the fix has a very 
> > minimal impact 
> > > on overall results.
> > > 
> > > Mike
> > > 
> > > 
> > > On 4 Nov 2005, at 17:29, christian1855 wrote:
> > > 
> > > > Can I use the CONNECTION COMPONENT:PLANTLOOP to build up a 
> > primary-
> > > > secondary plant loop system with different setpoint 
temperatures?
> > > > 
> > > > I've tried to adapt the TermReheatPri-SecLoop example:
> > > > Just added a new setpoint schedule with const. 12°C and used 
this 
> > > > schedule in the secondary loop setpoint manager.
> > > > But this did not work as expected. I.e. it does not change the 
> > > > temperature in the secondary loop.
> > > > Have I forgotten something?
> > > > 
> > > > 
> > > > And by the way, even the original TermReheatPri-SecLoop 
example 
> > gives 
> > > > a lot of warnings (E+ v1.2.3). 
> > > >  ** Warning ** Error -- Mass Flow Rate Calculation in Plant 
> > > > Loop=CHILLED WATER PRIMARY LOOP, Outlet and Inlet differ by 
more 
> > than 
> > > > tolerance.
> > > > Should I ignore this warnings?
> > > > 
> > > > Christian
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 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
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> 
> 
> 
> ========================================================
> Michael J. Witte, GARD Analytics, Inc.
> EnergyPlus Testing and Support      
> EnergyPlus-Support@g...
>






------------------------ Yahoo! Groups Sponsor --------------------~--> 
Get Bzzzy! (real tools to help you find a job). Welcome to the Sweet Life.
http://us.click.yahoo.com/A77XvD/vlQLAA/TtwFAA/dkFolB/TM
--------------------------------------------------------------------~-> 

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

<*> 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/