[TRNSYS-users] (no subject)

[thornton at tess-inc.com]

On 2022-04-29 05:13, berkane ahlem via TRNSYS-users wrote:

> I'm modeling a system where  the solar cycle is separate from the GSHP
> cycle for heating , cooling and DHW.  I have just a problem in
> passive cooling mode  , Diverting Valve-3 will send all of the flow to
> the borehole in periode (3624 h- 5832 h ) .The  relation expresses the
> control function  for Type11d-1 , Type11d-2 and  Diverting Valve-2 ,
> Diverting Valve-3  by Equa-1, Equa-2,Equa-3.
>  I am confused about the equations that I write. If they are correct,
> please  clear my confusion .

You have no capacitance in your loops (pipes), a 1 hour timestep (should 
be 1-5 minutes), and have paid no attention to the calling order.  I'm 
surprised that your simulation even runs without getting a ton of 
convergence errors.  As we have mentioned on this mailing list many, 
many times, you are best off starting with just one of the loops and get 
that working correctly (solar to tank look for example).  Then build in 
another smaller piece and make sure that's behaving as intended before 
adding the next loop/components.  And please take the time to make your 
model easier to understand by using varying line colors and thicknesses, 
changing the way the flow icons point, etc.  The time you take to make 
it look more understandable almost always pays off if you need to 
re-open your project after some time away from it...

I looked at your control equations and they are very difficult to 
understand.  Single variable names make it hard to figure out what you 
are trying to do.  What is easier to understand?

Control_SolarPump = OK_Differential1*OK_Differential2

-or -

a = b*c

The other thing to remember is that to use controllers with hysteresis 
whenever possible instead of boolean equations like a = GT(T,60).  
Convergence with boolean equations can be tricky.

Jeff
-- 
Jeff W. Thornton
President
Thermal Energy System Specialists LLC
3 N. Pinckney Street, Suite 202
Madison WI 53703 USA
(608) 274-2577
www.tess-inc.com