[TRNSYS-users] cooling rate in a solar powered cooling system, convergence problem

[David Bradley]

Sotiris,
 If your absorption chiller is producing chilled water at a particular 
flow rate and is connected to a series of fan coils then the only way to 
increase the capacity of the fan coils is to modify their air-side flow 
rate and to put on a larger absorption chiller. Changing the size of the 
absorption chiller involves changing the external files that are 
referenced by Type107.

 As for convergence, if you are getting a warning saying that 
convergence could not be reached, that means that TRNSYS was unable to 
solve your system to within the specified tolerances at that time step. 
If you are getting a few such warnings throughout an annual simulation, 
it is not something to be concerned about. If you are getting a lot of 
those warnings then probably the system or the controls are not well 
enough defined. I would recommend that you read a few sections of the 
documentation to get a good understanding of how TRNSYS is trying to 
solve your system:

Section 7.3.17 of the 07-TRNEdit manual "the SOLVER statement"
Section 5.1 of the 05-Mathematical Reference manual (the first section 
under "controllers")

Kind regards,
 David


SOTIRIS KONSTANTELOS wrote:
> Dear TRNSYS users,
>
> I'm trying to simulate a solar powered cooling system, which uses an 
> absorption chiller (type 107), in order to produce chilled water for 
> the fan coils which are connected to the building.The problem is that 
> i cannot increase the total cooling rate (fan coil's output) no matter 
> what i do.What parameters should i change and where should i focus 
> on?Is it probable an error between the components (at connections)?
>
> There is also another broblem.Sometimes error manager warns me about a 
> convergence problem in some units.How can i fix this problem?Maybe 
> from the control cards menu?What exactly is this convergence problem, 
> which is fixed if i use default parameter values?
>
> My regards,
> Sotiris
>
>
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Thermal Energy System Specialists (TESS), LLC 
David BRADLEY                      22 N. Carroll Street - Suite 370 
Partner                            Madison, WI 53703 
                                   USA
P: +1.608.274.2577 
F: +1.608.278.1475
E-mail: bradley at tess-inc.com 
Web Pages:  http://www.tess-inc.com    and      http://www.trnsys.com

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