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

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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