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[TRNSYS-users] Convergence problem for the internal regulation



Hello,

 

We need to modelize a few stories building in a cosimulation TRNSYS/CONTAM.

The thermal part is handled by TRNSYS with a Type 56 and the aeraulic part by CONTAM with a Type 98.

 

The model works but encounters several convergence problems as noticed in the *.lst file. The model includes daily windows openings that coincide with the convergence problem occurrences. Furthermore, most of the rooms are heated with an ideal system of which power is limited to 100 W.m-2. The setpoint temperature is fixed thanks to a schedule in the "Heating type manager"

 

Removing this heating resolves the convergence problem, but these convergence faults cannot be fixed by reducing the time step, modifying the number of iterations, or convergence tolerance of Simulation Studio. The following error message shows that the faults are not directly generated in the "simulation studio" calculation but by Type 56 and are indeed a consequence of the heating of the building Type 56 model.

 

--------------------------------------------------------

*** Notice at time        :       130.000000

    Generated by Unit     :    56

    Generated by Type     :    56

    Message               :  TIME =     130.000  More than 6 iterations for internal regulation HEATING/COOLING

 

 

*** Warning at time       :       130.000000

    Generated by Unit     :    56

    Generated by Type     :    56

    Message               :  TIME =     130.000  CONVERGENCE NOT ATTAINED USING INTERNAL REGULATION FOR HEATING/COOLING

-------------------------------------------------------

 

This fault appears while the *.dck maximal iteration is fixed to 500.

 

Has somebody already encountered this problem in Simulation studio ?

Is it possible and if yes, how the numerical parameters (tolerance of convergence, number of iterations, …) of Type56 can be modified? Do you have any idea for another solution to solve this problem?

 

Thank you