[TRNSYS-users] Trnsys message 441

[David BRADLEY]

Ali,

  If you are only getting one or two non convergence warnings throughout 
the simulation then I would not worry about them. If you are getting a 
lot of them then you probably need to shorten your time step (1-5 
minutes is appropriate) and add thermal capacitance to the loops. 
Types1, 5, and 114 are all quasi steady state models and so react 
instantaneously to controls and weather changes. Try adding pipes to the 
loop and make sure that their volume is greater than the volume that the 
pump can transfer in one timestep.

kind regards,

  David


On 06/06/2021 16:46, Ali Shahrouzian via TRNSYS-users wrote:
>
> Dear all
>
> Hi,
>
> I’m modelling a solar system for water heating applications. I’ve used 
> a type 1b(solar collector), a type 5b (HX) and a type 114 (pump) and 
> connected them as a closed loop. When I run a simulation, it gives: 
> TRNSYS Message 441 (_The inputs to the listed units have not converged 
> at this time step. The values at the last iteration will be used and 
> the simulation will proceed_).
>
> When I decrease the pump flowrate (for example around 50 kg/hr), it 
> works. However, it has another issue: the outlet temperature from heat 
> exchanger equals to the heat exchanger inlet temperature!!!
>
> I would appreciate if someone guide me in that case
>
> Ali
>
>
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> TRNSYS-users at lists.onebuilding.org
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI  53703 USA

P:+1.608.274.2577
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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