[TRNSYS-users] Problem Ventilation in TRNFLOW

[freppelw at noirot.fr]

Dear Jakob,

Thank you for your reply. Indeed, I didn't realize that there was a dead 
end in the CELLIER room. I added a duct to the ventilation network and 
now it works.

However, this doesn't solve my heating problem. I realized that when the 
heating power supply is not high enough to reach the target temperature, 
the simulation stops, saying that the number of iteration did not reach 
to a convergence.
Here is what I did exactly:
1) I set up a heating power supply in the room SALON3, with 3600 kJ/h
The simulation stopped before the end
2) I set up the heating demand to unlimited power
It worked
3) I set up a heating power supply in all rooms, with 3600kJ/h each
It worked

Does someone know why? it seems that TRNFLOW is not steady when the 
heating power supply is not high enough to reach the target setpoint. I 
don't quite get why?

King regards

Wirich


Le 2017-11-28 09:29, hotline via TRNSYS-users a écrit :
> Dear Wirich,
> 
> " Flow matrix is singular" means, that the flow network cannot be
> solved. This can happen if nodes are not well connected. Two rules
> must be applied here:
> 
>  	* All nodes have to be connected in ONE network
> 	* Dead ends are not allowed.
> 
> In your model, rule1 is applied but rule2 not (see red circle in the
> ).
> 
> I connected them with three dummy cracks to make it work…
> 
> LINK CR_001       : ID= 29 : FRNODE= P4         : TONODE= CELLIER    :
> FRHEIGHT=       0 : TOHEIGHT=        0 : WIOWNHF=       1 : FSCALE= 1
> 
> LINK CR_001       : ID= 32 : FRNODE= CELLIER    : TONODE= WC         :
> FRHEIGHT=       0 : TOHEIGHT=        0 : WIOWNHF=       1 : FSCALE= 1
> 
> LINK CR_001       : ID= 33 : FRNODE= WC         : TONODE= SDB        :
> FRHEIGHT=       0 : TOHEIGHT=        0 : WIOWNHF=       1 : FSCALE= 1
> 
> Best
> Jakob
> 
> __________________________________________________________________________________________________
> 
> 
> Jakob Merk M.Sc.
> 
> Transsolar Energietechnik GmbH
> 
> Curiestraße 2
> 
> 70563 Stuttgart
> 
> http://www.transsolar.com
> 
> Transsolar: KlimaEngineering- Technologien für energieeffizientes
> Bauen und Nutzerkomfort in Gebäuden
> 
> Stuttgart – München – New York – Paris
> 
> Geschäftsführer :Diplom-Ingenieur Matthias Schuler, Diplom-Ingenieur
> Thomas Auer, Diplom-Physiker Stefan Holst, Diplom-Betriebswirt Dieter
> Schnelle
> 
> Eingetragen beim Amtsgericht Stuttgart HRB 23347,
> 
> Steuernummer: 99073/00911,USt-IdNr.: DE 152272639
> 
> -----Ursprüngliche Nachricht-----
> Von: TRNSYS-users [mailto:trnsys-users-bounces at lists.onebuilding.org]
> Im Auftrag von Wirich via TRNSYS-users
> Gesendet: 24 November 2017 18:13
> An: trnsys-users at lists.onebuilding.org
> Cc: freppelw at noirot.fr
> Betreff: [TRNSYS-users] Problem Ventilation in TRNFLOW
> 
> Hi everyone,
> 
> I'm still encountering the same problem about ventilation in my
> project.
> 
> I've set all the ventilation network, and then I closed all the
> windows.
> 
> There is no heating device in the building.
> 
> I don't understand why, but at around 749 hours, I encounter this
> error:
> 
>   COMIS MESSAGE  ***** ERROR *****
> 
>   Flow matrix is singular ! This might be caused by a zone that has no
> 
> 
>   ventilation at all in this condition.
> 
>   Age of air and air change efficiency output is invalid !
> 
> And this occurs until the end of the simulation, though the simulation
> runs until the end. I only found that when I opened the .cer file.
> 
> Moreover, when I put a heating device in a room, with limited power,
> the simulation stops before the end, saying that convergence was not
> reached. Do you think this is related to the COMIS ERROR I showed just
> before?
> 
> If someone can help me, I attach all my project to this mail, with an
> illustration, in order to better understant what I did. I used
> TRNSYS17.
> 
> Thank you in advance.
> 
> King Regards
> 
> Wirich
> 
> PhD student
> 
> Laboratoy of innovative technologies, University of Picardie Jules
> Vernes Avenue des Facultés, Salouël
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