[TRNSYS-users] convergence problems because of high ventilation heat flux

[David BRADLEY]

Karol,

  Check your assumption about the way that the inside heat transfer 
coefficients are being calculated on the zone surfaces. If you have 
allowed the convection coefficients to be internally calculated then you 
can end up with convergence problems inside 56, particularly on inside 
window surfaces and even more particularly if the glass has a high u-value.

kind regards,

  David


On 08/16/2022 09:50, karol.bandurski--- via TRNSYS-users wrote:
>
> Dear Experts.
>
> We get convergence problem in Type 56. According to our investigation 
> source of error is sudden increase of ventilation flow in our schedule 
> and ventilation air temperature about 3 K lower then room air temperature.
>
> We would like to keep this control schedule and the same time avoid 
> convergence problem.
>
> So far we have increase indoor air heat capacity in zones (five 
> times), it help a bit.
>
> Do you  have any other ideas what we could do?
>
> Should we change something in Control Cards?
>
> Best,
>
> Karol
>
> ---------------------------------------------------------------------------
>
> Karol BANDURSKI Ph.D, Assistant Professor
>
> Faculty of Environmental and Energy Engineering
>
> Division of Heating, Air Conditioning and Air Protection
>
> Poznan University of Technology
>
> https://www.researchgate.net/profile/Karol_Bandurski 
> <https://www.researchgate.net/profile/Karol_Bandurski>
>
> ***
>
> dr inż. Karol BANDURSKI, Adiunkt
>
> Wydział Inżynierii Środowiska i Energetyki
>
> Zakład Ogrzewnictwa, Klimatyzacji i Ochrony Powietrza
>
> Politechnika Poznańska
>
>
> _______________________________________________
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> TRNSYS-users at lists.onebuilding.org
> http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org

-- 
***************************
David BRADLEY
Principal
Thermal Energy System 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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