[TRNSYS-users] problem of simulation for counter flow in the building by contam

David BRADLEY d.bradley at tess-inc.com
Mon Sep 27 07:17:33 PDT 2010


Tao,
   CONTAM itself has two different models for bi-directional flow; a 
"one opening" and a "two opening" model. Only the "two-opening" model is 
implemented in TRNSYS Type97. When you set up your *.air file in the 
CONTAM-W interface, specify all of the large vertical openings through 
which you want there to be two-way flow as "two-opening" air flow paths.

   As for your other question, I'm not sure exactly what is happening 
there but it seems clear that the model is simply not converging. If you 
do not connect the wind data to your building, Type97 (CONTAM's) 
assumption is that the windspeed is always zero. However, because the 
Type is trying to solve a pressure balance, you still need to make sure 
that there are enough openings in the envelope of your building because 
ambient pressure still has an important effect.

   What I would recommend that you do is to run the TRNSYS/CONTAM 
example and then begin modifying the project one step at a time to make 
it more like the building you are trying to simulate. For example, you 
could start by disconnecting the windspeed input to Type97, then you 
could change the zone volumes of both your Type56 and your Typr97 zones 
to be more like your real building, then you could alter the zones 
themselves (add more, remove some), etc.

Kind regards,
  David

On 9/24/2010 05:34, Yujun TAO wrote:
> Hello,
> I want to simulate some counter flows in the building by natural 
> ventilation with Contam, is it necessary to model 2 orifices in every 
> wall in the Contam model to give 2 directions different?
> Whatever, i tried 2 ways: 1 orifice and 2 orifices, but none works. I 
> always get a error message that there are a window panel is out of 
> bounds or a zone in the building attain the abosolute 0 K. I don't use 
> the wind data of the weather file because i study only the stack 
> effect. I can't understand. Someone could tell why?
> Here is attached file.
> Thanks in advance for your helps.
>
> TAO
>
>
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> TRNSYS-users at cae.wisc.edu
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>    

-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

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

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