[TRNSYS-users] Type 1716: ROTARY DESICANT DEHUMIDIFIER - Maximum air flow rate?

[David BRADLEY]

Marcus,
   Make sure that you are using a short timestep (1-5 minutes) and that 
there is enough thermal capacitance in your flow loops. It may be that 
10000 kg/h of air flowing through the device in the course of one time 
step is causing the system to be unstable. There was a recent post on 
this forum concerning a cooling tower connected to an absorption chiller 
that turned out to be exactly the same problem; far too much energy 
transferred in a system with far too little capacitance for the time 
step selected. The time step has to be shorter than the time constant of 
your system.
Kind regards,
  David


On 9/15/2013 08:36, Marcus wrote:
> I am running type 1716. When I run with 1000 kg/hr flow, it simulates 
> fine. When I increase to 10000, it causes psychometric SAT error  at 
> -273K.
>
> So far, I will use the wheel at 1/10 the flow, and then multiply after 
> the wheel to get back to our design flow, just wondering if this is a 
> known bug or I suppose the model isn't valid at such a flow rate?
>
> Cheers,
> Marcus
>
>
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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

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http://www.trnsys.com

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