[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TRNSYS-users] Types 2a and 2b



Hi David,

 

thanks for your answer. I followed your suggestion and unfortunately the problem is still there.  I set up the controller with 9/3, 10/2, and 11/1 which didn’t work. Going further would have significant impact on my results. Are there other ways to try to improve the operation of the controller?

 

Best regards,

Benjamin

 

 

From: David BRADLEY [mailto:d.bradley@tess-inc.com]
Sent: Tuesday, August 25, 2015 6:11 PM
To: TRNSYS users mailing list at OneBuilding.org; Manrique Delgado Benjamin
Subject: Re: [TRNSYS-users] Types 2a and 2b

 

Benjamin,
  The Type2 Powell's Method mode is not appropriate for what you are trying to do. If you are getting more chatter in your collector control than you want or if you are running at times when the collector cannot sustain an outlet temperature higher than the tank temperature then you need to modify the temperature deadbands in the differential controller that turns on and off the collector pump. A "turn on" temperature difference of 10C and a "turn off" temperature difference of 2C would be good starting places.
regards,
 David

On 08/25/2015 09:05, Manrique Delgado Benjamin wrote:

Hi,

 

I am getting poor results by using Type2b to control a solar collector, since it operates at some time-steps when it shouldn’t (for example, when the temperature coming out from the tank is higher than the SC output temperature, effectively cooling the tank). I tried to switch to Type 2a, and changed to Powell’s method, but the model won’t run since I am using an Aquastat in a different part of the model, and that one requires the Successive substitution method.

Has anyone faced this problem before?

I am using a 0.25 hour resolution.

 

In advance, thanks for your help.

 

Best regards,

Benjamin Manrique D.

 




_______________________________________________
TRNSYS-users mailing list
TRNSYS-users@lists.onebuilding.org
http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org



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