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<span lang="EN-US">Benjamin,<br>
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.<br>
regards,<br>
David<br>
<br>
</span><br>
<div class="moz-cite-prefix">On 08/25/2015 09:05, Manrique Delgado
Benjamin wrote:<br>
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<p class="MsoNormal"><span lang="EN-US">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">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.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Has anyone faced this
problem before?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I am using a 0.25 hour
resolution.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">In advance, thanks for
your help.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Benjamin Manrique D.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<pre class="moz-signature" cols="72">--
***************************
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
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