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<p>Roberto,</p>
<p> The two things to check in this situation are the timestep and
the amount of thermal capacitance in the system. A 0.1h timestep
is still fairly long in my experience. I typically use a 1 minute
timestep. As far as thermal capacitance is concerned, watch out
for loops that contain all quasi steady state models. For instance
your cooling tower loop and cooling coil loops do not have any
pipes in them. I would add sufficient volume (either piping or a
buffer tank) to each loop so that the volume of liquid transferred
by the pump in a single time step is less than the volume modeled
in the loop.</p>
<p>kind regards,</p>
<p> David</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 11/28/2021 22:51, Roberto Pippia via
TRNSYS-users wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAA4OOv9xr7Zy2NWde0Ht-dOtAm8S3vT-uSuKw3p461kOFtqNjw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">Hi,
<div>I have constructed a cooling system for a multi-zone
building, incorporating an absorption chiller, cooling tower,
and other components as shown in the attached image. When I
run the model in TRNSYS an error message eventually appears
due to the model reaching the maximum number of warnings that
are set in the settings for the model. The warnings stilled in
the error manager are all the same as shown below.</div>
<div><br>
</div>
<div><span style="background-color:rgb(255,255,255)"><font
color="#ff0000">TRNSYS Message 441: The inputs to the
listed units have not converged at this timestep. The
values at the last iteration will be used and the
simulation will proceed<br>
(Reported information : UNITS: 42 44 45 47 48</font></span><br>
</div>
<div><span style="background-color:rgb(255,255,255)"><font
color="#ff0000"><br>
</font></span></div>
<div><font color="#000000"><span style="caret-color: rgb(255, 0,
0);">I have tried adjusting the timestep in the settings
but that has not worked as the warning appears for each
timestep whether is it set at 0.1, 0.5, or 1 hr. I have
tried increasing the number of warnings in the settings to
see if the model would complete a one-year cycle before
the error message appears, but this has not worked either.
Does anyone know how to fix this issue and get my inputs
to converge at each timestep?</span></font></div>
<div><font color="#000000"><span style="caret-color: rgb(255, 0,
0);"><br>
</span></font></div>
<div><font color="#000000"><span style="caret-color: rgb(255, 0,
0);">Regards,</span></font></div>
<div><font color="#000000"><span style="caret-color: rgb(255, 0,
0);">Roberto</span></font></div>
</div>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
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</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI 53703 USA
P:+1.608.274.2577
<a class="moz-txt-link-abbreviated" href="mailto:d.bradley@tess-inc.com">d.bradley@tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.tess-inc.com">http://www.tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.trnsys.com">http://www.trnsys.com</a></pre>
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