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<p>Ali,</p>
<p> If you are only getting one or two non convergence warnings
throughout the simulation then I would not worry about them. If
you are getting a lot of them then you probably need to shorten
your time step (1-5 minutes is appropriate) and add thermal
capacitance to the loops. Types1, 5, and 114 are all quasi steady
state models and so react instantaneously to controls and weather
changes. Try adding pipes to the loop and make sure that their
volume is greater than the volume that the pump can transfer in
one timestep.</p>
<p>kind regards,</p>
<p> David</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 06/06/2021 16:46, Ali Shahrouzian
via TRNSYS-users wrote:<br>
</div>
<blockquote type="cite"
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<p class="MsoNormal"><span lang="EN-US">Dear all<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">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’m modelling a solar
system for water heating applications. I’ve used a type
1b(solar collector), a type 5b (HX) and a type 114 (pump)
and connected them as a closed loop. When I run a
simulation, it gives: TRNSYS Message 441 (<u>The inputs to
the listed units have not converged at this time step. The
values at the last iteration will be used and the
simulation will proceed</u>).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">When I decrease the pump
flowrate (for example around 50 kg/hr), it works. However,
it has another issue: the outlet temperature from heat
exchanger equals to the heat exchanger inlet temperature!!!<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 would appreciate if
someone guide me in that case<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">Ali<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<br>
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<pre class="moz-quote-pre" wrap="">_______________________________________________
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<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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