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Marco,<br>
It could be that because the VS pump, collector, and heat
exchanger model all neglect the effects of the thermal capacitance of the
liquid in the loop that you are getting a numerical problem. I would
suggest adding a pipe that has enough volume to store at least one
timestep of fluid given your simulation time step and the pump's maximum
output flow rate. You may set the losses of the pipe to 0 if you do not
wish to consider those in your simulation.<br>
Cheers,<br>
David<br><br>
<br>
At 06:44 7/10/2007, Marco Zeppetella wrote:<br>
<blockquote type=cite class=cite cite="">Content-class:
urn:content-classes:message<br>
Content-Type: multipart/alternative;<br>
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boundary="----_=_NextPart_001_01C7C2E7.ABFD7EFE"<br><br>
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<pre><font face="Courier New, Courier" size=2>Dear
users,</font></pre><font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2>I’m modelling a collector
loop that consists of a pump (variable speed), collector(type 1a), heat
exchangers…</font></pre><font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2>I’ve noticed that
increasing the mass flow rate entering in the solar collector, the output
temperature increase too… and at the contrary reducing the flow rate it
decrease.</font></pre><font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2>Probably I’m mistaking or
not considering something… but I don’t understand
what</font></pre><font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2> </font></pre>
<font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2>Best
regards</font></pre><font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2> </font></pre>
<font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2>Marco
Zeppetella</font></pre><font face="Courier New, Courier"></font><br>
<pre><font face="Courier New, Courier" size=2> </font></pre>
<font face="Courier New, Courier"></font><font size=2><b>
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Marco Zeppetella</b><br>
Departamento de Investigación, Desarrollo e
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