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Imen,<br>
I assume you are using TRNSYS 16 or 17. If so, you can use the PID
controller (Type23). Please pay particular attention to the mode
setting (parameter 1) and if you use mode zero, set a small time step
and make sure that you have some thermal capacitance in your system.
Most heat exchanger models ignore thermal capacitance and compute a
steady state solution. Without sufficient capacitance in the system (in
the form of pipes and tanks), it might be very hard to control the
outlet temperature of your heat exchanger.<br>
Best,<br>
David<br>
<br>
On 6/27/2010 10:17, imen chraief wrote:
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<p class="MsoNormal"
style="margin-bottom: 0.0001pt; line-height: normal;"><span
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lang="EN-US">Dear </span></p>
<p class="MsoNormal"
style="margin-bottom: 0.0001pt; line-height: normal;"><span
style="font-size: 12pt; font-family: "Times New Roman","serif";"
lang="EN-US">I used a heat exchanger (air /water) the hot side
fluid is water extracted from a storage tank connected to solar thermal
collector and the cold side fluid is an air.</span></p>
<p class="MsoNormal"
style="margin-bottom: 0.0001pt; line-height: normal;"><span
style="font-size: 12pt; font-family: "Times New Roman","serif";"
lang="EN-US">Hot side inlet temperature and cold side inlet
temperature are known and are in function of time, and the cold side
outlet
temperature is imposed 68°C; how achieve a constant temperature with
this model?
</span></p>
<pre><span
style="font-size: 12pt; font-family: "Times New Roman","serif";"
lang="EN-US">Please help me the fastest possible it is very urgent; thank you and <span
style=""> </span>apologize for this bad English <span style=""> </span>text</span></pre>
<pre><span
style="font-size: 12pt; font-family: "Times New Roman","serif";">Best regards</span></pre>
<pre><span
style="font-size: 12pt; font-family: "Times New Roman","serif";">imen</span></pre>
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<br>
<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI 53703 USA
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F:+1.608.278.1475
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