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Dear trnsys users,<br>
<br>
I am sorry to re-send my email, but I really need to know how the
conduction in the walls is handled with time speps shorter than the
timebase in order to explain these steps in my surfarce temperatures.
I've read the manual, but I'm afraid to say falsehoods...<br>
<br>
Any help GREATLY appreciated.<br>
Thanks in advance.<br>
<br>
Thibaut Vitte.<br>
<br>
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<th align="right" nowrap="nowrap" valign="baseline">Sujet : </th>
<td>Surface temperature</td>
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<th align="right" nowrap="nowrap" valign="baseline">Date : </th>
<td>Wed, 18 Nov 2009 18:43:03 +0100</td>
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<th align="right" nowrap="nowrap" valign="baseline">De : </th>
<td>Thibaut VITTE <a class="moz-txt-link-rfc2396E" href="mailto:thibaut.vitte@h3c-energies.fr"><thibaut.vitte@h3c-energies.fr></a></td>
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<th align="right" nowrap="nowrap" valign="baseline">Pour : </th>
<td><a class="moz-txt-link-abbreviated" href="mailto:trnsys-users@cae.wisc.edu">trnsys-users@cae.wisc.edu</a></td>
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<th align="right" nowrap="nowrap" valign="baseline">Références : </th>
<td><a class="moz-txt-link-rfc2396E" href="mailto:mailman.2398.1258477048.26873.trnsys-users@cae.wisc.edu"><mailman.2398.1258477048.26873.trnsys-users@cae.wisc.edu></a></td>
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Dear Trnsys users,<br>
<br>
I am studying an electric radiant floor heating, and studying precisely
its regulation.<br>
I need to make the calculations with a very short timestep of one
minute.<br>
I modelized my floor with an active layer. I did'nt look very well to
the flow specifications, segmentation, etc, since I put a flowrate
equals to zero, and put my regulator's output (the power delivered by
my electrical wires) as a gain to this active layer.<br>
When I looked to the results, I saw that the regulation seemed to have
a strange behaviour, with a type of hourly pattern. I saw the same
thing to my surface temperature. I tried to increase the timebase in
trnbuild, and my hourly "pattern" became a 2 hours pattern. (See
pictures attached)<br>
<br>
I understand that the behaviour of a radiant floor is clearly linked
with the timebase used. And, we can't decrease this timebase so much
for heavywalls.<br>
<br>
So my questions are:<br>
Am I right? Is it a consequence of the function transfers, that make
the surface temperature vary with hourly steps, even if the timestep is
smaller? <br>
Can someone explains me better this phenomenon?<br>
Is it possible to eliminate this behaviour?<br>
Are the calculations made still correct, or the energy balance is wrong
with this timestep? <br>
<br>
Thanks in advance.<br>
<br>
Regards<br>
<br>
Thibaut Vitte<br>
<br>
<img src="cid:part1.08020309.04030903@h3c-energies.fr" alt=""><br>
<br>
<img src="cid:part2.00040002.07030902@h3c-energies.fr" alt=""><br>
<br>
<img src="cid:part3.00090106.09070905@h3c-energies.fr" alt=""><br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Thibaut Vitte
<a class="moz-txt-link-abbreviated" href="mailto:thibaut.vitte@h3c-energies.fr">thibaut.vitte@h3c-energies.fr</a>
H3C Energies
Services et Conseils en énergie
35 Ch. du vieux Chêne
38 240 Meylan
Tel. 04 76 41 88 66
Fax. 04 76 41 28 94
Mob. 06 23 42 05 07
<a class="moz-txt-link-abbreviated" href="http://www.h3c-energies.fr">www.h3c-energies.fr</a></pre>
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