<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
Juan Francisco,<br>
Are you trying to model an electric heater that has a significant
thermal mass? Or is this a situation in which you have to limit the
power to the electric heater as it warms up and cools down? I think
if you are trying to model the first case, you can use Type963 from
the TESS HVAC Library. The model is of a simple lumped capacitance
so it would model the mass of your heater. It also has a heat gain
input to it for the actual output of the electric coil. In the
second case (limiting the power to the heater during
warmup/cooldown) you might start with Type980 in the TESS
Controllers Library. This Type computes the elapsed time since the
last time a control signal changed states.<br>
Best,<br>
David<br>
<br>
<br>
On 4/20/2012 05:49, JUAN FRANCISCO BELMONTE TOLEDO wrote:
<blockquote cite="mid:D23065E5-8312-47B3-A3B4-F9DF685B07F4@mimectl"
type="cite">
<div dir="ltr" id="idOWAReplyText8017">
<div dir="ltr"><font color="#000000" face="Theano Modern"
size="3">Hello all.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="Theano Modern">i need to model the
exponential power curve warm up/cool down of an electric
heater.</font></div>
<div dir="ltr"><font face="Theano Modern">In this way i would
need to create a kind of reset time (time=0) in a particular
moment of time (when a schedule [forcing funtion] says) to
initiate the <font face="Theano Modern">warm up/cool down
steps.</font></font></div>
<div dir="ltr"><font face="Theano Modern">My question is if this
can be done just by means of an equation type?, as i see
variable TIME is in hours and always from the beginning of
simulation.....</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font face="Theano Modern">Thanks and Regards.</font></div>
<div dir="ltr"> </div>
<div dir="ltr"><font color="#000000" face="Arial"><em><span
style="FONT-STYLE: normal; FONT-FAMILY: 'Comic Sans MS';
COLOR: blue; FONT-SIZE: 8pt; mso-bidi-font-style:
italic"><font size="1">Juan Francisco Belmonte Toledo</font></span></em><span
style="FONT-FAMILY: 'Comic Sans MS'; COLOR: blue;
FONT-SIZE: 8pt; mso-bidi-font-style: italic"><br>
</span><span style="FONT-FAMILY: 'Comic Sans MS'; COLOR:
blue; FONT-SIZE: 8pt; mso-bidi-font-style: italic"><font
size="1"><em><span style="FONT-STYLE: normal;
FONT-FAMILY: 'Comic Sans MS'; mso-bidi-font-style:
italic">Universidad de Castilla-La Mancha</span></em><br>
<em><span style="FONT-STYLE: normal; FONT-FAMILY: 'Comic
Sans MS'; mso-bidi-font-style: italic">Campus
Universitario. Avda. de España, s/n</span></em><br>
<em><span style="FONT-STYLE: normal; FONT-FAMILY: 'Comic
Sans MS'; mso-bidi-font-style: italic">02071
Albacete. Spain </span></em></font></span><span
style="FONT-FAMILY: 'Comic Sans MS'; FONT-SIZE: 8pt"><br>
<br>
</span></font></div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
TRNSYS-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:TRNSYS-users@cae.wisc.edu">TRNSYS-users@cae.wisc.edu</a>
<a class="moz-txt-link-freetext" href="https://mailman.cae.wisc.edu/listinfo/trnsys-users">https://mailman.cae.wisc.edu/listinfo/trnsys-users</a>
</pre>
</blockquote>
<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
P:+1.608.274.2577
F:+1.608.278.1475
<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>
</body>
</html>