<div dir="auto">Hi Amirreza,<div dir="auto"><br></div><div dir="auto">I am no expert but I would try to run the simulation with a much smaller timestep. Furthermore if the collectors have no thermal capacitance this control system is likely to be unstable and oscillate. Try using a temperature from the tank into the controller.</div><div dir="auto"><br></div><div dir="auto">Regards</div><div dir="auto"><br></div><div dir="auto">Oriol Casal</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Apr 29, 2017 09:36, "Amirreza Heidary via TRNSYS-users" <<a href="mailto:trnsys-users@lists.onebuilding.org">trnsys-users@lists.onebuilding.org</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><img width="0" height="0" class="m_7142883668499154845mailtrack-img" style="float:right" alt="" src="https://mailtrack.io/trace/mail/0a28719c14bd30ad7c353f53cc4b911f030d1d23.png?u=1249159">Dear All<div>I'm using a 5 collectors in series with a differential controller to turn on the pump when the difference of collector outlet and inlet temperatures is more than 5 and turn it off when it is less than 2.But the signal and collector output temperatures are fluctuating too much, also the signal is not compatible with temperature <a href="http://variations.as" target="_blank">variations.as</a> you can see in the following diagram, the signal is 1 when the outlet temperature is at maximum ! </div><div>(red line is collector outlet temperature and orange line is the controller signal)</div><div><img src="cid:ii_15bb8a2dac2c44f8" alt="Inline image 1" width="473" height="245"></div><div><img src="cid:ii_15bb8a3362afa50c" alt="Inline image 2" width="473" height="222"> <br clear="all"><div><div class="m_7142883668499154845gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div><div style="text-align:right"><div style="text-align:left"><br></div><div style="text-align:left">------------------------------<wbr>------------------------------<wbr>------------------------------<wbr>------------------------------<wbr>--------------------------<br><img src="https://docs.google.com/uc?id=0B56a_joPrCZuYUg5aFkzTlR2dTg&export=download" width="96" height="96"><br></div><div style="text-align:left;font-size:12.8px"><b><font face="georgia, serif">amirrezaheidary</font></b></div><div style="text-align:left;font-size:12.8px"><i><font color="#444444" face="trebuchet ms, sans-serif">master student of energy systems Engineering</font></i></div><div style="text-align:left;font-size:12.8px"><font color="#444444" face="trebuchet ms, sans-serif"><i>Sharif university of technology</i></font></div><div style="text-align:left;font-size:12.8px"><font color="#444444" face="trebuchet ms, sans-serif"><i>Tehran-Iran</i></font></div><div style="text-align:left;font-size:12.8px"><font face="georgia, serif"><i>E-mail address</i></font><font face="comic sans ms, sans-serif">:</font></div><blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;font-size:12.8px;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid"><p style="text-align:left"><font color="#1155cc" face="tahoma, sans-serif"><a href="mailto:heidari@energy.sharif.edu" target="_blank">heidari@energy.sharif.edu</a></font></p></blockquote><blockquote style="margin:0px 0px 0px 0.8ex;padding-left:1ex;font-size:12.8px;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid"><p style="text-align:left"><font face="tahoma, sans-serif" style="color:rgb(17,85,204)"><a style="color:rgb(17,85,204)" href="mailto:sm_mousavi@pwut.ac.ir" target="_blank">a</a><a href="mailto:mirrezaheidarysbu@gmail.com" target="_blank">mirrezaheidarysbu@gmail.com</a></font></p></blockquote><div style="text-align:left"><b style="color:rgb(0,0,0);font-family:"times new roman","new york",times,serif;font-size:small"><span lang="EN-GB" style="color:green;font-family:Webdings">P</span></b><i style="color:rgb(0,0,0);font-family:"times new roman","new york",times,serif;font-size:small"><span lang="EN-GB" style="color:navy"> </span></i><b style="color:rgb(0,0,0);font-family:"times new roman","new york",times,serif;font-size:small"><i><span lang="EN-GB" style="color:green">Save a tree... Please don't print this E-mail unless you really need to.</span></i></b><b><font color="#0000ff"><font size="1"> </font></font></b><br></div><br></div><font color="#0000ff"><font size="1"><br></font></font></div><div><font color="#0000ff"><font size="1"><br></font></font><div><div><font color="#0000ff"><font size="1"><br></font></font></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
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