<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=iso-8859-1"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:36.0pt;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:503395766;
mso-list-type:hybrid;
mso-list-template-ids:1425166686 201916431 201916441 201916443 201916431 201916441 201916443 201916431 201916441 201916443;}
@list l0:level1
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-AU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear TRNSYS folk,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I was wondering if anyone can shed some light on Type60, in particular low flow operation of the immersed heat exchanger model (IHX). I’m using the 16.01.0003 edition of TRNSYS and 2005-01-31 – Mku version of Type60.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’ve been happily simulating high-flows (>40kg/hr per m^2 collector area) but run into non-convergence warnings (and infinite loops) with, for example, a specific collector flow of 10kg/hr; storage volume 400 litres with 25 nodes and a simulation time step between 3 and 6 mins; <a href="http://sel.me.wisc.edu/trnsys/mailinglist/archive2004/msg00640.html">http://sel.me.wisc.edu/trnsys/mailinglist/archive2004/msg00640.html</a>. I have tried reducing the flow rate to a minute and even less but non-convergence persists (for an annual simulation that doesn’t abort I get between 2 and 5 thousand warnings). Some exemplary energy balances (measured with Type60) are as follows;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>10kg/hr:<o:p></o:p></p><p class=MsoNormal>Q_coll + Q_aux = 13934081.86 kJ<o:p></o:p></p><p class=MsoNormal>Q_losses + Q_dhw = 13920759.15 kJ<o:p></o:p></p><p class=MsoNormal>Q_coll + Q_aux – Q_losses – Q_dhw = Q_err = 13322.71 kJ<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>50kg/hr:<o:p></o:p></p><p class=MsoNormal>Q_coll + Q_aux = 13961476.57 kJ<o:p></o:p></p><p class=MsoNormal>Q_losses + Q_dhw = 13947209.16 kJ<o:p></o:p></p><p class=MsoNormal>Q_coll + Q_aux – Q_losses – Q_dhw = Q_err = 14267.41 kJ<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Is this all within reason? If not, any tips?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Kind regards,<o:p></o:p></p><div class=MsoNormal align=center style='text-align:center'><span lang=DE-CH style='font-size:12.0pt;font-family:"Times New Roman","serif"'><hr size=2 width="100%" align=center></span></div><p class=MsoNormal><b><span lang=DE-CH style='font-size:12.0pt;font-family:"Times New Roman","serif"'>William Logie</span></b><span lang=DE-CH style='font-size:10.0pt;font-family:"Arial","sans-serif"'><br>Forschung / Research</span><span lang=DE-CH style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><p class=MsoNormal><span lang=DE-CH style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Institut für Solartechnik SPF: <a href="http://www.solarenergy.ch/spf.php?lang=de&fam=44&tab=3" title="http://www.solarenergy.ch/spf.php?lang=de&fam=44&tab=3"><span style='color:blue'>Adresse</span></a> / <a href="http://www.solarenergy.ch/spf.php?lang=de&fam=41&tab=1" title="http://www.solarenergy.ch/spf.php?lang=de&fam=41&tab=1"><span style='color:blue'>Website</span></a><br>Hochschule für Technik Rapperswil HSR<br>Tel. +41 55 222 48 34<br>Fax +41 55 222 48 44</span><span lang=DE-CH style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p><div class=MsoNormal align=center style='text-align:center'><span lang=DE-CH style='font-size:12.0pt;font-family:"Times New Roman","serif"'><hr size=2 width="100%" align=center></span></div><p class=MsoNormal><o:p> </o:p></p></div></body></html>