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<div class=Section1>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi Christopher<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I found several things to correct in your model to find the
solution:<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The main thing is that you are withdrawing some heat from your
tank at the same time as you are heating it, because your “cold side flow
rate” input for the Tank is not set to 0. <o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>In your pump, if you want an ideal pump, set the conversion
coefficient to 0, so that the pump does not heat the fluid by its inefficiencies.<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>In your auxiliary heater, you’ll have to increase your “boiling
temperature” so that it continues heating when you reach 100C (because
you reach 100 C before the end of the 10h)<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>If you play with the time step (more accurate when smaller), you’ll
see that what I called Q_to_Tank tends to the 360,000 kJ. <o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span
style='mso-list:Ignore'>5.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>However, I also plotted the “internal energy change”,
which is exactly what you want to see, it is equal to the “Q_to_Tank_kJ”
up to the point where the temperature of the tank reaches 100 C, and then the
Tank cannot accept any more energy, so you’ll see that for the last
minutes of your simulation the “internal energy change” flattens
out.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I attached the tpf so you can see all that.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Regards,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>François Badinier<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#C0504D'>Development Engineer<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#00B050'>ICAX Ltd<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:9.0pt;font-family:"Calibri","sans-serif";
color:#00B050'>1 Hatfield House <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:9.0pt;font-family:"Calibri","sans-serif";
color:#00B050'>Baltic Street West<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:9.0pt;font-family:"Calibri","sans-serif";
color:#00B050'>London EC1Y OST<o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:8.0pt;font-family:"Courier New";
color:black'><a href="mailto:alan.kiff@icax.co.uk"><span lang=EN-GB>francois.badinier@icax.co.uk</span></a></span><span
style='font-size:8.0pt;font-family:"Courier New";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:8.0pt;font-family:"Courier New";
color:black'><a href="http://www.icax.co.uk"><span lang=EN-GB>www.icax.co.uk</span></a></span><span
style='font-size:8.0pt;font-family:"Courier New";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> Haluf, Christopher
[mailto:christopher.haluf@siemens.com] <br>
<b>Sent:</b> 18 December 2009 09:07<br>
<b>To:</b> trnsys-users@cae.wisc.edu<br>
<b>Subject:</b> [TRNSYS-users] Auxiliary Heater and Stratified Storage Tank<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Dear
TRNSYS-Users,<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>I'm
modelling an easy system that consists of a pump (Type 3b), an auxiliary heater
(Type 6) and a stratified storage tank (Type 4a). I've attached my .tpf-file,
so you can comprehend what I'm writing.<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>I'm
doing this simulation because I want to get familiar with the behavior of a
tank while it is loaded. I set the losses of each component to 0 and the
efficiencies to 1, so that I have a loss-free system. <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Concerning
the heater, I set the "maximum heating rate" to 10 kW and the
"set point temperature" to 100°C. I defined 3 nodes besides the top
and the bottom in the tank, so I have 5 nodes. I set the "initial
temperature" for each node to 20°C. The volume of the tank is 1m³ and I
disabled the internal heaters, so that all of the heat is provided by Type6.<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>What
I want to do, is to check if all of the energy which is provided by the Heater
gets into the tank. Therefore, I run the simulation for 10 hours. Now, I
calculate the energy provided by the heater which is 10 kW * 36.000 s = 360.000
kJ. In order to control if all of this energy got into the tank, I take the
highest and the lowest value of the average tank temperature which is the delta
T. Cp for water is 4.19 kJ/kg*K and the mass of the water is 1.000kg. Now, I
can calculate the internal energy of the tank (1000 kg * 4.19 kJ/kg*K *
(74.2°C-20°C) = 227.098 kJ). This value is definitely much lower than the
energy that is provided by the heater...<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Another
strange thing is, that the average tank temperature begins with a value of 0°C.
I don't understand this, because I set the initial temperature for all nodes to
20°C, so I think that the average tank temperature should have the same
value...<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Could
someone of you please have a look at my simulation and see if there is
something wrong. And if there is all right, could you please explain the
bahvior of the tank? It would be very helpfull for me!<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Thank
you in advance!<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Mit
freundlichen Grüßen / Kind regards<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Christopher
Haluf<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Intern<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Siemens
AG<o:p></o:p></span></p>
</div>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Corporate
Technology<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>CT
PS 3<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Günther-Scharowsky-Str.
1<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>91058
Erlangen, Deutschland<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Tel.:
+49 (9131) 7-24724 <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Fax:
+49 (9131) 7-21339 <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><a
href="mailto:christopher.haluf@siemens.com">mailto:christopher.haluf@siemens.com<span
style='color:gray'> </span></a><o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif"'>Siemens
Aktiengesellschaft: Vorsitzender des Aufsichtsrats: Gerhard Cromme; Vorstand:
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<p><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>No virus
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