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<p>If you are getting negative temperatures from the outlet of the
heat pump source side that means that the source liquid is coming
into the heat pump cold (probably from the ground). There are
legitimate reasons why this can happen in the real world. It could
be that your ground heat exchanger is small and therefore does not
absorb enough heat from the surrounding ground. It could also mean
that your application is in a cold climate and that the ground
temperature is too low for the heat exchanger to gain any useful
energy. It is possible to change to using a glycol working fluid
but that is often prohibitively expensive.</p>
<p>kind regards,</p>
<p> David</p>
<p><br>
</p>
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<div class="moz-cite-prefix">On 04/16/2018 00:42, berkane ahlem via
TRNSYS-users wrote:<br>
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cite="mid:CACC+vA6h=FzeXuv1BkwjYtME=FEqkbib73Mg-Zyssm89q8Ayqg@mail.gmail.com">
<pre wrap="">dear sirs,
i'am using the type 668 (water to water heat pump ) in trnsys16
coupled with horizontal ground heat exchange type556 for heating a
storage tank,when i'm using 1-minute time step and I'm increasing
pump flow rates The temperature of the outlet load is set,but I have
a problem with the values negatives temperature of outlet source . I
do not know where is the problem exactly
please find the attached program in trnsys
thanks
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<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>
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