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Shahen,<br>
It is quite normal to get COPs higher than the rated one. The
rated COP is simply the COP at a particular set of inlet conditions.
Those inlet conditions are not necessarily the inlet conditions at
which the machine operates at its most efficient point.<br>
regards<br>
David<br>
<br>
<br>
<div class="moz-cite-prefix">On 9/3/2014 14:54, Shahen Fakhraldin
wrote:<br>
</div>
<blockquote
cite="mid:1409774053.83482.YahooMailNeo@web121205.mail.ne1.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:verdana, helvetica, sans-serif;font-size:10pt">
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<div style="color: rgb(0, 0, 0); font-family: verdana,
helvetica, sans-serif; font-size: 10pt; background-color:
rgb(255, 255, 255);">
<div id="yiv6206190985">
<div id="yiv6206190985yui_3_16_0_1_1409773050248_3885">
<div style="color: rgb(0, 0, 0); font-family: verdana,
helvetica, sans-serif; font-size: 10pt;
background-color: rgb(255, 255, 255);"
class="yiv6206190985yui_3_16_0_1_1409773050248_3785"
id="yiv6206190985yui_3_16_0_1_1409773050248_3884">
<div id="yiv6206190985">
<div
id="yiv6206190985yui_3_16_0_1_1409745842588_13618">
<div style="color: rgb(0, 0, 0); font-family:
verdana, helvetica, sans-serif; font-size:
10pt; background-color: rgb(255, 255, 255);"
class="yiv6206190985yui_3_16_0_1_1409745842588_13555
yiv6206190985yui_3_16_0_1_1409773050248_3786"
id="yiv6206190985yui_3_16_0_1_1409745842588_13617">
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
class="yiv6206190985" style=""><span
id="yiv6206190985yui_3_16_0_6_1409745842588_20"
class="yiv6206190985" style="">Dear TRNSYS
user,</span></div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13558
yiv6206190985yui_3_16_0_1_1409773050248_3789"><span
id="yiv6206190985yui_3_16_0_6_1409745842588_48"
class="yiv6206190985" style=""><br
style="">
</span></div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13561
yiv6206190985yui_3_16_0_1_1409773050248_3792">Did anyone face a problem
of getting COPs greater than the rated one
in a solar assisted absorption system? Where
COP rises to around (0.8) at the start of
the simulation and gets down to an average
(0.75) for the rest of the day, whilst the
rated cop is (0.7).</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color:rgb(0, 0,
0);font-size:13.63636302948px;font-family:verdana,
helvetica,
sans-serif;font-style:normal;background-color:transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13561
yiv6206190985yui_3_16_0_1_1409773050248_3792
yui_3_16_0_1_1409773050248_9826">I assumed
the set point temp for the Aux heater 70 C
and the <span
id="yiv62061909853459d9b6-39d5-4054-bab9-6e798f76eee5"
class="yiv6206190985GINGER_SOFTWARE_mark"><span
id="dec4abe9-44e7-4637-97da-6f7cc688bf54"
ginger_software_uiphraseguid="2ce9a1e6-59d4-4e10-9682-4aa25a79d428"
class="GINGER_SOFTWARE_mark">timestep</span></span> was
1min</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13562
yiv6206190985yui_3_16_0_1_1409773050248_3793"><br
id="yiv6206190985yui_3_16_0_6_1409745842588_328"
class="yiv6206190985" style="">
</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13564
yiv6206190985yui_3_16_0_1_1409773050248_3795">In my project, a cold tank
(type 4) is used to connect between the
chiller and the building, with the aid of
using type 682 to impose the load.</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13565
yiv6206190985yui_3_16_0_1_1409773050248_3796"><span
style="font-size:13.63636302948px;background-color:transparent;"
id="yiv6206190985yui_3_16_0_6_1409773050248_24">Is it resulted from a
mistake in the connections of the cold
tank? </span><br>
</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13568
yiv6206190985yui_3_16_0_1_1409773050248_3799"><br>
</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13568
yiv6206190985yui_3_16_0_1_1409773050248_3799">Down below are the <span
style="font-size:13.63636302948px;background-color:transparent;"
id="yiv6206190985yui_3_16_0_1_1409745842588_6206"
class="yiv6206190985">links</span><span
style="font-size:13.63636302948px;background-color:transparent;"
id="yiv6206190985yui_3_16_0_1_1409745842588_6206" class="yiv6206190985">, where
a&b for chiller-tank loop and c&d
for tank-load loop</span></div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_4"
style="color: rgb(0, 0, 0); font-size:
13.63636302948px; font-family: verdana,
helvetica, sans-serif; font-style: normal;
background-color: transparent;"
class="yiv6206190985
yiv6206190985yui_3_16_0_1_1409745842588_13568
yiv6206190985yui_3_16_0_1_1409773050248_3802"><span
class="yiv6206190985"
id="yiv6206190985yui_3_16_0_6_1409745842588_164"
style="font-size:13.63636302948px;background-color:transparent;">a- </span><span
class="yiv6206190985"
id="yiv6206190985yui_3_16_0_1_1409745842588_6276"
style="font-size:10pt;background-color:transparent;">Chilled water
temperature and flow rate (chiller107)
---->> Cold-side temperature and
flow rate (cold tank)</span><br>
</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><span
id="yiv6206190985cb3df404-ecb5-41c5-84e7-c9df5231e498"
class="yiv6206190985GINGER_SOFTWARE_mark"><span
id="yiv6206190985c58ec2f8-fd5f-4984-bf91-203ebb3e56b5"
class="yiv6206190985GINGER_SOFTWARE_mark"><span
id="58f64090-63d7-4898-9fc8-714b8c5e5cc5"
ginger_software_uiphraseguid="a3135635-4030-4d6b-b255-f316a9b4e30f"
class="GINGER_SOFTWARE_mark">b</span></span></span>-
Temperature (and flow rate) to load (cold
tank) --->> Chilled water inlet temp
and flow rate (chiller) trough a constant
speed pump</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><span
id="yiv6206190985ce65c357-e3c2-455a-9a6b-54e7475c3d8d"
class="yiv6206190985GINGER_SOFTWARE_mark"
style="font-size:10pt;"><span
id="yiv6206190985122dba59-0ced-4ab2-aeae-5c40a18c083a"
class="yiv6206190985GINGER_SOFTWARE_mark"><span
id="4308a211-2d03-4f7d-a580-7cf07c4f48b8"
ginger_software_uiphraseguid="f20d83ad-c65e-4803-9521-3b18a6f9e01a"
class="GINGER_SOFTWARE_mark">c</span></span></span><span
style="font-size:10pt;"
id="yiv6206190985yui_3_16_0_1_1409773050248_4207">-
Outlet temperature and flow rate (type
682) --->> Hot-side temperature and
flow rate (cold tank) through a pump</span><br>
</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><span
id="yiv6206190985f19ff-4912-4c19-93e5-ac007df4293e"
class="yiv6206190985GINGER_SOFTWARE_mark"><span
id="yiv62061909853099ac69-70a9-4936-b78a-62527f405976"
class="yiv6206190985GINGER_SOFTWARE_mark"><span
id="5a82e45d-6157-416e-8843-2bc577fbc0f6"
ginger_software_uiphraseguid="0de4177e-2748-4de3-8679-2c51642e703e"
class="GINGER_SOFTWARE_mark">d</span></span></span>-
Temperature (and flow rate) to heat source
(cold tank) --->> Inlet temperature
and flow rate of type 682</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><span
style="font-size:10pt;"
id="yiv6206190985yui_3_16_0_6_1409773050248_37"><br>
</span></div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><span
style="font-size:10pt;"
id="yiv6206190985yui_3_16_0_6_1409745842588_406">Am
I right? If yes, a</span><span
style="font-size:10pt;"
id="yiv6206190985yui_3_16_0_1_1409745842588_14117">re
there other reasons, such as the set point
temp of the Aux heater, that might cause
this error?</span></div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><br>
</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style="">Kind regards,</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style="">Shahen</div>
<div
id="yiv6206190985yui_3_16_0_6_1409745842588_8"
class="yiv6206190985" style=""><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
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</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>
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