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Avishek,<br>
There are a number of issues with the project that you sent. <br>
<br>
First, the absorption chiller that you specified has a 425 ton
capacity while the collector has a 2m2 area. There is no pump in the
hot water loop to set the flow rate so because the absorption
chiller appears first in the component order, the flow rate in that
loop is a constant 58000 kg/h. There is no weather data reading
component attached to the solar collector.<br>
<br>
Second, the cooling water loop components (tower and pump) do not
appear to be sized to match the absorption chiller. The pump's rated
capacity is 1000 kg/h while the default cooling water flow rate for
the chiller is 279000 kg/h. There is no weather data reading
component attached to the cooling tower.<br>
<br>
Third, I am not clear on the intent of the chilled water loop. The
chilled water from the absorption chiller is passing across the
source side of a liquid to liquid heat exchanger (which would cool
down the liquid on the other side of the heat exchanger). However,
the other side of the heat exchanger is connected to the air coming
out of an electrically fired unit heater. Air presumably cooled down
by the heat exchanger is then returned to the unit heater but the
heater control signal is set so that the unit heater is not allowed
to turn off.<br>
<br>
Thermally I would guess that since there is no heat input into the
air circulating through the unit heater and the absorption chiller
is set to be constantly on the air is being driven to absolute zero,
well beyond the range of applicability for the psychrometrics
routine.<br>
<br>
When working with TRNSYS simulations it is vitally important to
construct systems one component at a time. The procedure that I
follow is to select an appropriate model from the library then open
it and make certain that its parameters are set appropriately for
the size of equipment that I intend to model. It is also important
to click on the "more" button for the parameters and for the input
initial (and constant) values so that I understand what information
they are asking me to provide. Once I have a component in place, I
connect its inputs and then use an online plotter to watch whatever
outputs are appropriate (usually temperatures and flow rates). I
often make a guess as to what I think I should see at the output of
a component, then run the simulation and test whether I was right or
wrong. Once I understand the output then I add another component.
Inputs that are not connected stay constant throughout your
simulation. <br>
<br>
I would recommend that you start by specifying only the absorption
chiller in your system and send the temperature and flow rate of its
three liquid streams to an online plotter. Set the chiller's control
signal using a forcing function so that it is on or off only as a
function of time. Once you understand the behavior of the model then
you could add a solar collector with a constant flow rate and a
weather file. However, do not yet connect the hot water output of
the chiller to the input of the solar collector. Connect only the
outlet of the solar collector to the input of the absorption
chiller. Set a constant flow rate into the collector by specifying
an input flow rate but do not connect the input. Change the size of
the solar collector until it is providing you with the temperature
and flow rate of water that is required by the absorption chiller
that you selected.<br>
<br>
Regards,<br>
David<br>
<br>
<br>
<div class="moz-cite-prefix">On 2/3/2015 06:42, avishek ray wrote:<br>
</div>
<blockquote
cite="mid:1634524501.846800.1422967331700.JavaMail.yahoo@mail.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff;
font-family:Helvetica Neue-Light, Helvetica Neue Light,
Helvetica Neue, Helvetica, Arial, Lucida Grande,
Sans-Serif;font-size:16px">
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style="color:#000;background-color:#fff;font-family:Helvetica
Neue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica,
Arial, Lucida Grande, Sans-Serif;font-size:16px;">
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style="color:#000;background-color:#fff;font-family:Helvetica
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Helvetica, Arial, Lucida Grande,
Sans-Serif;font-size:16px;">
<div><span></span></div>
<div id="yiv6181692330yui_3_16_0_1_1422962920054_3856">
<div id="yui_3_16_0_1_1422962920054_27617" dir="ltr"> Hi
All,</div>
<div id="yui_3_16_0_1_1422962920054_27791" dir="ltr">I
am a new user of TRNSYS. I have designed a solar hot
water fired vapour absorption cooling system of 1 TR
size. The diagram is given below. The error
displayed is having the message TRNSYS Message 114
---- The utility routine PSYCHOMETRICS which
calculates the thermodynamic properties of moist air
has been calledwith wet bulb temparature above the
maximum wet bulb temparature for a given pressure.
please check the routine which calls the
PSYCHOMETRICS routine for possible sources of error.
The .tpf file is also attached. Please enlighten me
to overcome this error<br>
</div>
</div>
<div id="yiv6181692330yui_3_16_0_1_1422962920054_3857"
class="yiv6181692330signature">
<div id="yui_3_16_0_1_1422962920054_28188"><span
id="yui_3_16_0_1_1422962920054_27864"
style="font-style:italic;font-weight:bold;"><br>
</span></div>
<div id="yui_3_16_0_1_1422962920054_28382"><span
id="yui_3_16_0_1_1422962920054_27864"
style="font-style:italic;font-weight:bold;"><br>
</span></div>
<div id="yui_3_16_0_1_1422962920054_28384"><span
id="yui_3_16_0_1_1422962920054_27864"
style="font-style:italic;font-weight:bold;">Avishek
Ray</span></div>
<br>
<span
id="yiv6181692330yui_3_16_0_1_1422962920054_3858"
style="font-style:italic;">Research Fellow and
Teaching Assistant<br>
Department of Energy Management<br>
Indian Institute Of Social Welfare and Business
Management; Kolkata-700073</span><br>
<br>
<span
id="yiv6181692330yui_3_16_0_1_1422962920054_3859"
style="font-style:italic;">M:9038707191</span></div>
</div>
</div>
</div>
</div>
</div>
<br>
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<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>
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