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<p>Alexandros,</p>
<br>
<blockquote type="cite"
cite="mid:8d58aeda-8076-efa7-2517-5ea67c1ba38c@uth.gr">1. Type
107 and Type680 use a normalized catalog data which has limited
values for Inlet Hot Water Temperature (from 108.89 (C) to 116.11
(C)), Entering Cooling Water Temperature (from 26.667 (C) to
32.222 (C)), Chilled Water Set point (from 5.556 (C)to 10.000
(C)). Ιf we use values outside this range, do we get wrong
results?
<br>
</blockquote>
possibly. As it mentions in the documentation the components can
interpolate within the data range given but they cannot extrapolate
beyond the range. You'll get a notice as to how much of the time the
components called the data files outside the range. If it happens
rarely then I would not worry about the consequences. If it is
happening all the time then the system needs to be better controlled
or alternative data (with a wider range) is needed. <br>
<blockquote type="cite"
cite="mid:8d58aeda-8076-efa7-2517-5ea67c1ba38c@uth.gr">
2. Τhe energy is discharged into the cooling water stream. If
we want energy rejection to be done in the air, can we achieve it
by changing the value of cp?
<br>
</blockquote>
I would not recommend doing so. Since the COP of the device is
looked up from a data file, the effectiveness of the rejection heat
exchanger is built-in to the performance data file. If the data
comes from a machine that rejects energy to a water stream then the
effectiveness built into the COP is that of a brine to water heat
exchanger. A brine to air heat exchanger would presumably have a
different effectiveness and therefore a different COP. <br>
<br>
In most applications that I have seen the cooling water stream goes
to a cooling tower where the energy us then rejected to the air. If
you have a device that rejects directly to air I would try very hard
to get its performance data and then yes, change the Cp of the
rejection stream. If you have a device that rejects to a water
stream and then to a cooling tower I would model it as such. <br>
<blockquote type="cite"
cite="mid:8d58aeda-8076-efa7-2517-5ea67c1ba38c@uth.gr">
3. Which working pair ( LiBr-H2O, H2O-NH3 ) is it used in the
data file? Ηow can we study the effect of the concentration in the
chilled power?
<br>
</blockquote>
I do not recall what brine was used in the example machine. If I had
to guess, I would say that it was LiBr-H2O. You cannot examine the
effect of the brine concentration on performance because performance
is read from a data file. If you have more than one data file (one
for a high concentration and one for a lower concentration) then you
could examine such a modification in the context of the system.<br>
<blockquote type="cite"
cite="mid:8d58aeda-8076-efa7-2517-5ea67c1ba38c@uth.gr">
4. The single effect hot water fired absorption chiller is used
to solve energy balances between hot water, cooling water, chilled
water, auxiliary electrical power. A more detailed analysis is it
possible?
<br>
</blockquote>
No, not really because this is a catalog data lookup table model.
You'd need to find (or write) a first principals model of the device
if you want to do a more detailed analysis.<br>
<br>
kind regards,<br>
David<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI 53703 USA
P:+1.608.274.2577
F:+1.608.278.1475
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