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<p class=MsoNormal>Hi All – I am wondering if anyone has much experience
with the geothermal well field capabilities of eQUEST, in particular with
vertical well fields. I am concerned about the accuracy of the
calculation methodology for the vertical well fields, primarily due to a large discrepancy
we are getting between the eQUEST results and the results of a separate
geothermal well field software produced by Gaia Geothermal. Here are the
parameters:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Vertical well field<o:p></o:p></p>
<p class=MsoNormal>Ground conditions & well field dimensions are identical
in both eQUEST and Gaia simulations.<o:p></o:p></p>
<p class=MsoNormal>Equest model has four 4x5 rectangular well fields (80 bore
holes total) with 200 ft bore depth. Plant report PS-C shows that the fourth
well field has no load, thus using at most 60 of the 200 ft wells. <o:p></o:p></p>
<p class=MsoNormal>Gaia software inputs load data from the DOE2 report SS-I for
each zone along with the matching heat pump size (specific to manufacturer) selected
for the project for the zone. This software uses its knowledge of the
heat pump performance to generate the required well-field size and depth.
The result is 120 well fields of 250 ft bore depth or 80 well fields of 350 ft
bore depth. <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I would expect some discrepancy between different software,
but in this case the eQUEST simulation is using only about 50% of the required
well-field size calculated by the Gaia software. The Gaia calculation is
coming out much larger than what the owner and design-build contractor had
planned for.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>How reliable is the eQUEST simulation on vertical
well-fields? <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I believe the primary difference is that Gaia software uses “real”
manufacturer performance data for heap pump models specified and eQUEST uses
PVVT system with default GSHP performance curves. Could this difference
really make such huge impact on the results?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks in advance for any insight.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Garamond","serif";
color:#960028'>Dan Russell<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:14.0pt;font-family:"Garamond","serif";
color:#C00000'><img width=197 height=140 id="Picture_x0020_1"
src="cid:image001.png@01CAE784.47A119C0" alt="EI Signature"></span><span
style='font-size:14.0pt;font-family:"Garamond","serif";color:#CA0002'><o:p></o:p></span></p>
<p class=MsoNormal><o:p> </o:p></p>
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