Environmental Engineering Reference
In-Depth Information
40
20
Light concrete
Bentonite
0
High-
performance
backfill
-20
Standard mass flow
Double mass flow
-40
Backfill heat conductivity
Figure 4.27 Influence of backfill heat conductivity on energy output
system (tube, backfill and surrounding soil), as derived from the first week of thermal
response tests, are 1.97 and 2 . 04Wm 1 K 1 respectively. Repeated measurements
were carried out to determine the measurement errors. The high-performance backfill
leads to a 3-7%higher effective heat conductivity. The thermal response tests were also
used to validate the above-mentioned numerical model and showed good agreement.
Figure 4.28 shows the measured and simulated mean values of input and output fluid
temperatures of both heat exchangers. The figure also shows that after 1 week of
Figure 4.28 Measured inlet and outlet temperatures for individual testing of two different geothermal
heat exchangers with standard and higher conductivity backfill material
Search WWH ::




Custom Search