Abstract
Geothermal heat pumps are broadly used in developed
countries but scarcely in Brazil, in part because
there is a lack of Brazilian soil temperature data. The
aims of this work are: to present soil temperature measurements
and to compare geothermal heat pump system
performances with conventional air conditioning systems.
Geothermal temperature measurement results are shown
for ten Paraná State cities, representing different soil and
climate conditions. The measurements were made yearlong
with calibrated equipment and digital data acquisition
system in different measuring stations. Geothermal
and ambient temperature data were used for simulations
of the coeficient of performance (COP), by means of a
working fluid pressure-enthalpy diagram based software
for vapor-compression cycle. It was verified that geothermal
temperature measured between January 13 to October
13, 2013, varied from 16 to 24 °C, while room temperature
has varied between 2 and 35 °C. Average COP
values for conventional system were 3.7 (cooling mode)
and 5.0 kW/kW (heating mode), corresponding to 5.9 and
7.9 kW/kW for geothermal system. Hence it was verified an
average eficiency gain of 59%with geothermal system utilization
in comparison with conventional system.
Analysis of geothermal temperatures for heat pumps application in Paraná (Brasil)
