448
Y. Shimada et al.
Table 29.3 (continued)
System boundary
List
Data source
Major
Minor
Drilling machine
Hearing investigation to
the pilot study research
group, transport distances
of 200 km
Mud pump
Installation
Diesel fuel
–
Waste transportation
Drilling mud
Transport distances of
200 km
Waste intermediate
treatment
Drilling mud
Calculated based on the
structure of the ground
heat exchanger
Operation
Electricity
Simulation result from
“3.2 System designing
and electricity
consumption”
Disposal
Waste transportation
Scrap metal
Scrap plastic
Transport distances of
200 km
Refrigerant
Waste intermediate
treatment
Scrap metal
Heat pump, buffer tank,
fan coil unit and
circulation pump
Scrap plastic
Distribution pipe and
ground heat exchanger
Refrigerant
ー
After determining the ranges of the sensitivity analysis parameters, the heat pump
inlet water temperature was simulated using “GroundClub” to determine the total
length of the ground heat exchanger. The total length of the ground heat exchanger
was optimally designed so that the 90th percentile value of heat pump inlet water
temperature did not exceed 38 °C, which is the same standards as in “3.2 system
designing and electricity consumption”. Table 29.4 shows the total length of ground
heat exchanger corresponding to the parameters of thermal conductivity and subsurface temperature. The total length of ground heat exchanger decreases as thermal
conductivity increases, and increases as subsurface temperature increases.
Lastly, the process data related to the ground heat exchanger were modified to be
proportional to the total length of ground heat exchanger to recalculate the LC–CO 2
emissions.