446
Y. Shimada et al.
Fig. 29.1 The system boundary of life-cycle inventory analysis
29.3.4 Sensitivity Analysis
The parameters of sensitivity analysis were “Thermal Conductivity” and “Subsurface
Temperature”. The ranges of each parameter were determined based on a literature
review.
The geologic column at the pilot study site described that subsurface soil in the
central area of Bangkok consisted of mainly clay and sand (Chokchai et al. 2018).
Thermal conductivity of saturated clay and sand are in the range of approximately
1.0–1.5 W/m·K (Hokkaido University geothermal utilization system engineering
course 2007). In case that the heat advection effect caused by the groundwater
flow can be expected, thermal conductivity was approximately twice as high as that
without the heat advection effect (Sakata et al. 2017). Based on above discussion,
we set the parameter of thermal conductivity as the range of 1.0–3.0 W/m·K.
According to a geological survey of Chao Phraya Plain, subsurface temperature
in whole Chao Phraya Plain at the depths between 20 and 50 m ranged from 27.8
to 31.5 °C (Yasukawa et al. 2009). Based on the result from the survey, subsurface
temperature was set as the range of 28.0–31.0 °C.
Y. Shimada et al.
Fig. 29.1 The system boundary of life-cycle inventory analysis
29.3.4 Sensitivity Analysis
The parameters of sensitivity analysis were “Thermal Conductivity” and “Subsurface
Temperature”. The ranges of each parameter were determined based on a literature
review.
The geologic column at the pilot study site described that subsurface soil in the
central area of Bangkok consisted of mainly clay and sand (Chokchai et al. 2018).
Thermal conductivity of saturated clay and sand are in the range of approximately
1.0–1.5 W/m·K (Hokkaido University geothermal utilization system engineering
course 2007). In case that the heat advection effect caused by the groundwater
flow can be expected, thermal conductivity was approximately twice as high as that
without the heat advection effect (Sakata et al. 2017). Based on above discussion,
we set the parameter of thermal conductivity as the range of 1.0–3.0 W/m·K.
According to a geological survey of Chao Phraya Plain, subsurface temperature
in whole Chao Phraya Plain at the depths between 20 and 50 m ranged from 27.8
to 31.5 °C (Yasukawa et al. 2009). Based on the result from the survey, subsurface
temperature was set as the range of 28.0–31.0 °C.