| Title | Simple Evaluation of Ground-Source Heat Pump System Installation Using Shallow Subsurface Geological Information in the Aizu Basin, Northeast Japan |
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| Authors | Takeshi Ishihara, Gaurav Shrestha, Shohei Kaneko, Youhei Uchida |
| Year | 2018 |
| Conference | Asian Geothermal Symposium |
| Keywords | ground-source heat pump system, Quaternary geological structure, effective thermal conductivity, depth-based distribution map, Aizu Basin |
| Abstract | Shallow subsurface geological structure mapping combined with ground effective thermal conductivity values at the basin scale provide an appropriate method to evaluate the installation potential of ground-source heat pump (GSHP) systems. In the Aizu Basin (Northeast Japan), the geological structure was analyzed using sedimentary cores and boring log and the distribution of average effective thermal conductivity in the range from 10 m to 100 m depth calculated from cores and logs was illustrated. Gravel layers are dominant in alluvial fans of the northern and southern basin areas, which are found to be associated with higher average effective thermal conductivity values, while central and western floodplain areas show lower values due to the existence of thick mud layers in the shallow subsurface. These results suggest that the conventional closed-loop systems are more suitable in northern and southern alluvial fan areas than in the central and western floodplain areas. It is the unique of this study that assessment for the GSHP systems installation potential using depth-based distribution maps of average effective thermal conductivity in the Quaternary sedimentary basin with highly complex geology. This approach is valuable and available for the simple assessment of the system installation in different sedimentary plains and basins in Japan and other countries. |