FREAパンフレット（英語）

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COLDHeatHOTWARMCOOLSummer seasonWinter seasonAir-conditionerHeat pumpCoolAir-conditionerHeat pumpWarmHeatHeatCoolSpace coolingHeat pump (cooling)Heat emissiongeological layer and groundwater (thermal storage)Heat pump (heating)Heat extractiongeological layer and groundwater (heat source)Space heating and snow meltingThe suitability of GSHP depends on the heat exchange rate, the potential of total heat exchange, and groundwater characteristicsGeology, groundwater level, velocity of groundwater flow, subsurface temperature, water quality, etc.Borehole heat exchangerHeat exchangeratesmalllargeGroundwater ow velocity16To use a GSHP system, it is important to understand the subsurface hydrogeological conditions of the site. Therefore, we conduct geological surveys by boring, groundwater temperature surveys by depth, regional heat transport simulations with advection eects of groundwater ow, etc. to investigate the suitability of a GSHP system according to the subsur-face environment of the area.The team also conducts studies on the development of GSHP systems suitable for dierent subsurface conditions. At a GSHP demonstration test site of FREA, the team conducts experiments using two types of heat exchangers: shallow (horizontal) and deep (vertical). The identical system is installed at the Geological Museum of AIST in Tsukuba City, Ibaraki Prefecture to investigate the dierences in heat exchange perfor-mance and in optimum heat exchange systems in each area having dierent hydrogeological settings.The team is mainly engaged in the following research and development themes:● Research on GSHP suitability assessmentJapan has many regions where there is abundant groundwater at a depth of several meters to a hundred meters, so the utilization of a GSHP system would be more ecient if the groundwater ow is considered.In order to promote the appropriate utilization of GSHP systems, the team conducts research studies in collaboration with Geological Survey of Japan, AIST. The team is also developing methods to assess the suitability of dierent GSHP systems based on eld surveys and numeri-cal analyses.The GSHP system is highly ecient and energy-saving compared to normal air conditioners (air-source heat pump systems). The team has been promoting the GSHP system by enhancing its performance and lowering its cost based on geological information.There are two types of GSHP systems: a closed-loop system exchanges heat by circulating brine or water in pipes buried underground, while an open-loop system pumps up groundwater to exchange heat at the ground surface. In Japan, since the existence of groundwater and its ow rate largely aects the heat exchange rate in both cases, it is important to investigate the groundwater level and ow rate. The Japanese approach to research on GSHP considering the groundwater system may be applicable and benecial for Southeast Asian countries. Therefore, we are engaged in the following research targets to develop GSHP systems suitable for the hydrogeological characteristics of a site:● GSHP suitability mapping based on eld data collection and schematic model construction● Conceptual designing on optimization technology of a GSHP system● Expansion of GSHP studies in Southeast Asia and other regions*COP: Coecient of performanceResearch TargetResearch OutlineConcept of ground-source heat pump systemSuitability assessment technologies for ground-source heat pump applicationSuitability mapping for ground-source heat pump (GSHP) systems considering the eects of groundwater is a new idea from AIST.Shallow Geothermal and Hydrogeology Team‒ Suitability Assessment of Ground-Source Heat Pump System and Its System Optimization Technology ‒A Ground-Source Heat Pump (GSHP) system is a technol-ogy that originally spread in western countries in the 1980s after the world oil crisis. Although the technology is not new, its use in Japan has been delayed since it was hardly known until around the year 2000. Because the existence of groundwater and its ow rate largely aects the heat exchange rate, it is important to understand the water level and ow rate of groundwater systems in order to eectively utilize GSHP systems in Japan. Energy Saving using UndergroundEnergy Saving using Underground