Elucidation of the mechanism of fluctuation in the apparent thermal conductivity and evaluation of the heat exchange capacity of shallow grounds

2015 Fiscal Year Final Research Report

• Project/Area Number: 25350418
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: Hirosaki University
• Principal Investigator: Ioka Seiichiro 弘前大学, 北日本新エネルギー研究所, 准教授 (40598520)
• Co-Investigator(Kenkyū-buntansha): FUJII Hikari 秋田大学, 大学院国際資源学研究科, 教授 (80332526)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 地中熱 / 地下水 / 浅層地盤

Outline of Final Research Achievements

For elucidating the mechanism of fluctuation in the apparent thermal conductivity and evaluating the heat exchange capacity of shallow grounds, a thermal response test was conducted using an underground heat exchanger with a length of approximately 8 m. Based on the assumption that the difference in the depth of the water table causes fluctuations in the apparent thermal conductivity in shallow grounds, a thermal response test was carried out in May, when the water table is generally shallow, and another in September, when the water table is deep. The results showed that the outlet temperature of the thermal response test in September was higher than that in May, and the amount of heat exchanged was smaller in September than that in May. Therefore, as a factor that influences the fluctuation mechanism of apparent thermal conductivity in shallow grounds, considering the variation in the depth of water table is important.

Free Research Field

地下水文学，地熱工学