부산대학교 도서관

The temperature profiles and apparent thermal conductivity (λ) values of both TCPs were consistent each other at many sites. On the other hand, at a few sites, several range of λ values of the TCP using heat transfer medium were extremely higher than that of the TCP using heating cable. The same section of temperature profiles of the TCP using heat transfer medium showed that the temperature recovered rapidly, suggesting that crossflow may be occurring in the annulus area in the BHEs. Since the TCP using heating cable can be tested in a borehole with a smaller annulus area than the BHEs, it was also confirmed that the risk (e.g., crossflow) of ground modification on the estimation of λ value can be minimized.