TY - JOUR
T1 - An improved thermal response test for U-tube ground heat exchanger based on optical fiber thermometers
AU - Fujii, Hikari
AU - Okubo, Hiroaki
AU - Nishi, Keita
AU - Itoi, Ryuichi
AU - Ohyama, Kunio
AU - Shibata, Kazuo
N1 - Funding Information:
This work was partly funded by Grant-in-Aid for Scientific Research (B) (No. 19360407) of Japan Society for the Promotion of Science. The authors thank the members of Geothermics’ Editorial Team for their valuable suggestions on the manuscript.
PY - 2009/12
Y1 - 2009/12
N2 - As part of a new thermal response test (TRT) and to determine ground thermal conductivities, vertical temperature profiles were obtained using retrievable optical fiber sensors inserted into the U-tubes of two ground heat exchangers (GHEs) installed at Maebaru City (Fukuoka, Kyushu) and Kushiro City (Hokkaido), Japan. Measured profiles and outlet temperatures from TRTs were history-matched with the cylindrical source function. Nonlinear regression was used to estimate the vertical distribution of ground thermal conductivities. The computed distribution is consistent with measured data indicating both the reliability of the optical fiber thermometer and TRT interpretation. It is expected that TRTs and optical fiber thermometers will prove to be increasingly useful for optimizing the depth of the GHEs installed in heterogeneous formations, and consequently will minimize installation costs of geothermal heat pump systems.
AB - As part of a new thermal response test (TRT) and to determine ground thermal conductivities, vertical temperature profiles were obtained using retrievable optical fiber sensors inserted into the U-tubes of two ground heat exchangers (GHEs) installed at Maebaru City (Fukuoka, Kyushu) and Kushiro City (Hokkaido), Japan. Measured profiles and outlet temperatures from TRTs were history-matched with the cylindrical source function. Nonlinear regression was used to estimate the vertical distribution of ground thermal conductivities. The computed distribution is consistent with measured data indicating both the reliability of the optical fiber thermometer and TRT interpretation. It is expected that TRTs and optical fiber thermometers will prove to be increasingly useful for optimizing the depth of the GHEs installed in heterogeneous formations, and consequently will minimize installation costs of geothermal heat pump systems.
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U2 - 10.1016/j.geothermics.2009.06.002
DO - 10.1016/j.geothermics.2009.06.002
M3 - Article
AN - SCOPUS:70350402110
SN - 0375-6505
VL - 38
SP - 399
EP - 406
JO - Geothermics
JF - Geothermics
IS - 4
ER -
