TY - JOUR
T1 - Thermal behavior and performance of shallow-deep-mixed borehole heat exchanger array for sustainable building cooling and heating
AU - Cheng, Nan
AU - Zhou, Chaohui
AU - Luo, Yongqiang
AU - Shen, Junhao
AU - Tian, Zhiyong
AU - Sun, Deyu
AU - Fan, Jianhua
AU - Zhang, Ling
AU - Deng, Jie
AU - Rosen, Marc A.
PY - 2023
Y1 - 2023
N2 - Geothermal energy system is a renewable, sustainable and clean source
for building heating and cooling, which is important for reducing both
building energy use and carbon emissions. Currently, both shallow
borehole heat exchangers (SBHEs) and deep borehole heat exchangers
(DBHEs) are popular in applications. However, SBHEs and DBHEs have
inherit limitations when used alone. SBHEs suffer from lower
heating/cooling capacities and ground imbalance problems in long run,
while DBHEs are mainly used for building heating. In this study,
combining both SBHEs and DBHEs is proposed as a shallow-deep-mixed
borehole heat exchanger (SD-BHE) array, and more importantly a new
scheme is proposed that the DBHE tube could be switched to SBHE tube in
summer. SD-BHE is a new design, focusing on the combination of DBHE and
shallow tube group. Its heat transfer model is established on the basis
of single tube heat transfer model and tube group heat transfer model.
In the analysis, the heat extraction capacity per linear meter of DBHE
and SBHE is compared and analyzed for various parameters. It is found
that when the cooling load of a building is greater than the heating
load, the shallow-deep-mixed borehole heat exchanger (SD-BHE) array has
less influence on ground temperature and provides better stability of
the outlet water temperature than the SBHE array. The present study can
offer a new paradigm for geothermal energy-based building
cooling/heating.
AB - Geothermal energy system is a renewable, sustainable and clean source
for building heating and cooling, which is important for reducing both
building energy use and carbon emissions. Currently, both shallow
borehole heat exchangers (SBHEs) and deep borehole heat exchangers
(DBHEs) are popular in applications. However, SBHEs and DBHEs have
inherit limitations when used alone. SBHEs suffer from lower
heating/cooling capacities and ground imbalance problems in long run,
while DBHEs are mainly used for building heating. In this study,
combining both SBHEs and DBHEs is proposed as a shallow-deep-mixed
borehole heat exchanger (SD-BHE) array, and more importantly a new
scheme is proposed that the DBHE tube could be switched to SBHE tube in
summer. SD-BHE is a new design, focusing on the combination of DBHE and
shallow tube group. Its heat transfer model is established on the basis
of single tube heat transfer model and tube group heat transfer model.
In the analysis, the heat extraction capacity per linear meter of DBHE
and SBHE is compared and analyzed for various parameters. It is found
that when the cooling load of a building is greater than the heating
load, the shallow-deep-mixed borehole heat exchanger (SD-BHE) array has
less influence on ground temperature and provides better stability of
the outlet water temperature than the SBHE array. The present study can
offer a new paradigm for geothermal energy-based building
cooling/heating.
KW - Analytical modeling
KW - Deep borehole heat exchanger
KW - Geothermal energy
KW - Ground source heat pump
KW - Shallow borehole heat exchanger
U2 - 10.1016/j.enbuild.2023.113108
DO - 10.1016/j.enbuild.2023.113108
M3 - Journal article
SN - 0378-7788
VL - 291
JO - Energy and Buildings
JF - Energy and Buildings
M1 - 113108
ER -
