Modeling the time evolution of geothermal boreholes during peak heating and cooling demands

Abstract A geothermal heat exchanger requires special care in its design when it comes to peak heating and cooling demands of the building as the installation may incur in material damages due to the extreme temperatures reached by the heat carrying liquid. The peak demands tend to last a few days at most and the theoretical model used to predict the thermal response of the geothermal heat exchanger has, therefore, to consider the thermal inertia of the heat carrying liquid, the grout, and the ground close to the boreholes. With this in mind, the present work discusses a theoretical model that provides, among other things, the heat injection rates per unit pipe length of the different pipes in the borehole in terms of the bulk temperatures of the heat carrying liquid during those peak heating and cooling demands.

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Numerical Investigation of the Physical Properties Effect on the Thermal Performance of a Vertical Geothermal Heat Exchanger

Engineering, Technology & Applied Science Research ◽

10.48084/etasr.1827 ◽

2018 ◽

Vol 8 (2) ◽

pp. 2715-2723

Author(s):

M. Benyoub ◽

B. Aour ◽

B. Bouhacina ◽

K. Sadek

Keyword(s):

Heat Exchanger ◽

Construction Materials ◽

Green Energy ◽

Filling Material ◽

Geothermal Heat ◽

Thermal Exchange ◽

Heating And Cooling ◽

Knowing That ◽

Shaped Tube ◽

Geothermal Heat Exchanger

Low-temperature geothermal energy is a promising technique for heating and cooling residential and commercial premises, especially since it is one of the green energy solutions that respect the environment. The principle of this technique is based on thermal exchange between the heat pump and the basement using a vertically buried heat exchanger. This is usually made of a U-shaped tube inserted vertically in a borehole made in the ground and filled with a filler material. The purpose of the present study is to vary the different construction materials of the U-tube, the filling material and the soil, in order to obtain the most energy-efficient parameters. The evolution of temperature and heat flux as a function of time has been highlighted for different combinations. Knowing that an experimental study requires a considerable monetary fund, the present model has been validated using previously literature results. Recommendations on the choice of different materials of the geothermal heat exchanger are proclaimed at the end of this work.

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The Comparison of the In-Situ Thermal Response Tests and CFD Analysis of Vertical-type Geothermal Heat Exchanger

Journal of the Korea Academia-Industrial cooperation Society ◽

10.5762/kais.2013.14.7.3164 ◽

2013 ◽

Vol 14 (7) ◽

pp. 3164-3169 ◽

Cited By ~ 1

Author(s):

Yong-Sub Sim ◽

Hee-Sang Lee

Keyword(s):

Heat Exchanger ◽

Thermal Response ◽

Cfd Analysis ◽

Geothermal Heat ◽

Geothermal Heat Exchanger

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Experimental Investigation on Thermal Performance of Double-U-tube Heat Exchanger Using CuO/water Nanofluid as Heat Transfer Fluid

E3S Web of Conferences ◽

10.1051/e3sconf/202016501022 ◽

2020 ◽

Vol 165 ◽

pp. 01022

Author(s):

Ruiqing Du ◽

Dandan Jiang ◽

Yong Wang

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Thermal Performance ◽

Transfer Process ◽

Heat Transfer Process ◽

Heat Transfer Fluid ◽

Geothermal Heat ◽

Tube Heat Exchanger ◽

Heating And Cooling ◽

Geothermal Heat Exchanger

By applying the shallow ground energy to supply building heating and cooling, the geothermal heat exchanger systems were considered as an energy-efficient building service system. In this study, the CuO/water nanofluid was employed as circuit fluids of the geothermal heat exchanger system, and the thermal performance of the heat exchanger was investigated. The results showed that the heat transfer process of CuO/water nanofluid became stable earlier than that water. Furthermore, the heat transfer rate of nanofluid was higher than that of water when the heat transfer process plateaued.

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