Results 141 to 150 of about 354 (185)
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FREEZING PROBLEMS IN BOREHOLE HEAT EXCHANGERS
2007There are approximately 300,000 borehole systems in Sweden with an annual growth rate of 30,000 systems. Such borehole systems are mainly used for heating of single family houses but in recent years several hundred larger systems, for both heating and cooling, have been constructed.
Bo Nordell, Anna-Karin Ahlström
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Thermal interaction between tunnel ground heat exchangers and borehole heat exchangers
Geomechanics for Energy and the Environment, 2017Renewable geothermal energy is an energy source that can be used for heating and cooling purposes. One common method of harvesting this energy is using engineering structures in contact with the ground, such as structural piles, diaphragm walls or tunnels (with geothermal loops integrated into the tunnel lining/invert (tunnel ground heat exchangers ...
Asal Bidarmaghz +4 more
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Heat transfer analysis of short helical borehole heat exchangers
Applied Energy, 2013Abstract In this paper a numerical model to analyze the thermal behaviour of vertical ground heat exchangers with a helical shaped pipe is presented. This type of configuration can be a suitable alternative to conventional ground heat exchangers, especially when the heating and cooling loads of the building are very low. The model describes the heat
ZARRELLA, ANGELO, DE CARLI, MICHELE
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Transient heat transfer in a coaxial borehole heat exchanger
Geothermics, 2014Ground-source heat pumps often use vertical boreholes to exchange heat with the ground. A transient heat transfer model has been developed for a thermal response test on a pipe-in-pipe coaxial borehole heat exchanger. The analytical model calculates the vertical temperature profiles in the fluid flowing through the pipes, which are coupled to the ...
Richard A. Beier +3 more
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Efficient numerical modeling of borehole heat exchangers
Computers & Geosciences, 2010This paper presents a finite element modeling technique for double U-tube borehole heat exchangers (BHE) and the surrounding soil mass. Focus is placed on presenting numerical analyses describing the capability of a BHE model, previously reported, to simulate three-dimensional heat transfer processes in multiple borehole heat exchangers embedded in a ...
R. Al-Khoury, T. Kölbel, R. Schramedei
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Experiences with the Borehole Heat Exchanger
2018Renewable energy sources have one thing in common; they all existed before man appeared on this planet. Wind, wave, hydro, solar, geothermal and tidal powers are all forces of nature and are mostly intermittent energy sources, geothermal is the only consistent phenomenon.
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A novel enhanced deep borehole heat exchanger for building heating
Applied Thermal Engineering, 2020Abstract Deep borehole heat exchanger (DBHE) technology can be used in various regions due to without dependence on the hot water reservoir. However, its performance can hardly be improved due to poor thermal conductivity of rocks and cement. Here a novel enhanced deep borehole heat exchanger (EDBHE) is first proposed, which applies composite filler,
Yujiang He, Xianbiao Bu
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Borehole resistance and vertical temperature profiles in coaxial borehole heat exchangers
Applied Energy, 2013Ground source heat pump systems are often coupled to the ground by circulating a fluid through vertical Borehole Heat Exchangers (BHEs). The design of a system requires estimates of the ground thermal conductivity and the borehole thermal resistance, which are usually determined by an in situ thermal response test on a completed borehole.
Richard A. Beier +3 more
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Spectral framework for geothermal borehole heat exchangers
International Journal of Numerical Methods for Heat & Fluid Flow, 2010PurposeThis paper aims to present a framework for deriving analytical and semi‐numerical models for coupled conductive‐convective heat transfer processes in a borehole heat exchanger subjected to general initial and boundary conditions.Design/methodology/approachThe discrete Fourier transform and the spectral element method have been utilized for ...
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Heat transfer analysis of ground heat exchangers with inclined boreholes
Applied Thermal Engineering, 2006Consisting of closed-loop of pipes buried in boreholes, ground heat exchangers (GHEs) are devised for extraction or injection of thermal energy from/into the ground. Evolved from the vertical borehole systems, the configuration of inclined boreholes is considered in order to reduce the land plots required to install the GHEs in densely populated areas.
Ping Cui, Hongxing Yang, Zhaohong Fang
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