Energy pile foundation simulation for different configurations of ground source heat exchanger

Mehrizi, Abbasali Abouei; Porkhial, Soheil; Bezyan, Behrad; Lotfizadeh, Hossein

doi:10.1016/j.icheatmasstransfer.2015.12.001

Cited by 58 publications

(17 citation statements)

References 17 publications

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“…shank spacing is adopted in the literature [46] to analyse heat transfer efficiency in an EP foundation, where a U-tube pipe with internal diameter of 0.02 m and external diameter of 0.028m is installed. 0.098m shank spacing is used in the literature [47] to test the EP thermal response, the EP diameter is 0.3m with a 0.032m diameter pipe installed.…”

Section: Effects Of U-tube Shank Spacingmentioning

confidence: 99%

3D transient heat transfer numerical analysis of multiple energy piles

Cui

Zhu

2017

Energy and Buildings

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This paper presents a three-dimensional (3D) transient heat transfer numerical model for multiple energy piles based on the finite volume method (FVM). The initial and boundary conditions are established and the effects of "thermal short-circulating" between two pipes of a U-tube in energy pile are investigated. Thermal partial differential equations are discretized at the spatial nodal points and solved by linear approximation method. Temperature variations of working fluid, energy pile and its surrounding soil from simulation program are compared with experimental data to validate the developed model. In addition, the influences of fluid flow rate and U-tube shank spacing are analysed. It is established that the shank spacing should be set in a range of 0.06m to 0.10m to reduce heat transfer between the two pipes and meet the structural requirement. Meanwhile, the flow rate should be controlled in a range of 0.5m 3 /h to 0.7m 3 /h to avoid the low outlet fluid temperature and decrease the influence of "thermal short-circuiting".

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Section: Effects Of U-tube Shank Spacingmentioning

confidence: 99%

3D transient heat transfer numerical analysis of multiple energy piles

Cui

Zhu

2017

Energy and Buildings

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“…A large number of different software types is being used in these investigations. Finite difference methods (FDM) used by TRNSYS [18,26] and IDA-ICE [27][28][29][30] are widely adopted, due to their ability to account for variable ground surface temperatures [31,32]. In some recent approaches, these can even be combined with probabilistic analysis [33].…”

Section: Introductionmentioning

confidence: 99%

Energy Pile Field Simulation in Large Buildings: Validation of Surface Boundary Assumptions

2019

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As the energy efficiency demands for future buildings become increasingly stringent, preliminary assessments of energy consumption are mandatory. These are possible only through numerical simulations, whose reliability crucially depends on boundary conditions. We therefore investigate their role in numerical estimates for the usage of geothermal energy, performing annual simulations of transient heat transfer for a building employing a geothermal heat pump plant and energy piles. Starting from actual measurements, we solve the heat equations in 2D and 3D using COMSOL Multiphysics and IDA-ICE, discovering a negligible impact of the multiregional ground surface boundary conditions. Moreover, we verify that the thermal mass of the soil medium induces a small vertical temperature gradient on the piles surface. We also find a roughly constant temperature on each horizontal cross-section, with nearly identical average values when either integrated over the full plane or evaluated at one single point. Calculating the yearly heating need for an entire building, we then show that the chosen upper boundary condition affects the energy balance dramatically. Using directly the pipes’ outlet temperature induces a 54% overestimation of the heat flux, while the exact ground surface temperature above the piles reduces the error to 0.03%.

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“…Since the foundation pile is commonly used in high rise buildings, combining the heat exchanger and building foundation pile can eliminate the drilling expense and land area requirement of borehole GHE. Therefore, utilization of building foundation piles as the GHE has received more and more attention (Mehrizi, et al 2016;Luo, et al 2016;Huerta and Krarti 2015;Loveridge and Powrie 2014). In existing studies, pipes are usually buried in foundation piles in configurations of U-tubes, W-tubes or spiral coils.…”

Section: Introductionmentioning

confidence: 99%