Geothermal energy piles and boreholes design with heat pump in a whole building simulation software

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

“…A large number of different software types is being used in these investigations. Finite difference methods (FDM) used by TRNSYS [17,25] and IDA-ICE [26][27][28][29] are widely adopted, due to their ability to account for variable ground surface temperatures [30,31]. In some recent approaches, these can even be combined with probabilistic analysis [32].The Finite Element Method (FEM) [33][34][35] is extensively used as well, for instance with ABAQUS [36][37][38] or COMSOL Multiphysics [39][40][41][42].…”

“…In the case of energy piles, this is generally described as the surface temperature of the building floor slab, which is assumed to coincide with the indoor air temperature. The soil region surrounding the building floor slab is exposed to outdoor air temperature, which unfortunately cannot be modelled in TRNSYS nor IDA-ICE due to lack of implementation [12,27]. Hypothetically, heat transfer in the soil region surrounding the building should affect the soil temperature development underneath, altering the heat transfer between the energy piles and, ultimately, their thermal yield.…”

“…We find that assuming a simple floor slab gives virtually no different result than a more complex multiregional b.c. proposed in [12], which can be safely disregarded in practical studies.Another known bottleneck of energy piles modelling in IDA-ICE, prior to the November 2017 release, is the lack of calculated ground surface temperature as disturbed by the operation of an energy piles plant [27]. Such temperature constitutes the boundary condition in the floor slab model of a zone located directly above the energy piles.…”

“…Another known bottleneck of energy piles modelling in IDA-ICE, prior to the November 2017 release, is the lack of calculated ground surface temperature as disturbed by the operation of an energy piles plant [27]. Such temperature constitutes the boundary condition in the floor slab model of a zone located directly above the energy piles.…”

Thermal Effect on Structural Interaction between Energy Pile and Its Host Soil

“…In connection with heat transfer in an energy pile, Gao et al (2008) studied the thermal performance and ground temperature of vertical pile-foundation heat exchangers and aimed at providing guidelines for improving the design of large-scale ground-coupled heat pumps in a district heating and cooling system [1]; Moon and Choi (2015) studied the heating performance characteristics of a GSHP system with energy piles and energy slabs [2]; Faizal et al (2016) analyzed the heat transfer enhancement mechanism of geothermal energy piles [3]; Caulk et al (2016) reported the parameterization of a calibrated geothermal energy pile model [4]; Ghasemi-Fare and Basu (2016) presented a predictive assessment of heat exchange performance of geothermal piles [5]. Regarding studies on laying of piles, Cui et al (2011) analyzed the heat transfer performance of pile geothermal heat exchangers with spiral coils [6]; Go et al (2014) designed an energy pile with a spiral coil by considering the effective thermal resistance of the borehole and the effects of groundwater advection [7]; Xiang et al (2015) developed a new practical numerical model for the energy pile with spiral coils [8]; Fadejev and Kurnitski (2015) used a whole building simulation software to simulate the geothermal energy piles and borehole design with heat pump [9]; studied the coil-type ground heat exchanger by considering the relative constructability and thermal performance of a cast-in-place concrete energy pile [10]; Park et al (2016) calculated the influence of coil pitch on the thermal performance of coil-type cast-in-place energy piles [11]; Yang et al (2016) conducted laboratory investigations to analyze the thermal performance of an energy pile with spiral coil ground heat exchanger [12]. Several scholars had conducted research on the heat exchange efficiency of energy piles.…”