Browsing Proceedings of the IGSHPA Technical/Research Conference and Expo 2017 by Issue Date
Now showing items 21-40 of 44
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Properties of different ethyl alcohol based secondary fluids used for GSHP in Europe and USA
(International Ground Source Heat Pump Association, 2017)The extensive use of ground source heat pumps (GSHP) for heating and cooling purposes has made Sweden the European leader in geothermal energy utilization, in terms of the installed capacity, as well as extracted thermal ... -
Modelling of alternative borehole configurations for geo-exchange
(International Ground Source Heat Pump Association, 2017)During the operation of a ground source heat pump (GSHP), the ground acts as a heat sink and heat source in cooling and heating modes, respectively. When the heating and cooling loads are extremely unbalanced, ground ... -
Providing low carbon cooling through pile foundations; the effect of thermal cycling on clay strength
(International Ground Source Heat Pump Association, 2017)Pile foundations provide a low-intrusive mechanism for installing heat exchangers into the ground, especially if the piles are being installed to support the building. The ground temperature is relatively constant at depths ... -
Three dimensional numerical simulation of double-U pile heat exchangers
(International Ground Source Heat Pump Association, 2017)The Ground Source Heat Pump system with pile heat exchangers has been used in engineering in recent years. In this paper, a three-dimensional numerical model of double-U pile heat exchangers is established which was verified ... -
Investigation of thermo-hydro-geochemical processes in a standing column well intersected by a fracture
(International Ground Source Heat Pump Association, 2017)Local thermal and chemical conditions may favor minerals' scaling which can cause undesirable operational problems to standing column well systems. Precipitation may reduce heat exchange in the well and the heat exchanger ... -
Minimum well separation for small groundwater heat pump (GWHP) systems in Korea: Preliminary analysis based on regional aquifer properties
(International Ground Source Heat Pump Association, 2017)Shallow geothermal energy has been estimated to have an excellent applicability in Korea, and its applications for space heating and cooling have steadily increased in recent years. Such application as ground source heat ... -
Can ground source heat pumps perform well in Alaska?
(International Ground Source Heat Pump Association, 2017)The long heating season and cold soils of Alaska provide a harsh testing ground for ground source heat pumps (GSHPs), even those designed and marketed for colder climates. Fairbanks, Alaska has 7,509°C heating degree-days18 ... -
Numerical simulation of pile geothermal heat exchanger with spiral tube considering its thermo-mechanical behavior
(International Ground Source Heat Pump Association, 2017)Pile geothermal heat exchanger (PGHE), which utilizes the building foundation piles as part of the geothermal heat exchangers (GHEs) for a ground-coupled heat pump (GCHP) system, has been attracting the interests of ... -
Influence of ground heat exchanger zoning operation on the GSHP system long-term operation performance
(International Ground Source Heat Pump Association, 2017)To alleviate the ground heat accumulation after long term running of ground source heat pumps (GSHP), ground heat exchanger (GHE) zoning operation can be adopted. Two GHE operation modes - zoning operation and full running ... -
New methods to spatially extend thermal response test assessments
(International Ground Source Heat Pump Association, 2017)Thermal response tests (TRTs), used to evaluate the subsurface thermal conductivity when designing ground source heat pump systems, are spatially limited to the vicinity of the borehole where a test is carried out. The ... -
Heat pump capacity effects on peak electricity consumption and total length of self- and solar-assisted shallow ground heat exchanger networks
(International Ground Source Heat Pump Association, 2017)A new "self-assisted" Ground Source Heat Pump (GSHP) system configuration is proposed to address the relatively high peak electricity demand of undersized GSHP systems equipped with auxiliary electric heater. In this ... -
Examination of ambient temperature variations effects on predicted fluid temperatures in vertical boreholes
(International Ground Source Heat Pump Association, 2017)A fully-coupled model of geothermal bore fields is presented, taking into account the axial variations of borehole wall temperatures and heat extraction rates along the borehole lengths, fluid temperature variations inside ... -
Model for ground temperature estimations and its impact on horizontal ground heat exchanger design
(International Ground Source Heat Pump Association, 2017)The ground-source heat pump systems are highly efficient and energy saving. Its main disadvantage is a significantly higher installation cost compared to conventional systems. The length of the ground heat exchanger (GHX) ... -
Comparison of the energy use for different heat transfer fluids in geothermal systems
(International Ground Source Heat Pump Association, 2017)Geothermal systems that operate under 0°C must use antifreeze mixtures instead of water to avoid operational problems. This paper examines the energy consumption of the circulating pump and heat pump for various heat ... -
Assessment of the gradient of an objective function by analytical derivation for optimization-based design of ground-coupled heat pump systems
(International Ground Source Heat Pump Association, 2017)Optimization-based design of ground heat exchangers requires derivation of the objective function with respect to the design parameters, which is usually done through finite-differentiation of the cost or utility function. ... -
Storage of solar thermal energy in borehole thermal energy storage systems
(International Ground Source Heat Pump Association, 2017)This study focuses on the evaluation of solar thermal energy storage in a medium-scale soil-borehole thermal energy storage (SBTES) system installed in San Diego, CA. The SBTES system consists of an array of thirteen 15 ... -
Fractal approach to calculate the thermal conductivity of moist soil
(International Ground Source Heat Pump Association, 2017)The ground heat exchanger (GHE) is a key component in the design of a GSHP system and the effective thermal conductivity is one of the most important parameters that determine the heat transfer underground. In this paper, ... -
Measurement of internal and effective borehole resistances during thermal response tests
(International Ground Source Heat Pump Association, 2017)In a conventional thermal response test (TRT), the main parameter evaluated is the bulk subsurface thermal conductivity surrounding the borehole. It is also possible to evaluate the borehole thermal resistance. Several ... -
Updated assessment of the technical potential of geothermal heat pump applications in the United States
(International Ground Source Heat Pump Association, 2017)This paper presents an updated assessment of the technical potential of applying geothermal heat pump (GHP) systems in businesses and homes of the United States. The assessed technical potential includes energy savings, ... -
Development of TPRT (Thermal Performance-Response Test) for borehole heat exchanger design
(International Ground Source Heat Pump Association, 2017)To obtain the effective thermal conductivity and borehole thermal resistance required to design borehole heat exchangers (BHEs), thermal response tests (TRTs) are usually conducted. Although many advanced TRT methods have ...