Browsing Proceedings of the IGSHPA Research Track 2018 by Issue Date
Now showing items 21-40 of 49
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Performance analysis of a single underground thermal storage borehole using phase change material
(International Ground Source Heat Pump Association, 2018)Ground source heat pumps (GSHP) are used to provide both heating and cooling to a given system. These heat pumps transfer heat efficiently between the system and the ground. Despite this high efficiency, there has been a ... -
Simulated temperature evolution of large BTES - case study from Finland
(International Ground Source Heat Pump Association, 2018)The largest borehole thermal energy storage system in Finland (also one of the largest systems in Europe) is located in Sipoo, Southern Finland. The system produces heating and cooling energy for a large logistics centre ... -
Video inspection of wells in open loop ground source heat pump systems in Norway
(International Ground Source Heat Pump Association, 2018)This paper presents results from video inspections of groundwater wells in Melhus and Elverum, in Norway. The method has identified iron hydroxides, bacterial growth and sand production as causes of clogging in different ... -
Extending the Ashrae Tp8 method for vertical borefield design to uniform BHE temperature boundary conditions
(International Ground Source Heat Pump Association, 2018)The Ashrae method is a fast algorithm for calculating the overall length of closed-loop borehole heat exchangers, considering the ground thermal response and the building thermal load profile. The method includes a corrective ... -
Virtual borehole for thermal response test unit calibration: Test facility and concept development
(International Ground Source Heat Pump Association, 2018)Precise calculation of the borehole length requires good estimation of the ground thermal conductivity. In practice, the ground thermal conductivity is measured in-situ at a specific location using what is referred to as ... -
Near-instant g-function construction with artificial neural networks
(International Ground Source Heat Pump Association, 2018)A g-function is a useful tool that simplifies the calculations of heat exchanges in a ground-coupled heat pump system. In this work, we show how an artificial neural network can be trained to construct a g-function with ... -
Development of a thermal conductivity map of Stockholm
(International Ground Source Heat Pump Association, 2018)New methods have been suggested to spatially extend in situ thermal response test (TRT) assessments based on geostatistical analysis. These methods can be used to determine a stochastic distribution of the subsurface thermal ... -
Model predictive control applied to residential self-assisted ground source heat pumps
(International Ground Source Heat Pump Association, 2018)The seasonal performance and feasibility of a "self-assisted" ground source heat pump system are examined. The system uses an electric heating element to inject heat into the ground and reduce peak energy demand by eliminating ... -
Thermal Response Test experiments and modelling applied to shallow geothermal piles of different geometry
(International Ground Source Heat Pump Association, 2018)Geothermal piles are structural elements that encountered interest in ground source heat pump (GCHP) applications thanks to the great potential in cost reduction compared to the traditional solutions based on borehole heat ... -
G-functions for bore fields with mixed parallel and series connections considering axial fluid temperature variations
(International Ground Source Heat Pump Association, 2018)A semi-analytical method based on the finite line source (FLS) solution is presented to evaluate thermal response factors for geothermal bore fields with mixed series and parallel connections between boreholes. Each borehole ... -
Seasonal performance assessment of a dual source heat pump system for heating, cooling and domestic hot water production
(International Ground Source Heat Pump Association, 2018)In order to contribute to a global CO2 emissions reduction in 2020, the increase in the use of highly efficient heat pumps for heating, cooling and domestic hot water production in buildings is very recommendable. In this ... -
Foundation wall heat exchanger model and validation study
(International Ground Source Heat Pump Association, 2018)Making use of foundation substructural elements as ground heat exchangers is an attractive option for larger non-residential buildings. An alternative to Energy Piles is to use wall substructures - so called diaphragm or ... -
On the role of vertical ground heat flux for analytical simulation of borehole heat exchangers
(International Ground Source Heat Pump Association, 2018)Analytical modelling techniques are frequently used for prediction of the impacts of borehole heat exchangers (BHEs) on the thermal conditions in the subsurface. They are appealing because they are easy to use, compact and ... -
Underground thermal energy storage in subarctic climates: A feasibility study conducted in Kuujjuaq (QC, Canada)
(International Ground Source Heat Pump Association, 2018)Underground thermal energy storage can provide space and water heating and has been used in temperate climates so far. A step forward is to evaluate the efficiency and viability in arctic to subarctic environments, where ... -
Carbon dioxide evaporation process in direct expansion geothermal boreholes
(International Ground Source Heat Pump Association, 2018)Ground Heat Exchangers (GHE) play an important role in the performance of Ground Source Heat Pumps (GSHP). The impact is even more significant in direct expansion GSHP (DX-GSHP) systems as the refrigerant used in the heat ... -
Financial assessment of ground source heat pump systems against other selected heating and cooling systems for Australian conditions
(International Ground Source Heat Pump Association, 2018)Ground source heat pump (GSHP) systems can provide cost-effective space heating and cooling for buildings while using less fossil fuel compared to many conventional systems. Despite these benefits, they typically have ... -
Thermal performance evaluation of horizontal spiral coil-type ground heat exchangers
(International Ground Source Heat Pump Association, 2018)Geothermal energy has been widely used over the world instead of fossil fuel for environmental merits. A ground-source heat pump (GSHP) system utilizes a constant ground temperature to absorb heat during winter and to emit ... -
Ates system monitoring project, first measurement and performance evaluation: Case study in Sweden
(International Ground Source Heat Pump Association, 2018)Performance of Aquifer Thermal Energy Storage (ATES) systems for seasonal thermal storage depends on the temperature of the extracted/injected groundwater, water pumping rates and the hydrogeological conditions of the ... -
Design of a laboratory borehole storage model
(International Ground Source Heat Pump Association, 2018)This paper presents the design process of a 4x4 Laboratory Borehole Storage (LABS) model through analytical and numerical analyses. This LABS is intended to generate reference Thermal Response Functions (TRFs) as well as ... -
Application of matched asymptotic expansion techniques to the analysis of geothermal heat exchangers
(International Ground Source Heat Pump Association, 2018)Most theoretical models for the thermal response of geothermal heat exchangers assume the mean azimuthal borehole wall temperature to be uniform along the boreholes. This simplifying assumption, closely related to the ...