Browsing Proceedings of the IGSHPA Technical/Research Conference and Expo 2017 by Title
Now showing items 11-30 of 44
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Direct expansion ground source heat pump using carbon dioxide as refrigerant: Test facility and theoretical model presentation
(International Ground Source Heat Pump Association, 2017)In an attempt to address recent challenges on using natural refrigerants and to develop further knowledge and expertise in the field of direct expansion ground source heat pump (DX-GSHP), an experimental transcritical ... -
Effect of an off-peak ground pre-cool control strategy on hybrid ground-source heat pump systems
(International Ground Source Heat Pump Association, 2017)Hybrid Ground-Source Heat Pump (HGSHP) systems have been introduced as an alternate system configuration to remedy the current financial hurdles associated to the installation of geo-exchange technology. However, there ... -
Energy performance evaluation of a recycled water heat pump system in cool and dry climate zone
(International Ground Source Heat Pump Association, 2017)This paper presents performance evaluation results for a recycled water heat pump (RWHP) system, which uses the recycled water from a municipal water system as a heat sink and heat source for heat pumps. The temperature ... -
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 ... -
Fast and accurate calculation of the soil temperature distribution around ground heat exchanger based on a response factor model
(International Ground Source Heat Pump Association, 2017)Ground heat exchanger (GHE) is an important component of ground coupled heat pump system (GCHP). To calculate the soil temperature around GHE accurately and fast, a refined response factor model (RF model) is proposed. It ... -
First measurements of a monitoring project on a BTES system
(International Ground Source Heat Pump Association, 2017)Performance of Borehole Thermal Energy Storage (BTES) systems depends on the temperature of the secondary fluid, circulating through the ground-loop heat exchangers. Borehole systems are therefore designed in order to ... -
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, ... -
Heat extraction distributed thermal response test: A methodological approach and in-situ experiment
(International Ground Source Heat Pump Association, 2017)The Thermal Response Test (TRT) is a worldwide adopted in-situ methodology able to estimate the ground thermal conductivity and borehole thermal resistance. During the test the carrier-fluid exchanges a constant heat flux ... -
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 ... -
High time-resolution analytical models for heat transfer through U-shaped ground heat exchangers
(International Ground Source Heat Pump Association, 2017)This paper reports a set of high time-resolution analytical models for heat transfer of GHEs, including a full scale line-source model for heat transfer outside U-shaped pipes and a quasi-3D heat transfer model for the ... -
Improving thermal conductivity and fluid loss properties of grouting materials: New mixed grout granules of bentonites and sands
(International Ground Source Heat Pump Association, 2017)We propose new granule type grouting materials with optimized ratio of bentonites and sands for use in the ground source heat pump systems. The grouting materials could be prepared in various size of 1.18 to 4.75 mm. The ... -
Influence of different ground thermal properties in a borehole heat exchanger's performance using the B2G dynamic model
(International Ground Source Heat Pump Association, 2017)Ground source heat pump (GSHP) systems for heating and cooling represent an efficient alternative to conventional air source heat pump systems, always provided that they present an efficient design and operation. In this ... -
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 ... -
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 ... -
Investigation on the effects of different time resolutions in the design and simulation of BHE fields
(International Ground Source Heat Pump Association, 2017)The correct design of a field of Borehole Heat Exch angers (BHE) requires the knowledge of ground thermal properties, heat pump performance and building heating and cooling demand. The sequence o f heat pulses from (to) ... -
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 ... -
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 ... -
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) ... -
Modelling and experimental validation of a novel co-axial spiral borehole heat exchanger
(International Ground Source Heat Pump Association, 2017)In order to optimize the operation of a ground source heat pump (GSHP) system, the development of dynamic models that integrate all the system components is a key factor. Particularly, the modelling of the ground source ... -
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 ...