Comparison of the thermal and hydraulic performance of single U-tube, double U-tube and coaxial medium-to-deep borehole heat exchangers

Geothermics, Journal Year: 2023, Volume and Issue: 117, P. 102888 - 102888

Published: Dec. 7, 2023

Decarbonisation of heat is essential in curbing carbon dioxide emissions and can be achieved through the use geothermal systems. Recently, single-well, closed-loop, deep borehole exchangers, using a coaxial design, have become focus attention, partly due to potential repurpose existing infrastructure (such as oil gas wells); however, few investigated for other types exchanger middle-deep Therefore, this study, comprehensive numerical analysis was undertaken OpenGeoSys software investigate thermal hydraulic performance coaxial, single U-tube double exchangers (MDBHEs). The purpose paper test maximum operational depth each type pipe configuration wells been completed depths exceeding 500 m single/double configurations. best performing MDBHEs should minimise parasitic losses, whilst maximising output. Furthermore, ground sourced pumps require electricity; therefore, at times where electricity prices are high (and drilling costs minimised) it may more beneficial utilise encounter greater temperatures. Results indicate that provide terms specific extraction lowest pressure/parasitic losses. Double similar but significantly pressure losses across all simulations, which translates pumping power costs. Single demonstrate poorest At end 25-year base case scenario 800 MDBHE, configurations, with fluid circulation rate 5 L/s, provided rates 39.1 W/m, 32.8 36.0 respectively, inlet temperature set constant °C. For these were estimated 85 kPa (coaxial), 1.46 MPa (single U-tube) 423 (double U-tube)—the value being close nominal 16 bar (1.6 Mpa) rating SDR11 density polyethylene pipe. Further parametric also undertaken, investigating depth, flow rate, rock conductivity, diameter shank spacing.

Language: Английский

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A comprehensive review of deep borehole heat exchangers (DBHEs): subsurface modelling studies and applications

Geothermal Energy, Journal Year: 2024, Volume and Issue: 12(1)

Published: June 10, 2024

Language: Английский

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Assessing the technical potential for underground thermal energy storage in the UK

Renewable and Sustainable Energy Reviews, Journal Year: 2024, Volume and Issue: 199, P. 114545 - 114545

Published: May 14, 2024

Heating and cooling both make up a large part of the total energy demand in UK; long-term seasonal thermal storage (STES) can address temporal imbalances between varying supply heat to buildings processes. Underground (UTES) play role decarbonisation by storing waste from space cooling, refrigeration, data processing, industrial processes, harvested summer solar or even generated surplus renewable (solar wind) electricity with fluctuating supply. This paper evaluates range UTES technologies UK context addresses geological suitability, capacity, low-carbon sources, surface sources demand. review concludes that there is significant potential for aquifer (ATES) borehole (BTES) systems, coinciding Therefore, uptake technology will help achieve net-zero carbon neutral targets 2050. There also scope utilise within existing subsurface infrastructure. are 464 oil gas wells which could be repurposed upon end life using different technologies. However, repurposing needs further evaluation; deep single well BTES systems have high area volume ratio storage, reducing efficiency such ATES limited issues associated contaminants. 23,000 abandoned mines underlay ∼25 % UKs population utilised minewater (MTES).

Language: Английский

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Investigating heat transmission in a wellbore for Low-Temperature, Open-Loop geothermal systems

Thermal Science and Engineering Progress, Journal Year: 2023, Volume and Issue: 48, P. 102352 - 102352

Published: Dec. 22, 2023

Heat transfer processes in geothermal wellbores are an essential component to overall system performance, but can be overlooked subsurface modelling studies that tend focus on reservoir response. This study addresses heat the wellbore through a comprehensive of 10 different parameters OpenGeoSys software designed evaluate losses during open-loop production conditions for typical low-temperature (<100 °C) single phase systems. Models were set-up effects only, using well with constant fluid inlet temperature boundary condition. Results indicate under base case 2-km deep surrounded by rock formations thermal conductivity 2.5 W/(m.K) and bottom-hole 60 °C, difference (reservoir) (wellhead) at end 40-year period is 2.06 °C. corresponds minimum into surrounding -63.3 W/m, which ∼7 % power recorded wellhead (assuming rejection 30 3.4 temperature. These significant, particularly when combination surface exchanger or breakthrough. Wellbore insulation reduce losses, it would appear this only impacts short-term. performance also improved, minimized, developing wells above interval low high gradients.

Language: Английский

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Investigation of the heat transfer of a single U-tube borehole heat exchanger for medium-shallow geothermal energy

International Communications in Heat and Mass Transfer, Journal Year: 2025, Volume and Issue: 162, P. 108644 - 108644

Published: Feb. 4, 2025

Language: Английский

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Geothermal production, injection, and storage engineering

Elsevier eBooks, Journal Year: 2025, Volume and Issue: unknown, P. 181 - 220

Published: Jan. 1, 2025

Language: Английский

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Investigating the impact of groundwater flow on multi-lateral, U-Type, advanced geothermal systems

Applied Thermal Engineering, Journal Year: 2025, Volume and Issue: unknown, P. 126269 - 126269

Published: March 1, 2025

Language: Английский

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Generic modelling to develop thermal yield nomograms for coaxial deep borehole heat exchangers (DBHE)

Quarterly Journal of Engineering Geology and Hydrogeology, Journal Year: 2024, Volume and Issue: 57(3)

Published: May 21, 2024

Numerical modelling of coaxial deep borehole heat exchangers (DBHEs) can be resource-intensive. Simpler, transparent analytical models and nomograms would valuable to developers geologists for evaluating thermal output. In this paper, Beier’s published computational model was used produce geothermal yield by systematically varying the DBHE depth rock conductivity, while assuming two generic simplified designs, a gradient 25°C km −1 fluid circulation rate 5 l s . Continuous 25 year yields from 1000 m range 27.3 54.8 kW conductivities 1.6–3.6 W K For 3000 DBHE, they 165 281 kW. Effective resistance ( R b,eff ) increases strongly as due internal transfer between upflow downflow elements. Simulations correspond well with results industry-standard Earth Energy Designer software shallow 200 BHE. They modestly underestimate OpenGeoSys numerical modelled 2–4% in 1000–3000 m. Modelled temperature evolution closely approximates an ‘line source’ approach, implying that simpler approaches are plausible simulation. Future research should focus on methods forward quantification

Language: Английский

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Decarbonising well-insulated buildings in a warming climate: The case of adaptive thermal comfort with geothermal space heating

Energy and Buildings, Journal Year: 2024, Volume and Issue: 319, P. 114466 - 114466

Published: June 28, 2024

Buildings contribute to 40% of global energy demand and are responsible for a third CO2 emissions. Strategies decarbonise buildings are, therefore, crucial reaching the net-zero emissions targets by most countries in world. This study investigates feasibility decarbonising well-insulated with current future weather scenarios applying adaptive thermal comfort strategy combination closed-loop deep geothermal system. An office building has been chosen as case because comprehensive sensor system installed which allows detailed data extraction analysis. The results show that building's heating cooling can be reduced 51% using an approach, while this decreases 45% 2080 under warming climate. Combined satisfy 50% at present when combined intermittent storage scenarios, 5 borehole heat exchangers (DBHEs) would required meet all directly. In conclusion, shows DBHE approach presents innovative low-cost opportunity significantly lower carbon

Language: Английский

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Geoscience for energy transition

Geology Today, Journal Year: 2024, Volume and Issue: 40(2), P. 63 - 71

Published: March 1, 2024

We are living in the midst of a great technological revolution history—the energy transition from today's fossil fuel‐dominated civilization to low‐carbon economies and industries. Geoscientists will significantly contribute science, policy technologies by advancing our knowledge base complex interacting processes substances Earth's lithosphere, oceans atmosphere. Mapping flow various forms intensities Earth systems, exploration resources minerals evaluating environmental impacts upstream downstream be increasingly embedded geoscience education, research workforce development. This article outlines major pathways how components transition.

Language: Английский

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