New Insights into Heat Transfer of Deep Coaxial Geothermal Heat Exchangers DOI

Shurun Wang,

Xianhua Deng,

Youjian Wu

et al.

Published: Jan. 1, 2023

Deep geothermal heat exchangers (DGHEs) have emerged as a potential approach to exploiting energy stable high-temperature source for ground-coupled pumps. This study aimed offer insights into the transfer of DGHEs by systematic numerical simulations. first created finite-volume model (FVM) DGHEs, which uses governing equations circulating fluid inside borehole time-varying boundary condition wall. The FVM was verified comparison with several reported models. analysis emphasized validity homogeneous-medium assumption about ground and characteristics flux on seems be only acceptable in cases limited thermal conductivity differences between layers (e.g., < 2.0 W/m·K). Not wall varies linearly depth, but slope interception line are linear functions logarithm time.

Language: Английский

Investigating the impact of groundwater flow on multi-lateral, U-Type, advanced geothermal systems DOI Creative Commons
Christopher S. Brown, Gioia Falcone

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

Published: March 1, 2025

Language: Английский

Citations

0
In-situ test and numerical investigation on the long-term performance of deep borehole heat exchanger coupled heat pump heating system DOI Creative Commons

Bin Liu,

Jiangfeng Wang, Hongyan Li

et al.

Case Studies in Thermal Engineering, Journal Year: 2024, Volume and Issue: 61, P. 104855 - 104855

Published: July 20, 2024

Given the substantial initial investment required by drilling and implementation of Deep Borehole Heat Exchanger (DBHE), it becomes imperative to quantitatively evaluate its long-term performance sustainability. This work introduces a pilot DBHE project in Xi'an, along with 500-h in-situ monitored data, which is used validate 3D numerical model established simulated OpenGeoSys (OGS) software. Based on validated model, series extended scenarios are executed influence design operational parameters sustainability system. The results show that depth most significant factor influences performance. On contrary, pipe diameter inner thermal conductivity have very limited impact. A comprehensive evaluation suggested determine flow rates real projects while considering energy consumption circulation pump. Moreover, heat extraction analysis coupled geothermal pump under intermittent operation also investigated. With fixed daily heating demand, longer operating time lower circulating temperature drops, advantageous for pump's efficiency operation.

Language: Английский

Citations

3
Heat transfer analysis of deep coaxial geothermal heat exchangers: Insights into heat-flux distribution on borehole wall DOI Creative Commons

Shurun Wang,

Xianhua Deng,

Jing Wang

et al.

Energy and Built Environment, Journal Year: 2024, Volume and Issue: unknown

Published: Feb. 1, 2024

Deep geothermal heat exchangers (DGHEs) have emerged as a potential approach to exploiting energy stable high-temperature source for ground-coupled pumps. This study aimed offer insights into the transfer of DGHEs by systematic numerical simulations. first created finite-volume model (FVM) DGHEs, which uses governing equations circulating fluid inside borehole time-varying boundary condition wall. The FVM was verified comparison with several reported models. analysis emphasized validity homogeneous-medium assumption about ground and characteristics flux on seems be only acceptable in cases limited thermal conductivity differences between layers (e.g., < 2.0 W/m·K). Not wall varies linearly depth, but slope interception line are linear functions logarithm time.

Language: Английский

Citations

2
Generic modelling to develop thermal yield nomograms for coaxial deep borehole heat exchangers (DBHE) DOI Creative Commons
David Banks, Christopher S. Brown, Isa Kolo

et al.

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

Citations

2
Decarbonising well-insulated buildings in a warming climate: The case of adaptive thermal comfort with geothermal space heating DOI Creative Commons
Hui Ben, Christopher S. Brown, Isa Kolo

et al.

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

Citations

2
Decarbonising heating and cooling using temperature setback and geothermal energy DOI Open Access
Hui Ben, Sara Walker, Christopher S. Brown

et al.

Journal of Physics Conference Series, Journal Year: 2023, Volume and Issue: 2600(2), P. 022015 - 022015

Published: Nov. 1, 2023

Abstract The lion’s share of buildings’ energy consumption is used for maintaining a thermally comfortable indoor environment. Strategies reducing heating and cooling demand can thus be crucial buildings to achieve net zero. This research aims investigate the extent which an occupancy-based temperature setback strategy geothermal supply decarbonise office building. objectives include: 1) exploring optimal maximum savings, both in present time under future climate scenarios, 2) evaluating borehole meet building’s demand. outcome shows that coupled with by around half. As overall building demand, make reduction over tenth while minimum fifth.

Language: Английский

Citations

2
Integrated thermal strategies for UK non-domestic building energy demand DOI Open Access
Hui Ben, Sara Walker

Building Simulation Conference proceedings, Journal Year: 2023, Volume and Issue: 18

Published: Sept. 4, 2023

Aim and Approach:To tackle climate change reach net zero, this paper investigates how building consumes energy in response to the opportunity of integrated thermal strategies, under warming climate. The aim is explore extent which demand can be met when considering adaptive comfort approach geothermal provision. objectives include: 1) comparing after extending temperature set-points integrate comfort; 2) examining future demand, such as heating cooling demands climate; 3) evaluating feasibility achieve renewable supply using a repurposed deep borehole. methodology work includes simulating case study its adjacent borehole based on monitoring data. impact form extended thermostat then evaluated model. After scenarios are examined, from USB investigated test what wellbore decarbonise building.Scientific Innovation Relevance:Buildings responsible for significant proportion worldwide consumption carbon emissions. lion's share buildings' used maintain occupants' comfort. Office buildings, particular, tend have relatively narrow maintaining comfort, whereas occupants adapt much wider range temperatures given control over their own environmental conditions.This examines - Urban Sciences Building (USB), located city Newcastle, UK. This has digital sensors installed throughout constantly monitor conditions use. A validated dynamic simulation model employed simulate USB's performance at present day scenarios. innovative multi-sensor system makes it possible accurate prediction building's extensive datasets collected building.Geothermal provides reliable source heat among various renewables, having recently gained traction also because wide availability. Meanwhile, there lack an would climate, especially concerning In addition, decarbonisation rarely been considered alongside approach. Thus, seeks bring these together, potential strategies non-domestic both warmer future.Results Conclusions:The results show that were applied, reliance non-renewables reduced by quarter. demonstrated low-cost viable way cutting down Under scenarios, modelling shows more decrease and, lesser extent, increase USB. However, with approach, reveals during summer season. Therefore, helping buildings reduce demand. indicates mechanical need not one might assume weather gets coming decades temperate like Further utilisation will needed office addition strategies.

Language: Английский

Citations

1
New Insights into Heat Transfer of Deep Coaxial Geothermal Heat Exchangers DOI

Shurun Wang,

Xianhua Deng,

Youjian Wu

et al.

Published: Jan. 1, 2023

Deep geothermal heat exchangers (DGHEs) have emerged as a potential approach to exploiting energy stable high-temperature source for ground-coupled pumps. This study aimed offer insights into the transfer of DGHEs by systematic numerical simulations. first created finite-volume model (FVM) DGHEs, which uses governing equations circulating fluid inside borehole time-varying boundary condition wall. The FVM was verified comparison with several reported models. analysis emphasized validity homogeneous-medium assumption about ground and characteristics flux on seems be only acceptable in cases limited thermal conductivity differences between layers (e.g., < 2.0 W/m·K). Not wall varies linearly depth, but slope interception line are linear functions logarithm time.

Language: Английский

Citations

0