Development and validation of a full-time-scale semi-analytical model for the short- and long-term simulation of vertical geothermal bore fields

Laferrière, Alex; Cimmino, Massimo; Picard, Damien; Helsen, Lieve

doi:10.1016/j.geothermics.2019.101788

Cited by 21 publications

(15 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Horizontal systems are often 10 to 40 W/m, strongly depending on the climatic conditions [28,29]. Each vertical borehole heat exchanger and the surrounding elements were modelled by a resistance-capacitance model, as proposed by Bauer et al [30] and modified by Laferrière et al [31]. The modifications allow a free division of the boreholes in the area, as well as the consideration of more precise heat flows within the field.…”

Section: Geothermal Heat Sourcesmentioning

confidence: 99%

See 1 more Smart Citation

Thermo-Economic Analysis of Near-Surface Geothermal Energy Considering Heat and Cold Supply within a Low-Temperature District Heating Network

2022

View full text Add to dashboard Cite

This study evaluates low-temperature district heating (LTDH) networks with different geothermal heat sources under thermo-economic criteria. In particular, the heat and cold supply of modern neighbourhoods are taken into account in a dynamic simulation model built on the modelling language Modelica. Both horizontal and vertical ground heat exchangers (GHE) were investigated in respect to the load profiles of the consumers, depending on dimension as well as location. The selected base case represents a LTDH network near Stuttgart (Germany). The corresponding results of an annual simulation show that a horizontal GHE is suitable for pure heat supply and can reduce costs by up to 12% compared to a vertical system. This economic advantage remains when the cooling demand is considered. Subsequently, a variation of the system location was carried out. It is shown that horizontal GHEs operate more economically in northern regions, whereas vertical ones are more advantageous in regions with increased cooling demand. For both cases, possible savings of between 3.0% and 4.2% resulted from the simulations. The heating-to-cooling demand ratio was used as a first decision criteria to weigh-up between the two systems. Vertical GHEs were more economical than horizontal systems as soon as the ratio dropped below 1.5.

show abstract

Section: Geothermal Heat Sourcesmentioning

confidence: 99%

“…For simplification, it is assumed that the entire mass of a cell is concentrated in one point. Furthermore, mass transfers such as rain and underground flows through the system boundary and associated heat inputs and outputs are neglected [31,32].…”

Section: Geothermal Heat Sourcesmentioning

confidence: 99%

Thermo-Economic Analysis of Near-Surface Geothermal Energy Considering Heat and Cold Supply within a Low-Temperature District Heating Network

2022

View full text Add to dashboard Cite

show abstract

“…The input parameters chosen in EED are given in Table 2. This information is used to calibrate the borefield model included in IDEAS, based on the implementation done by Laferrière et al [41]. The secondary system is chosen to be a condensing gas boiler (CGB) which is able to provide the yearly peak load of the building, assuming an efficiency of 100%.…”

Section: Energy Systemsmentioning

confidence: 99%

“…A common strategy in borefield modeling is to split the heat transfer process into two models; the heat transfer within the borehole and the heat transfer outside of the borehole, with the borefield wall temperature acting as a connector between the two models. The proposed model is based on the model developed by Picard and Helsen [43] and refined by Laferrière et al [41] for building energy simulations (BES). Its ground response model is based on the characteristic borefield thermal response function with corrections to adapt it to the short-term range and an improved load-aggregation algorithm.…”

Section: Borefieldmentioning

confidence: 99%

Short-term modeling of hybrid geothermal systems for Model Predictive Control

Figueroa

Picard

Helsen

2020

Energy and Buildings

Self Cite

View full text Add to dashboard Cite

Model Predictive Control (MPC) has shown significant energy savings potential in the operation of building energy systems, yet it needs accurate and simple models for optimization. In hybrid geothermal systems the source-side temperatures affect the system efficiency and its operational feasibility. Since the ground dynamics are rather slow, simplifications such as considering a constant coefficient of performance (COP) are made. We evaluate the added value of including a short-term dynamic borefield model to the controller. Simulations are performed in a heating-dominated building equipped with a hybrid geothermal system for two winter weeks. We consider 4 different modeling strategies where the formulation of the COP and the return fluid temperature from the borefield is varied in complexity. Results show that using a constant COP results in a bang-bang behavior of the heat pump, while with an accurate prediction of the COP the operation is smoother, saving 0.46%, 1.86% and 2.71% for low, average and high electricity-to-gas price ratios respectively. Including a short-term borefield model avoids shutting down the heat pump due to safety constraints which saves up to 8.12% more money while the use of the groundsource is quintupled. Despite reducing the optimization iteration number by almost 18%, simulation time is increased.

show abstract

“…The 3D heat transfer model of BHES includes FEM, FVM and FDM. It can be concluded that the 3D model has more obvious advantages in simulation accuracy and applicable scope than the 2D model [33,34]. The use of numerical simulation techniques for the shallow geothermal field can reveal the heat transfer process of buried pipes, the quantitative analysis of thermal equilibrium, and provide a rational basis for the utilization of shallow geothermal energy.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Shallow Geothermal Field in Operating of a Ground Source Heat Pump System—A Case Study in Nan Cha Village, Ping Gu District, Beijing

Zhang

Zheng

Liu

et al. 2020

Water

View full text Add to dashboard Cite

The inefficient use of single energy and cold accumulation in the shallow geothermal field seriously affect the efficient operation of the ground source heat pump system (GSHPS). The operation of solar-assisted GSHPS can effectively solve the above problems. In this paper, a shallow geothermal utilization project in Nan cha Village, Ping Gu District of Beijing, is chosen as the study area. A three-dimensional numerical model of groundwater flow and heat transfer considering ambient temperature and backfill materials is established, and the level of model integration and validation are novel features of this paper. The thermal response test data in summer and winter conditions are used to validate the model. The results show that increasing hydraulic gradient has a positive impact on the heat exchange. The mixture of sand and barite powder is recognized as a more efficient and economical backfill material. The changes of thermal influence radius, heat balance, and shallow geothermal field are simulated and analyzed by three schemes. It is demonstrated that the thermal influence radius is 5 m, 3.9 m and 3.9 m for Scheme 1, Scheme 2 and Scheme 3, respectively. The ground temperature is always lower than the initial formation temperature in Scheme 1 and Scheme 2; however, under Scheme 3 it is higher than the initial values. The closer the hole wall is, the larger the difference between the initial formation temperature and the ground temperature, and vice versa. The thermal equilibrium of Scheme 1, Scheme 2 and Scheme 3 is −728 × 106 KJ, −269 × 106 KJ and +514 × 106 KJ. Through comprehensive analysis of the above three factors, Scheme 3 is regarded as the most reasonable scheme for a solar system to assist GSHPS.

show abstract

Development and validation of a full-time-scale semi-analytical model for the short- and long-term simulation of vertical geothermal bore fields

Cited by 21 publications

References 28 publications

Thermo-Economic Analysis of Near-Surface Geothermal Energy Considering Heat and Cold Supply within a Low-Temperature District Heating Network

Thermo-Economic Analysis of Near-Surface Geothermal Energy Considering Heat and Cold Supply within a Low-Temperature District Heating Network

Short-term modeling of hybrid geothermal systems for Model Predictive Control

Numerical Simulation of Shallow Geothermal Field in Operating of a Ground Source Heat Pump System—A Case Study in Nan Cha Village, Ping Gu District, Beijing

Contact Info

Product

Resources

About