Modelling and Experimental Validation of an Innovative Coaxial Helical Borehole Heat Exchanger for a Dual Source Heat Pump System

Cazorla-Marín, Antonio

doi:10.4995/thesis/10251/125696

Cited by 3 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The tool used for simulating the dynamic energy performance of the system is the DSHP model developed in TRNSYS. The model was designed in the framework of the GEOTeCH project and, in the past years, was gradually enhanced by additional system components, such as the coaxial spiral BHE, and is described in numerous scientific publications [25][26][27][28]30]. The system designed in TRNSYS is modular, and its key elements that describe different components are grouped in macros mutually interconnected and governed by mathematical relations.…”

Section: Trnsys Modelmentioning

confidence: 99%

“…The core element in the system model is the heat pump, where the water coming from the different circuits is heated up or cooled down depending on the system control and the thermal demand. The final version of the model is extensively described in the Ph.D. dissertation by Cazorla-Marín [30] and includes in-depth specifications of all control strategies and subsystems.…”

Section: Trnsys Modelmentioning

confidence: 99%

“…The type "HP-Geotech_v3" corresponds to the DSHP model, based on the DSHP prototype developed in the GEOTeCH project, which is able to produce heating or cooling to the user, as well as to produce DHW using the air as a source/sink or the ground loop. This model was developed in previous works [25,30] and is defined as a black box in the TRNSYS model. The DSHP performance is calculated using polynomial correlations obtained from a test campaign [31] and calculated with the software IMST-ART [32].…”

Section: Heat Pump Modelmentioning

confidence: 99%

“…The BHE model used (B2G model) was developed by Cazorla-Marín et al to reproduce the dynamic behavior of a coaxial BHE [28]. Additionally, the long-term response of the ground, as well as the interaction between the different BHEs in the field, is considered in the ground loop using a model based on the infinite line source (ILS) model, called "Line Source Approach" (LSA) model and described in [30]. The ground loop macro is shown in Figure 2.…”

Section: Ground Loopmentioning

confidence: 99%

“…Energies 2022, 15, 8460 2 of 30 Often, to compare the feasibility of the GSHPs with other HVAC systems, the conventional air-source heat pump (ASHP) is used as a reference [4][5][6]. Due to the variation in external air temperature throughout the year, ASHPs are characterized by a variable energy performance which often leads to lower overall system efficiency, especially in cold climates.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Energy Analysis and Cost-Effective Design Solutions for a Dual-Source Heat Pump System in Representative Climates in Europe

2022

View full text Add to dashboard Cite

Ground-source heat pumps are an efficient technology for heating and cooling in buildings. However, the main limitation of their widespread application is the borehole heat exchanger’s (BHE) high investment cost. Hybridizing GSHP systems may overcome this limitation. This research work analyzes the long-term energy performance of a dual-source heat pump (DSHP) system, which uses the air or the ground as external heat/sink sources, in three representative European climates. First, a BHE cost-effective design solution is proposed for each climatology; then, a complete energy analysis is carried out, and the optimal source control parameters that best enhance the system performance in each climate are determined with the use of a complete dynamic model of the DSHP system developed in TRNSYS. Simulations were carried out for a 25-year operation period. Results show that the DSHP maintains the efficiency during the simulated period, with deviations lower than 1.7% in all cases. Finally, the source control optimization method results in only slight efficiency gains (<0.35%) but with a stronger effect on the ground/air use ratio (up to 25% use of air in cold climates), reducing the thermal imbalance of the ground and leading to a consequent BHE size length and cost reduction.

show abstract

Section: Trnsys Modelmentioning

confidence: 99%

Section: Trnsys Modelmentioning

confidence: 99%

Section: Heat Pump Modelmentioning

confidence: 99%

Section: Ground Loopmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Energy Analysis and Cost-Effective Design Solutions for a Dual-Source Heat Pump System in Representative Climates in Europe

2022

View full text Add to dashboard Cite

show abstract

Cloud-Based Optimal Control of Individual Borehole Heat Exchangers in a Geothermal Field

2022

View full text Add to dashboard Cite

Integrating renewable energy sources is a crucial component in reducing CO2 emissions in the building sector. In particular, shallow geothermal energy is expected to play a significant role in the regenerative energy supply of buildings. An effective control strategy for the geothermal field is crucial to reduce the overall energy consumption. This paper analyzes the benefits of controlling an existing field’s individual borehole heat exchangers (BHE) using nonlinear model predictive control (NMPC) and moving horizon estimation. The considered geothermal field consists of 41 BHEs and is used for heating and cooling. Each BHE is equipped with temperature sensors for in- and outflow and has individually controllable valves, while a central hydraulic pump feeds all BHEs. The sensor measurements are accessed through a cloud platform, enabling also set point writing for the pump speed and the valve positions. To control the BHEs individually, we propose a two-stage process. In the calibration stage, a moving horizon estimator estimates the actual borehole and ground temperatures for each BHE. In the second stage, first, a nonlinear model predictive controller optimizes the number of active BHEs necessary to meet the buildings’ energy demand. With the estimated ground temperatures as a basis, it is determined which BHEs shall be (de)-activated. The active BHEs are fed with a fixed volume flow of 24 L/min to ensure turbulent heat transfer. To reduce the power usage of the pumps, an optimal control problem based on a simple hydraulic model of the geothermal field is used. The methodology is analyzed through simulations first and then validated experimentally. The results show that half or more of the BHEs could be deactivated most of the time, leading to 67% savings in electricity consumption by the hydraulic pump.The experimental validation confirms the high energy saving potential of the proposed methodology, reducing the consumption of electrical energy by 71%. Additionally, the deactivated BHEs regenerate faster and improve the field’s long-term behavior. In conclusion, the proposed strategy improves the short and long-term performance of the geothermal field.

show abstract

A novel TRNSYS type of a coaxial borehole heat exchanger for both short and mid term simulations: B2G model

Cazorla-Marín

Montagud

Tinti

et al. 2020

Applied Thermal Engineering

View full text Add to dashboard Cite

Modelling and Experimental Validation of an Innovative Coaxial Helical Borehole Heat Exchanger for a Dual Source Heat Pump System

Cited by 3 publications

References 0 publications

Energy Analysis and Cost-Effective Design Solutions for a Dual-Source Heat Pump System in Representative Climates in Europe

Energy Analysis and Cost-Effective Design Solutions for a Dual-Source Heat Pump System in Representative Climates in Europe

Cloud-Based Optimal Control of Individual Borehole Heat Exchangers in a Geothermal Field

A novel TRNSYS type of a coaxial borehole heat exchanger for both short and mid term simulations: B2G model

Contact Info

Product

Resources

About