Design of a Gas-Driven Hybrid Adsorption Heat Pump Coupled To Geothermal Heat Exchangers for Retrofitting Applications

Conference paper presented in the 13th IEA Heat Pump Conference 2020 held online and in Jeju, Korea on April 26-29, 2021.

Title: Design of a Gas-Driven Hybrid Adsorption Heat Pump Coupled To Geothermal Heat Exchangers for Retrofitting Applications

Language: English

Authors: Valeria Palomba (*1), Antonio Bonanno (*1), Davide La Rosa (*1), Stefan Löwe (*2), Ralph Herrmann (*2), Andrea Frazzica (*1)

*1: Istituto di Tecnologie Avanzate per l’Energia CNR-ITAE, Messina (Italy)
*2: Fahrenheit GmbH, Halle (Germany)

Abstract: The need for retrofitting of residential buildings with energy efficient solutions requires for the development of a wide range of solutions, suitable for different climates and buildings. In the present paper, a concept based on a gas-driven sorption heat pump using geothermal source for evaporation is presented. A dynamic lupedparameter model was implemented in Dymola and used to verify the flexibility of the system in terms of response to variable load and comfort conditions. The outcomes of the activity will be used to propose an improved design of the system.

Discrete Element Modelling of Rock Drilling

Conference paper presented in European Geothermal Congress 2022 held in Berlin, 17-21 October

Title: Discrete Element Modelling of Rock Drilling

Language: English

Authors: Albin Wessling (*1), Jörgen Kajberg (*1), Simon Larsson (*1), Giselle Ramírez Sandoval (*2), Montserrat Vilaseca Llosada (*2)

*1: Division of Solid Mechanics, Luleå Univeristy of Technology
*2: Unit of Metallic and Ceramic Materials, Eurecat, Centre Tecnològic de Catalunya

Abstract: Percussive rotary drilling is recognized as the most efficient method for hard rock drilling. Despite clear advantages over conventional rotary methods, there are still some uncertainties associated with percussive drilling. For geothermal applications, drilling accounts for a large portion of the total cost. Specifically, the wear of drill bits when drilling in hard rock is a predominant cost factor and drilling parameters are often based on the experience of the field operator. Within the framework of the H2020 project GEOFIT, numerical simulations of percussive drilling are performed in order to evaluate the rock drilling process and gain insight about the trade-off between wear and Rate of Penetration (ROP). In the simulations, the rock material was represented by the Bonded Discrete Element Method (BDEM), the drill bit by the Finite Element Method (FEM), the drilling fluid by the Particle Finite Element Method (PFEM) and the abrasive wear on the surface of the drill bit was represented by Archard’s wear law. The drilling simulations were conducted for two rock materials; a sedimentary rock material corresponding to what was found when drilling at the GEOFIT pilot site in Aran Islands, Ireland, and a harder reference rock similar to granite. The results show that, at a drill bit impact force of 10 kN, the ROP in the sedimentary rock was 6.3 times faster than for granite. When increasing the impact force to 40 and 50 kN, however, the ROP for the sedimentary rock is only 1.9 and 1.6 times faster, respectively. Furthermore, the wear rate decreased with increased impact force when drilling in the granite rock. For the sedimentary rock, however, the loading resulting in the best trade-off between abrasive wear and ROP was the second highest loading of 40 kN, which suggests that an increase in impact energy may increase the rate of penetration but may not be economically motivated.

Techno-Economic Analysis of a Swimming Pool Heating System Retrofitting Through a Dual Source Heat Pump

Conference paper presented in European Geothermal Congress 2022 held in Berlin, 17-21 October

Title: Techno-Economic Analysis of a Swimming Pool Heating System Retrofitting Through a Dual Source Heat Pump

Language: English

Authors: Giuseppe Edoardo Dino (*1), Valeria Palomba (*1), Andrea Frazzica (*1), Adriaan Brebels (*2), Marco Calderoni (*3) and Luis Miguel Blanes Restoy (*4)

*1: CNR ITAE
*2: i.LECO NV
*3: R2M Solution s.r.l

*4: National University of Ireland Galway

Abstract: The European energy policies are aiming to the electrification of the heating sector as it is considered one of the solutions indicated for the decarbonization of the energy system. Heat pumps represent the most promising and widely adopted solution. However, there are some inherent technological problems to heat pumps, such as evaporator frosting for air-source heat pumps and ground thermal drift for ground source heat pumps. From this perspective a dual-source (air-geothermal) heat pumps represents a promising solution to overcome those challenges. GEOFIT H2020 project aims at developing a wide range of smart solutions for the retrofitting of thermal systems based on shallow and deep geothermal source. In this paper, the retrofitting of a gas boiler based system for the heating of a swimming pool in Galway (Ireland) with a dual-source heat pump with active regeneration of the soil is presented. Firstly, a swimming pool model developed in TRNSYS environment was validated through experimental campaign data retrieved by the Galway demo site. The baseline system composed by a gas boiler was simulated, then a reference retrofit solution composed by a dual source heat pump and an analogous system with a reduced design size were proposed and simulated for a long-term period (20 years). The analysis showed that a relevant primary energy saving is achievable and that the ground thermal drift is mitigated through the active ground heat regeneration. The techno-economic analysis revealed that the proposed system could have a replicability in retrofit solutions, especially in those with a seasonal inbalance where only heating loads are required during the whole year. Considering the current and foreseen increase of the fossil fuel costs, the economic competitiveness will be more favourable.

D5.1 Building Models Implementation

Deliverable 5.1 developed reduced order and transient dynamic models for three GEOFIT demonstration sites, i.e. San Cugat in Spain (Section 1), Bordeaux in France (Section 2) and Galway in Ireland (Section 3). The development of these models is part of the approach to select, design and integrate the GEOFIT Enhanced Geothermal Systems / Ground-Source Heat Pumps into the building according to its characteristics. The work presented here shows the capabilities of reduced order and transient models in building performance prediction and optimisation, as well as their flexibility to be used in building retrofit.