Ricerc@Sapienza

The geothermal sector has a strength point with respect to other renewable energy sources: the availability of a wide range of both thermal and power applications depending on the source temperature. Several researches have been focused on the possibility to produce geothermal energy without brine extraction, by means of a deep borehole heat exchanger. This solution may be the key to increase the social acceptance, to reduce the environmental impact of geothermal projects, and to exploit unconventional geothermal systems, where the extraction of brine is technically complex.

The decarbonisation of the energy sector is probably one of the main worldwide challenges of the future. Global changes urge a radical transformation and improvement of the energy-producing systems to meet the decarbonisation targets and a reduction of greenhouse gas emissions. The hydrocarbon industry also contributes to this transition path. In a mature stage of oil and gas fields, the production of hydrocarbons is associated with formation waters.

The available literature on the WellBore Heat eXchangers (WBHX) has been analyzed giving prominence to three aspects. First, the heat transfer through the geothermal reservoir and between the formation and the well has been analyzed. Then, the design of the WBHX and the modelling of the heat exchange has been reviewed. Lastly, the analysis of the performance of the WBHX in the production of thermal and/or electrical energy has been focused.

The present study investigates the sustainable use of a ground coupled heat pump (GCHP). In order to assess the performance of this type of installation, a computer model composed by two parts has been developed. The Borehole Heat Exchanger (BHE) model is developed in COMSOL Multiphysics, based on numerical methods. Part of the results are fed to the heat pump energy model, developed in MATLAB. A real case study has been used to validate the model: the Faculty of Engineering of La Sapienza University in Latina, undertaking a renewal project for an abandoned part of the building.

The proposed analysis is focused on the project and the technical and economical evaluation of a ground source heat pump system for heating and cooling an industrial building. The project of the plant consists of two phases: the design of the heating and cooling system and the design of the geothermal probes field. The optimization of the system has been the target of the entire design process. The proposed solution is an hybrid system: two ground source heat pumps, coupled with a back-up condensing boiler.

The Salcheto winery, located in Montepulciano (Italy) has undertaken a process of reduction of primary energy consumption and implementation of green energy technologies. Thanks to bio-architecture solutions, the winery has reduced the energy consumption of 54%. The rest of the energy is covered by photovoltaic panel, wood biomass and geothermal energy. A horizontal ground source heat exchanger (GSHE) plant is used to cooling a part of the pressed grapes and control the wine production temperature.

This paper analyses the use of a WBHX plant coupled with an ORC power plant in two different case studies: the depleted geopressurized oil field of Villafortuna Trecate and the magmatic area of Campi Flegrei. A comprehensive thermodynamic assessment of the WBHX – ORC plant has been carried out analysing each component, including the cooling tower and ancillary equipment. Different organic fluids have been tested in order to find the most advantageous in the two different cases.

This paper presents the project and the economic and environmental evaluation of a ground source heat pump system implemented in a sport centre located in Sora (Italy). The first step of the work has been the estimation and the analysis of the energy consumption of the building, using the energy bills to validate the results. In order to improve the energy system efficiency, three different solution have been proposed and analysed. The first option consists of a geothermal plant and a solar panel plant.

The paper presents a comprehensive energy and exergy analysis of a possible geothermal power plant located in the geothermal district of Campi Flegrei (Italy), made of a coaxial WellBore Heat eXchanger coupled to an Organic Rankine Cycle. We have accounted for all system components: the ground source, the WellBore Heat eXchanger, the Organic Rankine Cycle cycle, and cooling system. The energy and exergy performance indexes of each subsystems and overall system have been evaluated, thus calculating the net power, the First-Law efficiency, the Second-Law efficiency, the irreversibilities.

The present study investigates the sustainable use of a ground coupled heat pump (GCHP). In order to assess the performance of this type of installation, a computer model composed by two parts has been developed. The Borehole Heat Exchanger (BHE) model is developed in COMSOL Multiphysics, based on numerical methods. Part of the results are fed to the heat pump energy model, developed in MATLAB. A real case study has been used to validate the model: the Faculty of Engineering of La Sapienza University in Latina, undertaking a renewal project for an abandoned part of the building.