Vinsamlegast notið þetta auðkenni þegar þið vitnið til verksins eða tengið í það: http://hdl.handle.net/1946/31405
Three geothermal projects in the region of Alsace are currently being developed and executed by the companies Fonroche Géothermie and L’Electricié de Strasbourg (ES). With the aim of exploiting the thermal energy stored at 5000 m below the surface of the earth, these projects foresee the implementation of one binary power plant, and two cogenerating units that will be integrated to the local grid, and benefit from European and national incentives for sustainable energy production. This research focuses on the utilization of the geothermal energy available in Vendenheim, Eckbolsheim, and Illkirch. Special emphasis is made on the first and largest project in the city of Vendenheim, where an industrial ecosystem is also defined, next to the proposed geothermal binary power plant. The research is structured in three main sections, two of which (Thermodynamics and Economics) constitute the main pillars of the thesis. The first chapter provides preliminary information, current operations, and data leading to the proposed cascading applications fit for the region such as beet sugar production, beer production, hop drying, microalgae production and drying, wine distillation, and two power production scenarios. The second chapter focuses on the thermodynamic analysis of a binary power plant and a Combined Heat and Power Plant in Vendenheim, analyzing the second law efficiency and exergy flow through the system, and providing insight on the proposed direct applications. Comparing the real efficiencies of a Combined Heat and Power system shows that the efficiencies decrease considerably when introducing a cascading scenario, 44,43% for a full power only subcritical binary plant and 24,43% for a Combined Heat and Power system. The full power production proposal is thus selected for a thermoeconomic analysis to review the feasibility of using the geothermal resource for power production only. In the third chapter, the thermoeconomic analysis is computed for the full power production scenario, analyzing balancing costs and exergoeconomic factors of the components resulting from the exergy flow through the system. The proposed subcritical power plant in Vendenheim produces 7,5 MW of work at the turbine, showing the project to be feasible at the current electricity selling rates in Alsace (200 – 246 €/MWh for projects under 12 MWe of capacity). The research presents cost flow analyses associated with irreversibilities, providing insight on potential improvements of the system. Irreversibilities within power plant could be reduced and optimized, making alternative or advanced binary plants additionally feasible than the proposed subcritical system.
keywords: Thermoeconomics, Exergoeconomic, Exergy, Thermodynamics, Enhanced Geothermal Systems, ORC, Alsace, France