Subject: ENERGY CONVERSION SYSTEMS (A.A. 2023/2024)
Unit Macchine e Sistemi energetici
The course is intended to provide the basic knowledge and understanding of the main features and operating modes of the most important energy conversion systems using fossil and renewable sources.
At the end of the “Fluid Machinery and Energy Conversion Systems” course the student should be able to:
- know and understand the main technical and functional features of the most important energy conversion systems using fossil and renewable sources and of their fundamental components (steam power plants; gas turbine power plants; combined cycle gas and steam turbines power plants; cogeneration plants; wind and solar farms; hydroelectric and geothermal power plants; biomass, waves and tides energy converters);
- apply the acquired knowledge and ability to understand in order to identify, describe, analyse and evaluate the functional features and performance parameters relating to the different configurations of the aforementioned energy conversion systems and of their components;
- effectively communicate notions, concepts and models of the main types of energy conversion systems using fossil and renewable sources.
For a deeper understanding of the learning objectives, please refer to the expected learning outcomes of the course.
Basic skills and fundamentals of the following disciplines: Technical Physics, Industrial Fluid Dynamics and Mechanical Drawing.
More in detail, students will need to know the definitions of the main physical quantities and dimensionless groupings commonly used in fluid dynamics (pressure, velocity, density, mass and volumetric flow rate, Reynolds and Froude numbers), with the relative units of measurement, and the key features of the different types of fluid flow (laminar, turbulent and transitional).
Furthermore, students should be able to read and to correctly interpret the layout scheme of a power plant and the technical drawing of a mechanical assembly or component and to identify and understand its constructive and functional features.
The number of hours dedicated to the individual topics of the course has to be considered as purely indicative. Indeed, during the course of the lessons, there may be variations due to interactions with students.
- Course introduction and fundamentals of thermodynamics and fluid dynamics (8 hours): structure of the energy system and energy sources in Italy and in the world. Generalized equations of fluid motion: thermal and mechanical form. Bernoulli’s equation. Thermodynamic diagrams. Thermodynamic cycles: general definitions and equation for the calculation of the thermodynamic efficiency. Analysis of the fluid expansion process inside the turbines and of the fluid compression process inside the compressors. Unidirectional flow surface heat exchangers.
- Steam power plants (12 hours): presentation and detailed description of the layout scheme, of the reference thermodynamic cycle, of the main components and of the operating modes of a simple steam power plant with a single condensing turbine. Useful power delivered to the alternator and overall efficiency. Optimization of the cycle thermodynamic efficiency. Steam cycles with intermediate reheating and regenerative cycles (with bleeds). Steam power cycle with three bleeds.
- Gas turbine power plants (12 hours): presentation and detailed description of the layout scheme, of the reference thermodynamic cycle, of the main components and of the operating modes of a simple gas turbine power plant. The Brayton power cycle: thermodynamic processes and energy assessments. Gas turbine power plants overall efficiency. Regenerative gas turbines. Regulation of the delivered power output. Two-shaft gas turbine. Gas turbines with reheat and intercooling.
- Combined cycle gas and steam turbines power plants (8 hours): presentation and detailed description of the layout scheme, of the reference thermodynamic cycle, of the main components and of the operating modes of a one-pressure-level combined cycle gas and steam turbines power plant. Heat exchange diagram and efficiency of the heat recovery steam generator (HRSG). Overall efficiency of the combined cycle power plant. Two-pressure-level combined cycle power plant.
- Cogeneration power plants (8 hours): definition of the cogeneration concept and classification of the main types of cogeneration systems. Performance parameters of the cogeneration power plants: efficiencies and characteristic indices. Presentation and detailed description of the layout schemes, of the reference thermodynamic cycles and of the operating modes of cogeneration power plants with steam turbine (back-pressure and condensing), with gas turbine and with combined cycle gas and steam turbines.
- Energy conversion systems using renewable sources (4 hours): technical features and operating modes of the main types of systems for the production of electricity using renewable sources. Systems for energy storage in mechanical, electrical, chemical and thermal form.
- Laboratory exercises (20 hours): practical computer exercises aimed at the development of spreadsheets and simple computer programs for analyzing the operation and predicting the main performance parameters of the energy conversion systems presented during the lessons of the course.
The lessons will be held in presence and in Italian language. Teaching methods include: - theoretical lectures in the classroom, that will be carried out through the aid of audio-visual media (mainly presentations with animated slides); - practical computer exercises, aimed at the development and validation of spreadsheets and simple computer programs for analysing the operation and predicting the performance of the energy conversion systems presented during the lessons of the course. Attendance to both theoretical lectures and laboratory exercises is optional. Furthermore, in order to receive clarifications, explanations and personalized tutoring, student reception can be scheduled, only by appointment agreed by e-mail.
The examination will take place at the end of the course, according to the official calendar of the exam sessions that, well in advance, will be published by the teacher on the Esse3 website (https://www.esse3.unimore.it). The final examination is based on a single written test, lasting a maximum of two hours. During the execution of the exam, the use of checkered protocol sheets made available by the teacher is only allowed. The final examination is made by four questions, three theoretical and one numerical, aimed at verifying that the student has achieved the learning objectives of the course. As regards the three theoretical questions, the candidate will have to provide open textual answers, possibly also accompanied with drawings, tables, diagrams and analytic equations. Instead, the numerical question will be focused on the calculation of the main operational and performance parameters of an energy conversion system studied during the lessons of the course. During the examination, it is not allowed to consult notes, books, handouts and manuals. For each of the aforementioned four questions, the maximum achievable score will be clearly indicated on the text of the exam test. The evaluation indicators of the exam are the following: - ability to use and connect knowledge; - ability to discuss and deepen topics; - mastery of the technical terminology; - ability to synthesize, order and clarity of presentation; - ability to correctly apply a learned analytic equation. The grade achieved at the end of the exam will be computed as the sum of the scores obtained for each of the four proposed questions (for an overall score equal or higher than 31, the final grade is: 30 cum laude). The final results of the examination will be communicated not later than one week from its execution and will be published on the Esse3 website.
1) Knowledge and understanding
- To know, list and describe the classification of the different types of energy conversion systems using fossil and renewable sources and the related technical, functional and performance features.
- To read the layout scheme of an energy conversion system, drawn following the rules prescribed by the technical reference standard of this sector, identifying its main components.
- To read the technical drawing of a fluid machine or component, commonly employed within an energy conversion system, knowing how to identify its fundamental elements and its mechanical and operational features.
- To know the analytic equations useful for studying the operation and evaluating the performance of energy conversion systems using fossil and renewable sources.
2) Applied knowledge and understanding
- To recognize and clearly identify the general structure and the fundamental features of the main types of energy conversion systems using fossil and renewable sources.
- To select the most suitable types of fluid machines and components to be used within energy conversion systems using fossil and renewable sources, depending on the technical specifications defining the project and the technical reference standards of the application field.
- To apply simple analytic equations for studying the operation and for estimating the performance, in steady-state conditions, of the main types of energy conversion systems using fossil and renewable sources.
3) Autonomy of judgment
- To analyze and evaluate the most suitable design solutions in order to optimize the operation and performance parameters of the main types of energy conversion systems using fossil and renewable sources.
- To express a critical judgment on the fundamental factors that can cause the main operating problems affecting an energy conversion system and its components.
4) Communication skills
- To know the more suitable technical terminology in order to correctly and appropriately describe: the layout scheme and the structure of an energy conversion system and the technical and functional features of its components; the mechanical features and the operating modes of the main types of fluid machines and components, commonly employed within an energy conversion system.
- To express in a correct and logical way your own knowledge, recognizing the required topic and answering, in an accurate and comprehensive way, to the exam questions.
5) Learning capability
- To apply the learned knowledge and understanding in order to analyze and critically evaluate the technical features, the operating modes and problems, the performance parameters of other energy conversion systems using fossil and renewable sources, not discussed during the lessons but related to those covered by the teaching.
- To update independently the knowledge and understanding related to the mechanical and technical features, the operating modes and the performance parameters of the energy conversion systems, in light of the evolutions in progress and of the changes that will occur in the scientific and technological fields and in the technical regulations of this sector.
Testi di riferimento:
1) G. Cantore - “Macchine” - Casa editrice: Società Editrice Esculapio, Bologna - 1999 - ISBN: 9788874886500.
2) D. Cocco, P. Puddu - “Tecnologie delle Energie Rinnovabili” - Casa editrice: libreriauniversitaria.it Edizioni, Padova - 2022 - ISBN: 978-88-3359-451-4.
3) S. Sandrolini, G. Naldi - “Macchine. Vol. 3: Gli Impianti Motori Termici e i loro Componenti” - Casa editrice: Pitagora Editrice, Bologna - 2004 - ISBN: 88-371-1317-X.
4) G. Negri di Montenegro, M. Bianchi, A. Peretto - “Sistemi Energetici e Macchine a Fluido. Vol. 1” - Casa editrice: Pitagora Editrice, Bologna - 2009 - ISBN: 88-371-1761-2.
Inoltre, durante lo svolgimento del corso e nel rispetto dei diritti d’autore, il docente metterà a disposizione degli studenti presentazioni, appunti e dispense che costituiranno parte integrante del programma di esame. Questo ulteriore materiale didattico sarà caricato sulla piattaforma integrata di Ateneo per la didattica, Teams-Moodle (https://moodle.unimore.it).
Ulteriori testi di consultazione:
1) M. Bianchi, F. Melino, A. Peretto - “Sistemi energetici. Vol. 2 - Complementi” - Casa editrice: Pitagora Editrice, Bologna - 2008 - ISBN: 88-371-1755-8.
2) M. Bianchi, A. De Pascale, A. Gambarotta, A. Peretto - “Sistemi Energetici. Vol. 3 - Impatto Ambientale” - Casa editrice: Pitagora Editrice, Bologna - 2008 - ISBN: 88-371-1754-X.
3) S. Sandrolini, G. Naldi - “Macchine. Vol. 1: Fluidodinamica e Termodinamica delle Turbomacchine” - Casa editrice: Pitagora Editrice, Bologna - 1996 - ISBN: 88-371-0827-3.
4) S. Sandrolini, G. Naldi - “Macchine. Vol. 2: Le Turbomacchine Motrici e Operatrici” - Casa editrice: Pitagora Editrice, Bologna - 2019 - ISBN: 88-371-2106-8.