73111 - Energetic Systems and Machinery (2nd cycle)

Learning outcomes

The student is able to face the design of modern energy systems (combined groups, cogeneration groups) for the production of electricity and refrigeration cycles (compression, absorption, air). It is also able to deal with the fluid-dynamic design of the compressible  turbomachines. Finally, the student acquires the basic knowledge on systems for the production of electricity and heat from renewable sources.

Course contents

Primary energy sources

Potentiality, conversion systems and applications of solar, geothermic, hydroelectric, wind, wave tidal and nuclear energy.

 

Thermodynamic basics

Ideal gas compression and expansion: isentropic and polytropic work and efficiency, total enthalpy and temperature, speed of sound, polytropic transformations and thermodynamics diagrams.

  Boiler and steam generator

Combustion: stoichiometric oxidation reactions, heating values, energy density, CO2 emission, adiabatic temperature.

Typologies and applications, steam generator efficiency and water circulations.

 

Gas Turbine

Thermodynamic analysis and applications of Brayton and Advance cycles (recuperated, intercooled, reheated, etc.)

Component description: compressors, combustion chamber, expander, etc.

Environmental impact

 

Combined cycle power plant

Thermodynamic analysis of combined cycles with one or more pressure levels

Component description: heat recovery steam generator, condenser, steam turbine, cooling systems, etc.

Environmental impact

 

Cogeneration: Combined heat and power

Thermodynamics of CHP plants, comparative thermodynamic performance, economic assessment

Performance criteria for CHP plants

CHP applications and examples.

FLUID MACHINES:

Course contents

1) Equations of steady one-dimensional compressible flow of an ideal gas in a duct; isentropic flow in a duct of variable area.
2) Compressible fluid prime mover: the axial turbine stage, work  and efficiency for the stage. Different action turbine configurations, comparing the benefits and returns. Reaction turbine: work and efficiency for the stage. Mass flow imitations for applications in steam plants. Typical configurations of machines for applications in steam plants. The cooling of blades for applications in gas turbines for aeronautical applications.
3) Axial compressors: the thermodynamic process, off-design operating conditions of the compressor stage, aerodynamic coupling between stages, the overall performance of multistage axial compressor. Pumping and rotating stall.
Centrifugal compressor: The thermodynamic process, determination of work and performance of the stage.
Representation of the performance of compressors, and comparison between axial and centrifugal compressors.
4) Compressors and turbines matching in the gas turbine engine. Regulation of gas turbine engines. Land and aeronautical applications (turboprop, turbojet and turbofan).
Supercharging an internal combustion piston engine.
5) Volumetric reciprocating compressors: efficiency of charge and operating characteristics. Root and vane compressors.

Readings/Bibliography

ENERGETIC SYSTEMS:

Sistemi Energetici e loro componenti, G. Negri di Montenegro, M. Bianchi, A. Peretto
II Edizione – Pitagora Editore.

FLUID MACHINES:

Macchine a Fluido, Dossena, Ferrari, Gaetani, Montenegro, Onorati, Persico - Editore: CittàStudi

Recommended readings:

1.      Bettocchi R. - Turbomacchine - Pitagora, 1986.

2.      Acton O. - Turbomacchine - UTET, 1986.
3.      Acton O., Caputo C. - Introduzione allo studio delle macchine - UTET, 1979.
4.      Cohen H., Rogers G.F.C., Saravanamuttoo H.I.H. - Gas Turbine Theory – 5th Ed. – Prentice Hall, 2001
5.      Csanady G.T. - Theory of Turbomachines - McGraw Hill, 1964.
6.      Cumpsty N.A. - Compressor Aerodynamics - Longman, 1990.
7.      Fluid Mechanics, Thermodynamics of Turbomachinery - Pergamon Press, 1978.
8.      Horlock J.H. - Axial Flow Compressors - Butterworths, 1958.
9.  Horlock J.H. - Axial Flow Turbines - Butterworths, 1966.
10.  Osnaghi G. - Macchine fluidodinamiche - CLUP, Milano, 1979.
11.  Pfleiderer C., Peterman H. - Turbomacchine - Tecniche Nuove, 1985
12.  Sandrolini S., Borghi M., Naldi, G. – Turbomacchine termiche. Turbine – Pitagora, 1992.
13.  Sandrolini S., Naldi G. – Macchine 1. Fluidodinamica e termodinamica delle turbomacchine – Pitagora, 1997.
14.  Sandrolini S., Naldi G. – Macchine 2. Le turbomacchine motrici e operatrici,  Pitagora,1998.

Teaching methods

The lessons are frontal in the classroom. The teacher, replacing the traditional blackboard, uses a tablet connected to the projector to develop the concepts and to show the supporting teaching material. At the end of the lesson the teacher makes available the material shown in a pdf file, downloadable from IOL platform. ALL forms of distribution of this material are FORBIDDEN: every ENROLLED STUDENT can download it in AUTONOMY. This material is NOT intended as a DISPENSE but is ONLY a study support system. The teacher DOES NOT provide DISPENSE, but INVITES the students to use the TEXT BOOKS.

Attendance is strongly recommended for better learning of concepts and notions, but does not affect the final evaluation process.

Assessment methods

The main focus of the course is to give to the students the capability of facing the main problems related to the items listed in the course program. In particular an effort is made in order to look to the renowable energy with a critic point of view, giving to the students both the deficiency and the quality of the new energetic resources.

 

The assessment methods consist of an oral part lasting about 45 minutes, during which the student must answer two questions for energetic systems and one for fluid machines: the questions are extracted from the entire program. 

During the exam, with regard to fluid machines, their components and functions, is evaluated the student's ability to:

- use the thermodynamic instruments correctly;

- describe their operation;

- theoretically justify their architecture;

- represent their geometry with a free hand sketch;

- evaluate their performance;

The evaluation, expressed in thirtieths, will be higher the more the student is:

- autonomous in articulating responses to the two questions;

- exhaustive in explaining the arguments;

- precise in representing the functionality of the free-hand sketches.

 

The course is divided into two modules, but it is not an integrated course: it is therefore necessary to take the exam of both modules together.

The exam dates are comunicated in advance through the AlmaEsami web platform of the University of Bologna. It is possible to enroll to the exam upto 3 days before the exam date. At the time of the exam the student must carry an identification document.

Teaching tools

The course will be carried out through the use of:

- Tablet connected to the projector, used as an alternative to the    blackboard.
- Each lesson will be uploaded on the IOL platform of the teacher, as an aid to the students.

Office hours

See the website of Stefania Falfari