Teacher

prof. Giulio CROCE

Credits

6 CFU

Language

Italian

Objectives

Full understanding of first (energy) and second (entropy) principle balances. The course provide the basic tools for the energetic analysis of thermodynamic cycles of practical interest for industrial and residential applications.

Acquired skills

- Mechanical Energy balance for open and closed systems.
- Energy balance for open and closed systems.
- Entropy balance for open and closed systems.
- Energy analysis of combustion processes.
- Energy analysis of basic thermal power plants cycles (MCI, Rankine, Joule).
- Energy analysis of basic refrigeration and air conditioning systems cycles.
- Basic knowledge of compressible fluid flows.

Lectures and exercises (topics and specific content)

Units: international system units (SI), with a special regard to temperature scale definitions (2 hours).
Thermodynamic systems: mass conservation, mechanical work, mechanical energy balance in open (one-dimensional, stationary) and closed systems (5 hours).
First law of Thermodynamics: expression for open and closed systems; conversion efficiency in direct (power) and reverse (refrigerators and heat pumps) cycles; internal energy, enthalpy and specific heat (6 hours).
Second law of Thermodynamics: expressions; reversibility and irreversibility; Carnot cycle; thermodynamic temperature; entropy definition; solid and liquid entropy; Clausius inequality (6 hours).
Ideal gases: equation of state; specific heat; internal energy, enthalpy and entropy; transformations at constant volume, pressure, temperature, entropy; polytropic transformations and their efficiency (6 hours).
Energy and entropy balances: first law (energy) and second law (entropy) balances in open and closed systems (6 hours).
Steam, real gases, gas mixtures: thermodynamic charts, (p,T), (p,v), (T,s), (h,s) and (p,h); Clausius-Clapeyron equation; compressibility factor; real gas equation of state; mixture properties (6 hours).
Moisture and humid air: thermodynamic propertes; transformation of practical interest (6 hours).
Combustion: excess air; energy balance and heating value; exhaust temperature; combustion chambers and heat generator efficiencies; fuel powered cycle efficiency (4 hours).
Power cycles: standard air power cycles, Joule, Otto, Diesel; Steam Rankine cycle (5 hours).
Reverse cycles: vapour compression cycles, for refrigerators and heat pumps (4 hours).
Principles of compressible fluid flow: sound of speed in gases; mach number; isoentropic motion; converging-diverging nozzles (2 hours).
Exercises (16 hours).

References

- G. Comini e S. Savino, FONDAMENTI TERMODINAMICI DELL'ENERGETICA, SGEditoriali - Padova, 2011 (ISBN 978-88-89884-17-1)

Type of exam

Written and oral

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