Docente

prof. aggr. Stefano SAVINO

Credits

6 CFU

Language

Italian

Objectives

Objective of this module is providing students with the necessary background for the formulation of first law (energy) and second law (entropy) balances. The acquired notions are applied to the analysis of engineering cycles and thermal plants.

Acquired skills

- Mechanical energy balances for control mass and control volume systemsal warehouses and material handling systems.
- Energy balances (first law) for control mass and control volume systems.
- Entropy balances (second law) for control mass and control volume systems.
- Energy analysis of combustion processes.
- Energy analysis of thermal and air conditioning plant components.
- Energy analysis of direct and inverse thermodynamic cycles.

Lectures and exercises (Topics and specific content)

Systems of measuring units: international system of units (SI), with particular reference to the definition of the temperature scale (2 hours).
Thermodynamic systems: properties, states, processes; mass conservation; mechanical energy balances for control mass and control volume systems (9 hours).
First law of thermodynamics: formulation of the first law of thermodynamics for control mass and control volume systems; internal energy and enthalpy; thermal efficiency of power cycles and coefficient of performance of refrigeration and heat pump cycles; specific heat capacities (7 hours).
Second law of thermodynamics: formulation of the second law of thermodynamics; reversible and irreversible processes; Carnot cycle, thermodynamic temperature, entropy; Clausius inequality; second law (entropy) balances to control mass and control volume systems (7 hours).
Ideal gases: equation of state, internal energy, enthalpy, specific heat capacities, entropy; constant volume, constant pressure, constant temperature, isoentropic and polytropic processes; (p,v) and (T,s) diagrams for ideal gases (6 hours).
Vapours and real gases: (p,T), (p,v), (T,s), (h,s) and (p,h) diagrams; Clausius Clapeyron equation; compressibility factor; equations of state for real gases (6 hours).
Gas mixtures: Dalton and Amagat laws; molar, mass and volume fractions; properties of gas mixtures (3 hours).
Psychrometry: properties and processes of interest for psychrometric systems; psychrometric chart (6 hours).
Combustion processes: theoretical and excess air; energy balances and heating values; temperature of combustion products (4 hours).
Power cycles: air standard cycles, Joule, Otto, Diesel and dual cycles; superheat water-vapour Rankine cycle (6 hours).
Refrigeration and heat pump cycles: vapour-compression cycles for refrigeration and heat pump systems; refrigerants (4 hours).

References

- Comini, G. e Savino, S., Fondamenti termodinamici dell'energetica, II edizione, SGEditoriali, Padova, 2014 (ISBN 978-88-89884-27-0)
- Eserciziario di Termodinamica Applicata (available for download at page)

Type of exam

Written and oral