ADVANCED HEAT ENGINES
Learning outcomes of the course unit
According to the domestic classification, Macchine includes both fluid machinery (meant as components), and power plants (meant as primary energy converters). Following the course given at the third year (Macchine AB), this one completes the knowledge, as for theory and computational skills, required by a modern mechanical engineer.
Macchine (fundamentals), i.e.: Fundamentals of Heat Engines (AKA Thermal Machines), Fundamentals of Pumps & Compressors, Fundamentals of Turbomachinery
Course contents summary
Energy engineering and applied economy: history, exploitment of hydro-power recources; fundamentals of thermal plants, cycles and pseudo-cycles, 2nd law, quality number for direct cycles, fuel types and their properties; exploitment of nuclear energy resources.
Analysis criteria for fluid machinery: compression and expansion processes, adiabatic, polytropic and isothermal efficiency; Stodola’s 3D plot, internal and mechanical turbine characteristic; variable-speed pump (and compressor) operation in a circuit; ideal, perfect, and semi-perfect (with polynomials) gas models; energy balance in case of combustion, high temperature dissociation, adiabatic flame temperature, basic flame structure; fundamentals of thermal regeneration in power plants; similarity in the study of fluid machinery, 2D aerodynamics, lift and drag of wing sections.
Power plants: Sizing of hydraulic power plants, regenerative steam cycles, wet steam problems and reheating; fundamentals of nuclear reactors (gas, BWR, PWR, LMFBR), nuclear steam cycles; gas turbines, open cycle, matching of components, control techniques, off-design operation; breakdown of power in combined cycle power plants, duct burning, multiple pressure HRSGs, STIG; fundamentals of internal combustion engines, standard fuel-air cycles, volumetric efficiency, mean effective pressure, combustion process, energy balance.
Components of power plants: stage efficiency, Curtis turbine stage, 3D effects in turbines,large steam turbines and their design problems; seals, axial thrust; hydraulic turbines, types and their vector-diagrams, exhaust diffuser, cavitation; loss analysis in turbomachines; heat exchangers in steam power plants, condensers, subcooling, air condensers, cooling towers, air pre-heaters; turbocompressors, stall, surge, multistage compressor characteristic, operating field, choking, rotating stall; gas turbine combustors, heat recovery steam generators; reciprocating compressors, max pessure ratio, staging, intercooling, rotary (displacement) compressors, internal and backflow compression, reciprocating pumps, rotary pumps, pressure ripples and dampers.
Numerical applications: thermodynamic models of semy-perfect gas and of water steam; operation of a pump coupled to its circuit; combined cycle power plant..
Preliminary design: Pelton and Banki turbines, water pipe boiler, condenser, centrifugal pump, steam turbine, reciprocating compressor.
C. Caputo – Gli impianti convertitori di energia – Masson, Milano
C. Caputo – Le macchine volumetriche – Masson, Milano
C. Caputo – Le turbomacchine – Masson, Milano
Acton O. & Caputo C. – Collana di Macchine a fluido, 4 voll. – UTET, Torino
Haywood R.W. - Analysis of engineering cycles 3rd ed. – Pergamon press, Oxford
Horlock J.H. – Combined power plants – Krieger, Malabar
Horlock J.H. – Cogeneration – Krieger, Malabar
Lozza G. – Turbine a gas e cicli combinati – Progetto Leonardo, Bologna
Assessment methods and criteria
Written test: esercise and quizzes (3 h).
Oral test (20 min).
In order to undergo the oral test, the student must have completed the written test on a scheduled date (see the official calendar).