Diesel propulsion - a.y. 2016/2017
SSD: ING-IND/08 - ING-IND/09
Period (Year/Semester): I/I
Required/expected prior knowledge: Nothing
Lecturers: Gimelli Alfredo
The student acquires expertise in Diesel Internal Combustion Engines for rail applications. We want to highlight the potentialities and limitations of this rail traction type with respect to the most widespread electric traction.The way of conversion of thermal energy into mechanical energy is the leading thread of the course, highlighting the mechanisms and principles to maximize global conversion efficiency.The aspects of combustion, fuel characteristics, air exchange and heat exchange process are thoroughly analyzed.Finally, some of the present-day engines on the market will be presented.
Tables of contents:
Power Plants, Reciprocating Internal Combustion Engines (RICE), Diesel Engines. Efficiency chain, global efficiency, specific heat consumption and specific fuel consumption. Notes on the various fuels used in the RICEs. Lower and Higher heating values. Railway traction systems. RICE applications in rail traction. Geometric Parameters Characterizing RICEs. Reference thermodynamic cycles and importance of the Volumetric Compression Ratio. Engine Indicated Diagram. RICE Effective power and parameters influencing it: volumetric coefficient. Fundamentals of Combustion: air-fuel ratio, stoichiometric ratio, air index, equivalence ratio, chemical equilibrium, chemical kinetics, Arrhenius law, enthalpy formation. Combustion in the RICEs: Spark Ignition (SI) Engines, Compression Ignition (CI) Engines and Homogeneus Charge Compression Ignition (HCCI) Engines. Diesel Engine Injection Systems. Mechanical and Electronic Injection (Common Rail) in Diesel Engines. Fundamentals of thermo-dynamic simulation of RICEs. Emissions and pollutants: carbon monoxide (CO), Nitrogen Oxides (NOx), particulate matter (PM), Unburned hydrocarbons (UHC), greenhouse gases (CO2, CH4, ...). Pollutant formation processes in Diesel Engines.
Frontal lessons. Exercises with the aid of didactic softwares.
Textbooks and learning aids:
M. Migliaccio, R. della Volpe, “Motori per Autotrazione”, Ed. Liguori, ISBN 88-207-0193-6.
G. Ferrari, “Motori a Combustione Interna”, Ed. il capitello.
John B. Heywood, “Internal Combustion Engine Fundamentals”, Ed. McGraw-Hill International Edition, ISBN 0-07-100499-8.
Bertoli C., Migliaccio M., “Il Motore Diesel Veloce per la Trazione Stradale”, Rocco Curto Editore, 1989.
Notes and slides distributed by the teacher .
Assessment will be written and oral. Written elaboration to be submitted to the examination.