University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
FACOLTA’ DI INGEGNERIA - CLASSE “INDUSTRIALE”
LAUREA SPECIALISTICA IN INGEGNERIA GESTIONALE
PIANIFICAZIONE E GESTIONE DELLE
INFRASTRUTTURE ENERGETICHE
PRODUCTION OF MECHANICAL
ENERGY and ELECTRICAL ENERGY
Prof. Ing. Antonio Ficarella
http://www.ing.unile.it/didattica/
[email protected]
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
CONVERSION OF THERMAL ENERGY
 almost
all of the mechanical energy
produced today is produced from the
conversion of thermal energy in some sort
of a heat engine
 thermodynamic
power cycle
 series of thermodynamic processes that returns
the working fluid to its initial state
 to plot the cycle on a graph of property
coordinates (P-vs; T-s)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 the
cyclic integral of work is equal to the
cyclic integral of heat
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 specific
work w
 AN
HIGH VALUE OF SPECIFIC WORK IS
DESIDERABLE
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
REVERSIBLE CYCLES
 friction
 transfer
of heat across a finite temperature
difference
 (externally) reversible power cycles
 Carnot
cycle, Ericcson cycle, Stirling cycle
 two reversible isothermal processes for heat
addition and rejection
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
INTERNAL-COMBUSTION ENGINE
CYCLES
 internal
combustion
 external combustion
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 compression
 limit
ratio
to the max value of compression ratio
 detonation
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
DIESEL ENGINE
 compression-ignition
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
IC ENGINES
 four-stroke-cycle
 two-stroke-cycle
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
ROTARY ENGINES (WANKEL)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
ENGINE PERFORMANCE
 brake
horsepower (Bhp)
 power
delivered to the driveshaft
 indicated
 power
horsepower (Ihp)
delivered to the piston
 difference:
friction horsepower Fhp
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 brake
 net
mean effective pressure (Bmep)
work output per piston displacement
 indicate
mean effective pressure (Imep)
 HORSEPOWER (Bhp o Ihp) =
 =(Bmep
or Imep)VdisNp/60
 Np=number of power strokes per minute
C
= n. of cylinders, Ne = revolution per minute,
ζ=1 two-stroke, 2 four-stroke
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 brake
specific fuel consumption
 thermal
efficiency
 ηth=1/(Bsfc*LHV)
 volumetric
 can
efficiency
exceed 100% if supercharged
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
EXTERNAL-COMBUSTION SYSTEMS
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 rp=compressor
pressure ratio
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
REGENERATIVE BRAYTON CYCLE
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
VAPOR-POWER CYCLES
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
COMBINED CYCLES
 two
power cycles, A and B
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
STEAM TURBINES
 device
that converts the stored mechanical
energy in a fluid into a rotational mechanical
energy
 steam
turbine
 gas turbine
 water turbine
 wind turbine
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
TURBINE BLADING
 impulse
stage
 reaction stage
 IMPULSE STAGE
 all
of the steam first pass through a nozzle
block where the compressed-fluid potential
energy is converted into kinetic energy
 the
high-velocity steam jet is the directed
toward the moving blades – force on the
moving blade
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 POWER
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
HYDRAULIC TURBINES
 KAPLAN
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 FRANCIS
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 PELTON
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
WIND TURBINES
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
ELECTRIC MOTORS
when a direct current is passed through a
conductor, a magnetic field is produced
 magnetic flow from the north pole to the south
pole
 net force on the conductor

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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 direct-current
 ac
motor
motor
 direct
current supplied to the armature (rotor):
SYNCHRONOUS
 inducing a current in the rotor conductors
 SLIP: the armature runs at slower angular
velocity than the synchronous speed
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
ELECTROMAGNETIC PUMP
 converts
electrical energy directly into
kinetic energy of a conducting fluid
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
PRODUCTION OF ELECTRICAL
ENERGY

THERMAL ENERGY CONVERSION




NOT LIMITED TO THE EFFICIENCY OF A REVERSIBLE
ENGINE:
CHEMICAL ENERGY



fuel cell - battery
ELECTROMAGNETIC ENERGY


thermoelectric converter - thermoionic
max efficiency 1-TL/TH
photovoltaic (solar) cell
NUCLEAR ENERGY (nuclear battery)
MECHANICAL ENERGY


conventional generators
magneto hydrodynamic – electro gas dynamic
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
SEEBECK EFFECTS
a
voltage is produced in a circuit of two
dissimilar materials if the two junctions are
maintained at different temperatures
 PELTIER EFFECT
 if
a direct current is passed through a circuit of
dissimilar materials, one of the junctions will be
heated and the other cooled
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 thermoelectric
refrigerators
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
THERMOIONIC CONVERTERS
 the
electrons are boiled-off the hot cathode
and condensed on the cold anode
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
CHEMICAL ENERGY
 BATTERY
 FUEL
CELL
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
FUEL CELL PERFORMANCE
 the
total energy released in any chemical
reaction is equal to the change in the
enthalpy of formation
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 unfortunately,
in an oxidation reaction, some
of the chemical energy is converted into
thermal energy and only the balance can be
converted into electricity
 TΔS
is the reversible heat transfer
 Gibbs free energy
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
p
= partial pressure
 Eg
= cell voltage
 We = electrical power
 n = mol of electrons released
 Fy = charge associated with 1 kg*mol of
electrons
 NERNST EQUATION (θ=p)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 max
conversion efficiency
 actual
conversion efficiency
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
SOLAR CELLS
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
 max
conversion efficiency 25%
 actual efficiency range 15-20%
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
MECHANICAL ENERGY
 Faraday
effect
a
voltage gradient is produced in an electrical
conductor that is forced perpendicularly through
a magnetic field
 AC
generators
 DC
 DC
power supply for the field winding
generators
 DC
power supply for the field winding
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
MAGNETOHYDRODYNAMIC
GENERATORS
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
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University of Salento (Italy) - Dept. of Engineering for Innovation
Research Center for Energy and Environment (UNILECCE-DII-CREA)
ELECTROSTATIC MECHANICAL
GENERATORS
 electrons
are generated at the entrance of
the EGD (electrogasdynamic converter)
duct – the ionized-gas particles are carried
down the duct
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