2. Diesel Generator
A diesel generator is the
combination of a diesel
engine with an electric
generator and other
ancillary devices ( circuit
breaker, cooling
systems, lubrication
system ect..).
Its purpose is
to generate
electrical
energy
2
7. Working Principle
7
Chemical Energy of Fuel
Thermal Energy
Mechanical Energy
Electrical Energy
COMBUSTION
EXPANSION COOLING
OF GASES
GENERATOR
(electromagnetic induction)
9. 9
Diesel
Properties
Cetane No.
Measures the
readiness of a fuel to
auto-ignite.
High cetane means
the fuel will ignite
quickly at the
conditions in the
engine (does not
mean the fuel is
highly flammable or
explosive).
Most fuels have
cetane numbers
between 40 and 60.
12. 12
Diesel
Properties
Cloud Point
Corresponds to the
temperature at which fuel first
starts to crystallize (forms a
faint cloud in liquid) when
cooled.
No specific value is given in the
standard. Requirements vary
depending on location.
Producer reports cloud point at
point of sale
Cold Filter Plug Point (CFPP):
The temperature at which fuel
crystals have agglomerated in
sufficient amounts to cause a
test filter to plug.
The CFPP is less conservative
than the cloud point, and is
considered by some to be a
better indication of low
temperature operability.
13. 13
Diesel
Properties
Fuel Stability
Fuel will undergo
chemical
degradation if in
contact with
oxygen for long
periods or at high
temperatures.
There is no
method specified
in ASTM D 975 for
diesel fuels.
ASTM 6751 is
currently at 3 Hr.
and the EN
specification is 6
Hr.
14. 14
Diesel
Properties
Lubricity
The ability of a
fluid to minimize
friction between,
and damage to,
surfaces in relative
motion under
loaded conditions.
Diesel fuel
injection
equipment relies
on the lubricating
properties of the
fuel.
Biodiesel has
shown higher
lubricity properties
than petroleum
diesel
19. TDC
When the piston is at the very top of its travel,
this is called Top Dead Center, or TDC
19
Diesel
Engine
20. BDC
When the piston is at the bottom of its travel,
this is called Bottom Dead Center, or BDC
20
Diesel
Engine
21. Revolution
It is how many times per minute that the crankshaft is
rotating and, used as a measure of rotational speed of
a mechanical component.
21
Diesel
Engine
22. Compression Ratio
as the ratio of the volume of the cylinder at the beginning of the
compression stroke (when the piston is at BDC) to the volume of the
cylinder at the end of the compression stroke (when the piston is at
TDC).
The higher the compression ratio, the higher the air temperature
in the cylinder at the end of the compression stroke.
Common compression ignition ration: 14:1 to 25:1
22
Diesel
Engine
23. Cycle
Is the sequences of events that repeat themselves. It is the
thermodynamic cycle which approximates the pressure and
volume of the combustion chamber of the Diesel engine
23
Diesel
Engine
24. Short
Summary
24
Diesel
Engine
A diesel engine is an internal combustion engine.
It uses the heat of compression to initiate ignition to burn the fuel that has
been injected into the combustion chamber.
The engine was developed by German inventor Rudolf Diesel in 1893.
The engine works on the principle of diesel cycle
25. 25
Advantage Disadvantage
• More efficient.
• More reliable.
• More durable.
• Release less amount of harmful
fumes.
• Easily turbo-charged.
• Produce minimal carbon monoxide.
• Can easily accept synthetic fuels.
More expensive.
Occasionally servicing can be more
costly.
Parts tend to be more expensive.
The cost of diesel at the pump is higher.
Contribute to Greenhouse effect.
Generally more noisy.
Diesel
Engine
26. Two Stroke and
Four Stroke Operation
A 2-stroke cycle engine develops power
output for each engine revolution (2
Piston Stroke). Thus, one power stroke is
obtained in each revolution of the crank
shaft.
26
Diesel
Engine
A 4-stroke cycle engine develops power
output for each 2 engine revolutions. (4
Piston stroke). Thus, one power stroke is
obtained in each two revolutions of the crank
shaft.
28. 28
Diesel
Engine
Intake
Exhaust
Power
Compression
4
STROK
E
CYCLE
Piston descends from the TDC to BDC
increasing the volume of the cylinder. Air
is forced into the cylinder through the
intake port.
Intake
with both valves closed, the piston
returns to TDC compressing the air into
the combustion chamber of the cylinder
head. Temperature gets increased to
hundred degrees.
Compression
Power
Here, the piston once again returns to
top dead centre while the exhaust valve
is open. The spent fuel-air mixture is
expelled.
Exhaust
While the piston is close to TDC, the
compressed fuel injected into a diesel
engine ignites due to the heat generated
in the air during the compression stroke.
32. Piston
A sliding plug that
harnesses the force of the
burning gases in the
cylinder.
32
Diesel
Engine
33. Piston Ring
The rings seal the compression gases above the
piston keep the oil below the piston rings.
33
Diesel
Engine
34. Piston Pins
Also known as the wrist pin, it
connects the piston to the small
end of the connecting rod.
It transfers the force and allows
the rod to swing back and forth.
34
Diesel
Engine
36. Crankshaft
Along the the piston pin and
connecting rod it converts the up
and down motion (reciprocating) of
the engine to spinning (rotary)
motion.
36
Diesel
Engine
38. Cylinder Head
Forms the top of the
combustion chamber.
Contains the valves, the
passageways for the fuel
mixture to move in and out of
the engine.
38
Diesel
Engine