2. Diesel Generator
A diesel generator is the
combination of a diesel
engine with an electric
generator and other
ancillary devices ( circuit
Its purpose is
readiness of a fuel to
High cetane means
the fuel will ignite
quickly at the
conditions in the
engine (does not
mean the fuel is
highly flammable or
Most fuels have
between 40 and 60.
Corresponds to the
temperature at which fuel first
starts to crystallize (forms a
faint cloud in liquid) when
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
Fuel will undergo
degradation if in
oxygen for long
periods or at high
There is no
in ASTM D 975 for
ASTM 6751 is
currently at 3 Hr.
and the EN
specification is 6
The ability of a
fluid to minimize
and damage to,
surfaces in relative
on the lubricating
properties of the
When the piston is at the very top of its travel,
this is called Top Dead Center, or TDC
When the piston is at the bottom of its travel,
this is called Bottom Dead Center, or BDC
It is how many times per minute that the crankshaft is
rotating and, used as a measure of rotational speed of
a mechanical component.
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
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
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
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
• More efficient.
• More reliable.
• More durable.
• Release less amount of harmful
• Easily turbo-charged.
• Produce minimal carbon monoxide.
• Can easily accept synthetic fuels.
Occasionally servicing can be more
Parts tend to be more expensive.
The cost of diesel at the pump is higher.
Contribute to Greenhouse effect.
Generally more noisy.
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
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
Piston descends from the TDC to BDC
increasing the volume of the cylinder. Air
is forced into the cylinder through the
with both valves closed, the piston
returns to TDC compressing the air into
the combustion chamber of the cylinder
head. Temperature gets increased to
Here, the piston once again returns to
top dead centre while the exhaust valve
is open. The spent fuel-air mixture is
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.