By virtue of its inherent durability, and high thermal efficiency and therefore
low specific fuel consumption, the compression-ignition (ci) engine is by far
the most favoured power unit for commercial vehicles and is encroaching
significantly into the private car field too. The thermal efficiency of an
indirect (idi) diesel engine, Section 6.11, is about 25% higher than that of the
gasoline engine, while that of a direct injection (di) unit, Section 6.10, is of
the order of 15% higher still. A considerable disadvantage of both idi and di
types is their low power output relative to both weight and cylinder capacity,
compared with the spark ignition engine. However, to a large extent, this can
be offset by turbocharging the ci unit and even more so if charge cooling is
employed too.
The compression ignition type of power unit is sometimes called the oil
engine but is more widely known as the diesel engine, after the German
engineer, Dr Rudolph Diesel who, in 1892, took out a patent for a compression
ignition engine and, in 1893, exhibited his experimental engine. However,
his early engines were run on coal dust injected with a blast of air, and it was
not until 1897 that his first engine was running on a fuel of higher specific
gravity than gasoline. In the meantime, W.D. Priestman and H. Ackroyd
Stuart, both from Yorkshire, had been working in this field. Indeed, in 1891
Ackroyd Stuart exhibited an engine designed to run on a heavy fuel, which
was called gas oil, because it was used in the production of town gas. The
Ackroyd Stuart engines ran at a relatively low compression ratio so, for
starting, heat had to be applied to the induction system. The essential features
of compression ignition engines are the injection of the fuel into the cylinders
as their pistons approach inner, or top, dead centre, and a compression ratio
of not less than 12–13 : 1 for direct injection, and as high as 22 : 1 and more
for indirect injection.
And Now With Your Video Course that Describes every thing about diesel engine injection system and equipments.
1-Basic Principles
http://www.youtube.com/watch?v=v6zzYiTMnT4
2-Fuel, Compression Ratio & Governor
http://www.youtube.com/watch?v=nTyxq5soNjE
3-Diesel Fuel Cetane Rating
http://www.youtube.com/watch?v=Jefi4Vchi9Y
4-Tanks & Lines
http://www.youtube.com/watch?v=9R7IjqCzbsM
5-Filter
http://www.youtube.com/watch?v=K9y6-wxHFV0
6-Fuel Lift Pumps
http://www.youtube.com/watch?v=9qo_4hQS_VQ
7-Plunger & Vane Pumps
http://www.youtube.com/watch?v=jVPvOA-NYVk
8-Fuel Pump Primers
http://www.youtube.com/watch?v=fXooZgXuUPE
9-Inline Injection Pump
http://www.youtube.com/watch?v=Bewpxx7dc8E
10-Mechanical - Pneumatic Governors
http://www.youtube.com/watch?v=83EDgU89xuw
11-Distributor-Type Injection Pump
http://www.youtube.com/watch?v=N3HauD_X-xI
12-Diesel Injectors
http://www.youtube.com/watch?v=v9ac2NRR27M
