Diesel Engine

2. Diesel Engine
 Two types
oTwo Stroke
oFour Stroke
Air and fuel does not mix before compression.
 the heat from the compression is used to ignite the fuel.

3. Engine Starting system

4. Fuel supply system

5. Lubrication System
Frictional forces between rubbing parts results in wear and tear
Lubricants reduce friction between parts by
oCool surfaces
oAbsorb shcok
oSeal spaces adjoining surfaces
Three types of lubricants are used
oLiquid
oSolid
oSemi-solid

6. Cooling System
The need for the engine to be cooled arises due to the following
oVoluetric & thermal efficiency decrease with high temperature
oHigh temperature will cause the lubrication oil to burn
oPrevent pre-ignition probblems
Two types of cooling system are used in general
oDirect cooling (Air)
oIndirect cooling (liquid)

7. Exhaust System
• Discharge engine exhaust into atmosphere
• Things to account for when designing exhaust system
oReducing exhaust noise level
oHuman breathimg level should be free from pollution
oAttempts should be made to recover heat
oVibrations should be isolated

8. Admission System
Filters air to prevent damage to the engine
Filters may be dry or oil bath
Silencer is used between the engine and the intake system
Things to consider when constructing admission system
oDo not use small diameter or long length for air intake line
oDo not install air intake filters in an un-accessible area

9. Supercharging System
• Raise the volumetric efficiency
• Increases the rated power output capacity
• Supercharging is achieved through use of a compressor
oPositive displacement type
oCentrifugal
oTurbo type