Diesel Engines

1
Diesel Engines

• Transportation
• Mr. ORourke

2
History

• Invented in the 1890s in Germany by Rudolf
  Diesel.
• Invented because of the inefficiency of steam
  power (10 efficient)

3
How it Works

• Internal Combustion engine
• Similar to gasoline powered
• Compression ignition vs.
• spark ignition
• Usually 4-stroke, sometimes 2-stroke
• http//www.youtube.com/watch?vx9yS2xdPJSU

4
How it Works (contd)

• Intake- The intake valve opens up, letting in air
  only.
• Compression-The piston moves back up and
  compresses the air.
• Combustion -As the piston reaches the top, fuel
  is injected at just the right moment and ignited
  by heat from compression, forcing the piston back
  down.
• Exhaust-The piston moves back to the top, pushing
  out the exhaust created from the combustion out
  of the exhaust valve.

5
Gas vs. Diesel Engines

• No Carburetor or port injection in Diesels
• Uses direct injection into cylinder
• No spark plugs
• Glow plugs to heat engine
• Much more compression than gasoline engine
  (approx 2-3 times more)
• Highest thermal efficiency of all engine types

6
Important Notes

• Compression heats air to approx 1000 degrees F.
• Air intake is constant unless a turbo is used
• Only fuel is added when throttle is applied
• Fuel is added as a mist into cylinder
• abrupt increase in pressure above the piston
  causes knocking sound

7
Advantages

• Due to high compression and expansion ratio,
  diesels are 45 efficient compared to gasoline at
  30
• No high voltage electrical system needed
• Diesel engines usually last 2x longer than
  gasoline due to stronger parts and better
  lubrication

8
Advantages (contd)

• Diesel fuel is safer than gasoline (not
  explosive)
• Fuel efficiency remains constant
• Much more torque than gas due to longer piston
  stroke (large diameter crankshaft needed)
• More potential for power due to adding of turbo
  or sometimes supercharger

9
Disadvantages

• Louder engine due to large amount of rapidly
  expanding gas
• Diesel fuel is more expensive
• Higher initial cost
• Lower performance overall compared to gas in
  regular driving
• Problematic in cold weather
• Low sulfur fuel now used but exhaust can still
  smell and smoke

10
Uses

• 90 of transportation industry
• Power generators
• Large boats/ships
• Locomotives
• Construction machinery
• Cars and trucks
• Largest diesel engine
• 109,000 hp _at_102rpm

11
Costs/Future

• Costs more per gallon due to demand
• Higher initial costs, lower overall costs
• Newer, cleaner fuels now being used
• More cars using diesel
• Quieter, more available cars

12

• http//www.youtube.com/watch?vvGhlgphrBxA