Diesel Engines Transportation Mr ORourke History Invented in

Diesel Engines Transportation Mr. O’Rourke

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

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? v=x 9 y. S 2 xd. PJSU

How it Works (cont’d): 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.

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

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

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 2 x longer than gasoline due to stronger parts and better lubrication

Advantages (cont’d): 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

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

Uses: 90% of transportation industry Power generators Large boats/ships Locomotives Construction machinery Cars and trucks Largest diesel engine 109, 000 hp @102 rpm

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

http: //www. youtube. com/watch? v=v. Ghlgph r. Bx. A