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Internal Combustion Engines – The Diesel

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Presentation on theme: "Internal Combustion Engines – The Diesel"— Presentation transcript:

1 Internal Combustion Engines – The Diesel

2 Objectives Uses for internal combustion engines
Thermodynamic principles involved Components and purposes of each Operation of systems Two stroke engines Four stroke engines

3 The Diesel is a Hacker

4 Engine Uses Emergency Diesel Generators (EDG) Propulsion
Certain amphibious landing ships Mine warfare ships Patrol craft Tug boats Small boats Outboard motors

5 Thermodynamic Principles
All internal combustion Open cycle, heated engine Gasoline (Otto) engine Spark ignition Compresses air-fuel mixture Diesel engine Compressed ignition Compresses air only

6 Structural Components
Cylinder Block Part of engine frame that contains cylinders in which piston moves Supports liners & head

7 Structural Components
Cylinder Head/Assembly Serves to admit, confine, and release fuel/air Cover to cylinder block Supports valve train Crankcase Engine frame section that houses the crankshaft Oil sump Reservoir for collecting and holding lube oil

8 Moving Components Three Groups – according to motion
Reciprocating only (pistons and valves) Reciprocation & rotary (connecting rods) Rotary only (crankshafts and camshafts)

9 Moving Components Piston Piston Rings Piston Pin Connecting Rod
Acted on by combustion gases Lightweight but strong/durable Piston Rings Transfer heat from piston to cylinder Seal cylinder & distribute lube oil Piston Pin Pivot point connecting piston to connecting rod Connecting Rod Connects piston & crankshaft reciprocating rotating motion

10 Moving Components Crankshaft Flywheel
Combines work done by each piston Drives camshafts, generator, pumps, etc. Flywheel Absorbs and releases kinetic energy of piston strokes -> smoothes rotation of crankshaft

11 Moving Components Valves Camshaft & Cams
Intake: open to admit air to cylinder (with fuel in Otto cycle) Exhaust: open to allow gases to be rejected Camshaft & Cams Used to time the addition of intake and exhaust valves Operates valves via pushrods & rocker arms

12 Operation Increased pressure of combustion gases acts on piston -> converted to rotary motion Can be 2 or 4 stroke engines 2-stroke: 1 power stroke per 1 crankshaft rev 4-stroke: 1 power stroke per 2 crankshaft rev

13 Operation Engine stroke
A stroke is a single traverse of the cylinder by the piston (from TDC to BDC) 1 revolution of crankshaft = 2 strokes of piston

14 Four-Stroke Diesel Engine
Intake stroke Intake valve open, exhaust valve shut Piston travels from TDC to BDC Air drawn in Compression stroke Intake and exhaust valves shut Piston travels from BDC to TDC Temperature and pressure of air increase

15 Four-Stroke Diesel Engine
Power stroke Intake and exhaust valves shut Fuel injected into cylinder and ignites Piston forced from TDC to BDC Exhaust stroke Intake valve shut, exhaust valve open Piston moves from BDC to TDC Combustion gases expelled

16 Four-Stroke Diesel Engine
Strokes Intake Compression Power Exhaust

17 Two-Stroke Diesel Engine
1 power stroke every crankshaft revolution (vice every two w/ 4-stroke) Uses pressurized air to simultaneously supply new air and expel combustion gases Scavenging Exhaust valve open, inlet port exposed Pressurized air enters, expels combustion gases Piston near BDC

18 Two-Stroke Diesel Engine
Compression Intake and exhaust valves shut Piston travels from BDC to TDC Temperature and pressure of air increase Power stroke Fuel injected into cylinder and ignites Piston forced from TDC to BDC

19 Two-Stroke Diesel Engine
Strokes Compression Power (Intake/Exhaust)

20 Two vs. Four-Stroke Engines
Two-stroke advantages Higher power to weight ratio Less complicated valve train Four-stroke advantages More efficient burning process As size increases, power-to-weight ratio improves

21 Gasoline vs. Diesel Engine

22 Supporting Systems Air system Fuel System Supplies & removes air/gases
Air supplied at constant pressure by blower/compressor Fuel System Carburetor: mixes air & fuel in proper proportion (NOT on diesels) Fuel injector: sprays fuel in (more efficient)

23 Supporting Systems Ignition system Cooling system Lubrication system
Diesel has compression ignition Gasoline has spark plugs Cooling system Uses fresh water and/or salt water to cool Lubrication system Provide lubrication and cooling Drive Train – Direct or Indirect

24 Safety Precautions Noise Fuel Flammability Maintenance Water Issues

25 Questions?

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