[ppt]ship propulsion · web viewship propulsion ship (marine) propulsion mechanism used to move a...
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SHIP PROPULSION
Ship (Marine) propulsion Mechanism used to move a ship across water
(engine turning a propeller)
Choice of a suitable powerplant depends on:– size of the ship – speed (type of cargo)– length, duration of voyage– cost (operational expenses)– fuel
Diesel Engine
In 1892 Rudolph Diesel invented the compression ignition engine
The most widely used propulsion
Two-stroke (large engines) Four-stroke (auxiliary e.)
Diesel Engine
PROS: – most efficient prime
mover– lower fuel
consumption – less bunker space
CONS:– more expensive to
build and maintain– more noise and
vibration– heavier
Steam Turbine Marine steam turbine was
developed by Sir Charles Algernon Parsons
Low noise, low weight, low maintenance costs, more space obtained (power /weight ratio raised)
BUT higher fuel consumption
Steam Turbine Most new-build ships with
steam turbines are specialist vessels such as nuclear-powered vessels, and certain merchant vessels (LNG, coal carriers) where cargo can be used as bunker fuel.
Diesel electric drive Large cruiser, tankers,
ferries, ro-ro passenger ships and LNG carriers
PRINCIPLE 1. diesel engine
connected to a generator 2. Generators drive
electric motors 3. Electric motors drive
the shaft
Turbo-electric drive PRINCIPLE 1.Turbines generate
mechanical energy and drive generators
Generators convert mechanical into electrical energy and drive motors
Motors convert back the electrical into mechanical energy and drive the propeller shaft
Gas turbine A compressor draws in
and compresses atmospheric air.
A combustion system where fuel is injected, mixed with compressed air and burned.
Power turbine to the shaft. Poor thermal efficiency at
low power.
Nuclear propulsion
Submarines, navy ships (air-craft carriers), icebreakers.