Transcript SHIP PROPULSION - Pomorski fakultet u Rijeci

SHIP PROPULSION
Ship (Marine) propulsion
 Mechanism used to move a ship across water
(engine turning a propeller)
 Choice of a suitable powerplant depends on:
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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 (aircraft carriers),
icebreakers.