Presentation on theme: "SHIP PROPULSION. Ship (Marine) propulsion 4 Mechanism used to move a ship across water (engine turning a propeller) 4 Choice of a suitable powerplant."— Presentation transcript:
Ship (Marine) propulsion 4 Mechanism used to move a ship across water (engine turning a propeller) 4 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 4 In 1892 Rudolph Diesel invented the compression ignition engine 4 The most widely used propulsion 4 Two-stroke (large engines) Four-stroke (auxiliary e.)
Diesel Engine 4 PROS: –most efficient prime mover –lower fuel consumption –less bunker space 4 CONS: –more expensive to build and maintain –more noise and vibration –heavier
Steam Turbine 4 Marine steam turbine was developed by Sir Charles Algernon ParsonsCharles Algernon Parsons 4 Low noise, low weight, low maintenance costs, more space obtained (power /weight ratio raised) 4 BUT higher fuel consumption
Steam Turbine 4 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 4 Large cruiser, tankers, ferries, ro-ro passenger ships and LNG carriers 4 PRINCIPLE 4 1. diesel engine connected to a generator 4 2. Generators drive electric motors 4 3. Electric motors drive the shaft
Turbo-electric drive 4 PRINCIPLE 4 1.Turbines generate mechanical energy and drive generators 4 Generators convert mechanical into electrical energy and drive motors 4 Motors convert back the electrical into mechanical energy and drive the propeller shaft
Gas turbine 4 A compressor draws in and compresses atmospheric air. 4 A combustion system where fuel is injected, mixed with compressed air and burned. 4 Power turbine to the shaft. 4 Poor thermal efficiency at low power.