Into the belly of the ship:

Into the belly of the ship: Energy transfer processes in ships’ engines

Session outline: The bigger picture: Generating thrust and auxiliary power on ships Into the belly of the ship: How engines work and the conservation of waste heat energy on ships

Did you know? British shipping earns the UK economy £162 per second!* *SeaVision UK Why shipping is important Employs 250,000 in the UK Generates £37 billion to UK economy per year The fishing industry provides us with a good source of protein for our diets Cargo shipping provides us with 95% of the products we use on a day-to-day basis

The bigger picture: Ships need to be able to move! Need to generate thrust to overcome water resistance so that ships can move from A to B – It’s all about forces What supplies the energy for this thrust?... Engines

The bigger picture: Ships need energy for auxiliary operations too Auxiliary power is electrical power used to run secondary devices on ships Auxiliary power on ships is used for: - Manoeuvring (rudders) - Cargo handling equipment e.g. cranes - Lighting e.g., decks, rooms - Steering - Navigational equipment e.g. GPS - Radio equipment

Fuel Thermal energy Wasted energy Chemical energy Engine How thrust is generated on ships Combustion HC’s + O2 CO2 + H20 Propeller shaft Oxygen Friction Work done Kinetic energy Wasted energy Sound Wasted energy Thrust

Into the belly of the ship: The generation of auxiliary power EXHAUST/FLUE GAS HIGH PRESSURE STEAM TURBINE GENERATOR WATER BOILER Chemical Energy Heat Energy Kinetic Energy Electrical Energy

Some important rules about energy transfer THE LAW OF CONSERVATION OF ENERGY Energy can never be created or destroyed. It can only be converted from one form into another. Total energy=useful energy+waste energy

Mapping energy loss: Sankey diagrams Thermal Energy 500J 150J Chemical Energy Sound Energy Kinetic Energy Thrust Ein Eout 2,000J 1,000J Friction 1,500J 1,000J useful 1,150J 1,000J waste Energy is measured in Joules (J) 350J

Heat energy Involves the transfer of heat energy from hot areas to cool areas Can happen in three ways: Can pass through: Solids: Liquids: Gases:

Conduction The transfer of heat energy from hotter parts to cooler parts without any movement of the substance itself Transfers heat energy best in solids: HOT COLD Heat flow VIBRATING PARTICLES

Convection The transfer of heat energy through the movement of particles from hotter parts to cooler parts of a substance Transfers heat energy best in fluids (liquids and gases): CONVECTION CURRENT HEAT

Radiation The transfer of heat energy by waves. This type of energy transfer does not require particles and so can happen in a vacuum e.g. space VACUUM INFRARED RADIATION WAVES OF HEAT ENERGY

Conserving heat energy:Reducing radiation Insulators • Prevents heat energy from escaping • Particles very far apart or arranged in such a way that they are unable to vibrate well • Used on exhaust pipes, boiler, rooms, - Reduces radiation losses of heat energy

Conserving heat energy:Convection Secondary boilers • Uses waste flue/exhaust gas • Secondary boilers are good thermal conductors • Heats water by the process of convection • Steam produced which generates power for either thrust or auxiliary operations

Conserving heat energy:Conduction and Convection STEAM FRESH WATER OUT SEAWATER HEAT ENERGY SECONDARY BOILER HEAT EXCHANGER FILTERED COLD SEAWATER IN

Take home messages Shipping is a very important industry, from delivering over 95% of the products we all use on a day-to-day basis to contributing over £37 billion to the UK economy per year. To operate, ships need to be able to generate THRUST and AUXILIARY POWER. This involves energy transfer from chemical energy to kinetic and electrical energy. Energy can NEVER BE CREATED OR DESTROYED, only TRANSFERRED from one form to another. Energy is always CONSERVED. One of the key sources of wasted energy that can be recovered on ships is HEAT ENERGY. Heat energy is transferred using CONDUCTION, CONVECTION and RADIATION.

Into the belly of the ship: