160 likes | 353 Vues
Power and Energy. The History of Engines. History of Engines. Basic type of engines have been in use since the fifteenth century , and many of our power production facilities still use processes that are very similar to those early engines. Historical Engines.
E N D
Power and Energy The History of Engines
History of Engines • Basic type of engines have been in use since the fifteenth century, and many of our power production facilities still use processes that are very similar to those early engines.
Historical Engines • Historically, engines were external combustion engines. • The most common types of engines in history are the steam engine and the Sterling Cycle Engine.
Steam Engine • Invented by Thomas Newcomen in 1705, greatly improved by James Watt in 1769. • Heat engine that performs mechanical work using steam as its working fluid, through boiling water (external combustion). • External Combustion: when an internal working fluid is heated by combustion of an external source, ex. a flame. • Developed very early in history. • Because of the boilers, steam sometimes escaped and cause boiler explosions and have caused great loss of life in the past. http://science.howstuffworks.com/transport/engines-equipment/steam1.htm
Stirling Engine • Invented in 1816 by Rev. Robert Stirling of Scotland. • Very simple engine, and was often billed as a safe alternative to steam, since there’s no risk of a boiler explosion. • Working gas (usually air but sometimes helium or hydrogen) is alternately heated and cooled by shifting the gas to different temperature locations within the system. • One cylinder is kept hot, while the other is kept cold. • All gases kept inside – no exhaust.
Stirling Engine – The Stirling Cycle • A fixed amount of a gas is sealed inside the engine. • Series of events that change the pressure of the gas inside the engine, causing it to do work. http://auto.howstuffworks.com/stirling-engine2.htm http://auto.howstuffworks.com/stirling-engine3.htm
Steam vs. Stirling • Steam engines use water as their liquid which heats and condenses in a cycle such that heat energy is lost at each transition • • The Sterling cycle engine uses air as its liquid, which resolves many of the issues with steam. It is not as dangerous as steam and does not lose as much energy in transition, because it does not transition.
Make and Break Engines in NL • A one-cylinder engine used for inshore fishing in Newfoundland and Labrador. http://www.youtube.com/watch?v=0OepxgRRX3U
Internal Combustion Engines • An internal combustion engine is one in which the explosive combustion of a fuel is used to push a piston within a cylinder - the piston’s movement turns a crankshaft that then provides mechanical power for use.
Internal Combustion Engines • No longer is the engine powered by external combustion, but it is now powered by internal combustion within the engine. • Once the fuel is compressed, the spark plug initiates a spark – causing a mini-explosion within the cylinder. This “explosion” pushes the piston, creating a linear (forward) motion with the crankshaft.
Types of Engines • Th e common engine types are: • 2 stroke cycle • 4 stroke cycle • Compression (Diesel) • Rotary • Rocket • Jet (Hache) • Gas Turbines
Jet Engine Internal Combustion Engines
Diesel Engine Gas Turbine Engine
Assignment • Describe an Engine.