Introduction to Gas Turbines
A turbine is any kind of spinning device that uses the action of a fluid to produce work. Typical fluids are: air, wind, water, steam and helium. Windmills and hydroelectric dams have used turbine action for decades to turn the core of an electrical generator to produce power for both industrial and residential consumption. Simpler turbines are much older, with the first known appearance dating to the time of ancient Greece. In the history of energy conversion, however, the gas turbine is relatively new. The first practical gas turbine used to generate electricity ran at Neuchatel, Switzerland in 1939, and was developed by the Brown Boveri Company. The first gas turbine powered airplane flight also took place in 1939 in Germany, using the gas turbine developed by Hans P. von Ohain. In England, the 1930s’ invention and development of the aircraft gas turbine by Frank Whittle resulted in a similar British flight in 1941.
Figure 1. Schematic for a) an aircraft jet engine; and b) a land-based gas turbine
The name "gas turbine" is somewhat misleading, because too many it implies a turbine engine that uses gas as its fuel. Actually a gas turbine (as shown schematically in Fig. 1) has a compressor to draw in and compress gas (most usually air); a combustor (or burner) to add fuel to heat the compressed air; and a turbine to extract power from the hot air flow. The gas turbine is an internal combustion (IC) engine employing a continuous combustion process. This differs from the intermittent combustion occurring in Diesel and automotive IC engines. Because the 1939 origin of the gas turbine lies simultaneously in the electric power field and in aviation, there have been a profusion of "other names" for the gas turbine. For electrical power generation and marine applications it is generally called a gas turbine, also a combustion turbine (CT), a turbo shaft engine, and sometimes a gas turbine engine. For aviation applications it is usually called a jet engine, and various other names depending on the particular engine configuration or application, such as: jet turbine engine; turbojet; turbofan; fanjet; and turboprop or prop jet (if it is used to drive a propeller). The compressor combustor-turbine part of the gas turbine (Fig. 1) is commonly termed the gas generator.
* 1791: A patent was given to John Barber, an Englishman, for the first true gas turbine. His invention had most of the elements present in the modern day gas turbines. The turbine was designed to power a horseless carriage. * 1872: A gas turbine engine was designed by Dr. Franz Stolze, but the engine never ran under its own power. * 1894: Sir Charles Parsons patented the idea of propelling a ship with a steam turbine, and built a demonstration vessel, the Turbinia, easily the fastest vessel afloat at the time. This principle of propulsion is still of some use. * 1895: Three 4-ton 100 kW Parsons radial flow generators were installed in Cambridge Power Station, and used to power the first electric street lighting scheme in the city. * 1903: A Norwegian, Ægidius Elling, was able to build the first gas turbine that was able to produce more power than needed to run its own components, which was considered an achievement in a time when knowledge about aerodynamics was limited. Using rotary compressors and turbines it produced 11 hp (massive for those days). His work was later used by Sir Frank Whittle. * 1906: The Armengaud-Lemale turbine engine in France with water-cooled combustion chamber. * 1910: Holzwarth impulse turbine (pulse combustion) achieved 150 kilowatts. * 1913: Nikola Tesla patents the Tesla turbine based on the boundary layer effect. * 1914: Application for a gas turbine engine filed by Charles Curtis. * 1918: One of the leading gas turbine manufacturers of today, General Electric, started their gas turbine division. * 1920: The practical theory of gas flow through...
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