Steam turbines are a common site at many industrial plants. The applications of steam turbines are numerous due to their high efficiency and high reliability. Although steam turbines can be used as prime movers to drive pumps and other small/medium sized machinery items, they are most commonly associated with the power generation industry, where they are used to provide mechanical power to a generator, thus producing electricity. Another common application of steam turbine’s is for ship propulsion.

This article discusses the history of steam turbines, their main components, designs, how they work, their associated system (oil, steam etc.) and factors affecting their efficiency.

History of Steam Turbines

Steam turbines have been mentioned in history as far back as the 1^st century, but the modern steam turbine design was created in 1884 and is accredited to the engineer Charles Parsons. Mr Parsonsbecame one of the founders of the power generation industry after he constructed an electrical generating set using a direct coupled steam turbine as the prime mover. This initial simple design was patented and later became a great commercial success.

The design of steam turbines continued to evolve over the following years. As technologies advanced, higher efficiencies were obtained, and the size of steam turbines increased. Steam turbines are now powering some of the world’s largest electrical generators. Over 80% of all electricity generated today is generated using steam turbine prime movers.

There were previously many turbine manufactures such as Pametrada, British Thompson Houston, Parsons, John Brown, Kawasaki, Westinghouse, Curtis, Stal Laval etc. but the current market is dominated by relatively few manufacturers, such as Siemens, General Electric, Alstom, Toshiba and Mitsubishi Heavy Industries.

Steam Turbine Applications

Steam turbines are used as prime movers where the conversion of heat energy into mechanical rotary motion is required. Applications of steam turbines include large power stations, ship propulsion, compressors, and even small pumps.