Turbo generator

Last updated
250 kW steam turbine generator set (1910) TMW 773 - Steam turbine generator set.jpg
250 kW steam turbine generator set (1910)
500 MW Siemens multi stage steam turbine with generator set (rear, red) Turbogenerator01.jpg
500 MW Siemens multi stage steam turbine with generator set (rear, red)
Parsons first 1 MW steam turbine driven "Turbogenerator" (made 1900 for a plant in Elberfeld, Germany) 1900 Elberfeld 1MW Generator.jpg
Parsons first 1 MW steam turbine driven "Turbogenerator" (made 1900 for a plant in Elberfeld, Germany)
Otto Blathy in the armature of a Ganz turbo generator (1904) Blathy in a Ganz turbogenerator.jpg
Ottó Bláthy in the armature of a Ganz turbo generator (1904)
Small RP4 steam turbo generator set 500W/24V for a steam locomotive: alternator (left) + turbine (right) Turbogenerator przekroj.jpg
Small RP4 steam turbo generator set 500W/24V for a steam locomotive: alternator (left) + turbine (right)

A turbo generator is an electric generator connected to the shaft of a turbine (water, steam, or gas) for the generation of electric power. [note 1] Large steam-powered turbo generators provide the majority of the world's electricity and are also used by steam-powered turbo-electric ships. [1]

Contents

Small turbo-generators driven by gas turbines are often used as auxiliary power units (APU, mainly for aircraft).

History

Turbine construction at the Ganz Company around 1886 Turbinaszereles.jpg
Turbine construction at the Ganz Company around 1886

The first turbo-generators were electric generators powered by water turbines. The first Hungarian water turbine was designed by the engineers of the Ganz Works in 1866; industrial-scale production with dynamo generators started only in 1883. [2] Engineer Charles Algernon Parsons demonstrated a DC steam-powered turbo generator using a dynamo in 1887, [3] and by 1901 had supplied the first large industrial AC turbo generator of megawatt power to a plant in Elberfeld, Germany. [4]

Turbo generators were also used on steam locomotives as a power source for coach lighting and water pumps for heating systems.

Construction features

Turbo generators are used for high shaft rotational speeds, typical of steam and gas turbines. The rotor of a turbo generator is a non-salient pole type usually with two poles. [5]

The normal speed of a turbo generator is 1500 or 3000 rpm with four or two poles at 50 Hz (1800 or 3600 rpm with four or two poles at 60 Hz). The rotating parts of a turbo generator are subjected to high mechanical stresses because of the high operation speed. To make the rotor mechanically resistant in large turbo-alternators, the rotor is normally forged from solid steel and alloys like chromium-nickel-steel or chromium-nickel-molybdenum are used. The overhang of windings at the periphery will be secured by steel retaining rings. Heavy non-magnetic metal wedges on top of the slots hold the field windings against centrifugal forces. Hard composition insulating materials, like mica and asbestos, are normally used in the slots of the rotor. These materials can withstand high temperatures and high crushing forces. [6]

The stator of large turbo generators may be built of two or more parts while in smaller turbo-generators it is built up in one complete piece. [7]

Hydrogen-cooled turbo generator

Based on the air-cooled turbo generator, gaseous hydrogen first went into service as the coolant in a hydrogen-cooled turbo generator in October 1937, at the Dayton Power & Light Co. in Dayton, Ohio. [8] Hydrogen is used as the coolant in the rotor and sometimes the stator, allowing an increase in specific utilization and a 99.0% efficiency. Because of the high thermal conductivity, high specific heat and low density of hydrogen gas, this is the most common type in its field today. The hydrogen can be manufactured on-site by electrolysis.

The generator is hermetically sealed to prevent escape of the hydrogen gas. The absence of oxygen in the atmosphere within significantly reduces the damage of the windings' insulation by eventual corona discharges. The hydrogen gas is circulated within the rotor enclosure, and cooled by a gas-to-water heat exchanger. [9]

See also

Notes

  1. For the purposes of this article, the term turbo generator means the electrical machine that converts mechanical power from a rotating turbine shaft to electrical power. However, there is inconsistency between sources about the definition of turbo-generator. Some online dictionaries give a definition: "A turbo generator is the combination of a turbine directly connected to an electric generator for the generation of electric power" , and there is a similar definition here . Other dictionaries and most electrical engineering sources give a definition that is limited to the electrical machine, with the turbine identified as a separate entity. See , , and from the IEEE: and . Sources from manufacturers also support the definition being limited to the electrical machine. and , and "Turbo generators for thermal power plants". ANDRITZ. Archived from the original on May 31, 2023.

    Related Research Articles

    <span class="mw-page-title-main">Engine</span> Machine that converts one or more forms of energy into mechanical energy (of motion)

    An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.

    <span class="mw-page-title-main">Steam turbine</span> Machine that uses steam to rotate a shaft

    A steam turbine or steam turbine engine is a machine or heat engine that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Charles Parsons in 1884. Fabrication of a modern steam turbine involves advanced metalwork to form high-grade steel alloys into precision parts using technologies that first became available in the 20th century; continued advances in durability and efficiency of steam turbines remains central to the energy economics of the 21st century.

    <span class="mw-page-title-main">Turbine</span> Device that extracts energy from a fluid flow

    A turbine is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced can be used for generating electrical power when combined with a generator. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor.

    <span class="mw-page-title-main">Gas turbine</span> Type of internal and continuous combustion engine

    A gas turbine or gas turbine engine is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part and are, in the direction of flow:

    <span class="mw-page-title-main">Electric generator</span> Device that converts other energy to electrical energy

    In electricity generation, a generator is a device that converts motion-based power or fuel-based power into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all the power for electrical grids.

    <span class="mw-page-title-main">Alternator</span> Device converting mechanical into electrical energy

    An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature. Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually, the term refers to small rotating machines driven by automotive and other internal combustion engines.

    <span class="mw-page-title-main">Combined cycle power plant</span> Assembly of heat engines that work in tandem from the same source of heat

    A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. On land, when used to make electricity the most common type is called a combined cycle gas turbine (CCGT) plant, which is a kind of gas-fired power plant. The same principle is also used for marine propulsion, where it is called a combined gas and steam (COGAS) plant. Combining two or more thermodynamic cycles improves overall efficiency, which reduces fuel costs.

    <span class="mw-page-title-main">Motor–generator</span> Device for converting electrical power to another form

    A motor–generator is a device for converting electrical power to another form. Motor–generator sets are used to convert frequency, voltage, or phase of power. They may also be used to isolate electrical loads from the electrical power supply line. Large motor–generators were widely used to convert industrial amounts of power while smaller motor–generators were used to convert battery power to higher DC voltages.

    <span class="mw-page-title-main">Turbomachinery</span> Machine for exchanging energy with a fluid

    Turbomachinery, in mechanical engineering, describes machines that transfer energy between a rotor and a fluid, including both turbines and compressors. While a turbine transfers energy from a fluid to a rotor, a compressor transfers energy from a rotor to a fluid. It is an important application of fluid mechanics.

    <span class="mw-page-title-main">Armature (electrical)</span> Power-producing component of an electric machine

    In electrical engineering, the armature is the winding of an electric machine which carries alternating current. The armature windings conduct AC even on DC machines, due to the commutator action or due to electronic commutation, as in brushless DC motors. The armature can be on either the rotor or the stator, depending on the type of electric machine.

    <span class="mw-page-title-main">Thermal power station</span> Power plant that generates electricity from heat energy

    A thermal power station, also known as a thermal power plant, is a type of power station in which the heat energy generated from various fuel sources is converted to electrical energy. The heat from the source is converted into mechanical energy using a thermodynamic power cycle. The most common cycle involves a working fluid heated and boiled under high pressure in a pressure vessel to produce high-pressure steam. This high pressure-steam is then directed to a turbine, where it rotates the turbine's blades. The rotating turbine is mechanically connected to an electric generator which converts rotary motion into electricity. Fuels such as natural gas or oil can also be burnt directly in gas turbines, skipping the steam generation step. These plants can be of the open cycle or the more efficient combined cycle type.

    <span class="mw-page-title-main">Folsom Powerhouse State Historic Park</span> United States historic place

    Folsom Powerhouse State Historic Park is a historical site preserving an 1895 alternating current (AC) hydroelectric power station—one of the first in the United States.

    In electrical engineering, electric machine is a general term for machines using electromagnetic forces, such as electric motors, electric generators, and others. They are electromechanical energy converters: an electric motor converts electricity to mechanical power while an electric generator converts mechanical power to electricity. The moving parts in a machine can be rotating or linear. While transformers are occasionally called "static electric machines", since they do not have moving parts, generally they are not considered "machines", but as electrical devices "closely related" to the electrical machines.

    <span class="mw-page-title-main">West Burton power stations</span> Coal and gas fired power stations in Nottinghamshire, England

    The West Burton power stations are a pair of power stations on the River Trent, near Gainsborough, Lincolnshire, England. West Burton A was a coal-fired power station, one of the Hinton Heavies which was commissioned in 1966 and operated until 2023. West Burton B on the other hand, is a combined cycle gas turbine power station, commissioned in 2013. West Burton A is owned by EDF Energy, while West Burton B is owned and operated by Totalenergies.

    <span class="mw-page-title-main">Hydrogen-cooled turbo generator</span> Turbo generator with gaseous hydrogen as a coolant

    A hydrogen-cooled turbo generator is a turbo generator with gaseous hydrogen as a coolant. Hydrogen-cooled turbo generators are designed to provide a low-drag atmosphere and cooling for single-shaft and combined-cycle applications in combination with steam turbines. Because of the high thermal conductivity and other favorable properties of hydrogen gas, this is the most common type in its field today.

    A permanent magnet synchronous generator is a generator where the excitation field is provided by a permanent magnet instead of a coil. The term synchronous refers here to the fact that the rotor and magnetic field rotate with the same speed, because the magnetic field is generated through a shaft-mounted permanent magnet mechanism, and current is induced into the stationary armature.

    <span class="mw-page-title-main">Magneto</span> Electricity-producing machine

    A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, although it is usually considered distinct from most other alternators, which use field coils rather than permanent magnets.

    <span class="mw-page-title-main">Flux switching alternator</span>

    A flux switching alternator is a form of high-speed alternator, an AC electrical generator, intended for direct drive by a turbine. They are simple in design with the rotor containing no coils or magnets, making them rugged and capable of high rotation speeds. This makes them suitable for their only widespread use, in guided missiles.

    <span class="mw-page-title-main">Alternator (automotive)</span> Devices in automobiles to charge the battery and power the electrical system

    An alternator is a type of electric generator used in modern automobiles to charge the battery and to power the electrical system when its engine is running.

    <span class="mw-page-title-main">Single-phase generator</span>

    Single-phase generator is an alternating current electrical generator that produces a single, continuously alternating voltage. Single-phase generators can be used to generate power in single-phase electric power systems. However, polyphase generators are generally used to deliver power in three-phase distribution system and the current is converted to single-phase near the single-phase loads instead. Therefore, single-phase generators are found in applications that are most often used when the loads being driven are relatively light, and not connected to a three-phase distribution, for instance, portable engine-generators. Larger single-phase generators are also used in special applications such as single-phase traction power for railway electrification systems.

    References

    1. Ginet, C.; Joho, R.; Verrier, M. "The turbogenerator – A continuous engineering challenge" (PDF). Archived from the original (PDF) on 2010-08-21.
    2. "Vízenergia hasznosítás szigetközi szemmel Avagy mi lesz veled, Dunakiliti?" (PDF). Archived from the original (PDF) on 2013-10-15. Retrieved 2013-10-15.
    3. Smil, Vaclav (2005). Creating the Twentieth Century . Oxford University Press. pp.  63–64. ISBN   0195168747.
    4. Scientific American , 27 April 1901
    5. Basic Electrical Engineering (Be 104). McGraw-Hill Education (India) Pvt Limited. 1990. p. 8.1. ISBN   978-1-259-08116-3. Archived from the original on 11 February 2018. Retrieved 8 August 2017.
    6. Basic Electrical Engineering (Be 104). McGraw-Hill Education (India) Pvt Limited. 1990. p. 8.3. ISBN   978-1-259-08116-3. Archived from the original on 11 February 2018. Retrieved 8 August 2017.
    7. Basic Electrical Engineering (Be 104). McGraw-Hill Education (India) Pvt Limited. 1990. p. 8.4. ISBN   978-1-259-08116-3. Archived from the original on 11 February 2018. Retrieved 8 August 2017.
    8. National Electrical Manufacturers Association (11 February 2018). "A chronological history of electrical development from 600 B.C." New York, N.Y., National Electrical Manufacturers Association via Internet Archive.
    9. "Aeroderivative & Heavy-Duty Gas Turbines - GE Power". www.gepower.com. Archived from the original on 2010-05-05.