A Brief Introduction To The Rotors Of Various Turbines

Working principle of impulse turbines

A working fluid contains potential energy (power head) and kinetic energy (velocity head). The fluid may be compressible or incompressible. Several physical principles used by turbines to collect this energy.

Impulse turbines

These turbines change the direction of flow of a liquid or high-speed gas jet. The resulting impulse to turn the turbine and the fluid flow of grass with a kinetic energy decreased. There is no change in pressure in the liquid or gas turbine rotor blades in the case of a steam turbine or gas, any pressure drop in the wings still.

created by the nozzle before reaching the blades on the rotor. Newton's second law

Before reaching the turbine, the pressure head of liquid is changed to velocity head by accelerating the fluid with a nozzle. Leather in the wheels and Laval turbines use this process completely. Impulse turbines do not require a pressure casement around the rotor because the liquid jet is w describes the transfer of energy from the turbine action.

Types of wind turbines

Steam turbines *. used to generate electricity in thermal power plants that burn coal or oil or nuclear. They were once used to directly drive mechanical devices such as propellers of ships, but especially those applications now use the gear down or a transition period, electric step, where the mill used to generate electricity which then powers a electric motor connected to mechanical stress. Machines turbo-electric ship has been particularly popular in the period immediately before and during World War II, mainly due to the lack of adequate gear cutting facilities in shipyards.

* Gas ​​turbines. are sometimes referred to as turbine engines. These engines usually the quality of supply, fan, compressor, combustion chamber and nozzle (perhaps other assemblies) in addition to one or more turbines.

* Transonic wind tunnel. The gas flow in most of the turbines used in gas turbine engines remains subsonic throughout the development. In a gas flow becomes supersonic transonic turbine when it leaves the vanes, while downstream speeds normally become subsonic. Transonic turbines operate at a rate higher pressure than normal, but is generally less effective and unique.

* Contra-rotating turbines. With axial turbines, some improvements in efficiency can be obtained if a lower turbine rotates in the opposite direction to drive the current. However, the complication may be counter-productive. A steam turbine counter-rotating, usually known as the Ljungström turbine was originally made by the Swedish engineer Fredrik Ljungström (1875-1964) in Stockholm and in collaboration with his brother won a Birger Ljungström Copyright 1894. The design is essentially a multi-stage radial turbine (or a pair of rotors "nested" the turbine) and met with some success, especially in marine applications, where it's compact size and low weight for turbo-electric applications . This radial arrangement, the overall efficiency is generally lower than that of Parsons turbines or Laval.

* Stator less wind. Multi-stage turbines have a set of static (ie static) as inlet guide vanes direct the gas flow on rotating blades. In a stream of gas turbine stator, the lower the output of a rotor upstream encroach on a downstream rotor without an intermediate set of stator vanes individual encountered.

* Ceramic grinder. Conventional turbine blades high-pressure (and blades) are made of nickel alloys and often use complicated internal cooling passages of the air to prevent the metal from overheating. In recent years, experimental ceramic blades are manufactured and tested in gas turbines, with a view to increasing the rotor inlet temperatures with possibly removing the cooling air. Ceramic knives are more fragile than their metal counterparts, and carry a greater risk of breakage of a blade catastrophic. This has tended to limit their use in jet engines and gas turbines for the stator (stationary) waves.

* Wrapped turbine. Many rotor blades of the turbine were wrapped on top, which is associated with the leaves adjacent to increase damping and thereby reduce blade flutter. In large production of onshore wind power of steam, the endowment is often supplemented, especially in long waves of low pressure turbine, the son of string. They are the son pass through the holes in their leaves far enough away from the root and the child are usually welded sheets, where they pass through. The son of cord are designed to reduce blade flutter in the middle of the leaf. The introduction of the child's cord significantly reduces the breakdown of the blade of a wind turbine on the high or low pressure.

* Cover the turbine less. At present there is, if possible, to eliminate the mystery surrounding the rotor, thereby reducing the load on the blade centrifugal and cooling needs.

* Turbine Bladeless. Use the boundary layer effect and not interfere with smooth blades as in a conventional turbine.

* Water turbines

* Pelt, a turbine, the type of water turbine.

* Francis turbine, a type widely used water turbine.

* Kaplan Turbine, a variation of Francis turbine.

* Vent. It is generally act as a single stage without nozzle vanes and international scene. An exception is the Belle Helene, which has a stator and a rotor, thus being a true wind.

Uses of turbines

* Some power on Earth is produced with a turbine of some sort. Highly effective control of steam turbines by 40% of thermal energy, while the rest as heat exhaustion.

* Most of the jet engines rely on turbines to supply mechanical work on their work, and the liquid fuel, like all nuclear power plants and ships.

* Turbines are a normal part of a larger machine. Gas turbine, for example, can refer to the internal combustion engine, comprising a turbine, ducts, compressor, heat exchanger, burner, fan, and (if one intended to produce electricity) charger. It should be noted however, that the collective known as the turbine engine in this case, is designed to transmit energy through the liquid fuel burning device as a method of transport, energy and transfer of fluid through the turbine, the turbine as is the case of turbines used for electricity supply, etc.

* Reciprocating piston engines such as aircraft engines use a turbine powered by their exhaust to drive a compressor inlet air, a configuration known as a turbocharger (turbine compressor), or colloquially, a "turbo ".

* Turbines can have a very high power density (ie the ratio between the power of weight, power, or volume). This is due to their ability to operate at very high speeds. The Space Shuttle main engines using turbo-pumps (machines, consisting of a pump to drive the turbine engine) to feed the propellants (liquid oxygen and liquid hydrogen) into the combustion chamber of the engine. Liquid hydrogen turbo pump is slightly larger than a car engine (which weighs about 700 pounds) and produce almost 70 000 hp (52.2 MW).

* Turbo expanders are widely used as a source of heat for industrial processes.

* Turbines can also be used as a system of power transmission to a remote controlled device that creates a dynamic and raise the level of the earth.

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