What is Turbine and its types.
Turbine
A turbine is a mechanical device which extracts the energy from fluid - such as water,steam,air or combustion gasses and converts its into useful works. The work produced by the turbine are used to produce electricity, with the help of generator. Generator converted the mechanical (works) energies into electric energy.The are classified as such because engine are simply technologies that take an input and generate an output. A simple turbine is composed of a series of blades , and allows the fluid to enter the turbine, pushing and blades. These blades are spin and eject the fluid which now has less energy it did then when it entered the turbine. Some of the energy is captured by the turbine and used.
Turbine are used many different areas such as wind power, hydropower, and in heat engine and for propulsion. Turbine are extremely important because of the facts that nearly all electricity is generated by them.
Main Parts of Turbine
The main parts of turbine are :1. Nozzle :
It guides the steam to flow in designed directions and velocity.
2. Runner :
It is the rotating part of the turbine and blades are attached to the runner.
3. Blades :
It is the part of the turbine on which the fast moving fluid strikes and rotates the runner.
4. Casing :
It is the outer air tight covering of the turbine which contains the runner and blades. It protects the internal parts of the turbine.
Working Principle
- A fast moving fluid ( such as- water,gas ,stream or wind) is made to strike on the blades of the turbine.
- As the fluid strikes the blades, it rotates the runner.Hence then energy of moving fluid is converted into rotational energy.
- A generator is coupled with the shaft of the turbine.with the rotation of the runner of the turbine, the shaft of the generator also rotates. and the generator converts the mechanical energy of the runner into electrical energy.
Types of Turbine
Basically the turbines are four types-- Water Turbine
- Steam Turbine
- Gas Turbine
- Wind Turbine
Water turbine or Hydraulic Turbine
Water Turbine is a rotary machine which converted the kinetic and potential energy of water in to mechanical works. They are mostly used for electric power generation. Water turbines are developed in 19th century.
Water Turbine also known as Hydraulic turbine.
The Hydraulic turbines are classified on the following basis-
1. According to type of energy available at inlet.
- Impulse Turbine: If the energy available at the inlet of the turbine is only kinetic energy, the turbine is known as Impulse turbine.
- Reaction turbine: If the energy available at the inlet of the kinetic energy and also pressure energy ,this turbine is known as Reaction turbine.
2.According to the direction of the flow
- Tangential Flow Turbine : If the water flows along the tangent of the runner, the turbine is known as tangent flow turbine. Example- Pelton Turbine
- Radial flow Turbine :
If the water flows along the radial of the runner, the turbine is known as radial flow turbine.
- Axial flow Turbine:
If the water flow through the runner along the direction parallel to the axis of rotation of the runner of the turbine this turbine is called the axial flow turbine.
- Mixed flow Turbine : If the water flows through the runner in the radial direction but leaves in the direction parallel to the axis of rotation of the runner, the turbine is known as mixed flow turbine. example- Kaplan Turbine.
3. According to head of the inlet of Turbine
- High head turbine : The head of this turbine is 150 m to 2000 m or more. Its required small quantity of water.. Eg- Pelton turbine.
- Medium head turbine : in this turbine the head is 30 m to 150 m. It requires moderate quantity of water. Eg- Francis turbine.
- Low head turbine: In this of turbine the net head is 30 m. It required the large no of water quantity. Eg- Kaplan Turbine,.
4. According to specific speed of the Turbine
- Low specific speed turbine: It has specific speed less the 50. Eg- Pelton Turbine.
- Medium Specific Speed turbine : Specific speed varies from 50 to 250. eg- Francis Turbine
- High Specific speed turbine :speed more than 250. Eg-Kaplan Turbine.
Steam Turbine
A turbine which extracts energy from the moving steam and converted it into electrical energy ,it is called steam turbine.
Types of steam turbine
1. According to the mode of steam action
- Impulse turbine: If the steam available at the inlet has only kinetic energy the turbine is known as impulse turbine.
- Reaction turbine : If the turbine steam at the inlet has both kinetic and pressure energies are available then it is called the reaction turbine.
2.According to the direction of the stem flow:
- Axial flow turbine : if the steam flows through the runner in the direction parallel to the axis of rotation of the runner , then this turbine is known as axial flow turbine
- Radial flow turbine : if the stem flows through the runner in the radial direction , the turbine is called radial flow turbine.
3. According to the exhaust condition of steam
- Condensing turbine : A turbine in which the steam is considered, when it comes out of the turbine is called condensing turbine. it produced large output with single unit.
- Non Condensing turbine : In non condensing turbine, the exhaust steam leaves the turbine at atmospheric pressure or low pressure. there is no condensation of steam takes place in the turbine.
4. According to the pressure of the steam :
These are the three types-
- High pressure turbine
- Medium pressure turbine
- Low pressure turbine.
5. According to the no of stages
- Single stage steam turbine : In this stage of turbine , the steam after leaving the nozzle , impinges on the end of the blades, gliding over the inner surface, leaves the blade and exhaust into the condenser.
- Multi stage steam turbine : in this stage , sometimes the stem after leaving the moving blade is again made of flow through a fixed blade rings and again impinges on second moving blades. here the fixed blade is used to make the steam flow at a desired angle. In multi stage steam turbine more then one set of rotor blades are used.
Gas Turbine
A turbine which extracts energy from the hot moving gas and converts it into electricity, it is called gas turbine.
Types of gas turbine
1. According to the path of working substances
- Closed cycle gas turbine : In closed cycle gas turbine the air(gas) is continuously circulates within the turbine.
- Open cycle gas turbine : In this type of turbine , the air is not circulate continuously within the turbine. the air after flowing over the blades of the turbine exhaust in the atmosphere.
- Semi closed gas turbine : In this, as the name is indicates the semi closed gas turbine, is the combustion of both the turbine one is working of the open cycle and other is working on closed cycle.
2. According to the process of heat Absorption
- Constant pressure gas turbine: In this type of the turbine the air is heated at the constant pressure in the combustion chamber is called constant pressure gas turbine.
- Constant volume gas turbine : In this turbine , the air is heated at constant volume in the combustion chamber is called constant volume gas turbine.
Wind Turbine
A wind turbine extracts the energy from the fast moving winds and converts it into electricity , is called wind turbine..Types of Wind Turbine
The wind turbine are two types-- Horizontal axis wind turbine : A wind turbine in which the shaft of the turbine is horizontal to the ground is called axis wind turbine.
- Vertical axis wind turbine : A wind turbine in which the shaft of the turbine is vertical to the ground is called vertical axis wind turbine.
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