Today we will learn about what is turbine and types of turbines used in industries. We have heard many time the word "turbine" but most of us don't know more about It. Turbine is mostly used in the hydro power plant and in steam power plant to generate electric power. It is one of the hydraulic machines. Hydraulic machine is defined as those machines which convert hydraulic energy into mechanical energy or mechanical energy into hydraulic energy.
What is turbine?
A hydraulic machine which converts hydraulic energy into mechanical energy is known as turbine. Turbine is a device which transfers kinetic energy of water, air, gas or steam to the shaft which cause rotates the shaft. Simply turbine is a rotor which has vanes at the peripheral of it. In the power plant industries, it is situated at the end of electromagnet (generator) which causes to rotate it and generate electric power. Turbine is mostly used in hydroelectric power plant such as dams etc. which is the cheapest method of power generation.
We know that turbine is mostly used in hydroelectric power plant. As shown in diagram a dam is constructed across a river to store water. There is the elevation difference between turbine and dam. Turbine and dam is connected by a large diameter pipe called penstock which carries water under pressure from the storage reservoir to the turbine. The turbine is connected to the electromagnet. Turbine has different types of vanes fitted on rotter. The water under pressure strikes the turbine, and rotate it, which further rotate the electromagnet or generator to generate power. The water is carried to tailrace after worked on the turbine.
Types of Turbines:
Turbine can be classified according to direction of flowing fluid, head at the inlet of turbine etc. These are
According to the type of energy at inlet:
1. Impulse turbine:
If the energy available at inlet of turbine is only kinetic energy, the turbine so known as impulse turbine. The available energy at inlet is only kinetic energy if the inlet pressure and outlet pressure is same equal to atmospheric pressure. The water use only its kinetic energy to rotate the turbine and the pressure of water remain constant. Pelton wheel turbine is a one of the impulse turbine.
|Pelton Wheel Turbine|
2. Reaction turbine:
If the pressure at the inlet of turbine and outlet of turbine is different or the water use its kinetic energy as well as pressure energy to rotate the turbine is known as reaction turbine. When the water under pressure flows through the turbine, some of its pressure energy convert into kinetic energy which rotate the turbine. In this turbine pressure change during the energy transfer so it is air tight. The Francis and Kaplan turbine is the example of this turbine.
|Kaplan Turbine (Reaction Turbine)|
According to the direction of flow through runner:
1. Tangential flow turbine:
If the water flows along the tangent of the runner, the turbine is known as tangential flow turbine. Pelton wheel turbine is the example of tangential flow turbine.
2. Radial flow turbine:
If the water flows in the radial direction through the runner, the turbine is called radial flow turbine. If the water flows from outward to inward, radially, the turbine is known as inward radial flow turbine and if oppose the turbine is known as outward radial flow turbine.
3. Axial flow turbine:
If the water flows along the direction parallel to the axis of the runner, the turbine is known as axial flow turbine. Francis turbine is the example of axial flow turbine.
4. 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 called mixed flow turbine.
According to head at the inlet of turbine:
1. High head turbine
2. Medium head turbine
3. Low head turbine
According to specific speed of turbine:
1. Low specific speed turbine
2. Medium specific speed turbine
3. High specific speed turbine
3. High specific speed turbine
Today we have learnt about what is turbine and types of turbines. If you have any doubt regarding this article, ask by commenting.