Hydraulic Turbines

Introduction

Hydraulic turbines are the machines which convert hydraulic energy into mechanical energy. In other words, hydraulic turbines are mortars or prime movers which run with hydraulic energy.

The mechanical energy developed by a turbine can be converted into electrical energy by coupling the turbine to an electric generator.

the electric power which is obtained from the hydraulic energy is known as Hydroelectric power. At present hydroelectric power is the cheapest as compared by the power generated by other sources such as oil, coal, etc.

It is installed at the places where a continuous water supply under a high head is available. Sometimes, a natural lake or reservoir may be utilized for this purpose or an artificial reservoir may be formed by constructing a dam.

 

CLASSIFICATION OF HYDRAULIC TURBINES

1.According to the type of energy at inlet

(i) Impulse turbine

(ii) reaction turbine

2. According to the direction of flow through runner

(i) tangential flow turbine

(ii) radial flow turbine

(iii) axial flow turbine

(iv) mixed flow turbine

3. According to the head at the inlet of turbines

(i) high head turbine

(ii) medium head turbine

(iii)low head turbine

4. According to the specific speed of the turbine

(i) low specific speed turbine  

(ii) medium-specific speed turbine

(iii) high specific speed turbine

 

  1.IMPULSE TURBINE

Hyduralic Turbines|by GOODNEWZ
IMPULSE TURBINE

 

If at the inlet of the turbine, the energy available is only kinetic energy, the turbine is known as impulse turbine

EX: Pelton Wheel

 

  2.REACTION TURBINE

 
Hyduralic Turbines|by GOODNEWZ

             REACTION TURBINE

If at the inlet of the turbine, the water possesses kinetic energy as well as pressure energy, the turbine is known as the reaction turbine.

As the water flows through the runner, the water is under pressure and the pressure energy goes on changing into kinetic energy. The runner is completely enclosed in the air-tight casing is completely full of water.

EX: Francis turbine, Kaplan turbine

 

  3.TANGENTIAL FLOW TURBINE

 
Hyduralic Turbines|by GOODNEWZ

               TANGENTIAL FLOW TURBINE

If the water flows along the tangent of the runner, the turbine is known as tangential flow turbine

EX: Pelton wheel

 

4.RADIAL FLOW TURBINE

 
Hyduralic Turbines|by GOODNEWZ

                    RADIAL FLOW TURBINE

If the water flows in the radial direction through the runner, the turbine is called radial flow turbine

EX: Francis Turbine

 

5.AXIAL FLOW TURBINE

 
Hyduralic Turbines|by GOODNEWZ

                    AXIAL FLOW TURBINE

If the water flows through the runner along the direction parallel to the axis of the rotation of the turbine is called the axial flow turbine

EX: Kaplan Turbine

 

6.MIXED FLOW TURBINE

 
Hyduralic Turbines|by GOODNEWZ

                 MIXED FLOW TURBINE

If the water flows through the runner in the radial direction but leaves in the direction parallel to the axis of the rotation of the runner, the turbine is called a mixed turbine.

EX: Morden Francis Turbine

 

7.HIGH HEAD, MEDIUM HEAD, AND LOW HEAD TURBINES

 
Hyduralic Turbines|by GOODNEWZ

      HIGH HEAD, MEDIUM HEAD, AND LOW HEAD TURBINES

High turbines are those which are capable of working under high heads varies from 250 M to a few thousand meters. 

A medium turbine works under a head of 60 m to 250 m.

The turbine working under less head than 60 m is termed as low head turbine

 

  8.LOW, MEDIUM AND HIGH SPECIFIC SPEED TURBINES

 

Low specific speed turbines have a specific speed less than 50. 

Medium specific speed turbines have the speed 50 to 25.

 If the specific speed of a particular turbine is greater than 250, it is termed as high specific speed turbine