1. Hydraulic Turbines Presented By: Vinod Dahiya
Lecturer Mechanical Engg.
RGGP Narwana

2. Outline Introduction Classification of Hydraulic Turbines Pelton Wheel
Francis Turbine
Kaplan Turbine
Turbine Selection graph 2

3. What is Hydraulic Machines?
 Hydraulic machines are defined as those machines which convert either hydraulic energy (energy possessed by water) into mechanical energy (P.E+K.E) or mechanical energy into hydraulic energy. 3

4. What is Turbine?
The hydraulic machines, which converts the hydraulic energy into mechanical energy, are called turbines.
This mechanical energy is used to in running an electric generator which is directly coupled to the shaft of the turbine. 4

5. Types of turbines Steam Turbines Gas Turbines (Combustion Turbines)
Hydraulic Turbines (Water Turbines) 5

6. Hydraulic Turbine
The hydraulic machines, which converts hydro power (energy of water) into mechanical energy, are called Hydraulic Turbines.
Mechanical energy is used in running an electric generator which is coupled to the turbine shaft. 6

7. Classification of Water Turbines
According to the type of energy at inlet:
Impulse Turbine, and (b) Reaction turbine.
According to the direction of flow through runner:
(a) Tangential flow,
(c) Axial flow, and
(b) Radial flow,
(d) mixed flow.
According to the head at the inlet of turbine:
High head, (b) Medium head, and
(c) Low head.
According to the specific speed of the turbine:
Low specific speed, (b) Medium Specific Speed,
(c) High specific speed. 7
1 April 2015

8. Pelton Turbine (Pelton Wheel or Free Jet Turbine)
 High head, Tangential flow, Impulse
turbine,
Horizontal shaft.
This turbine is named after L.A Pelton, an American engineer.
The water strikes the bucket along the tangent of the runner.
Head= 50m to1300m
Specific speed= 8.5 to 30 (single jet)
Specific speed= 30 to 51 (two or more jets) 8

9. Pelton Turbine 9
1 April 2015

10. Pelton Turbine – The Basic Working Principle
 Working principle of Pelton turbine is simple. When a high speed water jet injected through a nozzle hits buckets of Pelton wheel; it induces an impulsive force. This force makes the turbine rotate.

11. Number of Buckets in Pelton Wheel
 One of the most important parameter of Pelton turbine design is number of buckets on the disk. If number of buckets is inadequate, this will result in loss in water jet. So there should be an appropriate number of buckets, which will make sure that no water is lost.

12. Pelton Runner with Buckets
Fig. Shows the runner of a Pelton wheel.
The shape of buckets is of a double hemispherical cup or Bowl.
Water jet is split into 2 equal components with help of a splitter. The special shape of
bucket almost
makes the jet
180 degree.
turn This
produces an impulsive force on bucket.

13. Any Questions ??? 13

14. Francis Turbine  Head = 40-600 m.  Flow rate = 10-700 m^3/s.
The inward flow reaction turbine having radial discharge at outlet.
This turbine is named after an American scientist
J.B. Francis.
Mixed flow, medium head reaction turbine.
 Head = m.
 Flow rate = m^3/s.
Specific Speed = 51 to 255.

15. Francis Turbine
 In modern Francis Turbine, the water enters the runner of the turbine in the radial direction at outlet and leaves in the axial direction at the inlet of the runner. Thus the modern Francis Turbine is a mixed flow type turbine.

16. Francis Turbine - Runner
 Most important part of Francis turbine is its runner. It is fitted with a collection of complex shaped blades as shown in Fig.

17. Francis Turbine - Runner
 In runner water enters radially, and leaves axially. During the course of flow, water glides over runner blades as shown in figure below.

18. Francis Turbine - Runner
 Blades of Francis turbine are specially shaped. So when water flows over it, a low pressure will be induced on one side, and high pressure on the other side. This will result in a lift force.

19. Any Questions ???

20. Kaplan Turbine This turbine is named after an Austrian Engineer,
V. Kaplan.
Axial flow, low head reaction turbine.
Kaplan turbines are suitable for power extraction when water energy is available at low head and high flow rate. Following are the operating conditions Kaplan turbine is best suitable for
Head = 2-25 m
Flow rate = m^3/s Specific speed = 255 to 860

21. Kaplan Turbine
 In an axial flow reaction turbine the shaft is vertical. The lower end of the shaft is larger and is known as ‘hub’ or ‘boss’. It is on this
SHAFT
hub that the vanes are attached. If the vanes are adjustable then it is known as Kaplan Turbine and if the vanes are non adjustable then it is known as Propeller Turbine.
VANES
HUBB OR BOSS

22. Flow in Kaplan Turbine
 In Kaplan turbine flow is entered through a spiral casing. Decreasing area of casing makes sure that flow is entered to the central portion almost at uniform velocity throughout the perimeter. Water after crossing the guide vanes passes over the runner. Finally it leaves through a draft tube.

23. Turbine Selection graph
Head verses Flow graph
Turbines Efficiency graph
May 23, 2017

24. Any Questions ???