PPT On Hydraulic Machines - Turbines

1. CORE JAVAPresented On :- Hydraulic Machines - Turbines
Presented By :- ANAND KUMAR (ME/13/710)

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

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.
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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.
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5. Types of turbines
1. Steam Turbines
2. Gas Turbines (Combustion Turbines)
3. Hydraulic Turbines (Water Turbines)
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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.
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7. Classification of Water Turbines
1. According to the type of energy at inlet:
(a) Impulse Turbine, and (b) Reaction turbine.
2. According to the direction of flow through runner:
(a) Tangential flow, (b) Radial flow,
(c) Axial flow, and (d) mixed flow.
3. According to the head at the inlet of turbine:
(a) High head, (b) Medium head, and
(c) Low head.
4. According to the specific speed of the turbine:
(a) Low specific speed, (b) Medium Specific Speed,
(c) High specific speed.
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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)
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9. Pelton Turbine
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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.
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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.
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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 makes the jet turn
almost 180 degree. This
produces an impulsive force
on bucket.
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13. Any Questions ???
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14. Francis Turbine
 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 = 40-600 m.
 Flow rate = 10-700 m^3/s.
 Specific Speed = 51 to 255.
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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.
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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.
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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.
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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.
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19. Any Questions ???
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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 = 70-800 m^3/s
Specific speed = 255 to 860
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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
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.
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SHAFT
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.
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23. Turbine Selection graph
Head verses Flow graph Turbines Efficiency graph
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24. Any Questions ???
May 23, 201724

25. CORE JAVA
THANK YOU