Hydroelectricity

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 Author: harrisk2 ID: 251358 Filename: Hydroelectricity Updated: 2013-12-07 13:42:42 Tags: Hydroelectricity Folders: Description: Hydroelectricity Show Answers:

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1. Hydroelectricity
Energy of falling water
Vertical fall
3. Power equation derivation
• The power of water:
4. Francis Turbine diagram
5. Francis Turbine traits (5)
• most common type
• medium or large scale plants
• completely submerged
• radial and axial flow (mixed flow) turbine
6. Francis Turbine working principle
Water enters radially and emerges out axially so the discharge is parallel to the axis of shaft
7. Francis Turbine maximizing efficiency
Adjustment of the pitch -> we can change the angle of the blades to match the new conditions, can reduce the output power by turning the guide vanes when demand falls
8. Kaplan Turbine (Reaction turbine) Diagram
9. Kaplan Turbine traits (3)
• Axial flow turbine
• Rapid rate of revolution
• Require large quantity of water (low head)
10. Kaplan Turbine improved efficiency
Change the angle of blades when the power demand changes
11. Pelton Wheel (Impulse turbine) Diagram
12. Pelton Wheel traits (4)
• Require lower quantity of water
• High heat turbine
• Tangential flow turbine
• Has double cups
13. Turgo Turbine
Variant of the Pelton Wheel - vary cup depth
14. Hydroelectricity Diagram
15. Types of flow direction (4)
• Tangential
• Axial
16. Types of actions of flowing water
• Reaction
• Impulse
17. Impulse Turbine
The water hits the turbine as a jet in an open environment with the power deriving from kinetic energy of the flow
18. Reaction Turbine
The turbine is totally embedded in the fluid and is powered from the pressure drop across the device
• Greater than 250m
• Pelton Wheel
• Impulse turbines

• 50m to 250m
• Francis Turbine

• Less than 60m
• Kaplan Turbine
• Reaction Turbine

22. Propellers Diagram
23. Propellers
• Axial-flow turbine
• Area that water enters is the entire swept area
• Good for large volume (low head) flows
24. Cross-flow turbines
• Impulse type
• Water enters in a flat sheet rather than a round jet
• Infinitely renewable
• No fuel required
• Non-polluting
• 80% efficiency
• Flood water can be used for agriculture
• Long life equipment
• Limited required maintenance
• long lasting
• last for 50+ years