23-03-2011, 04:07 PM
PRESENTED BY
ASHISH SAHU
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INTRODUCTION
Hydraulics is part of the more general discipline of fluid power. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties
Working
Force that is applied at one point is transmitted to another point using an incompressible fluid.
Layout of Hydroelectric Power Plants
(1) Dam
(2) Spillway
(3) Penstock and Tunnel
(4) Surge Tank
(5) Power Station
Classification of turbine
Pelton wheel
The Pelton wheel extracts energy from the impulse (momentum) of moving water, as opposed to its weight like traditional overshot water wheel.
Applications
There exist a lots of Pelton wheels mounted on vertical oil pad in hydroelectric plants.
Some of these systems utilize household plumbing fixtures for water delivery.
These small units are recommended for use with thirty meters or more of head,
Francis turbine
They operate in a range of ten meters to several hundred meters and are primarily used for electrical power production
Application
designed for a wide range of heads and flows
also be used for pumped storage
used to generate power during peak demand.
Kaplan turbine
The Kaplan turbine is a propeller-type water turbine which has adjustable blades
Applications
Kaplan turbines are widely used throughout the world for electrical power production.
It can be used to get highest possible efficiency, typically over 90%.
Speed Governor of turbine
for controlling the speed of the prime mover, usually controlling the amount of fuel or steam or water that is admitted to the prime mover.
Turbine Efficiency
Gas Turbines.
A gas turbine is a heat engine that uses high temperature, high-pressure gas as the working fluid to spin the turbine and generate power.
Steam Turbines
Steam turbines work on the same basic principles as gas turbines, but use steam as the working fluid. This steam is typically generated in an external boiler and fired by an external heat source.
Combined-Cycle.
A combined-cycle integrates Brayton and Rankine cycles. High quality exhaust heat from a gas turbine generates steam in a heat recovery steam generator to power a steam turbine, significantly enhancing efficiency.
Advantages:
more efficient & consistent work or power output.
easier to spot during ground maintenance operation.
it is able to sustain its airworthiness viscosity, density & fluid temperature even if it subjected under extreme heat.
Disadvantages:
highly corrosive to most of the materials.
heavy loads experienced in a typical hydraulic system.
susceptible to contaminations & foreign object damage.
hydraulic fluid and its gas fumes without proper equipment and precautions is a health risk.
If disposed improperly, a hydraulic fluid is an environmental risk.
