23-08-2012, 03:01 PM
Study of Hydro Power Plants and Detailed Design of Large Hydro Generators
1Study of Hydro Power.pdf (Size: 2.36 MB / Downloads: 111)
ABSTRACT
This project report includes the overview of a typical hydropower plant and describes the
technical aspects of designing a hydropower plant. It also includes detailed study of turbines,
large hydro generators. The report discusses the various design parameters of a hydro
generator and the ways to calculate them. To automate this task, we have also developed an
application in Visual Basic 6.0 which accepts rating of a generator as input from the user,
computes the design parameters and the user has option to save the result in excel format.
Annexure I, at the end of the project report, includes the screenshots of the application.
GENERAL INTRODUCTION
Oceans cover more than 70% of the earth's surface, making them the world's largest
source of hydro energy. There are many different ways to extract energy from water.
Seawater is the source of deuterium, the ideal fuel for nuclear fusion. Surface water
also stores a massive amount of solar energy that can be exploited to design
thermal power plants. In addition, water contains mechanical energy that can be
converted to useful work in the form of the potential energy of waterfalls, tides, and
ocean waves. According to some estimates, these resources have the potential to
produce 1-2 terawatts of electricity, enough to cover the energy demands of the
entire globe, but tapping into most of that potential is not yet economically feasible.
HYDROPOWER GENERATION AND ITS PRINCIPLES
Egyptians harnessed energy from flowing water about 2,000 years ago by turning
waterwheels to grind their grain. These primitive devices allowed the force of falling
water to act on a waterwheel and provide rotational energy or shaft power. Through
the centuries, mechanisms were designed to facilitate many other applications
beyond the simple grain mills of the Egyptians. By the time of the industrial
revolution, waterpower was used to drive tens of thousands of waterwheels. Today,
hydropower is the most widely available renewable energy, and is used almost
exclusively for electric power generation. Hydropower provides 19% of all electricity
used around the world.
Two medieval varieties of waterwheels were undershot and overshot wheels.
Undershot refers to a paddle wheel fixed to the bank of a river or hung from an
overhead bridge. It is turned by the impulse of the water current. Overshot water
mills work by bringing a stream of water through a pipe or canal and pouring it onto
the wheel from above.
HYDROPOWER PLANT
The most common type of hydropower plant uses a dam on a river to store water in
a reservoir. Water released from the reservoir flows through a turbine, spinning it,
which, in turn, activates a generator to produce electricity. But hydropower doesn't
necessarily require a large dam. Some hydropower plants just use a small canal to
channel the river water through a turbine.
PLANT DESIGN
Water used by a hydroelectric plant is usually stored behind a dam at a certain
elevation above the turbine. Turbines are devices that are used to convert the
energy of a moving fluid (usually water, steam, or air) into the rotational energy of a
shaft. The water flows through a penstock and through the blades of the turbine,
causing the turbine to rotate. The turbine shaft then turns a generator shaft and
electricity is produced. Gates and valves depending on the amount of electric energy
required can control the flow through the turbine.