Now we are going to share with you HOW HYDROTURBINES WORK!
Water flows from a dam or reservoir through a valve called a penstock that regulates the flow. It then passes through a spiral-shaped pipe to make the water spin. The spinning water makes a turbine turn. The turbine then powers an electrical generator while the water is released downstream.
To make the generator work properly the turbine must spin at a constant speed. Using a speed governor to open and close water gates surrounding the turbine does this. This controls the speed and volume of water flowing to the turbine.
It is also possible to turn off the flow of water altogether using an enormous valve, so that maintenance can occur.
The amount of electricity that can be produced by hydroelectricity generation depends on two things: the rate at which the water flows and the head of water. This is the difference in height between the water in the dam or reservoir and the water below the turbine.
The theory is to build a dam on a large river that has a large drop in elevation. The dam stores lots of water behind it in the reservoir. Near the bottom of the dam wall there is the water intake. Gravity causes it to fall through the penstock inside the dam. At the end of the penstock, there is a turbine propeller, which is turned by the moving water. The shaft from the turbine goes up into the generator, which produces the power. Power lines are connected to the generator that carries electricity to your home and mine. The water continues past the propeller through the tailrace into the river past the dam. By the way, it is not a good idea to be playing in the water right below a dam when water is released!
Parts of a Hydroelectric Plant
Most conventional hydroelectric plants include four major components:
Dam. Raises the water level of the river to create falling water. Also controls the flow of water. The reservoir that is formed is, in effect, stored energy.
Turbine. The force of falling water pushing against the turbine's blades causes the turbine to spin. A water turbine is much like a windmill, except the energy is provided by falling water instead of wind. The turbine converts the kinetic energy of falling water into mechanical energy.
Generator. Connected to the turbine by shafts and possibly gears so when the turbine spins it causes the generator to spin also. Converts the mechanical energy from the turbine into electric energy. Generators in hydropower plants work just like the generators in other types of power plants.
Transmission lines. Conduct electricity from the hydropower plant to homes and business.
How Much Electricity Can a Hydroelectric Plant Make?
The amount of electricity a hydropower plant produces depends on two factors:
How Far the Water Falls. The farther the water falls, the more power it has. Generally, the distance that the water falls depends on the size of the dam. The higher the dam, the farther the water falls and the more power it has. Scientists would say that the power of falling water is "directly proportional" to the distance it falls. In other words, water falling twice as far has twice as much energy.
Amount of Water Falling. More water falling through the turbine will produce more power. The amount of water available depends on the amount of water flowing down the river. Bigger rivers have more flowing water and can produce more energy. Power is also "directly proportional" to river flow. A river with twice the amount of flowing water as another river can produce twice as much energy.
As you should know, the main part of the hydro turbine is the most important part—the generator! But do you know how does the hydro turbine works?
Well, hydraulic turbine converts the energy of flowing water into mechanical energy. A hydroelectric generator converts this mechanical energy into electricity. The operation of a generator is based on the principles discovered by Faraday. He found that when a magnet is moved past a conductor, it causes electricity to flow. In a large generator, electromagnets are made by circulating direct current through loops of wire wound around stacks of magnetic steel laminations. These are called field poles, and are mounted on the perimeter of the rotor. The rotor is attached to the turbine shaft, and rotates at a fixed speed. When the rotor turns, it causes the field poles (the electromagnets) to move past the conductors mounted in the stator. This, in turn, causes electricity to flow and a voltage to develop at the generator output terminals.:D
In the next post, we will be going into the details of the turbines.
Signing off,
Hydroelectricians!:D
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