Part-1 Introduction ofHYDRO ELECTRIC POWER PLANT
WHAT IS HYDRO POWER?The objective of a hydropower scheme is to convert thepotential energy of a mass of water, flowing in a stream withacertain fall to the turbine (termed the "head"), into electric energy at the lower end of the scheme, where thepowerhouse is located. The power output from the scheme isproportionalto the flow and to the head.
POWER HOUSE PENSTOCKRESEVOIR DAM TURBINE GENERATOR INTAKE POWER LINE TRANSFORMER
GENERAL ARRANGENENTOF HYDROPOWER PROJECTi. General available topography of the areaii. Available headiii. Available flowiv. Availability of other type of power station in the vicinityv. Requirements of power for industriesvi. Political influences of the areavii.Location of the power houseviii.economy
The movement of water can be used to make electricity. Energy fromwater is created by the force of water moving from a higher elevationto a lower elevation through a large pipe (penstock). When the waterreaches the end of the pipe, it hits and spins a water wheel or turbine.The turbine rotates the connected shaft, which then turns thegenerator, making electricity.
What are Spill ways?A dam failure can have sever effects downstream of the dam.During the lifetime of a dam different flow conditions will be experiencedand a dam must be able to safely accommodate high floods thatcan exceed normal flow conditions in the river. For this reason,carefully passages are corporated in the dams as part of structure.These passages are known as spillways.
PENSTOCKconveying water from the intake to the power house.Of concrete in low headsOf steel iis suitable for all heads
Penstock has:Automatic butterfly valve shuts off water flow if pen stock ruptures.Air valve internal pressure = atm pressureSurge Tank reducing water hammering in pipes which can cause damage to pipes. thereby regulating water flow and pressure inside the penstock.
TRASH RACK cleaning machine, which removes debris from water In order to save water ways and electromechanical equipment from any damage. Set steel bars on edge to the flow of water and space about 1“ apart A head gate or valve should be installed below the trash rack to control flow and to allow the turbine to be inspected and repaired.
Principle• As the turbine turns, the excitor sends an electrical current to the rotor. The rotor is a series of large electromagnets that spins inside a tightly-wound coil of copper wire, called the stator. The magnetic field between the coil and the magnets creates an electric current.
POWER HOUSE AND EQUIPMENTS:-In the scheme of hydropower the role of power house is toprotect the electromechanical equipment that convert thepotential energy of water into electricity.Following are the equipments of power plant:1.Valve 5.Condensor2.Turbine 6.Protection System3.Generator 7.DC emergency Supply4.Control System 8.Power and current transformer
Head gate• Controlling the water flowing into the channel.
Classification of HydelPlants• Classification of Hydro plants based on Hydraulic Characteristics.• On the basis of this characteristics, the hydro plants may be divided into the following types.• Storage plants• Run-off river plants• Pumped storage plants• Tidal plants
HEAD• The head is the vertical distance from the surface of the water at the dam down to the water in the stream below where the turbine is located
Low He ad S c he me• A low head scheme is one which uses water head of less than 15 m or so. A runoff river plant is essentially a low head scheme. In this Scheme, a weir or a barrage is constructed to raise the water level , and the power house is constructed either in continuation with the barrage or at some distance downstream of the barrage, where water is taken to the power house through an intake canal.
Medium head hydroelectric power plants• Water head is more than 30 meters but less than 300 meters• located in the mountainous regions where the rivers flows at high heights• large reservoir of water
High head hydroelectric power plants• 300 meters and it can extend even up to 1000 meters• most commonly constructed hydroelectric power plants• Water is mainly stored during the rainy seasons and it can be used throughout the year , thus it can generate electricity throughout the year• very important in the national grid because they can be adjusted easily to produce the power as per the required loads.• total height of the dam depends upon a number of factors like quantity of available water, power to be generated, surrounding areas, natural ecosystem etc.
Run-off Rive r Plants• Runoff river plants are those which utilizes the minimum flow in a river having no appreciable pondage on its upstream side. A weir or a barrage is some times constructed across a river simply to raise and maintain the water level at a pre- determined level within narrow limits of fluctuations, either solely for the power plants or for some other purpose where the power plant may be incidental. Such a scheme is essentially a low head scheme and may be suitable only on a perennial
Pumpe d S torage Plants• A pumped storage plant generates power during peak hours, but during the off-peak hours, water is pumped back from the tail water pool to the head water pool for future use. The pumps are run by some secondary power from some other plants in the system. The plants is thus primarily meant for assisting an existing thermal plant or some hydel plant.
Tidal Plants• Tidal plants for generation of hydro electric power are the recent and modern advancements and essentially works on the principle that there is a rise in a sea water during high tide period and a fall during the low tide period. The water rises and falls during the day. The advantage of this rise and fall is taken in a tidal plant. In other words the difference between high and low tide level is utilized to generate power. This is accomplished by constructing a basin separated from the ocean by a partition wall and installing turbines in openings through this wall. Water passes from the ocean to the basin drainage high tides, and thus running the turbines and generating electric power. During low tide, the water from the basin run back to the ocean which can again be utilized to generate electric power for either direction. Such a plants are useful where the tidal range is high.