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    Generation Hydro

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    whitehatesm
    The main three parts of a power system are generation, transmission, and distribution. Generation methods include hydro, thermal (using sources like coal, oil, natural gas), nuclear, wind, and solar. Hydro power generation uses the potential energy of water to produce mechanical and then electrical energy. The key elements of a hydro power plant are the intake, penstock, water turbine, generator, and tailrace. There are three basic types of hydro plants: storage, pumped storage, and run-of-river.

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    Generation Hydro

    Uploaded by

    whitehatesm
    8 views22 pages
    The main three parts of a power system are generation, transmission, and distribution. Generation methods include hydro, thermal (using sources like coal, oil, natural gas), nuclear, wind, and solar. Hydro power generation uses the potential energy of water to produce mechanical and then electrical energy. The key elements of a hydro power plant are the intake, penstock, water turbine, generator, and tailrace. There are three basic types of hydro plants: storage, pumped storage, and run-of-river.

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    5. Generation Hydro

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    The main three parts of a power system are generation, transmission, and distribution. Generation methods include hydro, thermal (using sources like coal, oil, natural gas), nuclear, wind, and solar. Hydro power generation uses the potential energy of water to produce mechanical and then electrical energy. The key elements of a hydro power plant are the intake, penstock, water turbine, generator, and tailrace. There are three basic types of hydro plants: storage, pumped storage, and run-of-river.

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    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    8 views22 pages

    Generation Hydro

    Uploaded by

    whitehatesm
    The main three parts of a power system are generation, transmission, and distribution. Generation methods include hydro, thermal (using sources like coal, oil, natural gas), nuclear, wind, and solar. Hydro power generation uses the potential energy of water to produce mechanical and then electrical energy. The key elements of a hydro power plant are the intake, penstock, water turbine, generator, and tailrace. There are three basic types of hydro plants: storage, pumped storage, and run-of-river.

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    Download as pdf or txt
    of 22

    What are the main three parts of power system?

    •Generation
    •Transmission
    •Distribution
    Thermal

    Hydro

    Generation Nuclear
    Methods Wind

    Solar

    ……
    Electricity Generation Sources: Two Different years
    16th August 2020 17th August 2020 07th October 2020
    Hydro 14.8 GWh 42% 13.87 GWh 50% 17.11 GWh 46%
    Thermal - Coal 17.66 GWh 50% 9.02 GWh 32% 19.39 GWh 40%
    Thermal - Oil 0.93 GWh 5% 4.15 GWh 15% 4.94 GWh 12%
    Other
    renewable
    Solar 1.84 GWh 3% 0.58 GWh 3% 0.81 GWh 2%
    Wind
    Mini hydro
    Power Stations in Sri Lanka - 2017

    Power Station Total Capacity

    Hydro 1391.4 MW

    Thermal (Coal) 900 MW Conventional


    Power Sources
    Thermal (Oil) 1233 MW

    Wind 131.5 MW

    Small Hydro 353.6 MW Non-Conventional


    Power Sources
    Other Renewable 77.5 MW
    Hydro Power
    Hydro Power
    Generation

    Potentialenergy -> Mechanical energy -> Electrical energy


    Elements of a hydro electrical power plant
    Mahaweli
    Complex Amba n
    Ga nga
    Laxapana
    Complex
    Elements of a hydro electrical power plant
    • Spillway/Spill gate
    Spill gate is used to discharge the excess water in a reservoir.
    Elements of a hydro electrical power plant

    • Intake
    This may consist of canals, flumes, pipelines and pressure tunnels. Mostly made out of
    concrete and has a small gradient. Purpose is to carry the water form reservoir to penstock.

    • Surge Tank / shaft


    Surge tank is a small reservoir or a tank. Purpose is to control the pressure variations
    resulting from the rapid changes in water flow in penstock.

    Increase in Wicked gates Pressure drops inside Water level falls in the
    load opened Penstock surge tank
    Decrease in Wicked gates Pressureincreases Water level rises in the
    load closed inside Penstock surge tank
    Elements of a hydro electrical power plant
    • Penstock
    It is a closed conduit with a high gradient which connects the surge tank to the scroll case of
    the turbine. Penstocks are built of steel or reinforced concrete and thickness is decided according to
    the maximum hydrostaticpressure which can occur.

    Tail race
    Tail race leads the discharged water flow from the turbine to the outside of the power
    plant.
    Elements of a hydro electrical power plant
    • Water turbines/ Prime Movers
    • In hydro power plants, water turbines are used as prime movers. Mainly
    there are three types of water turbines.
    • Kaplan turbine: Used for low head(<50m), large flow plants. Blade angel can be changed
    according to the head (e.g.: Udawalawa)
    • Francis turbine : Used for low and medium head plants (50m<h<400m) e.g.: Randengala,
    • Rantambe
    • Pelton Wheel: Used for high head (>500m), low flow plants. E.g.: New Laxapana
    HYDRO ELECTRICAL POWER PLANT

    Intake
    Basic Types of Hydro electric power plants

    1. Storage Type
    2. Pumped Storage type
    3. Run off river type
    1. Storage Type
    This is the most common hydro power plant type in Sri Lanka. Water is stored
    in wet season and use to generate electricity when needed in dry season. So
    these kinds of plants are often coupled with irrigation systems.

    2.Pumped Storage type


    Two water ponds are used in this kind of a plant and often act as a peaking
    Basic Types of plant.

    Hydro electric
    power plants
    The water in the tail water pond is pumped up to the head water pond during
    the off peak hours. And that water is used to generate electricity during the
    peak hours. Mostly used in countries like Japan which has limited hydro
    resources.

    3. Run off river type


    In these plants water flow of a river is directly used to rotate turbines, thus no
    control on the water flow. As no water storing is done, plant capacity depends
    on the water flow of the river. So in lean flow periods plant capacity drops
    down.
    Output power of a Hydro power plant

    • 𝑃 = 𝑄𝜌𝑔𝐻𝑛 ŋ𝑇ŋ𝐺
    • P- Output power
    • Q – Water flow rate

    ρ – Density of water Exercise :


    In a hydro power plant, 10 km2 catchment area
    g – Gravity of earth has an average annual rain fall of 1200mm. The
    power house is situated 100m below the river. If
    ηT = 0.9 and ηG = 0.95 calculate the average
    Hn – Net Head power output of the plant.

    ηT - Turbine efficiency
    ηG – Generator efficiency
    • Advantages of hydro power
    • No fuel cost.
    • Long life time.
    • Efficiency does not fall with time
    • Low operational and maintenance cost
    • Can be run up and synchronized in few minutes
    • Rapidly changing load demands can be met easily (dispatchable).
    • Very minimum impact on environment (no smoke or ash produced).
    • Can be used to serve purposes like irrigation and flood water control.

    • Disadvantages of hydro power


    • Requires a large area
    • Initial construction cost is high
    • As plants are located in hilly areas long transmission lines are required to transmit the power.
    • Power generation depends on the availability of water.
    • Can lead to social problems.

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