HYDRO-ELECTRIC POWER PLANT Prepared by SREEJITH K. & NICE MENACHERY APME APME JEC JEC

HYDRO-ELECTRIC POWER PLANT 2 Basics of Mechanical Engineering (SK/ APME)

Hydro-Electric Power Plant (UQ APRIL 2012) Hydro-electric power plant utilizes potential energy of water as the source of energy for power generation. Generation of hydro-electric power is the cheapest as compared to the other sources such as oil, coal etc. In addition to power generation hydro-electric power plants also helps for irrigation and flood control. The reservoirs (often made by constructing a dam across a river ) maintain the availability of water during all seasons of the year 3

Water flow during peak rainy season is stored in the reservoir  Carried to the prime-mover (Hydraulic Turbine or Water Turbine or simply Turbine) through a pipe known as Penstock (made of steel or concrete)  Potential energy (PE) of water is partially converted into Kinetic energy (KE) as it pass through the penstock  KE and PE of water is converted into Mechanical Energy by Turbine  Used to generate electrical power by electric generator  Transmitted through transformer  Transmitting towers  Consumers. 4

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Penstock

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Functions of Components Reservoir :- To store the water during rainy season and supply it during summer when the run off is low. Dam :-To create the artificial reservoir and artificial head, It is usually a concrete structure. Spillway:- Safety valve for the dam. Water overflows through spillway to prevent the increase of water level over a certain limit. Pressure Tunnel :-To carry water from the reservoir to surge tank. 13

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Surge Tank :- It is an additional storage space between reservoir and power house. It reduce the increase in pressure due to backflow of water when the load on turbine reduces, thereby preventing the damage of penstock. Penstock:-Is a pipe to carry water from surge tank to the turbine, made of steel or reinforced concrete to bear high pressure. Trash Rack:- To prevent the flow of debris, sand to the turbine. 16

Hydraulic Turbine:- To convert potential energy of water into mechanical energy. Draft tube :- Used in Reaction Turbines to convert part of KE into useful head. It also allows the turbine to place over tail race level. Generator:-To generate electric power using mechanical power of turbine. Basics of Mechanical Engineering (SK/ APME)17

Transformer:- To raise the voltage generated before transmitting the power to the consumers. Power House:- Is a building to protect and accommodates Turbine, Generator, Transformer and Control room. Basics of Mechanical Engineering (SK/ APME)18

Advantages of Hydro-electric Power plant Operation & Maintenance cost is minimum when compared to other power plants. No air Pollution. Can also used for irrigation and flood control. Quick starting and faster respond to rapid change in load. Useful life is high when compared to other power plants. Basics of Mechanical Engineering (SK/ APME)19

Disadvantages of Hydro-electric Power plant Initial cost is high when compared to other power plants. Long time is required for planning and commissioning. Power generation is not steady especially in the time of draught. Basics of Mechanical Engineering (SK/ APME)20