Hydro Electric Power Plant

Presented by

Vijay Marcel D

M.Tech(RE) - I Year

EnergyEnergy

Hydro power

Nuclear fuels

Renewable energy

Ocean energy

Non Renewable Energy

Solar energy

Wind energyFossil fuels

Hydro electric power plant - Intro

• Hydro electric power plant harness power from water under pressure to generate power.

• Nearly 30% of the total power generated by world is met by hydro electric.

• In India the first major hydro electric scheme was implemented as Sivasamudram scheme in Mysore with 4.5MW capacity.

Selection of site• The site for Hydraulic power plant is selected

considering the following factors Water available. Storage of water. Head of water. Distance from load center. Accessibility of the site. The land of site should be cheap and rocky.

Scheme of Hydro Electric power plant

Components of hydro electric power plant

Reservoir Dam Fore bay Trash rack Waterway Draft tube Surge tank Spillway Power house and equipment.

Water reservoir

• Reservoir is used to store water behind the dam which is utilized by hydro electric plant to produce the water.

• Reservoir may be natural or artificial.

• Water held in the upstream reservoir is called storage and water behind the dam at the plant is called pondage.

Dams

• A Dam is a structure of masonry built at a suitable location across a river.

• The primary function of the dam is to provider the head of water.

• Dams are classified based on Function Shape Construction materials Design

Dams - Classification

DAM

Functions

Shape

Constructionmaterial

Design

Storage Dams

Diversion Dams

Arch Dam

Trapezoidal

Stone masonry

RCC

Structural

HydraulicOverflow

Non-overflow

Buttress

Earth

Rock fill

Arch

Gravity

Forebay

• Forebay acts as a regulating reservoir temporarily

• The forebay has the following parts Entrance bay Spillway Flushing sluice Screens Valve chamber Penstock inlet

Trash rack• It is provided for preventing the debris from

getting into the intakes from dam or from the forebay

• Trash rack is made up of steel bars

• The spacing of bars depends upon the following factors

Type of turbine Size of floating material Velocity of flow through trash rack.

Waterway• A waterway is used to carry water from the dam to

powerhouse.

• It includes canal, penstock and tunnel

• Tunnel is the passage by cutting mountain to reduce the length of waterway to reservoir and the power house.

• The tunnel is either circular or horse shoe shaped.

• A canal is an open structure constructed on earth or rock.

• The canal should be located on the economically short route.

Waterway• Penstock is a pipe which carry the water from

reservoir to turbine house.

• Penstock is made up of steel or reinforced concrete or wood.

• Penstock should be sloping towards the powerhouse.

• Sharp bends should be avoided and require special anchorages .

• The intake of the penstock should be at a low level to provide adequate water seal under all conditions

Draft tube• A Draft tube connects the

runner exit to tail race.• Draft tube provides a

negative head at the runner outlet by which it is possible to attach a turbine above the tail race.

• The outlet velocity of water is reduced and a gain in pressure head i.e. the net working head of turbine is increased.

Surge tanks

• Surge tank is a storage reservoir fitted to a penstock .

• It controls the pressure variations resulting from the rapid change in water flow from penstock and thereby prevents water hammer effects.

• It’s function is to control water when load on turbine decreases and supplies water when the load on the turbine increases.

• In the powerhouse conversion of energy of water to electrical energy takes place.

• It has the following equipments Turbines Generators Relief valve for penstock fittings Transformers Switch board equipment and instruments Low tension and high tension bus bar Governors Flow measurement equipments

Power house and equipment

Turbines• Hydraulic turbines are classified into two types they

are Impulse turbines Reaction turbines

• Hydraulic turbine has the following parts Runner Guiding mechanism Tail race

• The impulse turbines are used for high head power plants and reaction turbines are used for low and medium head power plants.

Advantages of hydro electric power plant

• Water is cheapest and reliable source of generation of electric power.

• It’s maintenance cost is low

• No fuel transportation problem

• Running cost of plant is low

• The life of plant is more and effect of age is comparatively small on the overall efficiency of the plant

• In addition to power generation it is used for irrigation and flood control purposes.

Disadvantages of hydro electric power plant

• The power produced by the plant depends upon quantity of water in the dam and rainfall.

• The cost of transmission is high• Erection of the plant takes long time• Initial cost of the plant is high.

Thank you

With regardsVijay Marcel D

M.Tech(RE) – I Year