PRESENTATION ON LAYOUT OF HYDROPOWER PLANT

PRESENTATION ON LAYOUT OF HYDROPOWER PLANT

MAJOR COMPONENT OF HYDROPOWER PLANT

DAM is hydraulic structure used to store or divert water to water conductor system . Barrage is also used to regulate water to power generationThe location of diversion structure usually governed by by topographical and geological consideration.

Examples:1. Koldam is Earthen dam. 2.Pandoh dam is concrete gravity dam.

DAM OR BARRAGE

Alignment on contour plan of HPP

Major components of water conductor system are:-water intake structure.Head Race Tunnel (HRT)Surge Shaft.Penstock.Penstock protection valve.Draft tube.Tail Race Tunnel.(TRT)

2.Water conductor system

WATER INTAKE STRUCTURE

Water is conveyed from river and stream to the water conductor system of the power plant through intake structure. An intake is provided at the mouth of a water conveyance system for a hydropower project.It is designed such that the following points are complied, as far as possible:-1. There should be minimum head loss as water enters from the reservoir behind a dam or the pool behind a barrage into the water conducting system. 2. There should be minimum entry of sediment into the water conducting system.3. Floating material should not enter the water conducting system.

RUNOFF RIVER INTAKE.CANAL INTAKE.DAM INTAKE.TOWER INTAKE.

1.RUNOFF RIVER INTAKE:-These intakes are provided in runoff river plant and form an integral part of power house.Here bell mouthed entrance is guarded by RCC or steel grid, these entrance is protected with the help of trash racks , in case of silty river DISILTING arrangements are provided. TYPES OF INTAKES

2.CANAL INTAKE: These canal intakes are low head intakes, these canals are further linked to diversion canal before connecting them to turbine.

3.DAM INTAKE: In case of valley dam plant the intake structure is usually embedded in the body of dam.

4. TOWER INTAKE:- These are normally provided on hill side not too far from the dam , these are adopted when it is not convenient to provide simple intake directly on upstream face of dam.

Reservoir intakeCanal intake

Tower Intake

Runoff river intake

The initial portion of the tunnel from the intake up to the Surge-Tank is termed as the Head Race Tunnel (HRT) and beyond that it houses the penstock or steel-conduits, which sustains a larger pressure than the HRT. The HRT may either be unlined (in case of quite good quality rocks) or may be lined with concrete. The surge tank is provided to absorb any surge of water that could be generated during a sudden closure of valve at the turbine end. and the difference of levels depends upon the friction loss in the HRT. Usually a sedimentation chamber is introduced at the head of head race tunnel to exclude sediments.

HEAD RACE TUNNEL(HRT)

Thus, when the HRT runs full, it is subjected to a much low pressure compared to the penstock.If a HRT is concrete lined, the reinforcement in the concrete may be nominal as the lining is only to assist in preventing fallout of rock blocks into the tunnel. However, if the rock mass above the tunnel is very weak, then the tunnel lining may have to support a larger rock weight, in which case the reinforcement has to be designed accordingly. A tunnel should also be designed for the empty condition, assuming the outside rock to be saturated with water

18 A surge tank (or surge chamber) is a device introduced within a hydropower water conveyance system having a rather long pressure conduit to absorb the excess pressure rise in case of a sudden valve closure. It also acts as a small storage from which water may be supplied in case of a sudden valve opening of the turbine. In case of a sudden opening of turbine valve, there are chances of penstock collapse due to a negative pressure generation. If there is no surge tank. EFFECT OF WATER HAMMER. SURGESHAFT OR SURGE TANK

A penstock is a steel or reinforced concrete conduit to resist high pressure in the water conveyance system. and may take off directly from behind a dam, from a forebay, or from the surge tank end of a head race tunnel . Similar to a tunnel, a penstock needs to be designed for different types of loads. Further, they have to be equipped with different accessories, which may be different for over ground or ground embedded types.PRESSURE SHAFT is an inclined conduit i.e. when penstock or HRT is inclined then it is called PRESSURE SHAFT PENSTOCK

PENSTOCK

These valve are provided after the surge shaft to facilitate the maintenance of penstocks.

These valve are usually butterfly valve types .

These are operated hydraulically with provision of pressure accumulator in case of power failure.

PENSTOCK PROTECTION VALVE

DRAFT TUBE is located at lower ring of turbine and tailrace.It contains water after discharge from the turbine tunnel to tail race tunnel.

DRAFT TUBE

TAIL RACE carries outflow from turbine to the river or stream. It may be an open channel or a closed conduit running free or under pressure. In tailrace of considerable length it is necessary to provide surge tank.The tail race channel is aligned to meet the river tangentially or as smoothly as possible.There should not be bed load entry into tail race. TAIL RACE TUNNEL(TRT)

POWER HOUSE:It is a multi storey structure where power is generated

SUPERSTRUCTURE:- the part of structure generally lying above generator floor is known as superstructure.

INTERMEDIADE STRUCTURE:- it extends from generator floor to the top of draft tube.it houses TURBINE including there casing gate valve.

SUB STRUCTURE:- IT consist of water passage galleries work area for equipment services. Also it consist of excess galleries to the draft tube.

Classification on the basis of location

DEHAR POWER HOUSE

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