COMPONENTS OF SHP

BY:

RAJ KUMAR BAIRWA13512026M.TECH (AHES)IIT ROORKEE

TRASH RACK DIVERSION WEIRINTAKE CHANNELDESILTING HEADER BOX/TANKPOWER CHANNELFOREBAY TANKBYPASS CONDUIT/SPILLWAYSPENSTOCKINLET REGULATION VALVEHYDRO-TURBINESTAIL RACEGEAR BOXGENERATORSWITCHGEAR AND PROTECTION DEVICESTRANSFORMERSCONTROL AND MONITOR CPU/CONTROL PANELS

GENERAL COMPONENTS OF SHP

Fig.1 Schematic diagram showing SHP components

TRASH RACKA trash rack is a wooden or metal structure, that prevents water-borne debris (such as logs, boats, animals, masses of cut waterweed, etc.) from entering the intake of channel. This protects water penstock, and sluice gates from destruction.

Trash racks composed of vertical wooden strakes separated by narrow gaps are very common and perform extremely poorly. Metal gratings are sturdier and can have narrower strakes, and angling the trash rack properly can allow some self-cleaning from the action of the water.

Modern trash racks as used by hydroelectric plants can incorporate advanced feature as cleaning robots for their cleaning purposes.

Trash racks are designed for water velocity of around 2 feet/second (0.6 metres/second) to prevent excessive energy loss due to the head loss across the trash rack. Close spacing keeps out more small floating debris or fish

DIVERSION WEIRIt is an structure constructed in such a manner soas to direct water to the intake channel.

The advantages of diversion structures include the following:• Reduces the volume of flow across disturbed areas, thereby reducing the potential for erosion.• Breaks up the concentration of water on long slopes• Allows sediment basins and traps to function efficiently by maintaining a separationbetween clean water and sediment-laden water• Easily constructed with equipment found on most construction sites

The limitations of diversion structures include the following:• High flow velocities can cause erosion in the diversion structure• Diversion structures must be stabilized immediately after installation

INTAKE CHANNEL

It is the channel to which water is diverted by the diversion weir and fed into the desilting tank.The purpose of creating intake channel is:

Assured water supply Suitable quality of water Control over supply of water Safety against flood

DESILTING TANK

It is the tank from which silt is excluded from the water which has entered into the intake channel. There are two types of de-silting arrangements:

Preventive : The entry of sediment checkedbefore its entry into the head regulation.These are constructed in the streams.

Curative : The sediment is excluded from thechannel after its entry with the channel.These are constructed in the channel.

POWER CHANNEL

It is the channel through which water is being carried to the forebay tank for feeding to penstock. The various types of power channels are listed below:-

Open Channel• Rectangular• Trapezoidal• Triangular

Closed Conduit• Reinforced concrete pipe• PVC pipes• Steel pipes

FOREBAY TANKIt is a reservoir, basin or tank located just before the entrance to the penstock.

The purpose of the forebay is:

To provide immediate water demand on starting thegenerating unit It can serve as a final settling basin The forebay provides some storage in case of suddenfailure of the system To spill the extra water

Forebay components include:Basin, Spillway,Gate or Valve,Outlet,Trashrack, Air Vent,1 to 2% of penstock area.

PENSTOCK

A penstock is an enclosed pipe that delivers water to hydraulic turbines for the power generation purpose. Hydraulic Turbines act as a prime mover for the generator shaft due to which we get electrical power. Penstocks for hydroelectric installations are normally equipped with a gate system and a surge tank. Flow is regulated by turbine operation and is nil when turbines are not in service. The materials used for penstock construction are:

Steel Pipe P.V.C Reinforced Concrete Pipe Glass fibre reinforced plastic pipe Wood stave Glass fibre reinforced concrete

INLET REGULATION VALVE

The inlet valve in a Hydro Power station is used as a safety device. The inlet valve is used for regulating flow of water into the turbine.

It is also used for isolating the Hydro-turbine for maintenance purposes.

HYDRO TURBINESHydro turbines are needed for the conversion of hydro energy to mechanical energy.The various types of turbines are shown below:

IMPULSE TURBINE REACTION TURBINE

CONSTANT PRESSURE VARIABLE PRESSURE

CONSTANT CROSS-SECTION VARIABLE CROSS-SECTION

ONLY K.E IS UTILISED K.E AND PRESSURE ENERGY ARE UTILISED

NOZZLE FOR DISCHARGE CONTROL

HIGH HEAD,LOW DISCHARGE

GUIDE VANES FOR DISCHARGE CONTROL

LOW HEAD,HIGH DISCHARGE

IMPULSE Vs REACTION TURBINE

SELECTION OF TURBINES

GENERATORSINDUCTION GENERATOR:

An induction generator or asynchronous generator is a type of AC electrical generator that uses the principles of induction motors to produce power. Induction generators operate by mechanically turning their rotor faster than the synchronous speed, giving negative slip. A regular AC asynchronous motor usually can be used as a generator, without any internal modifications. Induction generators are useful in applications such as hydro- power plants, wind turbines etc.It has following features-LOW COST SIMPLER CONTROLSSINGLY EXCITED MACHINELOWER EFFICIENCYGRID DEPENDENTABSORBER OF REACTIVE POWER FROM THE SYSTEM

SPEED Vs TORQUE CHARACTERISTICS OF AN INDUCTION MACHINE

INDUCTION GENERATOR

SYNCHRONOUS GENERATORS:

A synchronous generator is an electrical machine producing alternating emf (Elect-tromotive force or voltage) of constant frequency. In our country the standard commercial frequency of AC supply is 50 Hz. In U.S.A. and a few other countries the frequency is 60 Hz. These are of two types-Cylindrical or Round rotor type and Salient Pole type but in Hydropower applications Salient Pole synchronous alternators are used.They have the following features:

HIGHER EFFICIENCYHIGHER COSTDOUBLY EXCITEDSTAND ALONEREACTIVE POWER CAN BE SUPPLIED OR ABSORBED

SYNCHRONOUS GENERATOR

SWITCHGEAR AND PROTECTION DEVICESIn an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is important because it is directly linked to the reliability of the electricity supply.

RELAY AND CB OPERATION

TRANSFORMERS

CONTROL PANELS

REFERENCES

nptel.iitm.ac.inKarassik, Igor J. et al, eds.; Pump Handbook (3rd Edition), McGraw-Hill 2001 ISBN 978-0-07-034032-9 page 10-5U.S. Army Corps of Engineers, Ice Engineering - Engineering and Design (EM 1110-2-1612) ISBN 978-1-61583-638-3 page 20-11www.wisegeek.comwww.greenworks.tvwww.canyonhydro.comwww.powermin.nic.inwww.hydropower.orgwww.msbte.comwww.ahec.org.inFluid Mechanics: Fundamentals and Applications, 2/eYunus A Çengel, University of Nevada, RenoJohn M Cimbala, Pennsylvania State University

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