Career Point Cares

CAREER POINT UNIVERSITY

POWER ENGINEERING ASSIGNMENT

Submitted to: Submitted by:MR. KAMAL ARORA ALFIYA SHEIKHDEAN B.TECH EECPU 3rd yr/5th sem UID=K11617

AUXILIARY POWER SUPPLY SCHEME FOR THERMAL POWER PLANT

CONTENTS

• THERMAL POWER PLANT• AUXILIARY POWER• AUXILIARY SYSTEMS BOILER AUXILIARIES BOILER MAKE-UP WATER TREATMENT PLANT AND STORAGE FUEL PREPARATION SYSTEM BARRING GEAR OIL SYSTEM GENERATOR COOLING GENERATOR HIGH-VOLTAGE SYSTEM MONITORING AND ALARM SYSTEM BATTERY-SUPPLIED EMERGENCY LIGHTING AND COMMUNICATION CIRCULATING WATER SYSTEM

THERMAL POWER PLANT

Thermal power station is a power plant in which heat energy is converted to electric power.

• In most of the places the turbine is steam-driven• Water is heated, turns into steam and spins

a steam turbine which drives an electrical generator

AUXILIARY POWER

• Auxiliary power is electric power that is provided by an alternate source

• It serves as backup for the primary power source• auxiliary system power supply in large power plants

is a key factor for normal operation, transient states, start-ups and shutdowns during fault conditions

• Depending upon the type of fuel and environmental control system required, a thermal power plant may consume as much as 10% of its total generation for auxiliary power

Auxiliary systems

• steam generating plant consists of a boiler for the production of steam and other auxiliary equipment for the utilization of flue gases

BOILER• The heat of combustion of coal in the boiler is utilized

to convert water into steam • The flue gases from the boiler make their journey

through superheater , economiser ,air pre-heater and are finally exhausted to atmosphere through the chimney.

BOILER AUXILIARY

• FORCED DRAUGHT FAN• INDUCED DRAUGHT FAN• PRIMARY AIR FAN• SUPER HEATER • ECONOMISER• AIR PRE-HEATER

ECONOMISER extracts a part of heat from the flue gases and uses for heating the feed water.

SUPER HEATER is used to remove the moisture content from the steam (above 540 degree C)

AIR PRE-HEATER is used to preheat the air before entering into furnace

Boiler make-up water treatment plant and storage

• to maintain desired water level in boiler steam drum continuous make-up water is added to boiler

• Water is hard due to Impurities(ca & mg) in the raw water input

• Hardness will form deposits on the tube water surfaces which will lead to failure of the tubes.

• Thus, the salts have to be removed from the water by a water demineralising treatment plant (DM)

• The storage tank for DM water is made from PVC

Fuel preparation system

Three types of fuels can be burnt in steam generating plant : solid,liquid,gas

The boiler furnace auxiliary equipment includes• coal feed nozzles • igniter guns• soot blowers• water lancing • observation ports (in the furnace walls) for

observation of the furnace interior

• In coal-fired power stations, the raw coal is first crushed into small pieces and then conveyed to the coal feed hoppers at the boilers.

• The coal is next pulverized into a very fine powder.

• The pulverizers are types of grinders.

Barring gear• Barring gear is the mechanism provided to rotate the

turbine generator shaft at a very low speed after unit stoppages.

• Once the unit is tripped there is a tendency for the turbine shaft to bend

• small shaft deflection detectable by eccentricity meters• Disadvantage cause vibration • The shaft is therefore automatically turned at low

speed by the barring gear until it has cooled sufficiently to permit a complete stop

Oil system

• An auxiliary oil system pump is used to supply oil at the start-up of the steam turbine generator.

• It supplies the hydraulic oil system required for- steam turbine's main inlet steam stop valve governing control valvesbearing and seal oil systems and other mechanisms.

Generator cooling

• Hydrogen gas cooling, used because it has highest known heat transfer coefficient

• This system requires special handling during start-up air in the generator first displaced by carbon dioxide before filling with hydrogen. This ensures that the highly flammable hydrogen does not mix with oxygen in the air.

• The hydrogen pressure inside the casing is maintained higher

• Seal oil is used to prevent the hydrogen gas leakage

Generator high-voltage system

• generator voltage ranges from 11 kV to 30 kV • generator high-voltage leads are large

aluminium channels because of high current• enclosed in well-grounded aluminium bus

ducts and are supported on suitable insulators• The necessary protection and metering

devices are included for the high-voltage leads

Monitoring and alarm system

• Most of the power plant operational controls are automatic. However, at times, manual intervention may be required

• plant is provided with monitors and alarm systems that alert the plant operators when certain operating parameters are seriously deviating from their normal range.

Battery-supplied emergency lighting and communication

• A central battery system consisting of lead acid cell units units is provided to supply emergency electric power

• It supply emergency electric power to- power plant's control systems communication systemsgenerator hydrogen seal system turbine lube oil pumpsemergency lightingThis is essential for a safe, damage-free shutdown of the

units in an emergency situation.

Circulating water system

• To dissipate the thermal load of main turbine exhaust steam a continuous supply of cooling water is provided to the main condenser thereby leading to condensation

THANK YOU