Summer Training Report @CTPS Rohit anand 10bme0153 4th semester VIT VELLORE
CONTENTS About the company Introduction General layout Components Coal cycle Condensation cycle Steam cycle Power cycle Ash treatment exhaust
About The Company• Damodar valley corporation, popularly known as DVC , came into being on July 7, 1948.this was first multi-purpose river valley project of independent India.• CTPS: chandrapura thermal power station is situated in Bokaro district of Jharkhand. This has a installed capacity of 1600 MW.
MISSION VISION• To generate adequate and • To be the best power utility reliable power most in the country and one of economically , efficiently the best in the world. and eco-friendly.• To spearhead accelerated power development by planning and implementing new power projects
INTRODUCTION• A thermal power plant converts the heat energy of coal into electrical energy. Coal is burned in a boiler which converts water into steam. The expansion of steam produces mechanical power drives alternator coupled to turbine
COMPONENTS main auxiliary Coal mill • FD fan Boiler • ID fan • Safety valve Turbine • Gauge valve Generator • Conveyer Condenser • Transmission lines super heater • Air pre-heater • De-aerator • Reheater • ESPs
Coal Handling Plant Wagon unloading system Crushing system Conveying systemUnload the coal from wagon for standardization andselection and then the coal is stored in STOCK YARD.Through conveyer system , the coal is sent in hopper.Hopper allows to pass coal pieces<200 mmFrom it coal falls on vibrator which is supported byroller
Crushing System• The gear box: contains worm wheel and worm gear which moves the wheel.• Motor: this provides energy for both worm gear and exhaust fan to move.• Exhaust fan: it sucks the coal dust , mixes it with pre-heated air (to maintain coal temperature) and send it through pipes in to boiler.• One coal mill unit sends 8 pipes into boiler.• Grinding roll fixed with mill body as shown in fig. brings coal to 20 mm size.
Coal + Air Supply Atmospheric airCombustion intake Air pre heater Fd fan Coal pulveriser Coal +air Burner floor Primary superheater
Air Supply DRAFT SYSTEMNaturalMechanicalIn mechanical systems fans are used to createdraft .At CTPS balanced draft system is used inwhich both FD and ID fans are used
• FD fan-forced draft fan , this creates a negative pressure in the boiler and via this pressure difference atmospheric air is drawn in the boiler• ID fan-this sucks the treated flue gas out and ejects it through chimney.the mechanical draft is created by fan• Now the pre heated air goes into coal pulverizer and then sent into burner floor of boiler where through corner firing system(CFS) fire balls are made , which burn the coal laden air stream coming from below. Thus producing required heat for super heating.
Air Pre-heater• This is a general term to describe any device designed to heat air before another process(for ex. Combustion in a boiler). The air comes through combustion intake pipeline, assisted by FD fan.
CONDENSATE CYCLE L.P. turbine River waterSurface condenser reservoir Cooling tower Alum house sumpCondensate pump Water treatment De-aerator Pure waterFeed water heater Condensate pumpFeed water pump economizer
Water Supply• Majority of water supply for steam generation is condensed water. The steam fromL.P. turbine is sent into surface condenser which• Changes the phase from steam to water.• Now, this water is sent to cooling towers which are evaporative coolers used for cooling water. these evaporate some part of condensed water to reject heat. At CTPS cooling towers are of hyperboloid structure
DE-aerator Feed water heater• Device for air removal and • This is used to pre heat corrosive dissolved gases water delivered to a steam because corrosion can generating boiler, improving render pipe networks efficiency. Feed water heaters allow the water to useless and rusty be brought upto saturatiuon temperature very gradually. This reduces costs and help prevent thermal shocks to boiler material. •
• Feed water pump: these pumps are high pressure units that overcome steam pressure to force water into the boiler drum.• ECONOMIZER :in boilers, these are heat exchangers that heat fluids usually water, upto its saturation point, they use the energy from the heat of flue gas and thus reduce heat in put and costs. It is placed in the passage of flue gas between outlet and chimney
Make Up Water• This is additional water added in feed water stream . but before that it Is treated in water treatment plant• At CTPS, there are 4 treatment units• 1)dirty water from reservoir. Sedimentation removes majority suspensions particles: trough perforations clean water drips into well 2)
• (2) alum is mixed in 2)with water coming from 1) micelle formation and this micelle is removed by mechanical arrangement; by forcing this trough a slope.• 3)clean water comes from 2) into (3) via perforations.• This treated water is sent into feed stream , where it mixes with condensed water, to form “final water”.
STEAM CYCLE• fe Feed water Gauge valve Primary super heater Secondary super economizer Ceiling tube heater Platen Boiler drum Boiler drum superheater Ring header Riser tube turbine Water valve Input header
Boiler Operations The feed water enters into economizer reaches upto saturation point. It is sent into boiler steam drumBOILER STEAM DRUMIt is reservoirof water/steam at the top end of the water tubes in the water-tubeboiler. They store the steam generated in the water tubes and act asaphase separator for the steam/water mixture. The difference indensities between hot and cold water helps in the accumulation ofthe“hotter”-water/and saturated –steam into steam drum.
• The• separated steam is drawn out from the top section of the drum.• Saturated steam is drawn off the top of the drum. The steam will reenter• the furnace in through a super heater, while the saturated water• at the bottom of steam drum flows down to the mud- drum /feed water• drum by down comer tubes accessories include a safety valve, water• level indicator and fuse plug. A steam drum is used in the company of• a mud-drum/feed water drum which is located at a lower level. So that• it acts as a sump for the sludge or sediments which have a tendency to go to bottom
Super Heater Tubes• At CTPS types of super heater are :• Primary -straight pipes• Secondary- U shaped• Platen - BENT shaped• This all tubing has same function to super heat water: to heat the steam extracted from drum, increasing it’s thermal energy and decreasing the likelihood that it will condense in pipe network or in turbine section
• The superheated steam is sent into high pressure turbine, at 540 degree celcius and 145 kg per square cm• And the thin ash particles are collected by ESP and thick ash fall into ash hopper below.• Turbine section:• A steam turbine is a device that extracts thermal energy from pressurized steam and used it to do mechanical work on a rotary output shaft. this is a form of heat engine that derives much of its improvement in thermodynamic efficiency through the use of multi stagesin expansion of steam
• There are three turbines:• High pressure – 5 stages• Intermediate pressure-12 stages• Low pressure -9 stages• Turbine types:(based on stages)• Impulse turbine: stage is set of moving blade behind the nozzle.• Reaction turbine: each row of blades is called a stage.• Blades:• in H.P., the blading used is impulse blading because it extracts more work from high pressure steam than reaction blading.
• Impulse blading:it is in shape of half moon. As steam impact the moving blade, it pushes the blade forward. this causes steam to lose velocity without losing pressure.• The steam coming out from the H.P. turbine gas into reheater through inlet and comes back trough outlet attaining thermal energy can be extracted in I.P. turbine and L.P. turbine.• I.P. and L.P. turbines: the steam at low pressure and temperature enter into this turbine pair respectively: so reaction blading is used
• REACTION BLADING: works on same concept as a jet engine. A jet engine is designed to take in air. Each moving reaction blade is designed to act as a nozzle.as the steam passes trough a reaction blade it causes the reaction blade to be propelled forward , resulting in rotation of L.P. turbine rotor• Intercept valve: this is in H.P. turbine and governs the the steam flow amount.• There is a surface condenser below L.P. turbine, explained in water supply previously.• all the three turbines are mechanically linked trough a rotor and the generator is coupled at the end of the system. At CTPS it is hydrogen cooled.
Ash Treatment Plant• ESP: electro static precipitator is a particulate device that removes particles from a flowing gas, using force of an induced electrical charge.automatic rapping systems and hopper evacuation system remove the collected particulate matter while in line allowing esps to stay in operation for years at a time.• From the hoppers these are collected in the collector tank.• this collector tank has wet line trough which water comes.both ash and water are mixed and sent into collector tank. the hydrovactor is vaccum creating machine, that creates vaccum by removing water and air ,thus ensuring necessary pressure difference.• A VACCUM BREAKER is like a plate, it maintains and releases vaccum as and when required.• The slury is sent into sump from where it is carried 4 km away from CTPS using suitable pumps and pipe network.
• There is air washer in conjunction with hydrovactor, that cleans air of its dust and susrensions, etc.• For thick ash, metal or stones which are falling in ash hopper below,where they are crushed using grinde. Using grinder. Using a power cylinder to open the gate and remove the pulverized debris with water into sump tank and discharged.
Exhaust CycleFlue gas ESP Ash treatment plant ID fan Flue
exhaust• The dust and ash are taken into ash treatment plant as mentioned earlier.• The rest flue gas moves through flue gas stack which is a type of chimney, a vertical pipe or channel for the exhaust gas outlet.