Kolaghat Thermal Power Station & Bakreswar Thermal Power Station Report Submitted By: NAME ROLL NO SARTHAKCHATTERJEE GHOSH KRISHNENDU 11501619019 11501619042 Content 1.Introduction of WBPDCL 2.Introduction of KTPP 3.Introduction of BKTPP 4.Introduction of thermal power plant 5.Working diagram of thermal power plant 6.Working of thermal power plant 7.Three Major Inputs to Power Station 8.Fire and Safety 9.Types of Fire Extinguisher 10.Coal Handling Plant 11.Pulverizing Plant 12.Boiler 13.Steam Turbine 14.Generator 15.Condenser 16.Hot-Well 17.Cooling Towers & Ponds 18.Feed Water Heater 19.Economizer 20.Air Pre-heater 21.Switch Yard 22.Ash Handling Plant 23.Boiler Feed Water Treatment 24.Conclusion West Bengal Power Development Corporation Limited (WBPDCL) West Bengal Power Development Corporation Limited (WBPDCL) is a company owned by the Government of West Bengal with the goal to carry on interlay the business of electric power generation and supply in the state of West Bengal, India. The main thermal power plants under WBPDCL are in Kolaghat, Bakreswar, Sagardighi, Santaldih,and Bandel. The registered & Corporate Office of The West Bengal Power Development Corporation Limited has been functioning from its newly constructed own office building at Plot 3/C, Bidyut Unnayan Bhaban, LA Block, Sector III, Bidhannagar, Kolkata, West Bengal 700098 on and from 27th October 2008 (Monday) after shifting the office from New Secretariate Buildings. WBPDCL Formed in July 1985 with only one generating unit at Kolaghat having turnover of Rs.64 Crore paced up further to Rs.2728 Crores in 2007-08 with 20 units at Kolaghat, Bandel, Bakreswar,Santaldih and Sagardighi. Kolaghat Thermal Power Station involves a total installed capacity of 1260 MW. There are Bakreshwar Thermal Power Station plants having a capacity of 1050MW & Sagardighi Thermal Power Project having capacity of 600MW Bandel Thermal Power Station and Santaldih Thermal Power Station have been undertaken by WBPDCL as per re-organization measures of power sector in West Bengal. Kolaghat Thermal Power plant (KTPS): Kolaghat is a census town situated on the banks of the Rupnarayan River in the Midnapore East district of West Bengal. It is located in the Panskura II CD Block of the Tamluk subdivision. It is also the headquarters of the outback panskura (Panskura II block). Kolaghat Thermal Power Station is located here, which is one of the largest power sector in the state and managed by West Bengal Power Development Corporation Limited (WBPDCL), a department of the State Government of West Bengal. Kolaghat Thermal Power Station has six units of 210 MW each for a total capacity of 1260 MW The units were commissioned in two stages during the period of 1984 to 1995. Bakreswar Thermal Power Plant (BkTPP) Bakreswar Thermal Power Project, under The West Bengal Power Development Corporation Limited, is one of the most reliable and prestigious coal-fired power plants in West Bengal and in India as well. In two stages the total capacity of the plant is (05 X 210)MW. Funded by the Overseas Economic Co-Operation Fund(OECF) of Japan Govt. — subsequently constituted as Japan Bank for International Cooperation (JBIC) — this project is one of the first Fast Track projects to be successfully completed within scheduled time. Bakreshwar Dam and Reservoir Project:Constructed across river Bakreshwar, it is an integral part of Bakreshwar Thermal Power Project, which relies on the reservoir for fulfilling its raw water requirements during the months of April, May and June. Thermal Power Plant: A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a steam turbine connected to an electrical generator. The lowpressure exhaust from the turbine enters a steam condenser where it is cooled to produce hot condensate which is recycled to the heating process to generate more high pressure steam. This is known as a Rankine cycle. Working diagram of thermal power plant: THREE MAJOR INPUTS TO POWER STATION: • Water: Water has been taken from nearby river or dam. This water is lifted by raw water pumps and is sent to clarifier to remove turbidity of water. The clear water is sent to water treatment plant, cooling water system and service water system. The water is de-mineralized (DM) by water treatment plant. The DM water is stored in condensate storage tanks from where it is used in boiler. • Fuel Oil: The fuel oil used is of two types:(a) Low Sulphur high stock oil (LSHS) (b) High speed diesel oil (HSD)The high-speed diesel oil reaches the power station through the lorry tankers. The oil is stored in large tanks for the future use in the boiler. Heavy oil is stored in storage tanks in oil storage yard and is conveyed to the front through a set of pumps and strainers. The whole length of piping from the boiler front in stream traced to maintain the temperature and hence its fluidity so that it can freely flow in the pipelines. • Coal: The coal reaches the plant in the railway's wagons. The unloading of coal is done mechanically by tilting the wagons by tippler. The coal is sent to the coal storage yard through the conveyor belts. The crushed coal from store is sent to the mill bunkers through conveyor belts. The air which takes away the coal dust passes upward into the classifier where the direction of flow is changed abruptly This causes the coarse particle in the air coal stream to finer coal dust along with the primary air leaves the classifier onto the coal transport piping from where it goes to nozzle. Pulverized coal obtained from coal mill can not be burnt directly. Working of TPP: Coal is delivered to the plant via road, rail or ship, and deposited in a coal yard. Stacker reclaimers are used to gather coal and deposit it into hoppers, the hoppers then feed flatbed conveyors. Conveyors transport the coal from the coal yard to day silos within the main power station building. Each day silo contains enough coal for a set period of time when the power station is fully loaded e.g. one day silo may contain enough coal for one boiler at 12 hours of full load operation. The day silos ensure that any disruption to the supply chain from the coal yard to the day silos will not cause a disruption to the boiler and consequently power generation. Larger power stations may have several large watertube boilers, steam turbines and generators. It is standard practice for each power generation building to be referred to as a ‘Block’ e.g. Block A, Block B etc. Firetube boilers are used to provide the initial heating of the power plant steam systems. Day silos feed the boiler directly (old design and uncommon), or, by passing the coal through a coal pulverizer (standard design and common). Coal pulverizer increase the coal’s contact surface area with the air by grinding the coal into small pieces. The pulverizer also dries the coal in order that combustion can more easily occur (reduced moisture content). The heat to dry the coal is recovered from the boiler exhaust gas stream. Pulverized coal from the pulverizer is blown into the boiler with the primary air stream. The coal at this stage is finely ground and very dry, both of these characteristics aid combustion. Combustion occurs and heat is generated (this plant is a ‘thermal power plant'). The heat generated by the water tube boiler is used to change the state of water to steam. The steam is then discharged to a condenser steam turbine. The steam turbine is connected via a gearbox to an a.c. electrical generator. Alternating current then passes through switchgear prior to being distributed to an electrical transformer; the switchgear used will often be of the SF6 or vacuum design. The electrical transformer increases the output voltage and is referred to as a ‘generator step-up (GSU)’ transformer. The GSU increases the output voltage to match that of the electrical grid, this may be several hundred thousand volts e.g. 110kV, 220kV etc. Increasing the voltage reduces transmission losses and reduces the thickness of the transmission cables required (higher voltage means lower amps, lower amps means thinner conductors/cables can be used). FIRE AND SAFETY • USE OF PERSONA PROTECTIVE EQUIPMENT'S: • Appropriate PPE's need to be used based for the job. • The minimum PPE's to be used for entry or working in the plant premises are Helmets, Safety Shoes & High VizJacket. • For working at height more than 1.8 meters full body harness must be worn and authorized through Work Permit. • For welding, welding shield and leather hand gloves need to be used. • Use earplugs while working in high noise areas. • During mixer cleaning use of face shield is required and authorized through work permit. • Wear close fitting uniforms made of cotton materials. ➢THINGS TO REMEMBER WHILE USING PPE'S: • Always take good care of your PPE's and report any defects to supervisor. • While working near rotating machinery do not use of hand gloves and loose clothing. • The safety harness must be inspected for any damages (wear out of ropes, condition of joints) prior to use implant. • Never watch a welder at work with unprotected eyes. • Always wear ear plugs before you enter an area where there is loud noise. • Damaged personnel protection (PPE) equipment should not be used. DURING EMERGENCY PRIORITY IS TOWARDS SAVING HUMAN LIFE: • Do's • Evacuate immediately from the workplace. • Proceed towards to emergency assembly point or safe assembly point. • Report to emergency rescue team member at Emergency assembly area. • Inform missing person information to the rescue team if you are aware. • Assist to carry seriously injured personnel to hospital. • Wait for instructions from emergency coordinator. • Go back to the work area only after receiving clearance from emergency coordinator. • DON'TS • Do not panic and run. • Do not attend the emergency if you are not trained. TYPES OF FIRE EXTINGUISHERS: Coal handling plant: Some picture of ktps and bktps chp: Pulverizing Plant The main function of the Pulverizers in thermal power plant is to crush or grind the raw coal coming from coal handling plant through coal feeder into a pre-determined size in order to increase the surface area of the coal. If the coal is not pulverized , the coal might not burn completely, thus resulting in wastage of fuel. Also, pulverization of coal helps the boiler to respond to load variations more promptly. Type of coal Pulverizers 1.Slow speed mills like ball mill 2.Medium speed mills like bowl mill 3.High speed impact mill The slow speed and medium speed mills are selected for coals ranging from sub-bituminous to anthracite. The high-speed mills are used for lignite. Types of Coal Pulveriser 1.Bowl Mill 2.Ball Mill 3.Impact Mill Operation of Bowl mill: In Bowl Mill pulveriser raw coal coming from feeder gets around between three grinding rolls and bull ring segments installed on the revolving bowl. Bowl is made to rotate at medium speed for proper pulverization of coal. Spring exert necessary pressure on rolls for grinding. Hot air through the mill besides removing coal moisture pressure on rolls for grinding . Hot air through the mill besides removing coal moisture , picks up the lighter particle and takes them through the classifier and drop down the higher size particles for further grinding. Fine coal mixture leaves the mill and enters the piping system. Tramp iron pieces which are not required to grind leaves the bowl due to centrifugal force and removed through the mill reject handling system. Operation of ball mill: The Ball mill pulveriser is basically horizontal cylindrical tube rotating at low speed on its axis , whose length is slightly more to its diameter . The inside of the cylinder shell is fitted with heavy cast liners and is filled with cast or forged balls for grinding , to approximately 1/3 of the diameter. Raw coal to be ground is fed from the end and the product is discharged through the discharge end. As the shell rotates the balls are lifted up on the rising side of the shell and they cascade down from near the top of the shell. Larger pieces of coal are broken by impact and the fine grinding is done by attrition and crushing as the balls roll and slide within the charge. Hot air flow is induced through the mill in order to dry the coal and remove the fines from the pulverizing zone. If the rate of feed is increased , coarser product will be obtained and if the speed of rotation is increased the fineness for the given capacity increases. During grinding , balls themselves wear and are continuously replaced by new ones. Some picture of BKTPS Pulverizer: A boiler is a pressure vessel which is used to generate high-pressure steam at a saturated temperature. At this high pressure and temperature generally, bi-drum water tube boilers are used. Thermodyne Engineering Systems manufactures water tube boilers of various sizes and capacities that can run on various fuels. Water-tube boiler consists of a furnace enclosed by the water tubes membrane. The crushed fuel from the crushers is fed into the boiler furnace over the grate. The hot air from the Forced Draft (FD) fan is mixed with the crushed fuel causing combustion of fuel. Combustion of fuel generates a lot of radiation heat which is transferred to water in the membrane tubes. Flue gases generated during combustion travel at high velocity across the convection bank of tubes thereby heating water through convection heat transfer. Hot water is sent to a boiler drum at high pressure through the feed-water pump. The boiler tubes which are in contact with low temperature acts as downcomers to circulate the water while the tubes which are in contact with high temperature acts as risers to carryBoiler steam. This leads to an effective circulation of water thereby preventing the tubes from getting overheated. The steam leaving the boiler is at saturated temperature and pressure but there are a lot of heat losses during its transportation to the turbines. So to increase the quality of steam, steam Superheater is installed in a radiate section of a boiler to increase its temperature and dryness fraction without increasing its pressure as well as to accommodate for the transportation temperature losses. The exhaust gases leaving the boiler are generally at high temperature and this waste heat is extracted by installing an Economizer or Water Preheaters to preheat the feed water to the boiler and Air Preheaters to pre-heat the air coming from the Forced Draft Fan required for the combustion of fuel. Installing this equipment help to decrease the flue gas temperature thereby increasing the efficiency. The flue gases leaving the boiler also contain some ash particles, so to reduce the air pollution, flue gases are allowed to pass through the Dust Collectors and Bag Filters to remove the ash particulates from the flue gases and are sometimes passed through the Wet Scrubbers to decrease the sulfur content from the gases. The flue gases are drawn through this equipment using an Induced Draft (ID) Fan which is designed for a fixed capacity and head to prevent any backpressure. After the ID fan, flue gases are exhausted off into the atmosphere using a chimney Types of Boilers: • Based on tube content: • Fire Tube • Water Tube • Based on operating pressure: • Ultra-supercritical boiler: Pressure ≥ 27.0MPa or rated outlet temperature ≥ 590 ℃ boiler • Supercritical boiler: 22.1MPa ≤ Pressure ≤ 27.0MPa • Subcritical boiler: 16.7MPa ≤ Pressure ≤ 22.1MPa • Ultra-high pressure boiler: 13.7MPa ≤ Pressure ≤16.7MPa • High pressure boiler: 9.8MPa ≤ Pressure ≤ 13.7MPa • Sub-high pressure boiler: 5.4MPa ≤ Pressure ≤ 9.8MPa • Medium pressure boiler: 3.8MPa ≤ Pressure≤ 5.4MPa • Based on fuel used: • Solid Fuel Fired • Stoker Fired Boilers • Pulverized Fuel Boilers • Fluidized Bed Combustion (FBC) Boilers • Oil Fired • Gas Fired Boilers • Based on draught system: • Natural Draught • Mechanical Draught • Forced Draught System • Induced Draught System • Balanced Draught System Steam Turbine: A steam turbine is a machine that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Function of steam turbine:• The thermal power plant is equipped with boilers – some up to 90 meters long – heated by a burner ignited in a powder with coal, fuel oil vaporized into fine droplets or natural gas. • The heat produces used to raise the temperature of a circuit of water until it turns into steam, which is then run through a series of turbines under high pressure. • The construction of steam turbines is very simple. This is not a piston rod; flywheel or slide valves are attached to the turbine. It is a rotor and a set of rotating blades that attach to the shaft, and the shaft is placed in the middle of the rotor. • Turbines exploit a system of blades to spin and, through a shaft, drive the generator. The generator is composed of a moving part, rotor, and a stationary part, the stators. • The outers layer of the rotor is coated in electromagnets, and the inner wall of the stators is lined with coils of copper wires. • When the rotor turns, it creates a rotating magnetic field, which induces alternating currents in the stator. • The power generated is channeled through a transformer, which raises the voltage to an appropriate level for use in power transmission systems. Steam Turbine working diagram: Turbo generator The generator, typically about 30 feet (9 m) long and 12 feet (3.7 m) in diameter, contains a stationary stator and a spinning rotor, each containing miles of heavy copper conductor. There is generally no permanent magnet, thus preventing black starts. In operation it generates up to 21,000 amperes at 24,000 volts AC (504 MWe) as it spins at either 3,000 or 3,600 rpm, synchronized to the power grid. The rotor spins in a sealed chamber cooled with hydrogen gas, selected because it has the highest known heat transfer coefficient of any gas and for its low viscosity, which reduces windage losses. This system requires special handling during startup, with air in the chamber first displaced by carbon dioxide before filling with hydrogen. This ensures that a highly explosive hydrogen– oxygen environment is not created. The power grid frequency is 60 Hz across North America and 50 Hz in Europe, Oceania, Asia (Korea and parts of Japan are notable exceptions), and parts of Africa. The desired frequency affects the design of large turbines, since they are highly optimized for one particular speed. The electricity flows to a distribution yard where transformers increase the voltage for transmission to its destination. The steam turbine-driven generators have auxiliary systems enabling them to work satisfactorily and safely. The steam turbine generator, being rotating equipment, generally has a heavy, largediameter shaft. The shaft therefore requires not only supports but also has to be kept in position while running. To minimize the frictional resistance to the rotation, the shaft has a number of bearings. The bearing shells, in which the shaft rotates, are lined with a low-friction material like Babbitt metal. Oil lubrication is provided to further reduce the friction between shaft and bearing surface and to limit the heat generated. Turbo Generator Types: Turbo generators are available in three types which include the following. ❖Air-cooled Turbo Generator ❖Hydrogen-cooled Turbo Generator ❖Water-cooled Turbo Generator ❑Air-cooled Turbo Generator Air-cooled turbogenerators are used to provide a modern and high-quality solution for the operation of loads in different power plants with effortless and inexpensive maintenance. Air-cooled turbo generators are reliable, robust, and easily maintained. These turbo generators are very flexible to use with other turbines like steam and gas type within multi or single shaft configurations. These turbogenerators are very helpful in geothermal applications because due to some severe environmental conditions like humidity and hydrogen sulfide in the atmosphere. These turbogenerators include cooled stator windings indirectly & cooled rotor windings directly. These generators are ventilated independently within a closed circuit through air-to-water coolers. The pressurization kit allows further power extensions. The reduced impact of auxiliary systems simplifies unit management and cuts the cost of spare parts. ❑Hydrogen-cooled Turbo Generator A hydrogen-cooled turbo generator uses gaseous hydrogen like a coolant. These types of turbo generators are mainly designed to provide a low-drag environment, cooling for single-shaft & combined-cycle applications in combination through steam turbines. So, this generator is most frequently used in different fields due to its high thermal & hydrogen gas properties. The features of a Hydrogen cooled turbogenerator are long life and high performance. The hydrogen in this generator increases its performance, efficiency and provides low frictional losses. There are different models of turbo generators available in the market like optimum reliability, good quality, and high efficiency. These generators are strong, consistent, and easily maintainable. This turbo-generator is sealed hermetically to avoid hydrogen gas leakage. The deficiency of oxygen (O2) within the environment significantly decreases the damage of the insulation of windings. The hydrogen (H2) gas is dispersed in the rotor field & gets cooled through a heat exchanger of gas to water. ❑Water-cooled Turbo Generator Water-cooled Turbogenerators are the best solution for the maximum output ranges. These are used in large power plants due to their solid design. Water-cooled turbogenerators obey PED & ATEX regulations to provide safe operation when H2 gas is available. All generators including water-cooled stator windings are fixed through laminated press plates for decreasing different losses and also for eliminating hotspots. Some picture of BKTPS AND KTPS Condenser: The condenser condenses the steam from the exhaust of the turbine into liquid to allow it to be pumped . If the condenser can be made cooled , the pressure of the exhaust steam is reduced and efficiency of the cycle increases. The function of the condenser are:1. To provide lowest economic heat rejection temperature for steam. 2.To convert the exhaust steam to water for reserve thus saving on feed water requirement. 3.To introduce make up water. Hot well It acts as a reservoir, and the drain in its bottom allows the condensate to flow from the condenser, then follow a path to the boiler, where it will be recycled and put to renewed use within the power plant. The water droplets fall like rain from the tube surfaces into the hot well situated at the bottom of the condenser. This hot well is essentially a large basin that serves as a collection point for the condensed water, otherwise known as condensate. It’s important to collect the condensate in the hot well and not just empty it back into the lake, because condensate is water that has already undergone the process of purification. It’s been made to pass through a water treatment plant prior to being put to use in the boiler, and that purified water took both time and energy to create. The purified condensate also contains a lot of sensible heat energy which was added by the boiler to raise the water temperature to boiling point Cooling Towers Cooling of condensed water from the condenser is carried out by following methods : • (i) Natural draught cooling towers. • (ii) Forced draught cooling towers. Natural draught cooling towers : • The condensate water from the condenser to be cooled is pumped at about 10 m above the ground into the troughs and the nozzles at the bottom of the troughs, sprayed it in thin sheets. These thin sheets of water break under force of gravity and when it strikes with the hurdles. The circulation of air for cooling the water is induced by enclosing the heated air in the chimney. As the heated air is lighter than the surrounding air of atmosphere it produces a difference of pressure causing natural draught of air for cooling of water. There are two types of construction of natural draught cooling towers : (a) Rectangular timber tower . (b) Reinforced concrete hyperbolic type. Cooling Towers Forced draught cooling towers : In case of large capacity thermal plants, it requires very high rate of cooling water per hour. In such cases, the natural draught type cooling towers are not useful. Hence, It requires large amount of cooling air provided by fans. The principle of forced draught cooling towers is shown in Figure C. They are basically natural draught cooling towers, except that motor driven fan is also provided at the base. When a Impeller is used at the top of the cooling tower it is called as Induced draught cooling tower. The forced draught cooling towers have horizontal shaft fan on the side of the cooling tower. This fan discharges air towards the back of tower and then it is turned upwards by means of baffles. In the process it cools the falling water. Fan speeds of the order of 100 rpm are used for this purpose. The Induced draught type cooling towers are used for large capacity Installations They use large fans with vertical shaft located at the top of the towers, and they pull air upwards from the sides of the cooling tower. The warm air is exhausted at a considerable velocity upwards after cooling the water on its way. It requires low speed fans. For increasing efficiency of towers, water flow should be uniformly distributed and divided into fine droplets, a large wetted area should be used. In order to increase air contact time a series of baffles, shelves etc. should be used to obstruct the flow of air. Some picture of Bktps and ktps Feed waterused to A feed water heater is a power plant component heater pre-heat water delivered to a steam generating boiler. Preheating the feed water reduces the irreversibility's involved in steam generation and therefore improves the thermodynamic efficiency of the system. This reduces plant operating costs and also helps to avoid thermal shock to the boiler metal when the feed water is introduced back into the steam cycle. In a steam power plant (usually modeled as a modified Rankine cycle), feed water heaters allow the feed water to be brought up to the saturation temperature very gradually. This minimizes the inevitable irreversibility's associated with heat transfer to the working fluid (water). Economizer: The Economizer in Boiler works on the principle of Heat Transfer. Heat transfer usually takes place from high temperature to low temperature. In the case of Boilers, flue gases or exhaust from the boiler outlet are at high temperature and water that needs to be preheated is at low temperature. So, this temperature difference between water and flue gases helps to increase the feed water temperature. Depending on the type of operations, design of Economisers can be smoke tube type or water tube type. In smoke tube type flue gases are inside the tubes and water is on the shell side while in the water tube type, water is in the tube and flue gases are on the shell side. Air Pre-heater: Air heater is an important Boiler auxiliary which primarily preheats the combustion air for rapid and efficient combustion in the furnace. The air heater recovers the waste heat from the outgoing flue gas of a Boiler and transfers the same to the combustion air. In a utility Boiler the flue gas leaves the economizer at a temperature of around 3800C. As every 550C drop in flue gas temperature improves the Boiler efficiency by about 2.5%, having an air heater in the downstream of economizer the Boiler efficiency is considerably improved. Further the air heater may also be used for heating the air to dry the coal in the pulverizing plant. There are two main types of air heaters in use; the static recuperative type and the rotary regenerative type. In the recuperative type the flue gas in on one side of the surface and the air is on the other side The heat from the flue gas istransferred to the air through the heat transfer surface normally in form of tubes/ plates. In the regenerative type the gas flows through a closely packed matrix or heat transfer element giving up heat to the air heater elements and so raising the temperature of the matrix. Air is then pas through and recovers the heat. Either the matrix or the hoaxes may be rotated to achieve this heat transfer as a continuous process. Images of Air Pre-heater: Switch Yard • Switchyard is a switching station which is the main link between the generating plant and the transmission system. It can be considered as the heart of the power plant, the generated power will only be worthy if it can be transmitted and received by the consumers. Switchyard is a junction which carries the generated power to the destination, it plays a major part in the security of the system, it can control the reactive power devices which plays a major role in power quality. It is mostly an assemblage of switches, power circuits, breakers, and the auxiliary equipment which is used to collect power from the generators at the power plant and then it will be distributed to the transmission lines at a load point. Switchyard makes available the generated power at the plant to the people. The power generated at a power station is transmitted via a switchyard. When there is sudden damage outside the plant switchyard can protect the plant. A Switchyard consists of many equipment such as Current transformer (CT), Voltage transformer (VT), Lightning arrester (LA), Power transformers, Isolators support structure, Circuit breaker (CB), Wave traps, Earthling switch, Bus bar etc. • Thus ensuring their condition and proper operation is very important, Power Electronical has a vast experience in switchyard equipment testing analysis erecting and commissioning of them. We are also channel partners of ABB India. We conduct various tests on these equipment which can be mainly categorized into two i.e. Online Mode and Offline mode. Some picture of Bakreswar plant Some picture of kolaghat plant Ash Handling Plant: Ash handling plant in thermal power plant are used to cooled down the ash to manageable temperature , transferred to a disposal are or storage which is further utilized in other industries. Types of ash generated in TPP– Bottom Ash – Ash generated below furnace of the thermal power plant is called the bottom ash. The value of bottom ash generated is around 20% of total ash. Bottom ash is mostly coarse in nature hence to be further crushed before being transported to ash handling plant system. Fly ash- Around 80% of the ash generated in thermal power plant is fly ash. It is in form of very tiny particles which is collected via economizer hopper , air pre heater hopper and electrostatic precipitator (ESP). Equipment's used in ash handling plantElectrostatic precipitator , Feed/ Discharge/ Sluice Gate, Clinker Grinder, Jet Pump, Dewatering Bin, Transfer Bin, Storage Bin, Dry Bottom Ash Conveyor, Clinker Cooling Conveyor, Dry Bottom Ash System, Slurry Pump. Some picture of Bakreswar plant Boiler Feed Water Treatment: • What is a boiler feed water treatment system? A boiler feed water treatment system is a system made up of several individual technologies that address your specific boiler feed water treatment needs. Treating boiler feed water is essential for both highand low-pressure boilers. Ensuring the correct treatment is implemented before problems such as fouling, scaling, and corrosion occur, will go a long way in avoiding costly replacements/upgrades down the line. An efficient and well-designed boiler feed water treatment system should be able to:• Efficiently treat boiler feed water and remove harmful impurities prior to entering the boiler • Promote internal boiler chemistry control • Maximize use of steam condensate • Control return-line corrosion • Avoid plant downtime and boiler failure • Prolong equipment service life Boiler Feed Water Treatment: • What does a boiler feed water treatment system typically remove? A boiler feed water treatment system might be made up of the technologies necessary to remove problematic dissolved solids, suspended solids, and organic material, including any number of the following: • Iron: either soluble or insoluble, iron can deposit on boiler parts and tubes, damage downstream equipment, and affect the quality of certain manufacturing processes • Copper: can cause deposits to settle in high-pressure turbines, decreasing their efficiency and requiring costly cleaning or equipment change-outs • Silica: if not removed to low levels, especially in high-pressure boilers, silica can cause extremely hard scaling • Calcium: can cause scaling in several forms depending on the chemistry of the boiler feed water (e.g. calcium silicate, calcium phosphate, etc.) • Magnesium: if combined with phosphate, magnesium can stick to the interior of the boiler and coat tubes, attracting more solids and contributing to scale • Aluminum: deposits as scale on the boiler interior and can react with silica to increase the likelihood of scaling • Hardness: also causes deposits and scale on boiler parts and piping • Dissolved gasses: chemical reactions due to the presence of dissolved gases such as oxygen and carbon dioxide can cause severe corrosion on boiler pipes and parts Some picture of Bakreswar plant Some picture of kolaghat plant RESOURCES ❖Class notes ❖Wikipedia.org ❖Google.com Conclusion: My vocational training in KOLAGHAT THERMALPOWER STATION and BAKRESHWAR THERMAL POWER PLANT has enriched my knowledge about generation of electric power & also about different process associated with it.