NATIONAL THERMAL POWER COOPERATION BADARPUR THERMAL POWER STATION NEW DELHI Submitted by: Ravi Jain B.Tech 2nd Year 200...
NATIONAL THERMAL POWER COOPERATION BADARPUR THERMAL POWER STATION NEW DELHI
Submitted by: Ravi Jain B.Tech 2nd Year 20085063 Electronics and communication Engineering MNNIT ALLAHABAD Duration- 24/05/2010 to 19/06/2010
ACKNOWLEDGEMENT I am highly grateful to Proff. SATISH CHANDRA, Training and Placement Department, MNNIT ALLAHABAD, for providing this opportunity to carry out 4 weeks industrial training at NATIONAL THERMAL POWER CORPORATION , BADARPUR, NEW DELHI. I would like to express a deep sense of gratitude and thanks to Mr AJEET KUMAR OJHA-DGM(HR) without the wise counsel and able guidance, it would have been impossible to complete the report in this manner. The help rendered by Mrs RACHANA SINGH BHAL, Sr. Manager, National Thermal Power Corporation for experimentation is greatly acknowledged. I would also like to express gratitude to the HOD and other faculty members of department of Electronics and communication engineering, MNNIT for their intellectual support throughout the course of this work. Finally, I would like to thanks Er. SONIA SINGH and all other technical staff of B.T.P.S. for giving helping me throughout the training period.
Ravi Jain ECE-MNNIT ALLAHABD [email protected]
INTRODUCTION TO THE COMPANY
OPERATION OF POWER PLANT
VARIOUS CYCLE AT POWER STATION
CONTROL & INSTRUMENTATION
About The Company Vision Strategies Environmental Policy Evolution
About The Company NTPC, the largest power Company in India, was setup in 1975 to accelerate power development in the country. It is among the world’s largest and most efficient power generation companies. In Forbes list of World’s 2000 Largest Companies for the year 2007, NTPC occupies 411th place.
A View Of Badarpur Thermal Power Station, New-Delhi NTPC has installed capacity of 29,394 MW. It has 15 coal based power stations (23,395 MW), 7 gas based power stations (3,955 MW) and 4 power stations in Joint Ventures (1,794 MW). The company has power generating facilities in all major regions of the country. It plans to be a 75,000 MW company by 2017. Types Of Power Station Coal Based Power Station Gas Based Power Station Joint Venture
Number 15 7 4
Capacity(MW) 23,395 3,955 1,794
Total Capacity – 29,394 MW NTPC has gone beyond the thermal power generation. It has diversified into hydro power, coal mining, power equipment manufacturing, oil & gas exploration, power trading & distribution. NTPC is now in the entire power value chain and is poised to become an Integrated Power Major. NTPC's share on 31 Mar 2008 in the total installed capacity of the country was 19.1% and it contributed 28.50% of the total power generation of the country during 2007-08. NTPC has set new benchmarks for the power industry both in the area of power plant construction and operations. With its experience and expertise in the power sector, NTPC is extending consultancy services to various organizations in the power business. It provides consultancy in the area of power plant constructions and power generation to companies in India and abroad. In November 2004, NTPC came out with its Initial Public Offering (IPO) consisting of 5.25% as fresh issue and 5.25% as offer for sale by Government of India. NTPC thus became a listed company with Government holding 89.5% of the equity share capital and rest held by Institutional Investors and Public. The issue was a resounding success. NTPC is among the largest five companies in India in terms of market capitalization.
Growth Of NTPC Generation & PLF %
Recognizing its excellent performance and vast potential, Government of the India has identified NTPC as one of the jewels of Public Sector 'Navratnas'- a potential global giant. Inspired by its glorious past and vibrant present, NTPC is well on its way to realize its vision of being "A world class integrated power major, powering India's growth, with increasing global presence".
VISION Corporate vision: - “A world class integrated power major, powering India's growth with increasing global presence.” Mission :-Develop and provide reliable power related products and services at competitive prices, integrating multiple energy resources with innovative & Eco-friendly technologies and contribution to the society.
Core Values - BCOMIT • Business ethics • Customer Focus • Organizational & Professional Pride • Mutual Respect & Trust • Innovation & Speed • Total Quality for Excellence
A View Of Well Flourished Plant
Sustainable Development Nuturing
Fuel Security Exploit New Business Opportunities
Introduction of steam generators (boilers) of the size of 800 MW. Integrated Gasification Combined Cycle (IGCC) Technology. Launch of Energy Technology Center -A new initiative for development of technologies with focus on fundamental R&D. The company sets aside up to 0.5% of the profits for R&D. Roadmap developed for adopting ‘Clean Development. Mechanism’ to help get / earn ‘Certified Emission Reduction.
Corporate Social Responsibility
As a responsible corporate citizen NTPC has taken up number of CSR initiatives. NTPC Foundation formed to address Social issues at national level. NTPC has framed Corporate Social Responsibility Guidelines committing up to 0.5% of net profit annually for Community Welfare Measures on perennial basis. The welfare of project affected persons and the local population around NTPC projects are taken care of through well drawn Rehabilitation and Resettlement policies. The company has also taken up distributed generation for remote rural areas.
ENVIROMANTAL POLICY NTPC is committed to the environment, generating power at minimal environmental cost and preserving the ecology in the vicinity of the plants. NTPC has undertaken massive a forestation in the vicinity of its plants. Plantations have increased forest area and reduced barren land. The massive a forestation by NTPC in and around its Ramagundam Power station (2600 MW) have contributed reducing the temperature in the areas by about 3°c. NTPC has also taken proactive steps for ash utilization. In 1991, it set up Ash Utilization Division A "Centre for Power Efficiency and Environment Protection- CENPEE" has been established in NTPC with the assistance of United States Agency for International Development- USAID. CENPEEP is efficiency oriented, eco-friendly and eco-nurturing initiative - a symbol of NTPC's concern towards environmental protection and continued commitment to sustainable power development in India. As a responsible corporate citizen, NTPC is making constant efforts to improve the socio-economic status of the people affected by its projects. Through its Rehabilitation and Resettlement programmes, the company endeavors to improve the overall socio economic status Project Affected Persons. NTPC was among the first Public Sector Enterprises to enter into a Memorandum of UnderstandingMOU with the Government in 1987-88. NTPC has been placed under the 'Excellent category' (the best category) every year since the MOU system became operative.
Harmony between man and environment is the essence of healthy life and growth. Therefore, maintenance of ecological balance and a pristine environment has been of utmost importance to NTPC. It has been taking various measures discussed below for mitigation of environment pollution due to power generation.
NTPC is the second largest owner of trees in the country after the Forest department. Environment Policy & Environment Management System Driven by its commitment for sustainable growth of power, NTPC has evolved a well defined environment management policy and sound environment practices for minimizing environmental impact arising out of setting up of power plants and preserving the natural ecology.
NTPC Environment Policy As early as in November 1995, NTPC brought out a comprehensive document entitled "NTPC Environment Policy and Environment Management System". Amongst the guiding principles adopted in the document are company's proactive approach to environment, optimum utilization of equipment, adoption of latest technologies and continual environment improvement. The policy also envisages efficient utilization of resources, thereby minimizing waste, maximizing ash utilization and providing green belt all around the plant for maintaining ecological balance.
Environment Management, Occupational Health and Safety Systems: NTPC has actively gone for adoption of best international practices on environment, occupational health and safety areas. The organization has pursued the Environmental Management System (EMS) ISO 14001 and the Occupational Health and Safety Assessment System OHSAS 18001 at its different establishments. As a result of pursuing these practices, all NTPC power stations have been certified for ISO 14001 & OHSAS 18001 by reputed national and international Certifying Agencies.
Pollution Control systems: While deciding the appropriate technology for its projects, NTPC integrates many environmental provisions into the plant design. In order to ensure that NTPC comply with all the stipulated environment norms, various state-of-the-art pollution control systems / devices as discussed below have been installed to control air and water pollution.
Electrostatic Precipitators: The ash left behind after combustion of coal is arrested in high efficiency Electrostatic Precipitators (ESP’s) and particulate emission is controlled well within the stipulated norms. The ash collected in the ESP’s is disposed to Ash Ponds in slurry form.
Flue Gas Stacks: Tall Flue Gas Stacks have been provided for wide dispersion of the gaseous emissions (SOX, NOX etc) into the atmosphere.
Low-NOX Burners: In gas based NTPC power stations, NOx emissions are controlled by provision of Low-NOx Burners (dry or wet type) and in coal fired stations, by adopting best combustion practices.
Neutralisation Pits: Neutralisation pits have been provided in the Water Treatment Plant (WTP) for pH correction of the effluents before discharge into Effluent Treatment Plant (ETP) for further treatment and use.
Coal Settling Pits / Oil Settling Pits: In these Pits, coal dust and oil are removed from the effluents emanating from the Coal Handling Plant (CHP), coal yard and Fuel Oil Handling areas before discharge into ETP.
DE & DS Systems: Dust Extraction (DE) and Dust Suppression (DS) systems have been installed in all coal fired power stations in NTPC to contain and extract the fugitive dust released in the Coal Handling Plant (CHP).
Cooling Towers: Cooling Towers have been provided for cooling the hot Condenser cooling water in closed cycle Condenser Cooling Water (CCW) Systems. This helps in reduction in thermal pollution and conservation of fresh water.
Ash Dykes & Ash Disposal systems: Ash ponds have been provided at all coal based stations except Dadri where Dry Ash Disposal System has been provided. Ash Ponds have been divided into lagoons and provided with garlanding arrangements for changeover of the ash slurry feed points for even filling of the pond and for effective settlement of the ash particles. Ash in slurry form is discharged into the lagoons where ash particles get settled from the slurry and clear effluent water is discharged from the ash pond. The discharged effluents conform to standards specified by CPCB and the same is regularly monitored. At its Dadri Power Station, NTPC has set up a unique system for dry ash collection and disposal facility with Ash Mound formation. This has been envisaged for the first time in Asia which has resulted in progressive development of green belt besides far less requirement of land and less water requirement as compared to the wet ash disposal system.
Ash Water Recycling System: Further, in a number of NTPC stations, as a proactive measure, Ash Water Recycling System (AWRS) has been provided. In the AWRS, the effluent from ash pond is circulated back to the station for further ash sluicing to the ash pond. This helps in savings of fresh water requirements for transportation of ash from the plant. The ash water recycling system has already been installed and is in operation at Ramagundam, Simhadri, Rihand, Talcher Kaniha, Talcher Thermal, Kahalgaon, Korba and Vindhyachal. The scheme has helped stations to save huge quantity of fresh water required as make-up water for disposal of ash.
Dry Ash Extraction System (DAES): Dry ash has much higher utilization potential in ash-based products (such as bricks, aerated autoclaved concrete blocks, concrete, Portland pozzolana cement, etc.). DAES has been installed at Unchahar, Dadri, Simhadri, Ramagundam, Singrauli, Kahalgaon, Farakka, Talcher Thermal, Korba, Vindhyachal, Talcher Kaniha and BTPS.
Liquid Waste Treatment Plants & Management System: The objective of industrial liquid effluent treatment plant (ETP) is to discharge lesser and cleaner effluent from the power plants to meet environmental regulations. After primary treatment at the source of their generation, the effluents are sent to the ETP for further treatment. The composite liquid effluent treatment plant has been designed to treat all liquid effluents which originate within the power station e.g. Water Treatment Plant (WTP), Condensate Polishing Unit (CPU) effluent,
Coal Handling Plant (CHP) effluent, floor washings, service water drains etc. The scheme involves collection of various effluents and their appropriate treatment centrally and re-circulation of the treated effluent for various plant uses. NTPC has implemented such systems in a number of its power stations such as Ramagundam, Simhadri, Kayamkulam, Singrauli, Rihand, Vindhyachal, Korba, Jhanor Gandhar, Faridabad, Farakka, Kahalgaon and Talcher Kaniha. These plants have helped to control quality and quantity of the effluents discharged from the stations.
Sewage Treatment Plants & Facilities: Sewage Treatment Plants (STPs) sewage treatment facilities have been provided at all NTPC stations to take care of Sewage Effluent from Plant and township areas. In a number of NTPC projects modern type STPs with Clarifloculators, Mechanical Agitators, sludge drying beds, Gas Collection Chambers etc have been provided to improve the effluent quality. The effluent quality is monitored regularly and treated effluent conforming to the prescribed limit is discharged from the station. At several stations, treated effluents of STPs are being used for horticulture purpose.
Environmental Institutional Set-up: Realizing the importance of protection of the environment with speedy development of the power sector, the company has constituted different groups at project, regional and Corporate Centre level to carry out specific environment related functions. The Environment Management Group, Ash Utilisation Group and Centre for Power Efficiency & Environment Protection (CENPEEP) function from the Corporate Centre and initiate measures to mitigate the impact of power project implementation on the environment and preserve ecology in the vicinity of the projects. Environment Management and Ash Utilisation Groups established at each station, look after various environmental issues of the individual station.
Environment Reviews: To maintain constant vigil on environmental compliance, Environmental Reviews are carried out at all operating stations and remedial measures have been taken wherever necessary. As a feedback and follow-up of these Environmental Reviews, a number of retrofit and up-gradation measures have been undertaken at different stations. Such periodic Environmental Reviews and extensive monitoring of the facilities carried out at all stations have helped in compliance with the environmental norms and timely renewal of the Air and Water Consents.
Waste Management Various types of wastes such as Municipal or domestic wastes, hazardous wastes, Bio-Medical wastes get generated in power plant areas, plant hospital and the townships of projects. The wastes generated are a number of solid and hazardous wastes like used oils & waste oils, grease,
lead acid batteries, other lead bearing wastes (such as garkets etc.), oil & clarifier sludge, used resin, used photo-chemicals, asbestos packing, e-waste, metal scrap, C&I wastes, electricial scrap, empty cylinders (refillable), paper, rubber products, canteen (bio-degradable) wastes, buidling material wastes, silica gel, glass wool, fused lamps & tubes, fire resistant fluids etc. These wastes fall either under hazardous wastes category or non-hazardous wastes category as per classification given in Government of India’s notification on Hazardous Wastes (Management and Handling) Rules 1989 (as amended on 06.01.2000 & 20.05.2003). Handling and management of these wastes in NTPC stations have been discussed below.
• NTPC was set up in 1975 with 100% ownership by the Government of India. In the last 30 years, NTPC has grown into the largest power utility in India.
• In 1997, Government of India granted NTPC status of “Navratna" being one of the nine jewels of India, enhancing the powers to the Board of Directors.
• NTPC became a listed company with majority Government ownership of 89.5%. • NTPC becomes 3rd largest by Market Capitalization of listed companies
• The company rechristened as NTPC Limited in line with its changing business portfolio and transforms itself from a thermal power utility to an integrated power utility.
• National Thermal Power Corporation is the largest power generation company in India. Forbes Global 2000 for 2008 ranked it 411th in the world.
OPERATION OF POWER PLANT INTRODUCTION BASIC PRINCIPLE ELECTRICITY FROM COAL OPERATION OF BOILER OPERATION OF TURBINE
INTRODUCTION BADARPUR THERMAL POWER STATION was established on 1973 and it was the part of Central Government. On 01/04/1978 is was given as No Loss No Profit Plant of NTPC. Since then operating performance of NTPC has been considerably above the national average. The availability factor for coal stations has increased from 85.03 % in 1997-98 to 90.09 % in 2006-07, which compares favourably with international standards. The PLF has increased from 75.2% in 1997-98 to 89.4% during the year 2006-07 which is the highest since the inception of NTPC.
Capacity of BADARPUR THERMAL POWER STATION Sr. No. 1. 2.
Capacity(MW) 210 95
Number 2 3
Total Capacity(MW) 420 285
Overall Capacity- 705 MW
BASIC PRINCIPLE As per FARADAY’s Law- “Whenever the amount of magnetic flux linked with a circuit changes, an EMF is produced in the circuit. Generator works on the principle of producing electricity. To change the flux in the generator turbine is moved in a great speed with steam.” To produce steam, water is heated in the boilers by burning the coal. In a Badarpur Thermal Power
Station, steam is produced and used to spin a turbine that operates a generator. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser; this is known as a Rankine cycle. Shown here is a diagram of a conventional thermal power plant, which uses coal, oil, or natural gas as fuel to boil water to produce the steam. The electricity generated at the plant is sent to consumers through high-voltage power lines The Badarpur Thermal Power Plant has Steam Turbine-Driven Generators which has a collective capacity of 705MW. The fuel being used is Coal which is supplied from the Jharia Coal Field in Jharkhand. Water supply is given from the Agra Canal.
Electricity from Coal There are basically three main units of a thermal power plant: 1. Steam Generator or Boiler 2. Steam Turbine 3. Electric Generator
Basic Electricity Generation Chart
Functioning of Thermal Power Plant
Typical Diagram of Coal Based Power Plant
Its various parts are listed below:1. Cooling tower 2. Cooling water pump 3. Transmission line (3-phase) 4. Unit transformer (3-phase) 5. Electric generator (3-phase) 6. Low pressure turbine 7. Condensate extraction pump 8. Condenser
9. Intermediate pressure turbine 10. Steam governor valve 11. High pressure turbine 12. DE aerator 13. Feed heater 14. Coal conveyor 15. Coal hopper 16. Pulverised fuel mill 17. Boiler drum 18. Ash hopper 19. Super heater 20. Forced draught fan 21. Re heater 22. Air intake 23. Economiser 24. Air preheater 25. Precipitator 26. Induced draught fan 27. Fuel Gas Stack
1. Cooling towers Cooling Towers are evaporative coolers used for cooling water or other working medium to near the ambivalent web-bulb air temperature. Cooling tower use evaporation of water to reject heat from processes such as cooling the circulating water used in oil refineries, Chemical plants, power plants and building cooling, for example. The tower vary in size from small roof-top units to very large hyperboloid structures that can be up to 200 meters tall and 100 meters in diameter, or rectangular structure that can be over 40 meters tall and 80 meters long. Smaller towers are normally factory built, while larger ones are constructed on site. The primary use of large , industrial cooling tower system is to remove the heat absorbed in the circulating cooling water systems used in power plants , petroleum refineries, petrochemical and chemical plants, natural gas processing plants and other industrial facilities . The absorbed heat is rejected to the atmosphere by the evaporation of some of the cooling water in mechanical forceddraft or induced draft towers or in natural draft hyperbolic shaped cooling towers as seen at most nuclear power plants.
2. Cooling Water Pump It pumps the water from the cooling tower which goes to the condenser.
3.Three phase transmission line Three phase electric power is a common method of electric power transmission. It is a type of polyphase system mainly used to power motors and many other devices. A Three phase system uses less conductor material to transmit electric power than equivalent single phase, two phase, or direct current system at the same voltage. In a three phase system, three circuits reach their instantaneous peak values at different times. Taking one conductor as the reference, the other two current are delayed in time by one-third and two-third of one cycle of the electrical current. This delay between “phases” has the effect of giving constant power transfer over each cycle of the current and also makes it possible to produce a rotating magnetic field in an electric motor. At the power station, an electric generator converts mechanical power into a set of electric currents, one from each electromagnetic coil or winding of the generator. The current are sinusoidal functions of time, all at the same frequency but offset in time to give different phases. In a three phase system the phases are spaced equally, giving a phase separation of one-third one cycle. Generators output at a voltage that ranges from hundreds of volts to 30,000 volts.
4. Unit transformer (3-phase) At the power station, transformers: step-up” this voltage to one more suitable for transmission. After numerous further conversions in the transmission and distribution network the power is finally transformed to the standard mains voltage (i.e. the “household” voltage). The power may already have been split into single phase at this point or it may still be three phase. Where the step-down is 3 phase, the output of this transformer is usually star connected with the standard mains voltage being the phase-neutral voltage. Another system commonly seen in North America is to have a delta connected secondary with a center tap on one of the windings supplying the ground and neutral. This allows for 240 V three phase as well as three different single phase voltages( 120 V between two of the phases and neutral , 208 V between the third phase ( known as a wild leg) and neutral and 240 V between any two phase) to be available from the same supply.
5. Electrical generator An Electrical generator is a device that converts kinetic energy to electrical energy, generally using electromagnetic induction. The task of converting the electrical energy into mechanical energy is accomplished by using a motor. The source of mechanical energy may be a reciprocating or turbine steam engine, , water falling through the turbine are made in a variety of sizes ranging from small 1 hp (0.75 kW) units (rare) used as mechanical drives for pumps, compressors and other shaft driven equipment , to 2,000,000 hp(1,500,000 kW) turbines used to generate electricity. There are several classifications for modern steam turbines. Steam turbines are used in all of our major coal fired power stations to drive the generators or alternators, which produce electricity. The turbines themselves are driven by steam generated in „Boilers‟ or „steam generators‟ as they are sometimes called. Electrical power station use large stem turbines driving electric generators to produce most (about 86%) of the world‟s electricity. These centralized stations are of two types: fossil fuel power plants and nuclear power plants. The turbines used for electric power generation are most often directly coupled to their-generators .As the generators must rotate at constant synchronous speeds according to the frequency of the electric power system, the most common speeds are 3000 r/min for 50 Hz systems, and 3600 r/min for 60 Hz systems. Most large nuclear sets rotate at half those speeds, and have a 4-pole generator rather than the more common 2-pole one.
6. Low Pressure Turbine Energy in the steam after it leaves the boiler is converted into rotational energy as it passes through the turbine. The turbine normally consists of several stage with each stages consisting of a stationary blade (or nozzle) and a rotating blade. Stationary blades convert the potential energy of the steam into kinetic energy into forces, caused by pressure drop, which results in the rotation of the turbine shaft. The turbine shaft is connected to a generator, which produces the electrical energy. Low Pressure Turbine (LPT) consist of 4x2 stages. After passing through Intermediate Pressure Turbine is is passed through LPT which is made up of two parts- LPC REAR & LPC FRONT. As water gets cooler here it gathers into a HOTWELL placed in lower parts of Turbine.
7. Condensation Extraction Pump A Boiler feed water pump is a specific type of pump used to pump water into a steam boiler. The water may be freshly supplied or retuning condensation of the steam produced by the boiler. These pumps are normally high pressure units that use suction from a condensate return system and can be of the centrifugal pump type or positive displacement type.
Construction and operation Feed water pumps range in size up to many horsepower and the electric motor is usually separated from the pump body by some form of mechanical coupling. Large industrial condensate pumps may also serve as the feed water pump. In either case, to force the water into the boiler; the pump must generate sufficient pressure to overcome the steam pressure developed by the boiler. This is usually accomplished through the use of a centrifugal pump. Feed water pumps usually run intermittently and are controlled by a float switch or other similar level-sensing device energizing the pump when it detects a lowered liquid level in the boiler is substantially increased. Some pumps contain a two-stage switch. As liquid lowers to the trigger point of the first stage, the pump is activated. I f the liquid continues to drop (perhaps because the pump has failed, its supply has been cut off or exhausted, or its discharge is blocked); the second stage will
be triggered. This stage may switch off the boiler equipment (preventing the boiler from running dry and overheating), trigger an alarm, or both.
8. Condenser The steam coming out from the Low Pressure Turbine (a little above its boiling pump) is brought into thermal contact with cold water (pumped in from the cooling tower) in the condenser, where it condenses rapidly back into water, creating near vacuum-like conditions inside the condenser chest.
9. Intermediate Pressure Turbine Intermediate Pressure Turbine (IPT) consist of 11 stages. When the steam has been passed through HPT it gets enter into IPT. IPT has two ends named as FRONT & REAR. Steam enters through front end and leaves from Rear end.
10. Steam Governor Valve Steam locomotives and the steam engines used on ships and stationary applications such as power plants also required feed water pumps. In this situation, though, the pump was often powered using a small steam engine that ran using the steam produced by the boiler. A means had to be provided, of course, to put the initial charge of water into the boiler(before steam power was available to operate the steam-powered feed water pump).the pump was often a positive displacement pump that had steam valves and cylinders at one end and feed water cylinders at the other end; no crankshaft was required. In thermal plants, the primary purpose of surface condenser is to condense the exhaust steam from a steam turbine to obtain maximum efficiency and also to convert the turbine exhaust steam into pure water so that it may be reused in the steam generator or boiler as boiler feed water. By condensing the exhaust steam of a turbine at a pressure below atmospheric pressure, the steam pressure drop between the inlet and exhaust of the turbine is increased, which increases the amount heat available for conversion to mechanical power. Most of the heat liberated due to condensation of the exhaust steam is carried away by the cooling medium (water or air) used by the surface condenser. Control valves are valves used within industrial plants and elsewhere to control operating conditions such as temperature,pressure,flow,and liquid Level by fully partially opening or closing in response to signals received from controllers that compares a “set point” to a “process variable” whose value is provided by sensors that monitor changes in such conditions. The opening or closing of control valves is done by means of electrical, hydraulic or pneumatic systems
11.High Pressure Turbine Steam coming from Boiler directly feeds into HPT at a temperature of 540°C and at a pressure of 136 kg/cm2. Here it passes through 12 different stages due to which its temperature goes down to 329°C and pressure as 27 kg/cm2. This line is also called as CRH – COLD REHEAT LINE.
It is now passed to an REHEATER where its temperature rises to 540°C and called as HRH-HOT REHEATED LINE .
12. Deaerator A Dearator is a device for air removal and used to remove dissolved gases (an alternate would be the use of water treatment chemicals) from boiler feed water to make it non-corrosive. A dearator typically includes a vertical domed deaeration section as the deaeration boiler feed water tank. A Steam generating boiler requires that the circulating steam, condensate, and feed water should be devoid of dissolved gases, particularly corrosive ones and dissolved or suspended solids. The gases will give rise to corrosion of the metal. The solids will deposit on the heating surfaces giving rise to localized heating and tube ruptures due to overheating. Under some conditions it may give to stress corrosion cracking. Deaerator level and pressure must be controlled by adjusting control valves- the level by regulating condensate flow and the pressure by regulating steam flow. If operated properly, most deaerator vendors will guarantee that oxygen in the deaerated water will not exceed 7 ppb by weight (0.005 cm3/L)
13. Feed water heater A Feed water heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feed water reduces the irreversible 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 introduces back into the steam cycle. In a steam power (usually modelled as a modified Ranking 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). A belt conveyor consists of two pulleys, with a continuous loop of material- the conveyor Belt – that rotates about them. The pulleys are powered, moving the belt and the material on the belt forward. Conveyor belts are extensively used to transport industrial and agricultural material, such as grain, coal, ores etc.
14. Coal conveyor Coal conveyors are belts which are used to transfer coal from its storage place to Coal Hopper.
15. Coal Hopper Coal Hopper are the places which are used to feed coal to Fuel Mill. It also has the arrangement of entering of Hoy Air at 200°C inside it which solves our two purposes:1. If our Coal has moisture content then it dries it so that a proper combustion takes place. 2. It raises the temperature of coal so that its temperature is more near to its Ignite Temperature so that combustion is easy.
16. Pulverised Fuel Mill A pulveriser is a device for grinding coal for combustion in a furnace in a fossil fuel power plant.
17. Boiler Drum Steam Drums are a regular feature of water tube boilers. It is reservoir of water/steam at the top end of the water tubes in the water-tube boiler. They store the steam generated in the water tubes and act as a phase separator for the steam/water mixture. The difference in densities between hot and cold water helps in the accumulation of the “hotter”-water/and saturated –steam into steam drum. Made from high-grade steel (probably stainless) and its working involves temperatures 390‟C and pressure well above 350psi (2.4MPa). 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 re-enter 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.
18. Ash Hopper 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 the bottom.
19. Super Heater A Super heater is a device in a steam engine that heats the steam generated by the boiler again increasing its thermal energy and decreasing the likelihood that it will condense inside the engine. Super heaters increase the efficiency of the steam engine, and were widely adopted. Steam which has been superheated is logically known as superheated steam; non-superheated steam is called saturated steam or wet steam; Super heaters were applied to steam locomotives in quantity from the early 20th century, to most steam vehicles, and so stationary steam engines including power stations.
20. Force Draught Fan External fans are provided to give sufficient air for combustion. The forced draft fan takes air from the atmosphere and, first warming it in the air preheater for better combustion, injects it via the air nozzles on the furnace wall.
21. Reheater Reheater are heaters which are used to raise the temperature of air which has been fallen down due to various process.
22. Air Intake Air is taken from the environment by an air intake tower.
23. Economizers Economizer, or in the UK economizer, are mechanical devices intended to reduce energy consumption, or to perform another useful function like preheating a fluid. The term economizer is used for other purposes as well. Boiler, power plant, and heating, ventilating and air conditioning. In
boilers, economizer are heat exchange devices that heat fluids , usually water, up to but not normally beyond the boiling point of the fluid. Economizers are so named because they can make use of the enthalpy and improving the boiler‟s efficiency. They are a device fitted to a boiler which saves energy by using the exhaust gases from the boiler to preheat the cold water used the fill it (the feed water). Modern day boilers, such as those in cold fired power stations, are still fitted with economizer which is decedents of Green‟s original design. In this context they are turbines before it is pumped to the boilers. A common application of economizer is steam power plants is to capture the waste hit from boiler stack gases (flue gas) and transfer thus it to the boiler feed water thus lowering the needed energy input , in turn reducing the firing rates to accomplish the rated boiler output . Economizer lower stack temperatures which may cause condensation of acidic combustion gases and serious equipment corrosion damage if care is not taken in their design and material selection.
24. Air Preheater Air preheater is a general term to describe any device designed to heat air before another process (for example, combustion in a boiler). The purpose of the air preheater is to recover the heat from the boiler flue gas which increases the thermal efficiency of the boiler by reducing the useful heat lost in the fuel gas. As a consequence, the flue gases are also sent to the flue gas stack (or chimney) at a lower temperature allowing simplified design of the ducting and the flue gas stack. It also allows control over the temperature of gases leaving the stack.
25. Precipitator An Electrostatic precipitator (ESP) or electrostatic air cleaner is a particulate device that removes particles from a flowing gas (such As air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices, and can easily remove fine particulate matter such as dust and smoke from the air steam. ESP‟s continue to be excellent devices for control of many industrial particulate emissions, including smoke from electricity-generating utilities (coal and oil fired), salt cake collection from black liquor boilers in pump mills, and catalyst collection from fluidized bed catalytic crackers from several hundred thousand ACFM in the largest coal-fired boiler application. The original parallel plate-Weighted wire design (described above) has evolved as more efficient ( and robust) discharge electrode designs were developed, today focusing on rigid discharge electrodes to which many sharpened spikes are attached , maximizing corona production. Transformer –rectifier systems apply voltages of 50-100 Kilovolts at relatively high current densities. Modern controls minimize sparking and prevent arcing, avoiding damage to the components. Automatic rapping systems and hopper evacuation systems remove the collected particulate matter while on line allowing ESP‟s to stay in operation for years at a time.
26. Induced Draught Fan The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining a slightly negative pressure in the furnace to avoid backfiring through any opening. At the furnace outlet, and before the furnace gases are handled by the ID fan, fine dust carried by the outlet gases is removed to avoid atmospheric pollution. This is an environmental limitation prescribed by law, additionally minimizes erosion of the ID fan.
27. Fuel gas stack A Fuel gas stack is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called fuel gases are exhausted to the outside air. Fuel gases are produced when coal, oil, natural gas, wood or any other large combustion device. Fuel gas is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air. It also contains a small percentage of pollutants such as particulates matter, carbon mono oxide, nitrogen oxides and sulfur oxides. The flue gas stacks are often quite tall, up to 400 meters (1300 feet) or more, so as to disperse the exhaust pollutants over a greater aria and thereby reduce the concentration of the pollutants to the levels required by governmental environmental policies and regulations. When the fuel gases exhausted from stoves, ovens, fireplaces or other small sources within residential abodes, restaurants , hotels or other stacks are referred to as chimneys.
OPERATION OF BOILER The boiler is a rectangular furnace about 50 ft (15 m) on a side and 130 ft (40 m) tall. Its walls are made of a web of high pressure steel tubes about 2.3 inches (60 mm) in diameter. Pulverized coal is air-blown into the furnace from fuel nozzles at the four corners and it rapidly burns, forming a large fireball at the center. The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. The water circulation rate in the boiler is three to four times the throughput and is typically driven by pumps. As the water in the boiler circulates it absorbs heat and changes into steam at 700 °F (370 °C) and 22.1 MPa. It is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace. Here the steam is superheated to 1,000 °F (540 °C) to prepare it for the turbine. The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. The generator includes the economizer, the steam drum, the chemical dosing equipment, and the furnace with its steam generating tubes and the superheater coils. Necessary safety valves are located at suitable pointsvto avoid excessive boiler pressure. The air and flue gas path equipment include: forced draft (FD) fan, air preheater (APH), boiler furnace, induced draft (ID) fan, fly ash collectors (electrostatic precipitator or baghouse) and the flue gas stack.
Schematic diagram of a coal-fired power plant steam generator
Boiler Furnace and Steam Drum Once water inside the boiler or steam generator, the process of adding the latent heat of vaporization or enthalpy is underway. The boiler transfers energy to the water by the chemical reaction of burning some type of fuel. The water enters the boiler through a section in the convection pass called the economizer. From the economizer it passes to the steam drum. Once the water enters the steam drum it goes down the down comers to the lower inlet water wall headers. From the inlet headers the water rises through the water walls and is eventually turned into steam due to the heat being generated by the burners located on the front and rear water walls (typically). As the water is turned into steam/vapour in the water walls, the steam/vapor once again enters the steam drum.
Fuel Preparation System In coal-fired power stations, the raw feed coal from the coal storage area 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 may be ball mills, rotating drum grinders, or other types of grinders. Some power stations burn fuel oil rather than coal. The oil must kept warm (above its pour point) in the fuel oil storage tanks to prevent the oil from congealing and becoming un-pumpable. The oil is usually heated to about 100°C before being pumped through the furnace fuel oil spray nozzles.
Fuel Firing System and Ignite System From the pulverized coal bin, coal is blown by hot air through the furnace coal burners at an angle which imparts a swirling motion to the powdered coal to enhance mixing of the coal powder with the incoming preheated combustion air and thus to enhance the combustion. To provide sufficient combustion temperature in the furnace before igniting the powdered coal, the furnace temperature is raised by first burning some light fuel oil or processed natural gas (by using auxiliary burners and igniters provide for that purpose).
Air Path External fans are provided to give sufficient air for combustion. The forced draft fan takes air from the atmosphere and, first warming it in the air preheater for better combustion, injects it via the air nozzles on the furnace wall. The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining a slightly negative pressure in the furnace to avoid backfiring through any opening. At the furnace outlet, and before the furnace gases are handled by the ID fan, fine dust carried by the outlet gases is removed to avoid atmospheric pollution. This is an environmental limitation prescribed by law, and additionally minimizes erosion of the ID fan.
Fly Ash Collection Fly ash is captured and removed from the flue gas by electrostatic precipitators or fabric bag filters (or sometimes both) located at the outlet of the furnace and before the induced draft fan. The fly ash is periodically removed from the collection hoppers below the precipitators or bag filters. Generally, the fly ash is pneumatically transported to storage silos for subsequent transport by trucks or railroad cars.
Bottom Ash Collection and Disposal At the bottom of every boiler, a hopper has been provided for collection of the bottom ash from the bottom of the furnace. This hopper is always filled with water to quench the ash and clinkers falling down from the furnace. Some arrangement is included to crush the clinkers and for conveying the crushed clinkers and bottom ash to a storage site.
Boiler Make-up Water Treatment Plant and Storage Since there is continuous withdrawal of steam and continuous return of condensate to the boiler, losses due to blow-down and leakages have to be made up for so as to maintain the desired water level in the boiler steam drum. For this, continuous make-up water is added to the boiler water system. The impurities in the raw water input to the plant generally consist of calcium and magnesium salts which impart hardness to the water. Hardness in the make-up water to the boiler will form deposits on the tube water surfaces which will lead to overheating and failure of the tubes. Thus, the salts have to be removed from the water and that is done by a water demineralising treatment plant (DM).
OPERATION OF TURBINE Steam turbines are used in all of our major coal fired power stations to drive the generators or alternators, which produce electricity. The turbines themselves are driven by steam generated in 'Boilers' or 'Steam Generators' as they are sometimes called. Energy in the steam after it leaves the boiler is converted into rotational energy as it passes through the turbine. The turbine normally consists of several stages with each stage consisting of a stationary blade (or nozzle) and a rotating blade. Stationary blades convert the potential energy of the steam (temperature and pressure) into kinetic energy (velocity) and direct the flow onto the rotating blades. The rotating blades convert the kinetic energy into forces, caused by pressure drop, which results in the rotation of the turbine shaft. The turbine shaft is connected to a generator, which produces the electrical energy. The
rotational speed is 3000 rpm for Indian System (50 Hz) systems and 3600 for American (60 Hz) systems. In a typical larger power stations, the steam turbines are split into three separate stages, the first being the High Pressure (HP), the second the Intermediate Pressure (IP) and the third the Low Pressure (LP) stage, where high, intermediate and low describe the pressure of the steam. After the steam has passed through the HP stage, it is returned to the boiler to be re-heated to its original temperature although the pressure remains greatly reduced. The reheated steam then passes through the IP stage and finally to the LP stage of the turbine. High-pressure oil is injected into the bearings to provide lubrication.
VARIOUS CYCLES AT POWER STATION COAL CYCLE CONDENSATE CYCLE FEED WATER CYCLE STEAM CYCLE
Coal Stock Yard
From LP Turbine
FFED WATER CYCLE
Boiler Feed Pump
Feed Water Line
From Boiler Drum
LT Super Heater
Main Steam Line
Cold Reheat Line
Hot Reheat Line
Low pressure Line
CONTROL & INSTRUMENTATION INTRODUCTION C&I LABS CONTROL & MONITORING MECHENISM PRESSURE MONITORING TEMPERATURE MONITORING FLOW MEASUREMENT CONTROL VALVES
INTRODUCTION This division basically calibrates various instruments and takes care of any faults occur in any of the auxiliaries in the plant. “Instrumentation can be well defined as a technology of using instruments to measure and control the physical and chemical properties of a material.”
C&I LABS Control and Instrumentation Department has following labs: 1. 2. 3. 4. 5. 6.
Manometry Lab Protection and Interlocks Lab Automation Lab Electronics Lab Water Treatment Plant Furnaces Safety Supervisory System Lab
OPERATION AND MAINTAINANCE Control and Instrumentation Department has following Control Units: 1. 2. 3. 4.
Unit Control Board Main Control Board Analog & Digital Signal Control Current Signal Control
This department is the brain of the plant because from the relays to transmitters followed by the electronic computation chipsets and recorders and lastly the controlling circuitry, all fall under this.
A View of Control Room at BTPS
1. Manometry Lab TRANSMITTERS It is used for pressure measurements of gases and liquids, its working principle is that the input pressure is converted into electrostatic capacitance and from there it is conditioned and amplified. It gives an output of 4-20 ma DC. It can be mounted on a pipe or a wall. For liquid or steam measurement transmitters is mounted below main process piping and for gas measurement transmitter is placed above pipe.
MANOMETER It’s a tube which is bent, in U shape. It is filled with a liquid. This device corresponds to a difference in pressure across the two limbs.
BOURDEN PRESSURE GAUGE It’s an oval section tube. It’s one end is fixed. It is provided with a pointer to indicate the pressure on a calibrated scale. It is of 2 types: (a) Spiral type: for Low pressure measurement. (b) Helical Type: for High pressure measurement. While selecting Pressure Gauge these parameters should keep in mind1. 2. 3. 4.
Accuracy Safety Utility Price
ACCURACY Higher Accuracy implies Larger Dial Size for accuracy of small and readable pressure scale increments. SAFETY While selecting Pressure Gauge it should consider that Gauge Construction Material should be chemically compatible with the environment either inside or outside it. UTILITY It should keep it mind that range of the Gauge should be according to our need else Overpressure Failure may occur resulting in damage of Gauge. PRICE Lager the Gauge’s Dial size larger would be our price. Better Gauge’s Construction material also increses the cost. So they must be chosen according to our need.
2. Protection and Interlock Lab INTERLOCKING It is basically interconnecting two or more equipments so that if one equipment fails other one can perform the tasks. This type of interdependence is also created so that equipments connected together are started and shut down in the specific sequence to avoid damage. For protection of equipments tripping are provided for all the equipments. Tripping can be considered as the series of instructions connected through OR GATE, which trips the circuit. The main equipments of this lab are relay and circuit breakers. Some of the instrument uses for protection are:. RELAY It is a protective device. It can detect wrong condition in electrical circuits by constantly measuring the electrical quantities flowing under normal and faulty conditions. Some of the electrical quantities are voltage, current, phase angle and velocity. 2. FUSES It is a short piece of metal inserted in the circuit, which melts when heavy current flows through it and thus breaks the circuit. Usually silver is used as a fuse material because: a) The coefficient of expansion of silver is very small. As a result no critical fatigue occurs and thus the continuous full capacity normal current ratings are assured for the long time. b) The conductivity of the silver is unimpaired by the surges of the current that produces temperatures just near the melting point. c) Silver fusible elements can be raised from normal operating temperature to vaporization quicker than any other material because of its comparatively low specific heat. Miniature Circuit BreakerThey are used with combination of the control circuits to. a) Enable the staring of plant and distributors. b) Protect the circuit in case of a fault. In consists of current carrying contacts, one movable and other fixed. When a fault occurs the contacts separate and are is stuck between them. There are three types of trips I. MANUAL TRIP II. THERMAL TRIP III. SHORT CIRCUIT TRIP. Protection and Interlock System1. HIGH TENSION CONTROL CIRCUIT for high tension system the control system are excited by separate D.C supply. For starting the circuit conditions should be in series with the starting coil of the equipment to energize it. Because if even a single condition is not true then system will not start. 2. LOW TENSION CONTROL CIRCUIT For low tension system the control circuits are directly excited from the 0.415 KV A.C supply. The same circuit achieves both excitation and tripping. Hence the tripping coil is provided for emergency tripping if the interconnection fails.
3. AUTOMATION LAB This lab deals in automating the existing equipment and feeding routes. Earlier, the old technology dealt with only (DAS) Data Acquisition System and came to be known as primary systems. The modern technology or the secondary systems are coupled with (MIS) Management Information System. But this lab universally applies the pressure measuring instruments as the controlling force. However, the relays are also provided but they are used only for protection and interlocks.
4. PYROMETRY LAB LIQUID IN GLASS THERMOMETER – Mercury in the glass thermometer boils at 340° C which limits the range of temperature that can be measured. It is L shaped thermometer which is designed to reach all inaccessible places. 1. ULTRA VIOLET CENSORThis device is used in furnace and it measures the intensity of ultra violet rays there and according to the wave generated which directly indicates the temperature in the furnace. 2, THERMOCOUPLES – This device is based on SEEBACK and PELTIER effect. It comprises of two junctions at different temperature. Then the emf is induced in the circuit due to the flow of electrons. This is an important part in the plant. 3. RTD (RESISTANCE TEMPERATURE DETECTOR) – It performs the function of thermocouple basically but the difference is of a resistance. In this due to the change in the resistance the temperature difference is measured. In this lab, also the measuring devices can be calibrated in the oil bath or just boiling water (for low range devices) and in small furnace (for high range devices).
5. FURNACE SAFETY AND SUPERVISORY SYSTEM LAB This lab has the responsibility of starting fire in the furnace to enable the burning of coal. For first stage coal burners are in the front and rear of the furnace and for the second and third stage corner firing is employed. Unburnt coal is removed using forced draft or induced draft fan. The temperature inside the boiler is 1100°C and its heights 18 to 40 m. It is made up of mild steel. An ultra violet sensor is employed in furnace to measure the intensity of ultra violet rays inside the furnace and according to it a signal in the same order of same mV is generated which directly indicates the temperature of the furnace. For firing the furnace a 10 KV spark plug is operated for ten seconds over a spray of diesel fuel and pre-heater air along each of the feeder-mills. The furnace has six feeder mills each separated by warm air pipes fed from forced draft fans. In first stage indirect firing is employed that is feeder mills are not fed directly from coal but are fed from three feeders but are fed from pulverized coalbunkers. The furnace can operate on the minimum feed from three feeders but under no circumstances should anyone be left out under operation, to prevent creation of pressure different with in the furnace, which threatens to blast it.
6. ELECTRONICS LAB This lab undertakes the calibration and testing of various cards. It houses various types of analytical instruments like oscilloscopes, integrated circuits, cards auto analyzers etc. Various processes undertaken in this lab are: 1. Transmitter converts mV to mA. 2. Auto analyzer purifies the sample before it is sent to electrodes. It extracts the magnetic portion. ANNUNCIATIN CARDS They are used to keep any parameter like temperature etc. within limits. It gets a signal if parameter goes beyond limit. It has a switching transistor connected to relay that helps in alerting the UCB.
CONTROL & MONITORING MECHANISMS There are basically two types of Problems faced in a Power Plant 1. Metallurgical 2. Mechanical Mechanical Problem can be related to Turbines that is the max speed permissible for a turbine is 3000 rpm so speed should be monitored and maintained at that level. Metallurgical Problem can be view as the max Inlet Temperature for Turbine is 1060° C so temperature should be below the limit. Monitoring of all the parameters is necessary for the safety of both: 1. Employees 2. Machines So the Parameters to be monitored are: 1. Speed 2. Temperature 3. Current 4. Voltage 5. Pressure 6. Eccentricity 7. Flow of Gases 8. Vacuum Pressure 9. Valves 10. Level
PRESSURE MONITORING Pressure can be monitored by three types of basic mechanisms 1. Switches 2. Gauges 3. Transmitter type For gauges we use Bourdon tubes. The Bourdon Tube is a non-liquid pressure measurement device. It is widely used in applications where inexpensive static pressure measurements are needed. A typical Bourdon tube contains a curved tube that is open to external pressure input on one end and is coupled mechanically to an indicating needle on the other end, as shown schematically below.
Typical Bourdon Tube Pressure Gages
For Switches pressure switches are used and they can be used for digital means of monitoring as switch being ON is referred as high and being OFF is as low. All the monitored data is converted to either Current or Voltage parameter. The Plant standard for current and voltage are as under • Voltage : 0 – 10 Volts range • Current : 4 – 20 milli-Amperes
We use 4mA as the lower value so as to check for disturbances and wire breaks. Accuracy of such systems is very high. ACCURACY : ± 0.1 % Programmable Logic Circuits (PLCs) are used in the process as they are the heart of Instrumentation.
TEMPERATURE MONITORING We can use Thermocouples or RTDs for temperature monitoring. Normally RTDs are used for low temperatures. Thermocouple selection depends upon two factors: 1. Temperature Range 2. Accuracy Required Normally used Thermocouple is K Type Thermocouple: In this we use Chromel (Nickel-Chromium Alloy) / Alumel (Nickel-Aluminium Alloy) as two metals. This is the most commonly used general purpose thermocouple. It is inexpensive and, owing to its popularity, available in a wide variety of probes. They are available in the−200°C to +1200°C range. Sensitivity is approximately 41 μV/°C. RTDs are also used but not in protection systems due to vibrational errors. We pass a constant current through the RTD. So that if R changes then the Voltage also changes RTDs used in Industries are Pt100 and Pt1000 Pt100 : 0°C – 100 Ω ( 1 Ω = 2.5 0C ) Pt1000 : 0°C - 1000Ω Pt1000 is used for higher accuracy. The gauges used for Temperature measurements are mercury filled Temperature gauges. For Analog medium thermocouples are used and for Digital medium Switches are used which are basically mercury switches.
FLOW MEASUREMENT Flow measurement does not signify much and is measured just for metering purposes and for monitoring the processes
ROTAMETERS: A Rotameter is a device that measures the flow rate of liquid or gas in a closed tube. It isoccasionally misspelled as 'Rotometer'. It belongs to a class of meters called variable area meters, which measure flow rate by allowing the cross sectional area the fluid travels through to vary, causing some measurable effect. A rotameter consists of a tapered tube, typically made of glass, with a float inside that is pushed up by flow and pulled down by gravity. At a higher flow rate more area (between the float and the tube) is needed to accommodate the flow, so the float rises. Floats are made in many different shapes, with spheres and spherical ellipses being the most common. The float is shaped so that it rotates axially as the fluid passes. This allows you to tell if the float is stuck since it will only rotate if it is not. For Digital measurements Flap system is used. For Analog measurements we can use the following methods : 1. Flow meters 2. Venturimeters / Orifice meters 3. Turbines 4. Mass flow meters ( oil level ) 5. Ultrasonic Flow meters 6. Magnetic Flow meter ( water level ) Selection of flow meter depends upon the purpose, accuracy and liquid to be measured so different types of meters used .
TURBINE TYPE: They are simplest of all. They work on the principle that on each rotation of the turbine a pulse is generated and that pulse is counted to get the flow rate.
Referring to the diagram, using Bernoulli's equation in the special case of incompressible fluids (such as the approximation of a water jet), the theoretical pressure drop at the constriction would be given by (ρ/2)(v22 - v12). And we know that rate of flow is given by: Flow = k √ (D.P) Where DP is Differential Presure or the Pressure Drop.
CONTROL VALVES A valve is a device that regulates the flow of substances (either gases, fluidized solids, slurries, or liquids) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but usually are discussed separately. Valves are used in a variety of applications including industrial, military, commercial, residential, transportation. Plumbing valves are the most obvious in everyday life, but many more are used. Some valves are driven by pressure only, they are mainly used for safety purposes in steam engines and domestic heating or cooking appliances. Others are used in a controlled way, like in Otto cycle engines driven by a camshaft, where they play a major role in engine cycle control. Many valves are controlled manually with a handle attached to the valve stem. If the handle is turned a quarter of a full turn (90°) between operating positions, the valve is called a quarter-turn valve. Butterfly valves, ball valves, and plug valves are often quarter-turn valves. Valves can also be controlled by devices called actuators attached to the stem. They can be electromechanical actuators such as an electric motor or solenoid, pneumatic actuators which are controlled by air pressure, or hydraulic actuators which are controlled by the pressure of a liquid such as oil or water. So there are basically three types of valves that are used in power industries besides the handle valves. They are : · PNEUMATIC VALVES – They are air or gas controlled which is compressed to turn or move them · HYDRAULIC VALVES – They utilize oil in place of Air as oil has better compression
· MOTORISED VALVES – These valves are controlled by electric motors
FURNACE SAFEGUARD SUPERVISORY SYSTEM FSSS is also called as Burner Management System (BMS). It is a microprocessor based programmable logic controller of proven design incorporating all protection facilities required for such system. Main objective of FSSS is to ensure safety of the boiler. The 95 MW boilers are indirect type boilers. Fire takes place in front and in rear side. That’s why it’s called front and rear type boiler. The 210 MW boilers are direct type boilers (which means that HSD is in direct contact with coal) firing takes place from the corner. Thus it is also known as corner type boiler.
IGNITER SYSTEM Igniter system is an automatic system, it takes the charge from 110kv and this spark is brought in front of the oil guns, which spray aerated HSD on the coal for coal combustion. There is a 5 minute delay cycle before igniting, this is to evacuate or burn the HSD. This method is known as PURGING.
PRESSURE SWITCH Pressure switches are the devices that make or break a circuit. When pressure is applied, the switch under the switch gets pressed which is attached to a relay that makes or break the circuit. Time delay can also be included in sensing the pressure with the help of pressure valves. Examples of pressure valves: 1. Manual valves (tap) 2. Motorized valves (actuator) – works on motor action 3. Pneumatic valve (actuator) _ works due to pressure of compressed air 4. Hydraulic valve
IT DEPARTMENT IT BTPS VISION IT ROLE & RESPONSIBLITIES @BTPS IT APPLICATION @BTPS BENEFITS OF IT INNOVATION @ BTPS VARIOUS E-SERVICES @BTPS SMS ALERT @ BTPS REWARDS & RECOGNITION
BTPS IT VISION
INTEGRATED IT ENABLEMENT OF BUSINESS PROCESSES FOR EFFICIENT PLANT MANAGEMENT INFORMATION ANYTIME ANYWHERE
IT ROLE & RESPONSIBILITIES @ BTPS 1. Development, Implementation & Support for Local Applications 2. Procurement & Maintenance of IT Infrastructure ( PCs, Printers, Servers & Network LAN,WAN etc) 3. Support to users for ERP & modules to supplement ERP. 4. Customization & Implementation support for BTPS Applications to other projects.
IT APPLICATION @ BTPS At BTPS, Information Technology has been used extensively to manage following business processes1. Maintenance Management System 2. Materials Management System 3. Financial Accounting System 4. Contracts Management System 5. Operations & ABT Monitoring System 6. Coal Monitoring & Accounting System 7. Hospital Management System 8. HR, T/S & Training Management System 9. Office Automation & Communication System 10. E-Samadhan complaints monitoring system
Benefits of IT Innovations @ BTPS 1. OPERATIONS Important & critical parameters of Power Plant operation are monitored online to enable effective control on operation of various equipments and reduce down time. Online load analysis & Generation values are monitored to have optimum load balance of various units. Auxiliary power consumption monitored and controlled. Meritorial operation practicing enabled.
2. MAINTENANCE Better control over maintenance cost by way of online information available through the system.Based on failure analysis and equipment history, modified maintenance strategy of Preventive, Predictive and Risk Based maintenance is implemented. Equipment spares planning are streamlined by way of Annual
requirement, Vendor wise, linked to Equipment, Standardization of defects and repair codes for easy filling of Work Order Card, for future analysis.
3. MATERIALS Material Planning and Procurement system streamlined, resulting in reduction in Administrative lead Time. Further, procurement on Annual Rate Contract basis enabled through the system, Ordering on actual need basis (just in time). This further reduces lead time and Inventory carrying. Detection of duplicate and obsolete items, standardization of material description and specification, Cleaning and Weeding of redundant data, resulting in overall system improvement and functionalities, Availability of coal stock status online, reduction in demurrages paid to railways.
4. OFFICE AUTOMATION AND COMMUNICATION With implementation of e-Desk/e-broadcast, e-alerts, auto mail and BTPS website, information is available instantly to all and all time, resulting in tremendous reduction in paper communication and cost.
BTPS IT Applications Highlights 1. 2. 3. 4.
Single Login screen, Pass Word & Role based secured access . G.U. Interface, Easy information retrieval/search facility. Information captured once at source. Automation of routine activities.
A View of BTPS Login Page
ERP/SAP MODULES IMPLEMENTED (ERP-ENTERPRISE RESOURCES PLANNING)
Maintenance Management- PM Finance Management- FI Materials Management- MM Human Resource Management- HR Operations Management- OPN Employee Self Service- ESS
Maintenance Management system, Anurakshan @ BTPS 1. 2. 3. 4. 5. 6. 7.
Permit to Work Issue with detailed feedback. Daily Plant Meeting minutes generated online. Trends of defects priority wise /department wise for a period. Equipment history with detailed feedback available. Analysis of repeated equipment failure for corrective action. Standardization of defects & repair codes. Interface with Materials Management System & CMS for WOC cost
MATERIAL & CONTRACT MANAGEMENT SYSTEM (CMS) 1. Initiation and approval of Contract Proposal. 2. Preparation of Tender Documents and approvals. 3. Preparation and processing of Bills.
FINANANCIAL ACCOUNTING SYSTEM (FAS) 1. Status of Income Tax Details, PF slips, Leave, Accrued Interest, and Earning Card available online. 2. Fund Flow Statements & other Reports for day to day functioning. 3. Bank Reconciliation.
Coal Accounting System (CAS) 1. Online uploading of Wagon wise Weight from Wagon Tipplers. 2. Coal and Rail Freight bill payments accounting & reconciliation. 3. Tariff Summary, coal accounting and MIS reports generated from the system.
HOSPITAL MANAGEMENT SYSTEM (HMS) 1. Online patient registration 2. Doctor’s prescription 3. Medicines issues/availability
4. Investigation reports 5. Annual check-ups, patient history , referrals etc.
A View of Hospital Management System
HR/TRAINING MANAGEMENT SYSTEM 1. 2. 3. 4.
Computerized Attendance recording system. Employee database to record/ update information of employees Township/Quarter management system. Performance Management analysis & evaluation system.
A View of Tanning Management System
VARIOUS E-SERVICES @ BTPS
KEY FOCUS AREA
AUTOMATION & COMMUNICATION
TOWAREDS PAPERLESS OFFICE
E-Desk , E-Broadcast, SMS & E-Mail as Primary Communication & Document Delivery System.
SMS ALERT @ BTPS 1. 2. 3. 4.
One more IT initiative for fast & convenient way to information sharing thru SMS Automatic SMS alert is already in use for plant load & unit Trip. Send SMS instantly or scheduled date/time. SMS to groups or individual numbers.
Plant Load & Unit Trip SMS Alert
REWARDS & RECOGNITION
Badarpur has achieved unique distinction of being; First site in NTPC, with independent initiative of Development & Implementation of new Oracle based integrated online Applications, with in house effort. This has been appreciated by NTPC higher management. BTPS Received Golden Peacock award for IT Innovation in 2004.
TRAINING REPORTS OF PAST YEARS AT NALANDA LIBRARY INTERNET DOCUMENTS OF IT DEPARTMENT