THERMAL POWER PLANT
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20-10-2010, 02:44 PM
In India 65% of total power is generated by the Thermal Power Stations.
Yamunanagar Thermal Power Project i.e D.C.R.T..P.P(Deen Bandhu ChotuRam Thermal Power Plant) is a project and implimentation of Haryana Power Generation Corporation limited (HPGCL). It is situated at village Kalanor In Yamunanagar. Its total capacity is 600 MW as at present with two units working with capacity.
Having two unit of 2 x 300 MW = 600 MW
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02-03-2011, 09:35 AM
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THERMAL POWER PLANT
Now a day’s the electricity has become an essential commodity rather than luxury. In a state or region thermal power stations will become important, as hydro resources are inadequate. The concept of modern thermal power stations is that it should be situated at such a place that the basic requirements of fuel, water & land should be satisfied. Basically thermal stations are of two types,
1. Pit Head Stations.
2. Load Demand Stations.
Pit head stations are those which are near to the source of fuel and load demand stations are those which are near to the load centers.
The thermal power station is just like any other industry.
The basic requirements are:
a. Supply of raw materials at competitive costs. Coal and oil are the raw materials required for thermal plants.
b. Access to the markets for its products.
c. Labour force of the size and quantity required.
d. Means of disposal for any trade effluents that is by-products.
The other factors to be considered for selecting the site are:
1. Load Demand
3. Site Requirements
4. Access for Construction
5. Transmission Lines
7. Environmental Factors
Generally 1000 MW plant requires 90-200 acre land. The water requirements for thermal stations come under two main groups. The first requirement is for steam generation and the second requirement is for cooling purpose. Water for steam generation is low of the order of 3-4 tones per hour per megawatt, and make up quantity is 2-3% of the same. Whereas amount of water required for condensation is quite high. Coal for power stations in India, the principal source of commercial energy is amounting to 95% of the total primary energy resources of the country. The coal resources existing in the country are of the order of 1,30,000 million tones.
The main areas where the coal mines are located are the eastern region i.e. Bihar, Bengal central region, Singareni coal fields, Tamilnadu, Naively and small resources located in the rest of the country as well.
Other factors like transport, disposal of effluents, transmission, climatic conditions, proximity of air fields, fisheries and marine life, personnel required and amenities are also taken for considerations.
1.2 PRINCIPLE OF OPERATION:-
The fundamental forms of energy with which thermal stations are principally concerned are heat and work. Heat produces work and this work is further converts into electrical energy through a medium i.e. electrical generator. For the purpose of understanding of thermal plants, the phenomenon of thermodynamic vapour power cycles explained here under.
a. Rankine cycle
b. Reheat cycle
c. Regenerative cycle
a. RANKINE CYCLE:-
This is the simplest theoretical vapour cycle which is the basis for operation of a steam plant. Superheated steam from the boiler is fed into the prime mover and is expanded there. After which it enters the condenser emerging as the condensate. With the help of a pump this condensate is again fed into the boiler.
The main purpose of superheating steam and supplying it to the prime mover is to avoid too much wetness at the end of expansion. Moisture content of steam would result in undue blade erosion. The maximum wetness in the final stage of the steam that may be tolerated without any appreciable harm to the turbine blades is about 12%. Also the use of super heater in the boiler helps in reducing the stack temperature by extracting the heat from the flue gases before these are passed out of the chimney.
b. REHEAT CYCLE:-
In its simplest form the cycle involves with drawing the steam from the turbine at some intermediate stage, returning it to the steam generator where a separate super heater is provided in the gas path re-superheating the steam after which it is re introduced into the turbine at the following stage. It reduces the wetness of the steam at final stage and improves the efficiency of the cycle.
c. REGENERATIVE CYCLE:-
This cycle is an attempt to induce reversibility in the ordinary rankine cycle and thus to increase its efficiency. The mixing of coal condensate with the saturated steam and water mixture in the boiler constitute the principal irreversible process of the cycle and generation aims at reducing this irreversibility by heating the feed water near to the saturation temperature through the utilization of heat of the steam which is partially expanded in the prime mover. Since the purpose is the thermal regeneration of the condensate the cycle is known as regenerative cycle.
1.3 COAL TO STEAM PROCESS:-
Coal from mines is brought to plant through wagons and these wagons are unloaded in coal handling plant. The coal is transported to raw coal bunkers with the help of belt conveyors. Coal is then transported to mills through feeders where the coal is pulverized to powder form. This coal powder is lifted to the boiler with the help of primary air fans (PA fan). PA fan takes the air from the atmosphere, a part of which is sent to air pre heater for heating while a part goes directly to the mills for temperature control. Atmospheric air from FD fan heated in the air heaters and sent to the furnace as combustion air.
Water from the boiler feed pumps passes through the economizer and reaches the boiler drum. Water from the drum passes through the down comers and goes to bottom ring header. Water from the ring header is divided to all four sides of the furnace. Due to the heat and density difference the water raises up in the water wall tubes. Water is partially converted to steam as it rises up in the furnace. This steam and water mixture is taken to the boiler drum where the steam is separated from the water with the help of turbo separators. Water follows the same path while the steam is sent to superheaters for superheating. The superheaters are located inside the furnace and the steam is superheated (540o C) and finally it goes to turbine.
Flue gases from the furnace is extracted by the induced draft fans (ID fans), which maintains balance draft in the furnace with forced draft fan. This flue gases emit their heat energy to various superheaters in the pent house and finally passes through air preheaters and goes to electrostatic precipitator, where the ash particles are extracted. Electro static precipitators consist of metal plates, which are electrically charged. Ash particles are attracted on to these plates, so that they do not pass through the chimney to pollute the atmosphere. Regular mechanical hammers blows cause the accumulation of ash to fall to the bottom of the precipitator, where they are collected in a hopper for disposal. This ash is mixed with water to form slurry and is pumped to ash pond.
1.4 STEAM TO MECHANICAL POWER:-
A steam pipe conveys steam to the turbine through stop valve and control valves that automatically regulate the supply of the steam to the turbine. Steam from the control valves enters the high-pressure cylinder of the turbine, where it passes through a ring of stationary blades fixed to the cylinder wall. These act as nozzles and direct the steam into second ring of moving blades mounted on a disc secured to the turbine shaft. This second ring turns the shaft as a result of the force of the steam. The stationary and moving blades together constitute a stage of the turbine and in practice many stages are necessary so that cylinder contain a number of rings of stationary blades with rings of moving blades arranged between them. The steam passes through each stage in turn until it reaches the end of the high pressure cylinder and in its passage some of its heat energy is changed in to mechanical energy.
The steam leaving high pressure cylinder goes back to the boiler for reheating and enters into intermediate pressure cylinder through HRH lines. Hence it passes through another series of stationary and moving blades.
Finally steam is taken to the low pressure cylinders, each of which it enters at the center for following outwards in the opposite direction through the rows of turbine blades- an arrangement is known as double flow to the extremities of the cylinder. As the steam gives up its heat energy to drive the turbine, its temperature and pressure fall and it expands. Because of this expansion the blades are much larger and longer towards the low pressure end of the turbine.
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23-02-2012, 05:08 PM
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THERMAL POWER PLANT
54427928-Ind-Training-Report-NTPC-DADRI.doc (Size: 1.66 MB / Downloads: 106)
Overview of NTPC
NTPC was set up in the central sector in the 1975 in response to widening demand & supply gap with the main objective of planning, promoting & organizing an integrated development to thermal power in India. Ever since its inception, NTPC has never looked back and the corporation is treading steps of success one after the other. The only PSU to have achieved excellent rating in respect of MOU targets signed with Govt. of India each year. NTPC is poised to become a 40,000 MW gint corporation by the end of XI plan i.e. 2012 AD. Lighting up one fourth of the nation, NTPC has an installed capacity of 19,291 MW from its commitment to provide quality power; all the operating stations of NTPC located in the National Capital Region & western have acquired ISO 9002 certification. The service groups like Engineering, Contracts, materials and operation Services have also bagged the ISO 9001 certification. NTPC Dadri, Ramagundam, Vindhyachal and Korba station have also bagged ISO 14001 certification.Today NTPC contributes more than 3 / 5th of the total power generation in India.
Station At Glance
NTPC dadri is model project and implimentation of NTPC . also it tit the best project and implimentation of NTPC also known as NCPS ( National capital power station ). Situated 60 kms away from Delhi in the District of gautam budh Nagar, Uttar Pradesh. The station has an installed capacity of 1669 MW of power – 840 MW from Coal based units and 829 MW Gas Based Station . the station is excelling in performance ever since it’s commercial operation . consistently in receipts of meritorious project and implimentationivity awards, the coal based units of the station stood first in the country in terms of PLF for the financial year 1999 – 2000 by generating an all time national high PLF of 96.12 % with the most modern O & M Practices. NTPC – Dadri is committed to generated clean and green Power. The Station also houses the first HVDC station of the country (GEP project and implimentation) in association with centre for power efficiency and Environment protection (CENEEP) – NTPC & USAUID. The station has bagged ISO 14001 & ISO 9002 certification during the financial year 1999 – 2000, certified by Agency of International repute M/s DNV Netherlands M/s DNV Germany respectively
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12-04-2012, 03:51 PM
THERMAL POWER PLANT
thermal pwr plant.ppt (Size: 1.89 MB / Downloads: 158)
A Thermal Power Plant converts the heat energy of coal into electrical energy. Coal is burnt in a boiler which converts water into steam. The expansion of steam in turbine produces mechanical power which drives the alternator coupled to the turbine.Thermal Power Plants contribute maximum to the generation of Power for any country . Thermal Power Plants constitute 75.43% of the total installed captive and non-captive power generation in India . In thermal generating stations coal, oil, natural gas etc. are employed as primary sources of energy.
Coal handling plant
The function of coal handling plant is automatic feeding of coal to the boiler furnace.
A thermal power plant burns enormous amounts of coal.
A 200MW plant may require around 2000 tons of coal daily
The circulation of air is caused by a difference in pressure, known as Draft.
Draft is a differential pressure b/w atmosphere and inside the boiler.
It is necessary to cause the flow of gases through boiler setting
Superheater and reheater
Superheater is a component of a steam-generating unit in which steam, after it has left the boiler drum, is heated above its saturation temperature. The amount of superheat added to the steam is influenced by the location, arrangement, and amount of super heater surface installed, as well as the rating of the boiler. The super heater may consist of one or more stages of tube banks arranged to effectively transfer heat from the products of combustion. Super heaters are classified as convection , radiant or combination of these.
A steam turbine converts heat energy of steam into mechanical energy and drives the generator. It uses the principle that steam when issuing from a small opening attains a high velocity. This velocity attained during expansion depends on the initial and final heat content of the steam. This difference b/w initial and final heat content repesents the heat energy converted into kinetic energy.
These are of two types :-
Flue gases coming out of the boiler carry lot of heat. An economiser extracts a part of this heat from flue gases and uses it for heating feed water. This use of economiser results in saving coal consumption and higher boiler efficiency
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21-04-2012, 04:58 PM
THERMAL POWER PLANT
thermal power plant.pptx (Size: 1.37 MB / Downloads: 48)
Principle of a thermal power plant
The generation of power in any coal oriented plant is based on the Rankine cycle.
In a rankine cycle:-
Coal is burnt in a boiler which converts water in to steam.
The expansion of steam in turbine produces mechanical power which drives the alternator.
Thus, the main equipment in the Thermal Power Plant consists of Boiler, Turbine and an alternator.
Main functions of a thermal power station
How the power is generated ?
Which method is used for moving the turbine?
In RSWM THERMAL POWER PLANT the power is generated by steam turbine and this steam is produced by coal.
How much power is transmitted ?
HOW is the SWITCHYARD designed ?
In this plant 11kv generated and 132 kv is transmitted by a step up transformer.
PARTS OF THE POWER PLANT
According to the above mentioned functions the power plant has four main parts:-
C.H.P or the coal handling plant
Water tube boiler is used in this plant. Steam pressure at inlet is 102 kg/cm² & steam temp. at inlet is 535˚C. In this boiler , water is flow in the tube in furnace . Steam produces in tube & it collect in a drum which is situated on the top of boiler . Then steam goes to turbine .
The distributed control system(D.C.S)
A distributed control system (DCS) refers to a control system usually of a manufacturing system, process or any kind of dynamic system, in which the controller elements are not central in location (like the brain) but are distributed throughout the system.In R.S.W.M the D.C.S used is SPPA-T1000
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20-06-2012, 01:56 PM
THERMAL POWER PLANT
seminarreport on thermal powerplant.docx (Size: 150.31 KB / Downloads: 51)
For the power generation with 2x110 MW and 3x210 MW of K.T.P.S. authorities are required to be operative to active full operation. The auxiliaries are basically operation either on L.T. System i.e. 415 V 3 Ø power supply is made available to the system after providing the station transformer of 3x50 MVA capacity with voltage 220 KV/ 7.2/7.2 KV & different service transformers of capacity 1.0 MVA , 1.5 MVA , 2.0 MVA , which are located near the load centre as the transformer having the voltage of 6.6 KV /415 V. The 6.6 KV power is distributed through 6.6 KV interconnected Bus System for all the five units with a control through DC of 220 V.
The 415 V power supply is done through a L.T. SWGR (Switchgear) which are located nearby the distribution transformer as well as the load centers. The all in -comers, which are breaker controlled , are having the control the L.T. SWGR are having the control system on 110/ 220 V AC. The 6.6 KV power supply which are either MOCB (Minimum Oil Circuit Breaker) of JYOTI MAKE or Air Circuit Breakers.
The 6.6 KV power supply to various draining equipment’s i.e. more is made through breakers which are either MOCB of Jyoti make air circuit breaker which are either of voltage makers as well as SF 6 of NGEF make. The LT supply is also controlled through air break circuit breaker which are either L&T make or English Electric Company of India. The various H.T. motors are switched on / started through on direct ON line (DOL) in order to inverse the availability of equipment at full efficiency without time gap.
Further , the 6.6 KV system which is normally in delta configuration and terms as an unearthed system so also to keep the running motor complete in operating condition in case of any one .phase of motor winding is earthed due to any one reason. Earthling is detected by an protection system with alarm facility to take remedial measures immediately and at the same time to maintain the generation level in the same condition, prior to occurring the earth fault the single phase earth fault is detected in due course till the motor is not earthed to other or another phase.
“PUBLIC ADDRESS SYSTEM” is available through in area of each unit which helps in fast communication for prompt remedial measure.
Soot Blowers are there in the boiler area on the furnace side or Zone which helps in blowing the soot / ash deposition regularly of the furnace wall / economizer tubes to keep heat transfer at the required parameter.
In April 1973, Central Electricity Authority prepared a Project Report for power station comprising of the two units of each of capacity 110 MW for RSEB subsequently in September 1975 this was revised by the Consultant Thermal Design Organization, Central Electricity Authority for invention of 2x110 MW units being manufactured by BHEL, Hyderabad in 1st Stage.
The planning commission cleared the project and implimentation report in Sept 1976 for installation of two units each of 110 MW in first estimated cost of Rs. 143 Crores.
The Kota Thermal Power Station is ideally on the left bank of Chambal River at Up Stream of Kota Barrage . The large expanse of water reached by the barrage provides an efficient direct circulation of cooling system for the power station. The 220 KV GSS is within ½ Kms. from the power station.
Land measuring approx. 250 hectares was required for the project and implimentation in 1976, For disposal of ash tank very near to power station is acquired which the ash in slurry form is disposed off through ash and slurry disposal plants.
Coal India limited owns and operates all the major coal fields in India through its coal producing subsidiary companies viz. Eastern Coal Fields Limited, Western Coal Fields Limited Coal India limited is supply coal from its coal mines of coal producing subsidiaries BCCL, SECL & ECL to Kota Thermal Power Station through railway wagons. The average distances of SECL, ECL & BCCL are 800, 950 and 1350 Kms. Respectively.
The source of water for power station is reservoir formed by Kota Barrage on the Chambal River. In case of large capacity plants huge quantities of coal and water is required. The cost of transporting coal and water is particularly high. Therefore, as far as possible, the plant must be located near the pit rather than at load centre for load above 200 MW and 375 MW . The transportation of electrical energy is more economical as compared to the transportation of coal.
The satisfactory design consists of the flowing steps.
Estimation of cost.
Selection of site.
Capacity of Power Station.
Selection of Boiler & Turbine.
Selection of Condensing Unit.
Selection of Electrical Generator.
Selection of Cooling System.
Design of Control and instrumentation system.
The design of steam power station requires wide experience as the subsequent operation and maintenance are greatly affected by its design. The most efficient design consist of properly sized component designed to operate safely and conveniently along with its auxiliaries and installation.
General Layout & Basic Idea
A control system of station basically works on Rankin Cycle. Steam is produced in Boiler is exported in prime mover and is condensed in condenser to be fed into the boiler again. In practice of good number of modifications are affected so as to have heat economy and to increase the thermal efficiency of plant.
The Kota Thermal Power Station is divided into four main circuits :
Fuel and Ash Circuit.
Air and Gas Circuit.
Feed water and Steam Circuit.
Cooling Water Circuit.
Fuel & Ash Circuit
Fuel from the storage is fed to the boiler through fuel handling device . The fuel used in KTPS is coal , which on combustion in the boiler produced the ash. The quantity of ash produced is approximately 35-40% of coal used. This ash is collected at the back of the boiler and removed to ash storage tank through ash disposal equipment.
Air and Gas Circuit
Air from the atmosphere is supplied to the combustion chamber of Boiler through the action of forced draft fan and induced draft fan. The flue gas gases are first pass around the boiler tubes and super heated tubes in the
furnace, next through dust collector (ESP) & then economizer. Finally, they
are exhausted to the atmosphere through fans.
Feed Water and Steam Circuit
The condensate leaving the condenser is first heated in low pressure (LP) heaters through extracted steam from the lower pressure extraction of the turbine. Then its goes to dearator where extra air and non-condensable gases are removed from the hot water to avoid pitting / oxidation. From deaerator it goes to boiler feed pump which increases the pressure of the water. From the BFP it passes through the high pressure heaters. A small part of water and steam is lost while passing through different components therefore water is added in hot well. This water is called the make up water. Thereafter, feed water enters into the boiler drum through economizer. In boiler tubes water circulates because of density difference in lower and higher temperature section of the boiler. The wet steam passes through superheated. From superheated it goes into the HP turbine after expanding in the HP turbine. The low pressure steam called the cold reheat steam (CRH) goes to the reheater( boiler). From reheater it goes to IP turbine and then to the LP turbine and then exhausted through the condenser into hotwell.
Cooling Water Circuit
A large quantity of cooling water is required to condense the steam in condenser and marinating low pressure in it. The water is drawn from reservoir and after use it is drained into the river.
ELECTRICITY GENERATOR AT K.T.P.S.
Thermal power station burns the fuel and use the resultant heat to raise the steam which drives the turbo-generator. The fuel may be “Fossil” ( Coal , Oil and Natural Gas) whichever fuel is used the object is same to convert the heat into mechanical energy to electrical energy by rotating a magnet inside the set of winding. In a coal fired thermal power station other raw materials are air and water. The coal is brought to station by train or other means travels from the coal handling system.
i) By conveyer belts to coal bunkers from where it is fed to pulverizing mills.
ii) Mills grind it fine as face powder.
iii) Then this powdered coal mixed with preheated air is blow into boiler by a fan known as primary air fan (PA fan).
iv) When it burns more like a gas as solid in conventional domestic or industrial grate with additional amount of air called secondary air supplied by “Forced Draft Fan”.
As the coal has been grinded so resultant ash is also as fine as powder. Some of its fine particles blinds together to form lumps which falls into the ash pit at the bottom of furnace.
v) The water quenched ash from the bottom of furnace is carried out boiler to pit for subsequent disposal.
vi) Most of ash still in fine particles form is carried out to electrostatic precipitators where it is trapped by electrode charged with high voltage electricity. The dust is then conveyed to the disposal area or to bunkers for sale.
vii) Now after passing through ESP few gases are discharged upto chimney by “Induced Draft Fan”.
Meanwhile the heat reloaded from the coal has been absorbed by kilometers long tubes which lies in boiler walls inside the tubes “ Boiler Feed Water” which is transferred into turbine blades and makes them rotate.
To the end of the turbine rotor of generator is coupled, so that when turbine rotates the rotor turns with it. The rotor is housed inside the stator having coil of copper bars in which electric is produced through the movement of magnetic field created by rotor.
The electricity passes from the stator winding to the transformer which steps up the voltage so that it can be transmitted effectively over the power line of grid.
The steam which has given up its heat energy in changed back into a condenser so that it is ready for reuse. The cold water continuously pumped in condenser. The steam passing around the tubes looses heat and rapidly change into water. But these two types of water ( boiler feed water and cooling water ) must never mix together. The cooling water is drawn from the river but the Boiler Feed Water must be pure than potable water ( DM Water).
Now the question arises why do we bother to change steam from turbine to
water when it is to be heated up again immediately ?
Laws of Physics gives the answer which states that the boiling point of water is related to pressure. The lower the pressure lower the boiling point temperature. Turbine designer wants boiling point temperature as low as possible because it can only utilize the energy from steam when change back to water, he can get no more work out at it. So there is a condenser which by rapidly changing the steam into water a vacuum. The vacuum results in a must power at lower boiling points which in turn mean it can continue getting out of steam will below 1000C at which it would change into water.
To condense volume of cooling water is huge and continuous volume of cooling water is essential. In most of the power stations , the same water is to be used over and over again, so the heat which the water extract from the steam in the condenser is removed by pumping water out of cooling tower. The cooling tower is simple concrete shell acting of air. The water is sprayed out at top of tower and as it falls into pond beneath it cooled by the upward draft of air. The cold water in the pond is then re-circulated by pumps to condensers. Invariably however some of the water drawn upwards as vapor by the draft .
220 KV System
Two 220 KV bus bars have been provided in switch yard and are inter- connected through a bus coupler. Each of the two 110 MW generator is connected to this system through a step up of 125 MVA 240/ 11 KV yard generator transformer. There are two step down transformer each feeding 6.6 KV system (Station Switchyard ) viz. BS-IS & SB-IB. Each station transformer has two windings one secondary side and is rated for 50/25/25 mva , 270/7/7.2 kva four feeder take off from 220 switch yard, two to SKATPURA ,GSS and other to HEERAPURA , Jaipur GSS. Each of four feeder are provided with bypass isolators which is connected across line breaker and breaker isolator. By closing bus coupler between 220 KV buses and putting line feeders whose breaker required maintenance of any one bus through by pass isolators and all other line feeders whose breaker is by passed is then transformed to bus coupler breaker. A brief description of equipments of 220 KV system is as follows.
Each of generator transformer, station transformer, line feeder and bus coupler is provided with minimum oil circuit breaker of BHEL make. It is rated for 245 KW, 2500 A and 13400 MVA circuit breaker is used to break the circuit either in load condition or in no load condition.
All the isolators are provided in 220KV switchyard and are motor operated. Triple pole double breaker type and power switch yard L&T make these and are rates for 245 KV and 1250 A. The four isolators are provided with earth switch.
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19-10-2012, 10:44 PM
1.What are the different waste of thermal power plant & area of reuses /recycle.
2. What is the grade of Oil used in furnesh
Joined: Oct 2012
20-10-2012, 11:16 AM
to get information about the topic "THERMAL POWER PLANT" full report ppt and related topic refer the link bellow