28-04-2011, 02:25 PM
32553390-KSTPS-Traning-Report.doc (Size: 6.94 MB / Downloads: 627)
CHAPTER -1
INTRODUCTION
For the power generation with 2x110 MW and 3x210 MW of K.S.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 incomers, 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 report in Sept., 1976 for installation of two units each of 110 MW in first estimated cost of Rs. 143 Crores.
The KSTPS has four stage & six unit power station. In first stage there is 2 unit of 110 MW, in second stage 2 unit of 210 MW. In third & fourth stage, there each having 210MW &195 MW units respectively. The construction of fifth stage Of 195 MW is under construction and may be possibly completed up to sept. 2008. The total power generated in KSTPS is 1045 MW.
K.S.T.P.S. IS DESISIGNED IN FOLLOWING STAGES:-
STAGE I - 2x110 MW
STAGE II - 2X210 MW
STAGE III - 1X210 MW
STAGE IV - 1X195 MW
STAGE V - 1X195MW *
* Stage V is to be commissioned shortly in Sept. 2008.
LOCATION:-
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:-
Land measuring approx. 250 hectares was required for the project 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:-
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.
WATER:-
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.
DESIGN FEATURES:-
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.
CHAPTER -2
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 KSTPS 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 hot well.
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.
COAL HANDLING PLANT
INTRODUCTION:-
It can be called the heart of thermal power plant because it provided the fuel for combustion in boiler. The coal is brought to the KSTPS through rails there are fourteen tracks in all for transportation of coal through rails. The main coal sources for KSTPS are SECL (South Eastern Coalfields Limited), ECL (Eastern Coalfield Limited) and BCCL (Bharat Coking Coal Limited). Everyday 3 to 4 trains of coal are unloaded at KSTPS. Each train consists of 58 wagons and each wagons consists of 50 tonnes of coal. The approximate per day consumption at KSTPS is about 1400 metric tones. It costs approximate 2 crores of rupees per day including transportation expenses. The coal is firstly unloaded from wagon by wagon triplers then crushed by crushers and magnetic pulley and pulverized to be transformed to the boiler. The whole transportation of coal is through conveyor belt operated by 3-Ø Induction motor.
The coal handling plant can broadly be divided into three sections :-
1) Wagon Unloading System.
2) Crushing System.
3) Conveying System.
WAGON UNLOADING SYSTEM:-
Wagon Tripler:-
It unloads the coal from wagon to hopper. The hopper, which is made of Iron , is in the form of net so that coal pieces of only equal to and less than 200 mm. size pass through it. The bigger ones are broken by the workers with the help of hammers. From the hopper coal pieces fall on the vibrator. It is a mechanical system having two rollers each at its ends.
The rollers roll with the help of a rope moving on pulley operated by a slip ring induction motor with specification:
Rated Output. : 71 KW.
Rated Voltage. : 415 V.
Rated Current. : 14.22 Amp.
Rated Speed. : 975 rpm.
No. of phases. : 3
Frequency. : 50 Hz.
The four rollers place themselves respectively behind the first and the last pair of wheels of the wagon. When the motor operates the rollers roll in forward direction moving the wagon towards the “Wagon Table”. On the Wagon table a limit is specified in which wagon has to be kept otherwise the triple would not be achieved.
CRUSHING SYSTEM:-
Crusher House:-
It consists of crushers which are used to crush the coal to 20 mm. size. There are mainly two type of crushers working in KSTPS:-
Primary Crushers i.e. i) Rail crushers or ii) Rotary breaker.
Secondary Crushers. i.e. Ring granulators.
Primary Crushers:-
Primary crushers are provided in only CHP stage 3 system, which breaking of coal in CHO Stage 1 & Stage 2 system is done at wagon tripler hopper jail up to the size (-) 250 mm.
Roll Crusher:-
Type : 80” 5 A breakers.
Capacity : 1350 TPH Rates/ 1500 TPH Design.
Feed material : Rom Coal.
Feed size. : (-) 1200 mm. (approx.)
End Product size : (-) 500 mm.
Motor rating. : 2 Nos. 125 KW, 100 rpm.
Crushers. : 225.
Rotary Breaker:-
Type : 12’ x 21o Rotary Breaker.
Capacity : 800 TPH Rated/ 1000 TPH Design.
Feed Material. : Coal with rejects.
Feed size. : (-) 0-500 mm.
End product size : (-) 0-200 mm.
Motor rating. : 125 HP, 1500 rpm.
Secondary Crusher:-
Basically there are four ways to reduce material size : impact attrition , Shearing and Compression. Most of the crushers employ a combination of three crushing methods. Ring granulators crush by compressing accompanied by impact and shearing.The unique feature of this granulator is the minimum power required for tone for this type of material to be crushed compared to that of other type of crushers.