RE: industrial Visit ( KOTA SUPER THERMAL POWER STATION )
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This article is presented by:
(IV BE Electrical Engg.)
DEPARTMENT OF ELECTRICAL ENGINEERING,
JAIPUR ENGINEERING COLLEGE AND RESEARCH CENTRE,
TONK ROAD, SITAPURA,
KOTA SUPER THERMAL POWER STATION
The “KOTA SUPER THERMAL POWER STATION” is ideally located on the left bank of Chambal River at the upstream of “KOTA BARRAGE”. Thermal power station to produce electrical power for supply undertakings K.S.T.P.S. is designed for ultimate capacity of 1045 MW. First two unit of 110MW each, another three units of 210MW each and further the sixth unit of 195MW has been completed.
The state Rajasthan is predominantly rural and agricultural .While Rajasthan mineral sources are immense, its sources for power generation weren’t commensurable with its requirements. The large expense of water, stored by the “barrage” provides, as efficient direct circulation cooling system for the power station thus avoiding installation of cooling towers. For bringing in coal for power station and machinery and equipment etc. a 15Km long private siding from the Gurla Railway Station on Delhi-Bombay broad gauge line has been laid-up to the power station.
Keeping in view the higher demands of power, it was decided to house initially a 2 x 200 MW thermal power station at Kota on techno-economical reasons as follows-
• Availability of clean water required for station.
• Location of station on Broad gauge main railway line.
• Proximity to Madhya Pradesh Coal fields.
• Concentration of load in Kota region due to large No. of industries located.
The coal linkage for the power station is brought from Dudhichua mines of Singrauli coal field which is about 800 km from Kota.
The source of Water (cooling for the P.S.) is the reservoir formed by “Kota Barrage” on the Chambal River. The water is drawn from this reservoir and after use released near the left main canal of the barrage. The comparative use of water from barrage by the P.S. is 2.75 cusec for each 110 MW unit. A single chimney of 180 Meters height with two separate flues for the two units each of 110 MW is provided. Similarly another chimney with three separate flues is also provided for another three units of 210 MW each. The disposal for fifth unit till now is also through the second chimney.
For Thermal power station the other advantage for choosing Kota are:
• Availability of station amount of clean cooling water required for the station.
• Location of station on broad gauge main Delhi- Bombay Railway line.
• Concentration of load in Kota city and Kota region.
• Constant power supply.
• Proximity to M.P. coal fields.
• Transmission and Grid substation quite nearer to the site.
INSTALLATION AND COMMISSIONING OF UNITS:-
Construction work for stage-I started in 1977 and first unit of 110 MW was commissioned on 17th Jan. 1983.The second 110 MW unit was firstly synchronized in July 1983.
The second stage units are synchronized in 1989. The second unit of second stage was commissioned in Oct. 1989. After that unit of 210 Mw was started in April 11, 1984.
The commencement of unit VI, in Stage IV started in July, 2001 and the synchronization of the unit was done in July, 2003.
Thus the units in K.S.T.P.S. are as:
Stage I - (Two units each of 110 MW)
Stage II- (Two units each of 210 MW)
Stage III- (one unit of 210 MW)
Stage IV- (one unit of 195 MW)
NEED FOR POWER STATION:-
Rajasthan is the largest state in the country. About 30% population lives in villages which are local point of development while Rajasthan mineral resources are immense. But its resources for power station generation not upto requirements.Moreover the state government has drawn up a rural electrification program with a large demand on agricultural load with rapid adoption & modern method of agricultural and industrialization of towns. The mode of living of people in rural and urban areas is changing rapidly with requirement of more power.
The hydro potential available on the Chambal has already has nested fully by the construction of Gandhi Sagar Dam, Rana Pratap Sagar Dam, Jawahar Sagar Hydro P.S.
It is because lack of adequate resources for power development that a Nuclear Power Plant has been established at Rana Pratap Sagar Dam for meeting the anticipated demands of Rajasthan.
The feasibility report for K.S.T.P.S. was prepared by central Electrical authority, in April 73, envisaged an installed Capacity of 2 x 210 MW units and 1 x 200 MW units. The planning commission declared the project in Sep 76 for installation of 2 x 110 units at estimated cost of Rs. 8160 Lakhs. In Aug. 77 M/C Design (New Delhi) Pvt. Ltd., were appointed as consultants for carrying out designing and detailed Engineering of project.
Land measuring 235.5 Hct. was required for the project in 1976-77 for disposal of the ash; a tank very near to power station measuring 157.26 Hct has been acquired, where ash in slurry form is disposed through ash disposal pipe lines.
Rajasthan State Electricity Board (RSEB)completed the construction which is done by Raj. Bridge construction corporation (RBCC) and other auxiliaries are supplied by Bharat Heavy Electrical Limited (BHEL) & Instrumentation Limited (IL), Kota.
ENERGY GENERATED IN KSTPS
Total generation Capacity
= (2 x 210+2 x 210+1 x 210+ 1 x 195) = 1045MW
Total generated Electricity (in one hour)
= 1045MW x 1=10.45Lakh units
Total generated Electricity (in 24hours)
= 10.45 x 24= 250.8 Lakhs units
Amount of Coal required (per day) in KTPS is
= 0.5 x 250.8 x 100000 Kg.
= 125.4 x 100000Kg.
= 125.4 million Kg.
This amount of coal is supplied by 5 trains of coal.
Generator is the main part of thermal power station or any power plant. A generator is a machine which converts mechanical energy into electrical energy.
The generator has gas cooling construction enclosing the stator winding, core and hydrogen coolers .The cooling medium hydrogen is contained within the frame and circulation by fans mounted on either ends of the rotor .The generator is driven by directly coupled steam turbine at a speed of 3000 rpm.
Provision has been made for circulating the cooling water in order to maintain a constant temperature of the coolant i.e. H2 as measured at the fan section side which is in touch with the temperature of the winding, core and other parts as per load.
Each of the 2 units under stage-1 have been provided with BHEL make 3-phase turbo generator rated 137.5 MVA, 11KV, 0.8 pf, 7220 Amp, 3000 rpm and 50 cycles/sec .The generator has closed loop of hydrogen gas system for cooling of the stator and rotor at a pressure of 2.0 atm. is filled in a gas tight outer casing of the generator. H2 gas circulates inside the casing by two single stage rotor mounted fans on either side of the rotor .The heated H2 is in turn cooled by six surface type water coolers axially mounted inside the generator casing .The cooling water is supplied to H2 coolers from the BCW over head tank.
Each generator has terminal led out of its casing and a star point is formed by sorting the neutral side terminals by a sorting bar. The neutral is grounded by a 1-phase 11000/220V, 37.5 KVA. Neutral grounding transformer, whose secondary coil is laminated by laminated strip with mechanical ventilating holes, is connected across a 650V, class 0.4 ohm, 50 kW neutral grounding resistors and relays for protection of generator against stator earth faults and stator in turn faults (rating 1 amp).
The H2 gas inside the generator casing is prevented from leaking in between the rotor and shields, by a continuous oil film maintained between the rotor and sealing rings .The shaft sealing system have two independent oil sources associated pumps, regulators, coolers filters, electrical controls and alarm system. Two independent oil sources are provided for air side and H2 side sealing rings. The oil circuit of the H2 side of the shaft seal is closed and the oil is vacuum treated.
TURBO GENERATOR SPECIFICATIONS:-
(a) STAGE –I
Apparent Output 137.5MVA
Active Output 110 MW
Power factor 0.8 lagging
Rated voltage 11 KV
Rated current 7200 Amp.
Rated speed 3000 rpm
Frequency 50 Hz
Phase connections Double gen. star
No. of generator terminals 6
Max. Output with air cooling 68.75MVA
Excitation voltage 230V
(b) STAGE –II & III
Make KWVC Craftworks,Germany Manufacturer BHEL
Rated capacity 247 MVA
Rated Output 210 MW
Rated current 9050 Amp.
Rated terminal voltage 15.75 KV
Rated speed 3000 rpm
Power factor 0.8 lagging
Excitation voltage 310V
Phase sequence Double star
Insulation class B
No. of turns per phase/pole 10
Short circuit ratio 0.49
© STAGE –IV
Make KWVC Craftworks,German
Rated Capacity 247 MVA
Rated Output 210 MW
Rated Current 9050 Amp.
Rated Terminal Voltage 15.75 KV
Rated Speed 3000 Rpm
Power Factor 0.8 Lagging
Excitation Voltage 310 V
Phase Sequence Double Star
Insulation Class B
No. of Turns per Phase/Pole 10
Short Circuit Ratio 0.49