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| POWER PLANT |
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| Overview |
 The 1215 MW Captive Power Plant (CPP) of Vedanta Limited at Jharsuguda (Orissa) is the largest CPP of India. Situated about 5 KM away from the bustling town of Jharsuguda, this coal-based thermal power plant of Vedanta Limited has been built alongside one of India’s largest deposit of coal at IB Valley and Asia’s largest non-brackish reservoir – ‘Hirakud Reservoir’.
Commissioned in July 2008, the plant is configured with 9 nos. coal-fired sub-critical units of 135 MW. Each unit has sub-critical single-reheat condensing steam turbine and direct pulverized coal-fired natural-circulation boiler of ‘Sanghai Electric’ make. The plant has adopted the state-of-art Digital Control System, High Concentration Slurry Disposal (HCSD) of fly & bottom ash, counter-flow forced Cooling Towers, and multi-flue Stacks. It sources water from Hirakud Reservoir over a distance of 33 kilometers. Coal is transported from Mahanadi Coal Fields through bottom discharge wagons.
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| The Power Making Process |
| Boiler Operations |
In fossil-fueled power plants, water is taken to the boiler or steam generator where coal is burnt. The boiler transfers heat energy to the water in form of latent heat of vaporization or enthalpy by the chemical reaction of burning coal. External fans, such as PA fans and FD fans, are provided to give sufficient air for combustion. The steam generating boiler produces steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. The steam generator includes an economizer, a steam drum, and the furnace with its steam generating tubes, superheater coils and reheater coils. Necessary safety interlocks, fuel purging systems, safety valves are installed to ensure safe operation of the boiler. The air and flue gas path equipment include: forced draft (FD) fan, air preheater (APH), boiler furnace, induced draft (ID) fan, fly ash collectors (ESP or electrostatic precipitator) and the flue gas stack.
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| Steam Turbine |
Steam turbine uses the dynamic pressure generated by expanding steam to turn its blades. The power so produced by the electric generator which is coupled with the turning steam turbine is taken to the switchyard. The aluminium smelter draws power from the switchyard. Any additional requirement is met from the grid and the surplus power beyond requirement is sent to the grid. |
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Raw Materials |
The major input materials for a coal-based plant are coal and water. Continuous make-up water is added to the boiler water system after passing through pre-treatment plant and removal of the salts in a water demineralising (DM) plant. The raw feed coal as collected in the Track Hoppers is first crushed into small pieces and then conveyed to the coal feed bunkers at the boilers. The coal is next pulverized into a very fine powder. Each of the unit in Vedanta’s CPP has deployed four ball mill pulverizers. The boilers use LDO and HFO for initial start-up and low-load operation. |
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| Ash Treatment |
Ash is the major by-product of the plant. Fly ash is captured and removed from the flue gas by high efficient electrostatic precipitators located at the outlet of the furnace. The fly ash is periodically removed from the collection hoppers below the precipitators and is pneumatically transported to storage silos. Here, fly ash is given to cement manufacturers for reutilization. Balance ash is mixed with optimum water to be transported to the ash pond through high concentration slurry disposal. Here, at the bottom the ash collected through clinker grinders is also mixed in slurry form. |
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| Specification of Major Equipments |
| Boiler |
The boiler is superhigh pressure, once reheat, natural circulation, corner tangential firing pulverized coal boiler. It is rated for 400 t/h Superheater steam flow, 15.66 MPa Steam drum pressure, 14.29 MPa Superheated steam outlet pressure, 540 0C Superheated steam outlet temperature, 247 0C Feed watr temperature and 361 t/h Reheated steam flow. |
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| Steam Turbine |
The Steam Turbine is super-high pressure, double cylinder, double-flow, primary reheating, single shaft, extraction and condensing steam. It is rated for 135MW Rated power, 13.73Mpa (a) Initial steam pressure, 537 0C Initial steam temperature, 8.83kPa (a) Exhaust pressure, 407.317 t/h Steam flow (under rated condition) and 39 stages of steam flow path. |
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| World class practices |
VAL’s unparalleled technical expertise supports its perpetual endeavour to deliver the best products through a carefully coordinated business strategy. In keeping with this objective, VAL has entered into an operations and maintenance (O&M) contract with Korea Plant Service & Engineering Co. Ltd. (KPS), a leading provider of operation, maintenance and consulting services for a wide range of industrial facilities. KPS is currently engaged in O&M for a capacity of 60,000 MW in Korea and has put in place a robust equipment monitoring system for the power plant at Jharsuguda. |
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| Emission standards |
The Jharsuguda power plant is equipped with a range of technologies that facilitate adherence to the stringent emission norms in conformity with VAL’s focus on environmental sustainability. The plant has a pneumatic ash handling system that comes with the provision of dry ash evacuation. In addition to this, the effluent treatment plant (ETP) restricts the discharge of effluents outside the power plant. The cumulative emission from the plant is 75 mg/Nm3, which is within the mandated emission norms.
The power plant is the only one in India with an HCSD system, which combine both dry and bottom ash. The intrinsic cementing property of the system results in the solidification of the slurry with subsequent settlement of the ash particles. There is no fugitive emission and the system requires less water and land.
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