Power Plant Process

Indorama 2 X 30 MW

The basic Purpose of power plant is to produce reliable power & steam supply to the Customer.

The 2 X 30MW pulverized coal fired Co-generation power plant consists of two nos of 150T/H pulverized coal fired steam generators connected to two nos of Condensing extraction type steam turbine generators along with all the required auxiliaries.

The raw water is pumped from the intake pump house at Jatiluhur Lake, which is about 2Km from the power plant through pipeline. Suspended solids of the lake water are removed in the sedimentation tank by chemical process. This filtered water is collected in service water basin which is having the storing capacity of 8 hours. Service water basin is having many branches to supply the water to various applications of the power plant. Service water is used for equipment cooling, make up water for cooling tower, Chemical water for DM Plant, Fire water for fire protection system and living/domestic water.

DM water is used in the boiler to produce the steam. As the name implies, DM plant removes all the minerals from water. Service water is passed through an activated carbon filter, anion exchanged, cation exchanger and mixed bed to get the required quality of DM water.

Coal is stored in a closed shed of capacity about 17,000 MT sufficient for 21 days of consumption. Coal from the coal yard is conveyed to coal crushers where the coal is crushed to less than 25mm size and fed to the bunkers through the conveyors. Two steams of coal conveying system is provided, one running and the other standby. Coal bunkers are the day tanks for the pulverizers. Each boiler is equipped with three pulverizers, two running and one stand by.

ID Fans (Induced draft fans) pumps out the flue gasses from the boiler to the Chimney. FD Fans (Forced draft fans) supplies fresh air to the boiler. PA(Primary air fan) Fan pushes the coal from the pulverizers to the boiler.

Boiler Consist of pressure parts including water wall tubes, super heater, Economizers & Air pre heater with necessary mountings like safety valve .The safety valves are provided for the safety of the boiler during operation. Two scanner-cooling fans are provided for cooling the scanners. Light Diesel oil is pumped from the day storage tank to the boiler. There are two-day storage tanks (LDO) of capacity 70m3.Main LDO Storage tanks are located in Polyester division & whenever required LDO is pumped from the main storage tank to day tanks.

Eight nos of oil guns are fitted 2 at each corners for initial start up boiler & for emergency use.

Two Pulverizers are running for supplying the pulverized coal to boilers via coal transfer pipes at four corners of the boiler furnace. Boiler can generate 150T/H of steam for producing 30Mw power .

DCS (Distributed control System )  is given for controlling all the control loops of power plant. DCS will cater the need of control data acquisition , alarm monitoring, data logging & historical trending function of boilers & turbines , generators & their auxiliaries.

Three (3*170) t/h capacity motor driven pumps are there to supply the feed water to boiler in which two pumps are running during normal operation & one pump is standby.

Separate lubrication oil system is given for high speed pumps .The lubricating oil system 

 is supplying the oil to the motor & pump bearings.

Two 110% capacity condensate pumps for each unit is provided .One in operation & the other is standby. Each pump is controlled from the central control room.

The De aerator is provided for efficient removal of non-condensable gases from the feed water under all conditions of operation. It is located at 13mtr elevation & one de aerator each of each unit.

For protection of boiler tubes, drum, economizer, super heater from the corrosion chemical feed system is given which will control the quality of steam & water.

To satisfy the environment protection the flue gas will is go through the ESP( Electro static pre cipitator) in which all dust particles from the flue gas collected & dislodge in the ESP hoppers .From the ESP hoppers fly ash is conveyed to ash silos through pneumatic dense phase system . The flue gas further flows to De sulpherization system employing the NID process. The technology is provided for removing the SO2 from the flue gases. Two separated silos are provided one for ESP dust collection & one for FGD & Bag filter dust collection. All collected ash from silos is conveying to cement companies via closed capsule. Bottom ash also dried  & Conveyed to ash silos.

The steam turbine is of one Cylinder type. The rated pressure & superheated steam from boiler is rotating the steam turbine rotor. It is having one bottom casing fitted with six non adjustable extraction steam employed for both Medium pressure & Low pressure steam supply to polyester & also feeding to feed water heaters for heating the feed water.

The steam turbine is operating in conjunction with a regenerative feed water heating cycle consisting of low pressure feed water heaters, a deaerator & high pressure feed water heaters.

The lubricating oil system for the steam turbine generator bearing oil. The turbine rotor drives the main oil pump. AC motor driven auxiliary oil pump is supplying oil to all turbine & generator bearings. If AC oil pump fails DC lubricating oil pump will start. This all oil pumps is connected to main oil tank (MOT) Oil coolers are provided to reduce the temperature of oil so that rated temperature of oil supply to bearings. Oil coolers are of tube & shell type.

The turning gear system is provided with means to rotate the turbine rotor when it is in hot condition.

To prevent the leakage of the high pressure steam to the atmosphere or air leakage into the steam turbine, the steam turbine is provided with steam seal packing. The gland exhaust blowers are provided for each unit to exhaust the gases to gland steam condenser.

To control the turbine speed according to the fluctuation of the generator load digital electro hydraulic (DEH) governor control system is provided within the turbine. The DEH governor control system is built with turbine speed up system, over speed protection system  & load control system.

The turbine is fitted with main steam stop vale, regulating & check valves, and turbine exhaust check valves.

Each turbine is fitted with Condenser at the exhaust. The prime purpose of condenser is to condense the exhaust steam from the turbine & thus recovered the high quality feed water, which reuse in the cycle. Surface condenser is essentially shell & tube heat condensers , in which the primary heat transfer mechanisms are the condensing of the saturated steam outside of the tubes & forced convection heating of the circulating inside the tubes. The air from the system is extracted by water jet ejector mechanism.

The circulating water is supply by two circulating water pumps one for each unit & one standby for both the units. Outlet of condenser is going to the cooling tower & where the heat from the hot water is evaporated by mechanical draft cooling tower fans. Again cooled water is falling from the fills of cooling tower & collected in the basin

The generated power is evacuated at 20KV level. Generator transformer of each unit will deliver power to CPP 20KV indoor switchgear .The synchronous generator is totally enclosed, horizontal shaft , closed circuit air cooled typed , driven by steam turbine at 3000RPM..CPP 20KV switchgear is connected to polyester 20KV switchgear by XLPE power cable. Generating the voltage at 11 kv & further step up to 20 kv in 40MVA Generator transformer .A complete generator excitation & voltage regulating system is there for each unit.

Auto Synchronizer is provided which is monitoring the voltage & frequency of both incoming generators as well as the bus voltage & provides the control signals for correcting the reference of the Governor, the frequency matching & automatic voltage regulator reference for voltage matching. It gives the breaker closing command at a suitable time when the voltage & frequency difference is within the limits.

Essential supplies systems is provided to maintain unit output & to protect plant from damage due to loss of supply.220 V DC supplies is provided for essential functions such as protection, switchgear closing & tripping, alarms, control, emergency drives, emeregencey lightning, communication equipments. DC system is consists of 2*100 rated NI-Cad batteries.

Wastewater treatment plant is there to treat the all wastewater from all areas. Treated water is used for road washing & gardening.

Various methods of fire fighting & detection system used according to application. Independent high-pressure loop & net pipe work to supply fire-fighting water in all areas of CPP.

Automatic sprinkler system provided for protection of coal conveyors & transformers.

Three sets of Instrument air compressors are installed for both the units for the pneumatic control of the plant, either of the two sets is always in operation & one standby capable of being started by a low-pressure signal. Two sets of service air compressors for each unit is provided for transferring the fly ash to silos through enclosed pipes.



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