(0000) Efficiency improvement and CO2 emission reduction of coal fired power plant by repowering through pressurized pulverized coal combustion and waste heated feed water heating

Samiran Samanta, Sudip Ghosh


A theoretical analysis of partial repowering of a 250MW coal fired power plant is presented in this paper. In this repowering scheme, out of five coal mills, two mills are proposed to be taken out and the corresponding amount of pulverized coal is combusted in a pressurized combustion chamber (PPCC). The product gas is expanded in a Gas Turbine (GT) after proper cleaning of the hot gas. The GT exhaust is fed to the existing boiler with modified burners. Waste heat of flue gas, coming out from the repowered plant boiler, is proposed to be used for feed water heating which leads to saving of bleed steam and increase in the output of the steam cycle. The partial repowering increases the capacity and overall efficiency of the plant by about 30.7% each and decreases plant heat rate by about 23.5%. The specific CO2 emission of the plant decreases about 26.5% after repowering.


Repowering; power plant; PPCC; gas turbine; waste heat; capacity; efficiency; specific emission

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