Parametric study of 500MW subcritical Coal Power Plant with High Ash and Low Volatile Material indian Coal at Technical Minimum Load

Nowadays, intermitent uses of renewable energies as a base electric load of the grid are getng more importance for its enormous environmental benefts. Thereby, the conventonal coal based power generatng units are facing diferent challenges for its feeible operaton. In literatures, there is a huge gap of practcal based thermodynamic study of the power plants considering its operaton feeibility and thereby, this paper mainly focuses on the actual feasibility study of a 500MW Subcritcal (SubC) Coal based power plant for feeible operaton by using high ash and low volatile material (VM) Indian coal and diferent Parametric studies of the plant at technical minimum load conditon are also carried out in details. Efect of feeible operaton on the operatng parameters is study at ramp down conditon. Plant performance comparisons are also carried out and suggestve measures with diferent constraints for feeible operaton of the plant are also discussed in this paper. Overall study concludes that plant running with less numbers of mills with proper air-fuel rato enhance the combuston characteristc of coal and improves the fame and furnace conditon of the plant at technical minimum load operaton. It is also concluded that unit can be run at technical minimum load with running both turbine driven boiler feed pumps (TDBFPs) with suggestve measures. Ramp down and ramp up rate in the load range of 63–55% of rated load are found about 2.52 MW/minute and 1.48 MW/minute, respectvely which is comparatvely lower than the higher load range due to poor fame conditon. For the low VM coal, eecess oeygen and use of coal burner tlt should be within 4–4.5% and ±8^o for beter fame and furnace conditon. Special precautons are suggested during winter season to avoid acid corrosion in the fue gas duct from low fue gas eeit temperature and high vibraton in turbine from very low condenser back pressure. Deterioraton of plant performance are also observed at low load operaton compared to full load conditon but considering the environment friendly power generaton, switching of carbon-based energy supply to renewable energies (RE) based energy supply should be given more prority in modern society. Moreover, proper monitoring of condenser back pressure and hot reheat temperature may improve the plant performance.