Economic Analysis of an Oxygen-enriched Coal-fired Boiler at Different Modes of Flue Gas Recirculation

Taking a 300 MW oxygen-enriched coal-fired boiler as an object of study, flue gas loss and auxiliary power consumption of the boiler were calculated and compared at different modes of flue gas recirculation, while influence of flue gas recirculation mode on economy of the boiler analyzed. Results show that in the series arrangement of FGD + DCC and at the wet flue gas recirculation mode (no dehydration or desulfurization applied in the second flue gas recirculation), the flue gas loss is the lowest (5.6%) and the auxiliary power consumption is the highest(14 MW); whereas in the arrangement of only DCC and at the dry flue gas recirculation mode, the flue gas loss is the highest (7.56%) and the auxiliary power consumption is the least (13.23 MW).