By taking a boiler in power plant A as an example

thermodynamic calculation process of the ultra supercritical boilers was analyzed.Affected by the external circulation

the ultra supercritical boilers have a variety of calculation processes.Three calculation processes were employed to investigate the insufficient reheater steam temperature of the boiler

and a transformation scheme for the final reheater was put forward.Check calculation for performance parameters of the retrofitted boiler was carried out

under three conditions with different gas components.The results show that

after the modification

the reheater steam increased dramatically and the temperature rise of the reheater working fluid increased from 76℃to 98℃.This transformation scheme compensates the heat transfer loss in the final reheater caused by low furnace outlet temperature.