Taking a 300 MW unit coal-fired unit as the research object

a high temperature superheater surface optimization model is established under conditions with different flue gas velocities. Taking the minimum total investment cost of high temperature heat exchanger in unit time with the same heat exchange amount as the target

the optimum design structure and the most ideal flow rate of the flue gas for the high temperature superheater running in pressurized oxyfuel combustion atmosphere are determined. By setting four different boundary conditions

the change of the steam outlet temperature and the corresponding dynamic response time of the high temperature superheater are analyzed. The results show that

compared with the air atmosphere

when the steam inlet flow

gas inlet flow

steam inlet temperature and gas inlet temperature step increases by 10%

the response time of the steam temperautre in the pressurized oxygen enriched atmosphere is shortened by 11.88 s

7.92 s

10.89 s and 6.93 s

respectively

and the variation of the steam outlet temperature drop is reduced by 0.40 K

0.33 K

0.20 K and 5.34 K.