With the rapid expansion of new energy power generation capacity in China

the insufficient load regulation capability of coal-fired power plants has become increasingly evident. In order to explore the start-stop peak regulation capability of supercritical circulating fluidized bed(CFB) power units

a 350 MW supercritical CFB unit was taken as the research object

and experimental studies on banked-fire hot standby and rapid start-stop operations were conducted. The experimental results demonstrated that the supercritical CFB unit can rapidly reduce its load to near zero(with an average load change rate of about 10%Pe/min) during bank firing

and then maintain hot standby for 108 minutes. After banked firing

the boiler quickly switched to wet-state operation

with the main steam pressure decreasing rapidly at a rate of 0.13 MPa/min. By reasonably controlling the feedwater flow

the working fluid temperature and wall temperature of the water-cooled walls and water-cooled panels were kept stable. The heat released from the combustion of residual carbon caused the bed temperature to decrease slowly during banked firing

which also provided favorable conditions for re-ignition. During the load lift phase

the unit could be quickly started

with NO_x emission mass concentration reaching an instantaneous peak of 101 mg/m~3

while the hourly average was stable below 50 mg/m~3. Throughout the entire experimental period

SO_2 emission mass concentration was consistently below 35 mg/m~3

and pollutant emissions met the ultra-low-emission requirements. All parameters of the steam turbine and generator remained within normal ranges during the hot standby and startup/shutdown. The rapid decline in main steam pressure and the low superheat of the main steam temperature were the main factors limiting the duration of banked firing in this experiment. The relevant research work provides a reference for the start-stop peak regulation of higher-parameter supercritical and ultra-supercritical CFB units.