Combining with the characteristics of a subcritical 600MW direct air-cooling unit with opposed wall fired boiler

the mill tripping solutions during the unit's run back(RB)were summarized.Against the furnace pressure's rapid decline at initial stage of the RB action

optimization on conventional control strategy of the furnace pressure was conducted

and the adaptive PID control algorithm for furnace pressure was proposed.In this algorithm

the furnace pressure deviation is linearized

the integral calculation component is removed during RB

and the regulating proportional gain was calculated by adaptive method during the primary air fan's RB process.After the optimization

the decay ratio of the furnace pressure reached a maximum of 80% when the unit is in RB mode

and the transition time was reduced significantly.