In view of temperature difference on two sides after secondarystage desuperheater in the superheated steam system of boiler for 300MW thermal power unit

an optimization scheme of control system for superheated steam temperature has been determined. i.e. a secondary regulator has to be added

making each secondarystage waterspraying valve to be separately controlled by the output of secondary regulater in a cascade circuit. The optimized system can increase the spraying water quantity for the high temperature side

and decrease the spraying water quantity for the low temperature side

ensuring the total secondarystage spraying water quantity to maintain constant. After simulation test

the said scheme has already been used in practice

obtaining obvious effectiveness. The said scheme is suitable for using to boilers with distributed control system and with separative platen superheater.