Fuel metering and control optimization based on combustion state diagnosis

It is hard to accurately meter the fuel feed into the furnace for a double-in and double-out pulverizing system, which affects the fuel control quality and also the main steam pressure of a boiler. A correction method for the indirect measurement model of the coal metering feed into the furnace for double-in and double-out pulverizing system is proposed based on the combustion state diagnosis of a burner using fuzzy C-mean clustering method, of which is applied in a 620MW super critical power unit. The engineering application results suggested that the method of this work is effective to improve the fuel control quality during the mill start and stop process. By using the method of this work, the controlling deviation between the target value and the measured value of the main steam pressure is within 0.2 MPa, while it is about 0.6 MPa when the fuel control is without correction.