| 摘要 |
PURPOSE:To reduce the NOX concentration less than the designed value without deteriorating the burning safety by a method wherein the reducing limit of an air quantity is controlled to be not less than the lower limit value of the O2 concentration when an exhaust NOX concentration is reduced by adjusting a burning air quantity. CONSTITUTION:An NOX constant control device 3, an O2 constant control device 6 and an O2 constant control device 8 are controllers for outputting operational signals to control so that the deviation between an NOX concentration setting value 1, a normal O2 concentration setting valve 4, a lower limit O2 concentration setting value 7 and an NOX determined value 2, an O2 determined value 5 are made to be zero. The output operational signals from the NOX constant control device 3 and the O2 constant control device 6 are made to be selected and outputted the lower value of a burning air quantity by a lower signal selector 9. Further, the output is inputted to a higher signal selector 10 together with the output operational signal of the O2 constant control device 8. Thereupon, a higher value is selected in the same manner, finally, a burning air quantity operational signal 11 is outputted, thus, the actual air quantity control is performed. |
