摘要 |
PURPOSE:To enable to stabilizedly control NOx even if property specifications of fuel of feeding rate of fuel is changed, by controlling NOx, the rate of air, and the rate of fuel among stages in order to maintain the concentration of NOx at the outlet of a furnace at a target value, by using flame data. CONSTITUTION:A function 4000 to estimate reducing rate of NOx in a burner estimates the reducing rate 1400 of NOx at the outlet of a burner in each zone from flames data 1303. A function 4100 to estimate NOx by stage estimates NOx concentration 1500 in each zone from the rate of fuel 1300 in each zone, the primary, the secondary and the tertiary rates of air 1301-1303, and NOx concentration 1400. A function 4200 to determine a targer value of NOx to each stage determines an NOx targer value 2001 for each zone. A function block 4,400 to determine the operating rates of fuel and air by stage determines fuel distribution operating rate 3310, and the primary, the secondary and the tertiary air operating rates 3320-3340, using an NOx target value for each zone. A function block 4300 to estimate NOx ina furnace estimates NOx at the outlet of a furnace based on the estimated rate 1500 of NOx in each zone, determining an error between the estimated value and the measured value of NOx at the outlet of a furnace, correcting the estimated value 1500 of NOx, and determining NOx concentration 1501 for each zone. |