| 摘要 |
<p>PURPOSE:To reduce production of NOx without an NOx reducing device, by a method wherein a flow rate of each of air for combustion fed to each stage, air-fuel mixture extracted from exhaust gas, and primary gas is controlled according to the desired values of a load and a nitrogen oxide. CONSTITUTION:An amount of theoretical air to a fuel flow rate 101 is deter mined by means of a function generator 104, and gas concentration at an ECO outlet is corrected at 105 so that the concentration is kept at a specified value. Further, from a boiler input instruction and an NOx desired index, an air ratio is corrected at 107 to determine an air amount instruction value, and the opening of a burner inlet air damper 302 is controlled in a direction in which an amount of NOx is decreased. Similarly, air-fuel mixture damper 301 determines an air- fuel mixture flow rate desired value from an theoretical air amount 104 by means of a function generator 120 for correction, and control is effected in a direction in which an amount of NO2 is decreased. Further, in relation to primary gas 303 also, a primary gas flow rate set value is determined based on a fuel amount to performed control in a direction in which an amount of NOx is decreased. This constitution enables reduction of production of NO2 without mounting an NOx reducing device.</p> |
