ESTIMATION OF NOX FOR EACH BURNER AND UNBURNT COMBUSTIBLES IN ASH IN PULVERIZED COAL-FIRED BOILER

摘要

PURPOSE: To make an accurate estimate of NOx by a method wherein the coal NOx and heavy oil NOx are obtained by equations, NOx correction factors relative to the coal burners and heavy-oil burners are obtained from correction factors relating respectively to the loaded coal and heavy-oil burners and based on the number of the burners in use to correct the coal NOx and heavy oil NOx by multiplying them by the results, and the corrected coal NOx and heavy oil NOx are proportioned to the diagnosed flame temperature for each burner. ;CONSTITUTION: The coal NOx and heavy oil NOx of the coal firing and the mixed firing with heavy-oil are calculated by equations. For both coal and heavy oil these equations are worked out with a thermal NOx satisfying a formula, thermal NOx=0.04×(generator output MW)+6(ppm) making same for coal and heavy oil, and with the fuel NOx in heavy-oil firing set at 20% of the fuel NOx in coal firing. Next, from correction factors related respectively to the loaded coal and heavy-oil burners, obtained on the basis of the number of the burners in use, and indicating the burner loads NOx correction factors relative to the coal burners and heavy-oil burners are obtained by use of a function. By the resulting NOx correction factors relative to the coal and heavy-oil the coal NOx and heavy oil NOx are multiplied to correct them. The corrected coat NOx and corrected heavy oil NOx are proportioned to the diagnosed flame temperature to estimate NOx relative to the coal and heavy-oil burners. Note: coal NOx = thermal NOx + (measured NOx -thermal NOx)/(0.2 + 0.8 × ratio of coal in mixed firing), heavy o NOx = thermal NOx + 0.2 × (measured NOx-thermal NOx)/(0.2 + 0.8 × ratio of coal in mixed firing).;COPYRIGHT: (C)1996,JPO