Abstract:

Unburned combustible in fly ash and hightemperature exhausted gas is prevail in storagetype hot wind pulverized coal feeding system of lean coal boilers taking staged combustion.Tertiary air richlean separation and rearranging the tertiary air nozzles was proposed as a retrofit scheme. After retrofitting, when the content of volatile matter decreased,the mass concentration of NOx at the economizer outlet decreased from 620.75mg/m3 to 487.00mg/m3，and unburned combustible in fly ash and slag decreased as well，and so did the temperature of exhausted gas，which met the expectation of lownitrogen burner retrofit.

Key words:

font-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">burner, tertiary air；richfont-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">font-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">lean separating;storagefont-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">font-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">type hot air pulverized coal feeding system, lean coal boiler, mass concentration of NOfont-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">x