Testing & Research
Ni Shaoyi
2013, 27(3): 145-149.
To improve the thermal efficiency and performance indexes of a 1 913 t/h supercritical pressure once-through boiler, experimental tests were carried out, during which a large amount of operating data were obtained, so as to analyze the influence of following factors on the thermal efficiency, exhaust gas temperature, carbon content in fly ash and mass concentration of NOx emission of the boiler, such as the soot blowing mode, outlet air temperature of coal mill, fineness of pulverized coal, volume fraction (O2) of oxygen in exhaust gas, combination of separated overfire air (SOFA) doors in operation, and small opening of secondary air door, etc. Moreover, the energy loss and benefit of relevant factors were calculated. Results show that the optimal operation solution of the boiler at a load of 600 MW is as follows: carrying out soot blowing once every 24 h for the furnace, and once every 8 h for the horizontal flue gas duct, rear flue well, and air preheater; setting the coal mill outlet air temperature at 80 ℃ in summer and 75 ℃ in winter; setting the rotating speed of coal mill dynamic separator at 650~700 r/min; controlling (O2) in 3.4%~3.8%; putting the lower four layers of SOFA into operation, and setting the opening of offset air door at 35%.
