This invention discloses a
combustion system and method for the separate
grinding and co-firing of low-volatile and high-volatile coals, relating to the field of
coal-fired power generation. The
system includes a main air box, a
burnout air box, secondary air nozzles, high-volatile
coal pulverized
coal burners, low-volatile coal pulverized coal burners, and
burnout air nozzles. The main air box is divided into a high-volatile coal
combustion zone and a low-volatile coal
combustion zone, with the low-volatile coal combustion zone located in the lower part of the burner. The
burnout air box is located in the furnace height direction away from the main air box, forming a
nitrogen reduction and deswirl zone. This invention employs separate
grinding and pulverization, and zoned burner arrangement to match the different combustion characteristics and pulverization requirements of low-volatile and high-volatile coals. This achieves a high proportion of low-volatile coal co-firing, effectively improving the stability of the boiler
combustion system, increasing the pulverized coal burnout rate, reducing
NOx emissions, suppressing the rotation intensity of
flue gas at the furnace outlet, and reducing
flue gas temperature and
steam temperature deviations.