Study on low-NO_x emission of lignite-blended burning technology in the bin and feeder coal pulverizing system

摘要

A retrofit solution of mixing warm flue gas extracted from reversing chamber into the coal pulverizing system is provided so as to prevent the problems of the bituminous boiler caused by lignite blending in the bin and feeder coal pulverizing system. The radiant heat transfer with zone method in isotropic scattering media is established to simulate the temperature profile of the HG-670/140-9 boiler in Qing-He Electric Power Generation Co. Ltd. The numerical simulations show that the low-temperature combustion with blending lignite and recirculating warm flue gas can reduce the NO_x emission. The measurement results show that, the mean reduction ratio of NO_x emission is about 11%. It is an important technology to reduce pollutant emission with large ratio of lignite blended in the bituminous boiler with bin-feeder coal pulverizing system.