title: Industrial Application of an Improved Multiple Injection and Multiple Staging Combustion Technology in a 600 MWe Supercritical Down-Fired Boiler.
abstract: To solve the water wall overheating in lower furnace, and further reduce NOx emissions and carbon in fly ash, continuous improvement of the previously proposed multiple injection and multiple staging combustion (MIMSC) technology lies on three aspects: (1) along the furnace arch breadth, changing the previously centralized 12 burner groups into a more uniform pattern with 24 burners; (2) increasing the mass ratio of pulverized coal in fuel-rich flow to that in fuel-lean flow from 6:4 to 9:1; (3) reducing the arch-air momentum by 23% and increasing the tertiary-air momentum by 24%. Industrial-size measurements (i.e., adjusting overfire air (OFA) damper opening of 20-70%) uncovered that, compared with the prior MIMSC technology, the ignition distance of fuel-rich coal/air flow shortened by around 1 m. The gas temperature in the lower furnace was symmetric and higher, the flame kernel moved upward and therefore made the temperature in near-wall region of furnace hopper decrease by about 400 °C, the water wall overheating disappeared completely. Under the optimal OFA damper opening (i.e, 55%), NOx emissions and carbon in fly ash attained levels of 589 mg/m(3) at 6% O2 and 6.18%, respectively, achieving NOx and carbon in fly ash significant reduction by 33% and 37%, respectively.
authors.affiliation: School of Energy Science and Engineering, Harbin Institute of Technology , 92 West Dazhi Street, Harbin 150001, P.R. China.
authors.forename: Minhang
authors.initials: M
authors.lastname: Song
authors.affiliation: School of Energy Science and Engineering, Harbin Institute of Technology , 92 West Dazhi Street, Harbin 150001, P.R. China.|School of Chemical Engineering & Technology, Harbin Institute of Technology , 92 West Dazhi Street, Harbin 150001, P.R. China.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Zeng
authors.affiliation: School of Energy Science and Engineering, Harbin Institute of Technology , 92 West Dazhi Street, Harbin 150001, P.R. China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Energy Science and Engineering, Harbin Institute of Technology , 92 West Dazhi Street, Harbin 150001, P.R. China.
authors.forename: Zhengqi
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Energy Science and Engineering, Harbin Institute of Technology , 92 West Dazhi Street, Harbin 150001, P.R. China.
authors.forename: Qunyi
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Faculty of Maritime and Transportation, Ningbo University , Ningbo 315211, P.R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Kuang
mesh_terms: D000397:Air Pollution / Q000517:prevention & control*; D002244:Carbon / Q000032:analysis; D003031:Coal; D060729:Coal Ash; D007221:Industry; D011210:Power Plants / Q000295:instrumentation*; D013672:Technology; D013696:Temperature
chemical_list: D003031:Coal; D060729:Coal Ash; D002244:Carbon