Effects of Interaction between Axial and Radial Secondary Air and Reductive Intensity in Reduction Region on Combustion Characteristics and NO_(x) Emission of Coal Preheated by a Self-Preheating Burner  

作　　者：SU Kun DING Hongliang OUYANG Ziqu ZHANG Jinyang ZHU Shujun 

机构地区：[1]Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China

出　　处：《Journal of Thermal Science》2024年第1期249-267,共19页热科学学报（英文版）

基　　金：Youth Innovation Promotion Association,CAS (2019148);CAS Project for Young Scientists in Basic Research (YSBR-028);the National Natural Science Foundation of China (No.52006233) are gratefully acknowledged。

摘　　要：The study focused on the effects of the interaction between axial and radial secondary air and the reductive intensity in reduction region on combustion characteristics and NO_(x) emission in a 30 kW preheating combustion system.The results revealed that the interaction and reductive intensity influenced the combustion in the down-fired combustor(DFC) and NO_(x) emission greatly.For the temperature distribution,the interaction caused the position of the main combustion region to shift down as R_(2-12)(ratio of axial secondary air flow to radial secondary air flow) decreased or λ_(2)(total secondary air ratio) increased,and there was the interplay between both of their effects.As R_(3-12)(ratio of first-staged tertiary air flow to second-staged tertiary air flow)increased,the decrease in the reductive intensity also caused the above phenomenon,and the peak temperature increased in this region.For the NO_(x) emission,the interaction affected the NO_(x) reduction adversely when λ_(2) or R_(2-12) was higher,and the range of this effect was larger,so that the NO_x emission increased obviously as they increased.The decrease in the reductive intensity caused the NO_(x) emission increased under the homogeneous reduction mechanism,while was unchanged at a high level under the heterogeneous reduction mechanism.For the combustion efficiency,the interaction improved the combustion efficiency as λ_(2) increased when R_(2-12) was lower,while reduced it as λ_(2) increased excessively when R_(2-12) was higher.The proper decrease in the reductive intensity caused the combustion efficiency increased obviously,while was hardly improved further when the intensity decreased excessively.In this study,the lowest NO_(x) emission was only 41.75 mg/m^(3) without sacrificing the combustion efficiency by optimizing the interaction and reductive intensity.

关 键 词：self-preheating interaction of axial and radial secondary air reductive intensity combustion characteristic NO_(x)emission 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TQ534[动力工程及工程热物理—热能工程]