Effects of the Secondary Air Excess Ratio on the Self-Preheating Combustion Characteristics and NOx,Emission of Semi-Coke  

作　　者：DING Hongliang OUYANG Ziqu CAO Xiaoyang 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

出　　处：《Journal of Thermal Science》2023年第3期1263-1277,共15页热科学学报（英文版）

基　　金：supported by Strategic Priority Research Program of the CAS(XDA29010200);CAS Project for Young Scientists in Basic Research(YSBR-028);Youth Innovation Promotion Association of the CAS(2019148)。

摘　　要：The effects of the secondary air excess ratio(λ_(2))on the self-preheating combustion characteristics and NO_(x)emission of semi-coke have been experimentally studied on a bench-scale test rig.Flameless combustion of the high-temperature preheated fuel(coal gas&coal char)has been achieved in all experimental cases.Through fire-observation windows,the combustion zone was transparent and no flame fronts were seen.Additionally,differentλ_(2)in this study were basically within the common range of self-preheating combustion technology.The results manifested that the rapid ignition of coal gas and the recirculation of high-temperature flue gas resulted in relatively high combustion temperatures close to the secondary air nozzle exit.With the increase of.12,the unburned carbon content of fly ash increased slightly and combustion efficiencies of all experiments exceeded98%.Moreover,the exit NO_(x)emission was not reduced linearly,which was dissimilar from conventional air staging combustion.The main reason was that the volatile-N was released in the self-preheating device,and the air staging method could not effectively reduce the char-NO_(x).In the course of the experiments,the lowest NO_(x)emission was 64.35 mg/m3(@6%O2)whenλ_(2)was 0.40.

关 键 词：self-preheating pulverized coal NO EMISSION flameless combustion 

分 类 号：X701[环境科学与工程—环境工程]