基于平面火焰燃烧器的氨煤混燃着火、辐射特性及NOx排放特性实验研究OA

To address the issue of carbon emissions from coal combustion,ammonia-coal co-firing technology has emerged as a significant research direction.However,systematic studies on key combustion characteristics during this co-firing process such as ignition distance,combustion distance,flame morphology,and radiative heat flux are still lacking.In particular,the interactive effects of two critical parameters,namely the ammonia blending ratio and oxygen volume fraction,have not been fully elucidated.Therefore,this study employed a Hencken flat-flame combustion system to experimentally analyze the ignition process,flame radiation characteristics,and nitrogen oxide(NOx)formation patterns of ammonia-coal blended fuels under various operating conditions.This was achieved by systematically varying the ammonia blending ratio(0％～100％in 20％increments)and the ambient oxygen volume fraction(15％,20％,25％).The results show that as the ammonia blending ratio increases,the ignition distance of pulverized coal shortens,while the combustion distance first increases and then decreases,reaching a maximum at an ammonia blending ratio of approximately 40％.The flame gray-scale value and radiative heat flux at a height of 40 mm also exhibit a trend of initial decrease followed by an increase,both reaching their minimum values at an ammonia blending ratio of approximately 40％.Increasing the oxygen volume fraction significantly enhances flame luminosity,shortens the combustion distance,and increases radiative heat flux.In terms of emission characteristics,a higher ammonia blending ratio helps reduce CO emissions but promotes NOx formation.Moreover,the increase in NOx formation is sensitive to changes in oxygen volume fraction.