径向分级低污染燃烧室燃烧性能试验

Experimental study on combustion performance of radial-staged low emissions natural gas combustor

以某型径向三级燃烧室为研究对象,采用天然气为燃料,通过试验研究了各级不同燃料比例及燃烧模式下燃烧室的贫油点火、贫油熄火、出口温度场、污染物排放等燃烧性能。结果表明:在环形区扩散燃烧、主燃区预混燃烧模式下,贫油点火油气比为0.027 0~0.040 1,贫油熄火油气比为0.006 9~0.005 5,环形区改为预混燃烧模式后,点火油气比和熄火油气比均有所增大;随主燃区预混燃料当量比(当量比)的增加,出口温度系数逐步改善,至当量比0.54时则有所恶化,环形区改为预混燃烧模式后,主燃区当量比为0.51时,出口温度系数改善明显;随主燃区当量比的增加,CO、未燃碳氢(UHC)、Nox及碳烟排放均呈下降趋势,但当量比为0.54时,Nox排放有所增加,环形区改为预混燃烧模式后,各污染物排放指数降低,但未达到预期。建议径向分级燃烧室在低负荷工况下采用环形区扩散燃烧、主燃区预混燃烧模式,在高负荷工况下均采用预混燃烧方式。

Taking a three-stage radial combustor as the research object and using natural gas as fuel,the combustion performance of lean ignition,lean blowout,outlet temperature field and pollutant emission were experimentally studied under conditions with different fuel ratios and combustion modes.The results show that,in the mode of annular zone diffusion and premixed combustion in the main combustion zone,the fuel-air ratio of lean ignition was 0.027 0~0.040 1,and that of lean blowout was 0.006 9~0.005 5.When the annular zone was changed into premixed combustion mode,both the fuel-air ratio of the ignition and the blowout increased.With an increase in equivalence ratio of the main combustion zone,the outlet temperature coefficient gradually improved,but deteriorated when the equivalence ratio was 0.54.When the equivalent ratio of the main combustion zone was 0.51,the outlet temperature coefficient improved obviously.The mass concentration of CO,unburned hydrocarbon(UHC),Nox and soot emissions decreased with the increasing equivalence ratio in the main combustion zone,but the Nox emission increased when the equivalence ratio reached 0.54.When the annular zone was changed to premixed combustion mode,the pollution indexes decreased slightly.It suggests that the combustor should adopt the annular zone diffusion and main combustion zone premixed at lower loads,and the whole premixed combustion mode at higher loads.