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加压富氧燃烧技术由于受燃烧压力和烟气再循环富集SO2的影响,烟气中SO3的形成存在加剧的风险.本文通过详细化学反应机理和热力学平衡计算,对0.1～2.5 MPa范围内加压富氧燃烧条件下一些关键因素对SO3形成的影响进行分析.研究结果表明:加压燃烧显著缩短2SO2+O2 →2SO3总包反应体系达到平衡的时间,并促进了SO3的生成量,压力从0.1 MPa提高到1.5MPa,对应的SO3浓度升高到4倍,酸露点温度升高71℃.在高温火焰区(T≥1473K),0.1～2.5 MPa压力范围下,反应体系的平衡时间在1～100 ms的量级,SO3的生成率在0～6.5％;而在后火焰区(T≤1273 K),反应速率较慢,反应体系的平衡时间在1～1000 s的数量级.通过对火焰区SO3生成特性的热力学平衡评估发现SO3的生成量分别与SO2和O2的浓度呈1和0.5次方的关系.“,”The increase of pressure and enrichment of SO2 due to gas flue recycle,significantly intensify the formation of SO3 during pressurized oxy-fuel combustion.By using detailed chemical reaction mechanism and thermodynamic equilibrium calculation,investigation on the influence of key factors on the formation of SO3 was carried out.Results show that,under pressurized oxy-fuel combustion the time reaching to equilibrium of the overall reaction (2SO2+O2-2SO3) significantly shortened,and the formation of SO3 is promoted.With pressure increasing from 0.1 MPa to 1.5 MPa,the concentration and partial pressure of SO3 increase to 4 times and 56 times relatively,and the acid due point (ADPT) increased 71℃.In high temperature flame zone (T≥1473 K),the equilibrium time ranges within 1 and 100 ms and the ratio of SO3 formed ranges within 0 and 6.5％.While in post-flame zone,the reaction rate is slow and the equilibrium time ranges within 1 103 8.The evaluation of SO3 in post-flame zone using thermodynamic equilibrium reveals that the formation of SO3 is proportional to SO2 concentration and the 0.5th power of O2 concentration.