材料期刊网

羰基物是低温燃烧过程中产生的不完全氧化中间产物，主要产生在预混燃烧阶段。从化学反应动力学角度，分析了预混火焰条件下，燃油量、过量空气系数和调合比例等因素对生物柴油羰基物生成的影响。通过改变空气稀释比进行空气预处理，通过掺混氢气、掺混一氧化碳、掺混甲烷进行燃料预处理，对生物柴油羰基类污染物的排放控制进行了数值模拟。研究结果表明，生物柴油预混火焰中甲醛的形成与氧化分解受进口质量流率的影响不大；提高过量空气系数可以加快生物柴油的氧化反应速率和甲醛的进一步氧化；随着生物柴油调合比例的增大，甲醛分布区域向外焰位置漂移，甲醛的峰值浓度随着调合比例的增大而减小；生物柴油预混火焰中甲醛浓度受空气稀释比的影响较小；采用氢气、一氧化碳、甲烷作为燃料添加剂，可以有效改善油气混合，提高火焰温度和火焰绝热燃烧速度，有助于燃烧中间产物甲醛的再次氧化分解。

Carbonyl pollutants is a kind of Incomplete oxidized intermediates during the low- temperature combustion process, from fuel chemical kinetic perspective, the factors such as import mass flow rate, excess air coefficient and blending ratio were analyzed, which would impact carbonyl formation of biodiesel fuel in the premixed flame conditions. Air pretreatment was done by changing the dilution ratio, while fuel pretreatment was done by mixing hydrogen, carbon monoxide and methane, and numerical simulation of emissions control of biodiesel carbonyl pollutants was taken on. The results show that, the import mass flow rate has little effect on the formation and decomposition of formaldehyde in the biodiesel premixed flame. The oxidation and further oxidation speed of formaldehyde will be accelerated when the excess air ratio increased. The distribution region of formaldehyde in the flame location shift outside and the peak value of formaldehyde concentration declined, when the biodiesel blending ratio increased. Air dilution ratio has less affect on the concentration of formaldehyde in the biodiesel premixed flame. The pretreatment of biodiesel fuel by using hydrogen, carbon monoxide, methane as fuel additive, can effectively improve mixture quality and the adiabatic flame temperature, and it is beneficial to the oxidation and decomposition of formaldehyde.