气体燃料发动机排气道中HC氧化的CFD研究

A CFD Study on the Effect of Exhaust Port to the Oxidation of HC in Gaseous Fuel Engine

利用计算流体力学(CFD)软件耦合详细化学反应机理对气体燃料发动机排气过程中未燃HC在排气道的氧化及对甲醛(CH2O)生成的影响进行了研究。研究表明,未燃HC在排气道存在氧化反应,浓度约减少30%;排气温度对HC氧化和CH2O生成有较大影响;CH2O对HC氧化有促进作用;HC的氧化会使CH2O浓度升高或降低,这取决于CH2O浓度与HC浓度的比值。

In this paper, we studied The effect of exhaust port to the oxidation of hydrocarbon（HC） and its influence to the formation of formaldehyde in gaseous fuel engine using CFD software FLUENT coupled with detailed chemical kinetic mechanisrn. The result shows HC exists oxidation in the exhaust port, HC concentration decreases about 30% ; the oxidation of HC and production of formaldehyde are heavy affected by the exhaust temperature; the exist of formaldehyde can promote the oxidation of HC; partial oxidation of HC results net formation or net destruction of formaldehyde, depending on the formaldehyde/ HC concentration ratio.