含水乙醇汽油对发动机NO_x排放的影响

通过发动机台架试验,研究了燃用不同掺比的含水乙醇汽油对发动机NO_x排放及三元催化剂催化转化效率的影响。试验结果表明:发动机燃用含水乙醇汽油后怠速工况下催化器前NO_x排放下降,相比汽油E10,E20,E30的NO_x排放量分别降低64%,68%,69.5%;随着含水乙醇掺比的增加,NO_x的催化转化率降低,E10,E20,E30的NO_x催化转化率分别降低19%,24%,34%。含水乙醇汽油在低负荷时催化器前NO_x排放低于93号汽油,负荷加大后,燃用含水乙醇汽油的NO_x排放高于燃用汽油,NO_x排放由大到小依次为E20,E30,E10,93号汽油;E20的NO_x排放在中高负荷比93号汽油上升6%。在中高负荷工况,燃用含水乙醇汽油时催化器后的NO_x排放量要高于93号汽油,大负荷工况下,E10,E20,E30催化器后的NO_x排放量分别比93号汽油高15%,6%,29%;NO_x催化转化效率随着含水乙醇掺比的增大而降低,大负荷工况下E30的催化转化率约为93号汽油的92%。

Effects of Hydrous Ethanol Gasoline on Engine NOxEmission

The effects of gasoline mixed with different proportions of hydrous ethanol on NO xemission and catalytic conver-sion efficiency of three-way catalyst were studied by engine bench test.The experimental results show that NO xemission of E10,E20,and E30 before the catalytic converter in idle condition decreases by 64%,68% and 69.5% respectively after being fu-eled with hydrous ethanol gasoline.With the increase of hydrous ethanol proportion,the catalytic conversion efficiency of NO x decreases.The catalytic conversion efficiency of E10,E20,and E30 decreases by 19%,24% and 34% respectively.The NO xe-mission of hydrous ethanol gasoline before the catalytic converter is lower than that of 93# gasoline at low load and becomes higher after increasing the load.NO xemission of E20,E30,E10 and 93# gasoline decreases in turn.The NO xemission of E20 increases by 6% in medium and high load compared with 93# gasoline.The NO xemissions after the catalytic converter are higher than that of 93# gasoline in medium and high load and those of E10,E20 and E30 are 15%,6% and 29% higher than 93# gasoline respectively in high load.The catalytic conversion efficiency of NO xdecreases with the increase of hydrous etha-nol ratio and that of E30 is around 92% of 93# gasoline under high load conditions.