The exhaust emission of HC and CO2 decreased with the increase of hydrogen fraction in fuel mixture, this would be due to the increase in H/C ratio and excessive air ratio.

• 在试验条件下，发动机HC和CO2排放浓度随混合燃料中掺氢比例的增加而下降，这是因为掺氢增加了混合燃料中H/C比值和混合气过量空气系数。