It is an effective way to introduce syngas fuel into
gasoline engine
for blending combustion to improve combustion and reduce emissions.
In this paper, the combustion and emission characteristics of the
direct injection engine under the condition of mixed combustion of
syngas were analyzed by a numerical simulation method. The engine
ran at 2000 rpm, and the mass fraction of syngas was from 0 to 20%.
The results showed that with the increase in the mass ratio of syngas
in the dual fuel, the average pressure and temperature in the cylinder
increased first and then decreased. The maximum in-cylinder pressure
and in-cylinder temperature increased by 27.5 and 2.97%, respectively.
The instantaneous heat release rate also showed a law of first increasing
and then decreasing, in which the peak value of the instantaneous
heat release rate increased by 32.1% at the highest. In addition,
with the increase in the ratio of syngas, the emission of nitrogen
oxides in the cylinder gradually decreased, with a maximum reduction
of 27.4%. The unburned hydrocarbons first decreased and then increased,
with a maximum reduction of 7.6%. Meanwhile, the emission of carbon
dioxide was negatively correlated with the ratio of syngas in the
dual fuel. With the increase in hydrogen ratio in syngas, the carbon
monoxide was gradually reduced, with a maximum reduction of 65%. The
carbon dioxide increased first and then decreased, with a maximum
addition of 4.8%. The ratio of hydrogen and carbon monoxide in syngas
had little effect on the emission of unburned hydrocarbons.