Estimation of parameters affected in internal exhaust residual gases recirculation and the influence of exhaust residual gas on performance and emission of a spark ignition engine

摘要

In the effort of improving the internal combustion engine performance, the exhaust residual gases and effective release energy are sensitive factors, which effect on engine efficiency and emission formation. Herewith we estimated and summarized the parameters which affect the internal exhaust residual gases recirculation, and investigate the effect of internal exhaust residual gas on peak pressure rise, effective energy, and engine emissions, which weren't presented yet in the previous articles. It is knotty to investigate the residual gas ratio, the effective energy under the various testing conditions from the experiments. Through the simulation and experiment methods approach we eliminated certain above drawbacks. From results of the research, we thoroughly investigated the effects of engine speed, air-fuel ratio, valve overlap, combustion duration, intake port diameter-bore ratio, and bore-stroke ratio on the internal exhaust residual gases recirculation. We also found that the increase in the internal exhaust residual gas from 1% to 5% was due to the peak firing temperature decrease from 2900 K to 1250 K, the peak pressure rise decrease from 8 to 5.5 bar/deg, the effective release energy decrease from 0.85 to 0.53 kJ, the NOx emission reduction from 11.3 to 2.12 g/kwh and the engine brake torque decrease from 20.3 to 9 Nm.