生物柴油发动机的催化型连续再生系统的仿真研究

建立了CCRT系统模型,并根据试验参数对模型进行了标定。分别比较了不同工况下,燃用B20、BD50、BD100时DOC对常规排放气体的转化效率以及CPF的颗粒物再生情况。发现:DOC对NO的转换效率各工况差别较大,主要受排气温度影响;对CO及HC整体转化效率处于较高水平,去除效果较为理想。平衡时CPF内残留的颗粒物质量随转速升高而增加,随负荷增加而减少;低负荷、高转速工况是CPF再生效果最差的工况。随着生物柴油掺混比例的上升,DOC的NO_2出口浓度及NO转化效率上升,而对DOC的HC和CO去除效果影响较小; CPF残留颗粒物质量在高转速区域有所下降,而在中低负荷区域有所上升。主要原因是燃用生物柴油引发的排气温度降低和颗粒物排放降低。低负荷、高转速工况下,燃用BD50时CPF的再生效果最佳。

Simulation of Catalyzed Continuously Regenerating Trap for Biodiesel Engine

The model of CCRT system was established and calibrated according to the experimental parameters. The conventional gas emission conversion efficiency of DOC and the performance of the particle regeneration of CPF were compared under different working conditions, and with different fuels such as B20, BD50 and BD100.The results indicated that the NO conversion efficiency of DOC varied greatly among different working conditions, which was mainly affected by exhaust temperature, and the conversion efficiency of CO and HC was high and its removal efficiency was relatively ideal. The quality of residual particles in CPF at equilibrium increased with the increase of speed and decreased with the increase of load. The condition of low load and high speed was the one with the worst regeneration effect of CPF. With the increase of the proportion of biodiesel mixing, the density of NO₂ export of DOC and the conversion efficiency of NO increased, while had little effect on the removal effect of HC and CO of DOC.As the proportion of biodiesel mixing increased, the quality of CPF residual particles decreased in the high speed and increased in the middle and low load. The main reason could be the reduction of exhaust temperature and emission of particulate matter caused by biodiesel. Under the condition of low load and high speed, CPF had the best regeneration effect when burning BD50.