DOC+POC对重型柴油机性能及常规气态物排放特性的影响研究

IMPACT OF DOC + POC ON PERFORMANCE AND GASEOUS EMISSIONS CHARACTERISTICS FROM A HEAVY-DUTY DIESEL ENGINE

以某电控高压共轨重型柴油机为试验样机,在外特性以及最大转矩转速和额定转速两个不同转速的负荷特性下,对比研究了重型柴油机加装氧化催化转化器(diesel oxidation catalyst,DOC)耦合颗粒氧化催化器(particle oxidation catalyst,POC)后处理装置前后的动力经济性和常规气态物排放特性。研究结果表明:加装DOC+POC装置后,排气温度基本在后处理装置的工作温度范围里,随着转速增大,排气背压迅速增大;动力性和经济性变化不大,扭矩降幅在2%以内,燃油消耗率上升幅度也在2%左右;而CO和THC体积排放量有大幅下降,NOx也有小幅下降,分别平均下降98%、94%和3%,CO2排放有小幅的增加,平均增幅为4.3%。

Under external characteristic and load characteristic operation,the effects of DOC + POC after-treatment systems on power,fuel efficiency and regulated gaseous emissions from an electronically controlled high pressure common rail heavy-duty diesel engine were investigated. The results reveal that exhaust temperature is basically in the range of working temperature of after-treatment device. As engine speed increases,exhaust back pressure of diesel engine increases quickly. The torque of diesel engine declines slightly after the installation of DOC-POC after-treatment system,which is limited to 2%,and the rise in fuel consumption is around 2%. At the same time,the emission of CO and THC decrease significantly by 98% and 94%.NOxalso reduces slightly by 3%. However,the emission of CO2 increases slightly by 4. 3% due to the increased fuel consumption.