【摘要】 对CA498型车用直喷二甲醚发动机采用2种排气再循环(EGR)方案进行试验研究。结果表明,随着EGR率的增加,2种方案都可以降低二甲醚发动机的NOx排放量,其中采用方案2冷EGR时NOx排放量下降显著,EGR率达到20%时,NOx排放量可下降约40%,且二甲醚发动机的热效率无明显下降。在二甲醚发动机上加装氧化型催化反应后处理器的试验结果表明,氧化型催化反应器在所有工况下都可使二甲醚发动机的CO排放量显著下降。试验结果表明采用EGR、氧化型催化反应处理器是控制二甲醚发动机排放的有效措施。更多还原

【Abstract】 Experimental research on performance and emission of the CA498 vehicle direct-injection DME engine by means of two kinds of exhaust gas recirculation(EGR) scheme is carried out. Test results indicate that NO_x emission decreases with the rise of EGR ratio in two schemes and NO_x emission decreases sharply by scheme 2 in which NO_x emission decreases about 40% at 20% EGR ratio with less penalty on the brake thermal efficiency of DME engine. CO emission of DME engine drops greatly with oxidation catalytic reactor as the after-treatment at all operating conditions. Experiments prove that it is efficient of controlling NO_x emission by EGR and controlling CO emission by oxidation catalytic reactor on DME engine.更多还原