CAJ | 학술논문

在一台两缸二甲醚发动机上开展了不同废气再循环(EGR)率下发动机的性能和排放特性研究,测量了不同工况下发动机的油耗,HC、CO和NO_x的排放.研究表明:二甲醚发动机可承受的最大EGR率接近60%,但在高负荷时,过大的EGR率会导致发动机燃油消耗率显著升高;EGR率对发动机的NO_x排放量影响很大,随着EGR率的增加,发动机的NO_x排放量大幅度下降,高负荷时下降幅度更大;EGR率增大,HC和CO排放增加,高负荷时增加的幅度更大,特别是当EGR率超过一定范围时,EGR率的增大会引起HC和CO排放的急剧增加;低负荷时,最佳EGR率应保持在30%左右,而高负荷时,应采用较小的EGR率.
재일태량항이갑미발동궤상개전료불동폐기재순배(EGR)솔하발동궤적성능화배방특성연구,측량료불동공황하발동궤적유모,HC、CO화NO_x적배방.연구표명:이갑미발동궤가승수적최대EGR솔접근60%,단재고부하시,과대적EGR솔회도치발동궤연유소모솔현저승고;EGR솔대발동궤적NO_x배방량영향흔대,수착EGR솔적증가,발동궤적NO_x배방량대폭도하강,고부하시하강폭도경대;EGR솔증대,HC화CO배방증가,고부하시증가적폭도경대,특별시당EGR솔초과일정범위시,EGR솔적증대회인기HC화CO배방적급극증가;저부하시,최가EGR솔응보지재30%좌우,이고부하시,응채용교소적EGR솔.
To study the influences of the exhaust gas recirculation(EGR)rate on the emissions and performance of dimethyl ether (DME) engines, an experimental investigation was conducted on a 2-cylinder DME engine with EGR. Under the various operating conditions, the fuel consumption and emissions of HC, CO, and NO_x were measured. The results show that the maximum EGR rate of the DME engine can reach 60% approximately, however, under high load conditions, too large EGR rate will result in obvious deterioration in the engine brake specific fuel consumption. EGR has significant effects on NO_x emissions. NO_x emissions decrease clearly with the increase in the EGR rate, especially under high load conditions. HC and CO emissions increase with the in-crease in the EGR rate, particularly under high load conditions. When the EGR rate is over a cer-tain value, the increase of the EGR rate will lead to a quick increase in HC and CO emissions. It is suggested that the optimal EGR rate should be near 30% under low load conditions while the engine should run with low EGR rates under high load conditions.