米勒循环与EGR耦合对增压柴油机性能的影响

以某6缸四冲程两级增压船用柴油机为研究对象，建立两级增压柴油机米勒循环与废气再循环(Exhaust Gas Recirculation, EGR)耦合仿真模型，研究米勒循环和EGR耦合对两级增压柴油机燃油消耗率和NO_x排放的影响. 结果表明，当米勒度为?40°CA时，燃油消耗率相对原机降低3.5%，NO_x排放相对原机降低25.5%；EGR率为30%时，燃油消耗率相对原机增加5.0%，NO_x排放降低98.7%；当米勒度为?30°CA与EGR率为20%时，燃油消耗率相对原机仅增加0.1%，NO_x排放降低92.7%.

Influence of Miller cycle and EGR coupling on performance of turbocharged diesel engine

Taking a 6-cylinder, four-stroke, two-stage turbocharged marine diesel engine as the research object, the coupled simulation model of Miller cycle and exhaust gas recirculation (EGR) of two-stage turbocharged diesel engine was established, and the influences of Miller cycle and EGR coupling on the fuel consumption rate and NO_x emissions of the two-stage turbocharged diesel engine were studied. The results show that when the Miller timing is ?40°CA, compared with the original engine, the fuel consumption rate is reduced by 3.5%, and the NO_x emissions are reduced by 25.5%. When the EGR rate is 30%, the fuel consumption rate is increased by 5.0% and NO_x emissions are reduced by 98.7%. When the Miller timing is ?30°CA and EGR rate is 20%, compared with the original engine, the fuel consumption rate is only increased by 0.1% and NO_x emissions are reduced by 92.7%.