66 巻 (2000) 652 号 p. 3233-3240
Simultaneous reduction of NOχ and smoke under high load conditions could be obtained by MULDIC(MULtiple stage DIesel Combustion) where mixture was made stratified before ignition. In this investigation of the basic characteristics of MULDIC, gaseous fuels (DME, Propane) were charged into the intake air which led to the creation of homogeneous lean mixture, and liquid fuel was injected into the cylinder and made rich mixture. The results of the engine test showed that NOχ emissions could be reduced to less than 100 ppm and smoke emissions were also maintained 0 FSN even at higher loads. Moreover, homogeneous rich mixture test results showed that low smoke combustion could be obtained under equivalence ratio of 1.6. In MULDIC, increasing the ignition delay period of injected fuel, soot formation rate was decreased, because over rich region was avoided.