为降低船舶柴油机对环境的污染,在装配电控高压共轨系统的MWMTBD234V6船用电站柴油机上,研究喷射系统参数对柴油机燃烧和排放特性的影响.结果表明:喷油提前角是影响柴油机燃烧及排放的重要因素,当喷油提前角较大时,生成的碳烟在高温下充分氧化,从而柴油机的排放量较少；喷孔个数及孔径影响柴油机的排放；喷射夹角大则油耗和排温降低,空气噪声变大,NOx生成量增加,烟度值降低；使用长径较大的喷嘴时,在中低负荷下油耗、排温、碳烟生成量均降低,但在高负荷时油耗和碳烟生成量均增加；在中低负荷时,喷雾贯穿距较长的油滴混合充分,能增加空气利用率,提高预混燃烧的比例；在高负荷时,需要加强气穴对雾束的扰动,增大喷射夹角,减小贯穿距,减少碰壁的燃油量,从而改善燃油经济性,减少碳烟排放.%To reduce the environmental pollution of marine diesel engine, the effect of injection system parameters on the combustion and emission characteristics of diesel engine is studied on the MWMTBD234V6 marine diesel engine equipped with electronic-controlled high-pressure common rail system. The results show that the injection advance angle is the important factor that affects combustion and exhaust of diesel engine, and the soot is oxidized well at high temperature, which leads to less exhaust of diesel engine; the number of injection nozzle and nozzle diameter affects the exhaust of diesel engine; when the angle between two injections increases, the oil consumption and exhaust temperature become lower, the airborne noise becomes larger, the amount of Nox increases, and the soot level decreases; by using the injection nozzle with large draw ratio, the oil consumption, the exhaust temperature and the amount of soot decrease when the load is low, but the oil consumption and the amount of soot increase when the load is high; when the load is low or medium, the oil drops with long spray penetration are mixed enough, so the utilization rate of air increases and the proportion of premixed combustion increases too; when the load is high, it is needed to strengthen the disturbance of cavitation on oil spray, increase the angle between two injections, reduce the penetration distance and reduce the fuel oil sticking on combustion chamber wall, so as to improve the economical efficiency of fuel and decrease the soot exhaust.
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