| 摘要:以某V型12缸高速大功率柴油机为研究对象，利用AVL-BOOST软件建立发动机的一维热力学模型，并通过设计不同的米勒进气型线，开展米勒循环对发动机进气、缸内燃烧、油耗和排温的影响规律研究。仿真结果表明： 随着进气门关闭角的提前，进气量和最高燃烧压力逐渐降低，缸内燃烧温度逐渐升高； 当进气门提前关闭（early inlet valve closing，EIVC）角为60°时燃油消耗率达到最低。基于米勒循环的仿真分析结果，针对进气型线和缸盖气道流量系数重新进行优化设计，并开展台架试验进行验证。结果表明：当NOx排放与原机标定一致时，各工况的比油耗和排气烟度均有所下降，其中，100%负荷工况的比油耗下降7.3 g/（kW·h），排气烟度（FSN）下降0.84；当比油耗与原机标定一致时，NOx加权比排放由原机的6.69 g/（kW·h）降到5.85 g/（kW·h）。 |
| 关键词: 高速柴油机 米勒循环 NOx排放 进气门 |
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| Numerical and Experimental Study of Miller Cycle for High Speed Genset Diesel |
| CHEN Yue,HUANG Yongzhong |
| Guangxi Yuchai Marine and Genset Power Co.， Ltd.， Yulin 537005， China |
| Abstract:Taking a certain V-type 12-cylinder high-speed high-power diesel engine as the research object，1D thermodynamic model of engine was established by AVL-BOOST Software.The effects of Miller cycle on engine intake flow，in-cylinder combustion，fuel consumption and exhaust temperature were studied by designing different Miller intake lifts.The simulation results show that：as the intake valve closing angle is advanced，the intake air volume and maximum explosive pressure gradually decrease，while the combustion temperature in cylinder gradually increases；when the early intake valve closing（EIVC）timing is 60°，the fuel consumption rate reaches its lowest point. Based on the simulation analysis results of Miller cycle，the intake profile and the flow coefficient of the cylinder head were re-optimized and validated by bench test.The results showed that：when the NOx emission concentration is consistent with the original engine，the brake specific fuel consumption（BSFC）and exhaust smoke of each working condition were decreased，of which the BSFC and exhaust smoke （FSN）of 100% load condition were decreased by 7.3 g/（kW·h）and 0.84，respectively；when the BSFC was consistent with the original engine，the NOx weighting specific emission decreased from 6.69 g/（kW·h）of the original to 5.85 g/（kW·h）. |
| Key words: high speed diesel Miller cycle NOx emission intake valve |
