可变扫气口对低速机性能优化作用的仿真研究  

Simulation of Performance Optimization for Low-Speed Engine with Variable Scavenge Ports

作　　者：曹尔明 朱骏 李磊 刘博 桂勇 钱跃华 CAO Erming;ZHU Jun;LI Lei;LIU Bo;GUI Yong;QIAN Yuehua(China Shipbuilding Power Engineering Institute Co.,Ltd.,Shanghai 201206,China)

机构地区：[1]中船动力研究院有限公司,上海201206

出　　处：《内燃机工程》2021年第1期68-75,共8页Chinese Internal Combustion Engine Engineering

基　　金：船用低速机工程(一期)研制项目(工信部联装函[2017]21号)。

摘　　要：为了进一步提高低速机热效率,基于一台500 mm缸径的低速机的热力学仿真模型,研究了可变扫气口技术提升低速机热效率的潜力。计算了对称可变扫气口结构和非对称可变扫气口结构在不同发动机负荷、不同扫气口高度下的有效燃油消耗率、排气流量、排气温度等参数。在保证同样的NO x排放水平下,可变扫气口技术能有效提升低速机热效率,油耗最多可降低约4.3 g/(kW·h)。此外对带有选择性催化还原(selective catalytic reduction,SCR)系统的主机,可变扫气口使SCR主机排气流量减小,排气温度升高,有利于SCR系统的紧凑性设计和降低SCR系统的成本。In order to further improve the thermal efficiency of low-speed engines,the improvement of the potential thermal efficiency of low-speed engines equipped with variable scavenge ports was studied based on the thermodynamic simulation model of a low-speed engine with cylinder bore of 500 mm in diameter.Parameters sucha as brake specific fuel consumption(BSFC),exhaust flow rates and exhaust temperatures of low-speed engine with variable symmetric and asymmetric scavenge ports at different engine loads and with different scavenge port heights were calculated.At the same NO x emission level,the variable scavenge ports technology can effectively improve the thermal efficiency of the low-speed engine,reducing the fuel consumption by up to about 4.3 g/(kW·h).In addition,for an engine with selective catalytic reduction(SCR)system,the variable scavenge ports technology can reduce exhaust flow and increase exhaust temperature,which is beneficial to the compact design of a SCR system and reduces the cost of a SCR system.

关 键 词：低速机 可变扫气口 有效燃油消耗率 选择性催化还原 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]