进气加湿结合废气再循环技术对高压直喷双燃料低速机燃烧及排放的影响  

Effects of Intake Humidification Combined with Exhaust Gas Recirculation on Combustion and Emissions of a High-Pressure Direct Injection Dual-Fuel Low-Speed Marine Engine

作　　者：李长锟 王天友[1] 孙凯[1] 王怀印 LI Changkun;WANG Tianyou;SUN Kai;WANG Huaiyin(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《内燃机工程》2021年第1期1-6,共6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：基于CONVERGE软件建立了高压直喷双燃料船用发动机三维仿真模型,研究了空气加湿技术和废气再循环(exhaust gas recirculation,EGR)对发动机燃烧过程及排放的影响,并通过耦合进气加湿、EGR和天然气喷射策略等技术,最终得到满足TierⅢ排放法规的可行性技术路线。结果表明,进气加湿降低NO x排放潜力较大(约55%),且对燃料经济性恶化程度较小(约1.6%);单独采用进气加湿技术难以满足TierⅢ排放标准,60%进气加湿程度结合较低程度EGR率(20%)可进一步提高降低NO x排放的潜力(78%);为降低进气加湿和EGR带来的功率损失,在20%EGR率耦合60%进气加湿氛围下,提前2°曲轴转角喷射天然气可使天然气消耗率可降低约1 g/(kW·h),同时NO x排放满足TierⅢ排放法规要求。Based on CONVERGE,a three-dimensional simulation model of high-pressure direct injection(HPDI)dual-fuel marine engine was established.The effects of humid air motor(HAM)and exhaust gas recirculation(EGR)on engine combustion process and emissions were studied.With key technologies of intake humidification,EGR and natural gas injection strategy,a viable technical route was finally achieved to meet the TierⅢemission regulations.The results show that the intake humidification has great potential in reducing NO x(by about 55%)and it has a little impact on fuel economy(by about 1.6%).It is difficult to meet the TierⅢemission regulations by using the intake humidification technology alone.The combination of 60%intake humidification and a lower EGR rate(20%)can further reduce NO x emissions(by 78%).In order to reduce the power loss caused by the intake humidification and EGR when taking the measure of 20%EGR rate coupled with 60%intake humidification,the natural gas injection timing is advanced by 2°in crank angle,which can reduce the natural gas consumption by nearly 1 g/(kW·h)while NO x emissions meet the TierⅢemission regulations.

关 键 词：双燃料船机 进气加湿 废气再循环 高压直喷 燃烧 排放 

分 类 号：TK432[动力工程及工程热物理—动力机械及工程]