陈贵升,魏峰,李冰,等.不同进气氛围耦合废气再循环对双燃料发动机工作过程的影响[J].内燃机工程,2022,43(2):1-11.
不同进气氛围耦合废气再循环对双燃料发动机工作过程的影响
Effects of Different Intake Atmosphere Coupled with Exhaust Gas Recirculation on the Working Process of Dual Fuel Engines
DOI：10.13949/j.cnki.nrjgc.2022.02.001
关键词:双燃料发动机  进气氛围  废气再循环  燃烧  排放
Key Words:dual-fuel engine  intake atmosphere  exhaust gas recirculation  combustion  emission
基金项目:国家自然科学基金项目（51866004）；云南省教育厅科学研究基金项目（2022Y157）
作者单位E-mail
陈贵升* 昆明理工大学 云南省内燃机重点实验室，昆明 650500 cgs_yly@163.com 
魏峰 昆明理工大学 云南省内燃机重点实验室，昆明 650500  
李冰 昆明理工大学 云南省内燃机重点实验室，昆明 650500  
王震江 昆明理工大学 云南省内燃机重点实验室，昆明 650500  
黄震* 昆明理工大学 云南省内燃机重点实验室，昆明 650500 1329627964@qq.com 
罗赢 解放军31638部队，昆明 650051  
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摘要:基于正庚烷、甲烷、乙烷、丙烷多组分混合物简化动力学机理耦合三维计算流体力学（computational fluid dynamics， CFD）数值模型，模拟研究高替代率时不同进气氛围（H2、O2组分）耦合废气再循环（exhaust gas recirculation， EGR）对天然气/柴油双燃料发动机低负荷工作过程的影响机理。研究表明：在不同EGR率下，进气掺氢会使缸内燃烧速率显著加快，OH活性基浓度明显升高，CH4排放显著降低，但CO排放升高；进气掺氧后，缸压及瞬时放热率峰值、最大压力升高率、最高燃烧温度及OH活性基浓度均升高，碳烟、CO和CH4后期氧化作用增强使其最终排放降低，但NOx排放升高。在EGR率小于29%，掺氢比小于2.5%时，在实现较低CO、碳烟排放的同时能显著降低CH4排放和NO2/NOx比例；高EGR率时，进气掺氧能降低CO、碳烟排放，并改善CH4与NOx排放之间的折中关系。
Abstract:The effects of different intake atmosphere（H2， O2 composition） coupled with exhaust gas recirculation（EGR） on the mechanism of working process of natural gas/diesel dual fuel engine at low loads were studied based on three-dimensional computational fluid dynamics（CFD） simulation model， coupled with the simplified chemical kinetic mechanism of n-heptane/methane/ethane/propane multi-component mixture.Results show that under different EGR rates， the combustion rate in the cylinder and the concentration of OH active radical are increased significantly， and CH4 emissions are reduced significantly. But CO emissions are increased when H2 is added into the intake charge. Under different EGR rates， the peaks of cylinder pressure and instantaneous heat release rate， the maximum pressure rise rate， the maximum combustion temperature and the concentration of OH active radical are increased when O2 is added into the intake charge. At the same time， the post-oxidation of soot， CO and CH4 emissions are enhanced， so that the final emissions of soot， CO and CH4 are reduced， while NOx emissions are increased. CH4 emissions and the ratio of NO2 to NOx are significantly reduced while lower CO and soot emissions are achieved when the EGR rate is less than 29% and the volume mixing ratio of H2 is less than 2.5%. Adding O2 into the intake charge can reduce CO and soot emissions and improve the trade-off relationship between CH4 and NOx emissions.
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