Achieving simultaneous reduction of NOx,CO and unburned hydrocarbon(UHC) emissions without compromising engine performance at part loads is the current focus of dual fuel engine research.The present work focuses on an...Achieving simultaneous reduction of NOx,CO and unburned hydrocarbon(UHC) emissions without compromising engine performance at part loads is the current focus of dual fuel engine research.The present work focuses on an experimental investigation conducted on a dual fuel(diesel-natural gas) engine to examine the simultaneous effect of inlet air pre-heating and exhaust gas recirculation(EGR) ratio on performance and emission characteristics at part loads.The use of EGR at high levels seems to be unable to improve the engine performance at part loads.However,it is shown that EGR combined with pre-heating of inlet air can slightly increase thermal efficiency,resulting in reduced levels of both unburned hydrocarbon and NOx emissions.CO and UHC emissions are reduced by 24% and 31%,respectively,The NOx emissions decrease by 21% because of the lower combustion temperature due to the much inert gas brought by EGR and decreased oxygen concentration in the cylinder.展开更多
EGR(Exhaust Gas Re-circulation,EGR)阀作为汽车废弃循环系统的关键部件,具备控制精度高、响应速度快以及出色的稳定性等优点。但因其恶劣的工作环境,长期的工作会导致其极易发生故障,这对其可靠性的设计要求提出了很高的要求。本文针...EGR(Exhaust Gas Re-circulation,EGR)阀作为汽车废弃循环系统的关键部件,具备控制精度高、响应速度快以及出色的稳定性等优点。但因其恶劣的工作环境,长期的工作会导致其极易发生故障,这对其可靠性的设计要求提出了很高的要求。本文针对有限转角力矩电机式的EGR阀工作原理,建立对应的数学模型,并在Matlab/Simulink上搭建相应的仿真平台,通过对其电流特征进行分析,验证模型可靠性。基于仿真结果,设计了一套以STM32微处理器为核心的控制系统,驱动EGR阀的正常运转并进行位移与电流信息采集。根据采样的EGR阀的电流信号特征,将实验数据与理论数据的对比,提出了可靠的特征参数,验证了该诊断方法的可靠性与系统设计的准确性。展开更多
文摘Achieving simultaneous reduction of NOx,CO and unburned hydrocarbon(UHC) emissions without compromising engine performance at part loads is the current focus of dual fuel engine research.The present work focuses on an experimental investigation conducted on a dual fuel(diesel-natural gas) engine to examine the simultaneous effect of inlet air pre-heating and exhaust gas recirculation(EGR) ratio on performance and emission characteristics at part loads.The use of EGR at high levels seems to be unable to improve the engine performance at part loads.However,it is shown that EGR combined with pre-heating of inlet air can slightly increase thermal efficiency,resulting in reduced levels of both unburned hydrocarbon and NOx emissions.CO and UHC emissions are reduced by 24% and 31%,respectively,The NOx emissions decrease by 21% because of the lower combustion temperature due to the much inert gas brought by EGR and decreased oxygen concentration in the cylinder.
文摘EGR(Exhaust Gas Re-circulation,EGR)阀作为汽车废弃循环系统的关键部件,具备控制精度高、响应速度快以及出色的稳定性等优点。但因其恶劣的工作环境,长期的工作会导致其极易发生故障,这对其可靠性的设计要求提出了很高的要求。本文针对有限转角力矩电机式的EGR阀工作原理,建立对应的数学模型,并在Matlab/Simulink上搭建相应的仿真平台,通过对其电流特征进行分析,验证模型可靠性。基于仿真结果,设计了一套以STM32微处理器为核心的控制系统,驱动EGR阀的正常运转并进行位移与电流信息采集。根据采样的EGR阀的电流信号特征,将实验数据与理论数据的对比,提出了可靠的特征参数,验证了该诊断方法的可靠性与系统设计的准确性。
