EGR is one of the proven and well tested strategies within the specific operating range of the engine. Necessity of an implementation of this exhaust gas recirculation all over the engine operating range is emerging. Therefore, a systematic study has been carried out to identify the specific and frequent transient operations on newly developed dynamic cycles like WLTC and RDE. To perform detailed observations, these transients are imitated individually on the diesel engine test bench. High frequency gas analyzers are used to track the instantaneous CO₂ and NOx concentration respectively at the intake and exhaust lines of the engine. A parametric study has been carried out using different valve movement profiles of the LPEGR and HPEGR during severe engine load change operations. An analysis is presented suggesting the best suited valve control during these harsh transients which can be helpful for transient calibration of a turbocharged diesel engine. The effect of length of Long route LPEGR line is also acknowledged. This study reveals the dynamic behavior of a diesel engine during transient operation with exhaust gas recirculation. It outlines the trade-off between performance and NOx emission and opacity for the initial phase of the transient before acquiring the steady state situation.

中文翻译：

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高动态驾驶循环中的EGR瞬态运行

在发动机的特定工作范围内，EGR是一种经过验证且经过充分测试的策略之一。在整个发动机工作范围内都需要实施这种废气再循环。因此，已经进行了系统的研究，以确定在新开发的动态循环（例如WLTC和RDE）上特定且频繁的瞬态操作。为了进行详细观察，这些瞬变在柴油发动机测试台上被单独模仿。高频气体分析仪用于跟踪瞬时CO ₂和NOx浓度分别在发动机的进气和排气管处。在严重的发动机负荷变化操作过程中，已使用LPEGR和HPEGR的不同气门运动曲线进行了参数研究。提出的分析表明，在这些苛刻的瞬态过程中，最合适的气门控制可能有助于涡轮增压柴油机的瞬态校准。还确认了长距离LPEGR线的长度的影响。这项研究揭示了柴油机在带有废气再循环的瞬态运行过程中的动态行为。它概述了在获得稳态之前，瞬态初始阶段的性能，NOx排放和不透明度之间的权衡。