Yoo Jihyung, Prikhodko Vitaly, Parks James E, Perfetto Anthony, Geckler Sam, Partridge William P
National Transportation Research Center, Fuels, Engines, and Emissions Research Center, Oak Ridge National Laboratory, 2360 Cherahala Boulevard, Knoxville, TN 37932 USA.
Appl Spectrosc. 2015 Sep;69(9):1047-58. doi: 10.1366/14-07796. Epub 2015 Aug 6.
Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.
内燃机中的废气再循环（EGR）是一种在提高效率的同时减少氮氧化物排放的有效方法。然而，新鲜空气与废气之间混合不充分会导致多缸发动机各循环之间以及各气缸之间的充气混合气不均匀，进而降低发动机性能和效率。设计、制造了一种封装在紧凑型探头中的传感器，并将其应用于测量运行中发动机进气歧管内废气再循环的时空分布。该探头通过解析进气歧管不同位置处的高速原位二氧化碳浓度，推动了更高效、高性能发动机的发展。该研究采用了调谐到二氧化碳在4.3μm附近吸收带的中红外光源，这是确定废气再循环率的行业标准物质。经过校准的探头用于高精度绘制进气歧管内的空间废气再循环分布，并以高达1kHz的速率监测各循环分辨的特定气缸废气再循环波动。
