Cycle-resolved measurements of in-cylinder constituents during diesel engine transients and insight into their impact on emissions
Cycle-resolved measurements of in-cylinder constituents during diesel engine transients and insight into their impact on emissions
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柴油发动机瞬态期间缸内成分的循环解析测量并深入了解其对排放的影响
DOI：
10.1177/0954407011414997
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Z. Filipi
中科院分区：
文献类型：
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作者：
J R Hagena;D. Assanis;Z. Filipi
柴油机的瞬变，尤其是怠速负荷的快速增加，会导致柴油机的运行参数偏离正常的稳态运行。典型的瞬变事件是由燃料的突然增加和涡轮滞后期引发的。关键参数的轨迹，如增压压力、空燃比和气缸中的残留量，取决于控制系统行为、执行器响应和物理过程的时间尺度之间的复杂相互作用。最终结果是燃烧事件和排放形成的显著偏差。例如，已有研究表明，在一个城市驾驶周期中，烟尘的瞬时尖峰可能占到总颗粒物排放量的一半。本文介绍了一种实验技术，用于量化发动机过渡过程中循环分解的缸内预燃成分，并通过测量深入了解柴油机过渡过程中排放增加的机理。一台6.0升的V-8柴油发动机被用来测量喷油器针头升程和喷油压力，气缸压力，同时快速测量排气和气缸中的二氧化碳浓度，以及快速测量NO和颗粒物光谱。引入了分析技术来处理测量和确定燃料、空气和化学计量燃烧产物的循环分辨质量，从而提供了对瞬变期间排放显著变化的原因的洞察。这项技术被用来研究发动机在一个ftp-72驾驶周期内的行为。
Diesel engine transients, in particular the rapid increase of load from idle, lead to significant excursions of operating parameters from normal, steady-state operation. A typical transient event is initiated by a sudden increase of fuelling followed by a turbo lag period. The trajectories of key parameters, such as boost pressure, air/fuel ratio, and amount of residual in the cylinder, depend on the complex interplay between the control system behaviour, actuator response, and time scales of physical processes. The end result is a significant deviation of the combustion event and emission formation. For example, it has been shown that transient spikes of soot may be responsible for up to half of total particulate emissions during a city driving cycle. The present paper introduces an experimental technique to quantify cycle-resolved pre-combustion in-cylinder constituents during transient engine operation and uses measurements to generate insight into mechanisms that cause increased emissions during a diesel engine transient event. A 6.0-litre V-8 diesel engine is instrumented for fuel injector needle lift and injection pressure measurements, cylinder pressure, simultaneous fast measurements of CO2 concentrations in the exhaust and in the cylinder, and fast measurements of NO and particulate spectrum. Analytical techniques are introduced to process measurements and determine cycle-resolved mass of fuel, air, and stoichiometric combustion products, thus providing insight into reasons for significant variations of emission during the transient. The technique is utilized to study engine behaviour over an FTP-72 driving cycle.