Low emission Lean-Burn engines

与传统的化学计量均质充气发动机相比，稀燃天然气发动机具有更高的效率和更低的排放。然而，当混合气倾斜超过燃烧的稀薄极限时，发动机运行的稳定性降低，排放急剧增加。为了扩展天然气燃烧的稀薄极限，开发了一种独特的部分分层充气(PSC)发动机控制概念。这一新系统增强了稀燃发动机的点火和燃烧，从而减少了废气排放，提高了热效率。初步的“概念验证”测试表明，与传统的同质充气发动机相比，PSC系统提供了更高的发动机稳定性和更低的废气排放。拟议研究的总体目标是更好地了解如何使用PSC点火技术来改善低排放天然气发动机的性能。拟议的研究将包括基本的实验工作以及数值研究，以更全面地了解燃料-空气混合、点火和燃烧过程，这些过程发生在配备PSC点火系统的发动机中。这些基础研究的结果将指导PSC技术的进一步发展，使其在驱动天然气压缩机的大型稀燃固定式发动机上得到商业应用。

Lean-burn natural gas engines offer higher efficiency and lower exhaust emissions compared to conventional stoichiometric homogeneous charge engines. However, as the mixture is leaned out beyond the lean limit of combustion, the stability of engine operation is reduced, and emissions increase sharply. To extend the lean-limit of natural gas combustion, a unique partially stratified-charge (PSC) engine control concept has been developed. This new system provides enhanced ignition and combustion in lean-burn engines, resulting in reduced exhaust emissions and increased thermal efficiency. Initial "proof-of-concept" testing has shown that the PSC system provides increased engine stability and lower exhaust emissions compared to conventional homogeneous charge engine operation. The overall objective of the research being proposed is to develop a better understanding of how the PSC ignition technique can be used to improve the performance of low-emission natural gas engines. The proposed research will include fundamental experimental work as well as numerical studies to develop a more complete understanding of the fuel-air mixing, ignition, and combustion processes that take place in an engine equipped with a PSC ignition system. The results of these fundamental studies will guide further development of the PSC technique for commercial application in large lean-burn stationary engines used to drive natural gas compressors.