Multi-injection and advanced Miller timing in large-bore CI engine
The objective of this paper is to show the results gained from a medium-speed research engine using multiple injection in order to improve the engine performance and especially reduce exhaust emissions. The study is in fact carried out with a single-cylinder large-bore diesel engine (EVE), which is used only for research purposes. Its main feature is that the gas exchange valve timing is completely adjustable with an electro-hydraulic system that uses the engine lubrication oil to open the gas exchange valves. Moreover, the engine does not have a turbocharger, but a separate air compressor supply system that permits to change freely the intake charge air conditions; after the engine, a throttle valve tunes the exhaust back pressure. Many EVE components have been recently upgraded and the engine can withstand high indicated power and peak pressure values. This study includes the comparison between single- and multi-injection timing and the influence on the engine performance. The different injection strategy is also combined with different valve timing: the Miller technique is used in order to reduce NOx, whose regulation is becoming more and more stringent. The research is carried out at high engine load. The in-cylinder compression pressure and the injection quantity per stroke are the parameters that are unchanged in every tested point. The combustion process is analyzed and the different setups are compared to understand the influence of the chosen strategy. The results show that it is possible to achieve high NOx reduction but the injection strategy must be chosen carefully with the valve timing.
Matteo Imperato Jussi Nurmiranta Teemu Sarjovaara Martti Larmi Christer Wik
Aalto University,Finland W(a)rtsil(a) Oy Finland,Finland
国际会议
上海
英文
1-8
2013-05-13（万方平台首次上网日期，不代表论文的发表时间）