Abstract
Low-temperature combustions (LTCs), such as homogeneous charge compression ignition (HCCI), could achieve high thermal efficiency and low engine emissions by combining the advantages of spark-ignited (SI) engines and compression-ignited (CI) engines. Robust control of the ignition timing, however, still remains a hurdle to practical use. A novel technology of jet-controlled compression ignition (JCCI) was proposed to solve the issue. JCCI combustion phasing was controlled by hot jet formed from pre-chamber spark-ignited combustion. Experiments were done on a modified high-speed marine engine for JCCI characteristics research. The JCCI principle was verified by operating the engine individually in the mode of JCCI and in the mode of no pre-chamber jet under low- and medium-load working conditions. Effects of pre-chamber spark timing and intake charge temperature on JCCI process were tested. It was proven that the combustion phasing of the JCCI engine was closely related to the pre-chamber spark timing. A 20 °C temperature change of intake charge only caused a 2° crank angle change of the start of combustion. Extremely low nitrogen oxides (NOx) emission was achieved by JCCI combustion while keeping high thermal efficiency. The JCCI could be a promising technology for dual-fuel marine engines.
Highlights
The internal combustion engine (ICE) is still the most important prime mover of vehicles and ships after more than 100 years of development
The working process is as follows: First, the engine has a small pre-chamber in which natural gas is fed independently, and main chamber diesel fuel and air mixture is formed by in-cylinder early injection during compression stroke; second, the engine effective compression ratio is low enough that only low temperature exothermic reaction will happen [6,25]; third, pre-chamber gas mixture is ignited by spark plug at close to compression top dead center (TDC), and hot flame jet formed leads to the onset of ignition of main chamber mixture
This study aims to investigate the combustion and emissions characteristics of the jet-controlled compression ignition (JCCI) engine
Summary
The internal combustion engine (ICE) is still the most important prime mover of vehicles and ships after more than 100 years of development. The working process is as follows: First, the engine has a small pre-chamber in which natural gas is fed independently, and main chamber diesel fuel and air mixture is formed by in-cylinder early injection during compression stroke; second, the engine effective compression ratio is low enough that only low temperature exothermic reaction will happen [6,25]; third, pre-chamber gas mixture is ignited by spark plug at close to compression top dead center (TDC), and hot flame jet formed leads to the onset of ignition of main chamber mixture. The specific objectives are to verify the JCCI principle on the test engine and determine the effects of pre-chamber spark timing on main chamber ignition control and combustion process. Robust control of the JCCI process under different intake charge temperatures is proven
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
