TY - JOUR
T1 - Effects of split injection strategy on combustion stability and GHG emissions characteristics of natural gas/diesel RCCI engine under high load
AU - Liu, Junheng
AU - Liu, Yuan
AU - Ji, Qian
AU - Sun, Ping
AU - Zhang, Xuchao
AU - Wang, Xidong
AU - Ma, Hongjie
PY - 2022/12/26
Y1 - 2022/12/26
N2 - Natural gas/diesel RCCI mode is considered as a high-efficiency clean low-temperature combustion strategy with great application prospects. In order to solve the problem that RCCI engines are prone to knock combustion under high load, the effects of diesel start of main-injection (SOImain), start of pilot-injection (SOIpilot) and pilot-injection quantity (PIQ) on in-cylinder combustion and pollutant emissions of RCCI engine were systematically investigated. Results show that the advance of SOImain effectively reduces CO, HC, soot and CH4 emissions of RCCI engine, but increases knock tendency and NOx emissions. Split injection strategy makes combustion exothermic of RCCI mode present two-stage heat release phenomenon. When SOIpilot is advanced from −15°CA ATDC to −27°CA ATDC, the IMEP and combustion pressure peak increase, the knock tendency significantly decreases, and CO, HC, soot and CH4 emissions are reduced by 55.6%, 43.1%, 28.8% and 39.1% respectively. With the increase of PIQ, the in-cylinder combustion of RCCI engine gradually changes from single-stage to two-stage heat release, the ignition delay is shortened, and the knock tendency is enhanced. Compared with single injection strategy, split injection strategy can simultaneously reduce HC, CO and greenhouse gas emissions, as well as maximum pressure oscillation amplitude and pressure rise rate in RCCI mode.
AB - Natural gas/diesel RCCI mode is considered as a high-efficiency clean low-temperature combustion strategy with great application prospects. In order to solve the problem that RCCI engines are prone to knock combustion under high load, the effects of diesel start of main-injection (SOImain), start of pilot-injection (SOIpilot) and pilot-injection quantity (PIQ) on in-cylinder combustion and pollutant emissions of RCCI engine were systematically investigated. Results show that the advance of SOImain effectively reduces CO, HC, soot and CH4 emissions of RCCI engine, but increases knock tendency and NOx emissions. Split injection strategy makes combustion exothermic of RCCI mode present two-stage heat release phenomenon. When SOIpilot is advanced from −15°CA ATDC to −27°CA ATDC, the IMEP and combustion pressure peak increase, the knock tendency significantly decreases, and CO, HC, soot and CH4 emissions are reduced by 55.6%, 43.1%, 28.8% and 39.1% respectively. With the increase of PIQ, the in-cylinder combustion of RCCI engine gradually changes from single-stage to two-stage heat release, the ignition delay is shortened, and the knock tendency is enhanced. Compared with single injection strategy, split injection strategy can simultaneously reduce HC, CO and greenhouse gas emissions, as well as maximum pressure oscillation amplitude and pressure rise rate in RCCI mode.
KW - injection strategy
KW - natural gas
KW - dual-fuel engine
KW - low temperature combustion
KW - combustion stability
KW - emission characteristic
U2 - 10.1016/j.energy.2022.126542
DO - 10.1016/j.energy.2022.126542
M3 - Article
VL - 266
JO - Energy: The International Journal
JF - Energy: The International Journal
SN - 0360-5442
M1 - 126542
ER -