Analysis of Performance of Passive Pre-Chamber on a Lean-Burn Natural Gas Engine under Low Load

Stable ultra-lean combustion is an effective way for natural gas engines to reduce NOx emissions, but it also has higher requirements ignition stability. The passive pre-chamber can effectively increase the energy and extend lean-burn limit of engines. However, scavenging capacity limits its performance under low engine load. In this paper, several pre-chambers are designed, CFD simulation carried out investigate influence direction, number diameter nozzle on process. discharge residual in mainly affected by diameter, which varies from 5.9% 1% when increases 0.8 mm 1.6 mm. At same time, claw-shaped electrodes applied rate, validated a cylinder simulation. Finally, tested 6-cylinder 25% results show that, proper timing, excess air ratio (λ) reach 1.9 load propulsion characteristic with level cyclic variation. emission be as 0.34 g/kWh without aftertreatment equipment.