以一台四冲程高压直喷天然气发动机为研究对象，模拟研究了5种天然气预喷量耦合5种废气再循环（EGR）率对部分预喷天然气发动机的燃烧和排放特性的影响。结果表明，相比于高压直喷模式，部分预喷模式有着更高的缸内峰值压力、峰值热释放率和最大压力升高率。预喷比例的增加会提前发动机燃烧相位、缩短燃烧持续期，进而降低发动机的指示燃料消耗率，但是EGR的加入会削弱这种效果。较高的预喷量耦合中等比例EGR能够削弱NOx-soot的“trade-off”关系；30%EGR率耦合40%预喷量能够使发动机具有较低的指示燃油消耗率，产生较低的甲烷、未燃HC和CO排放，以及优于非预喷方案的NOx和soot排放特性。
Based on a four stroke high pressure direct injection natural gas engine, the coupling effects of five natural gas pre-injection volumes and five EGR rates were simulated and studied to compare and discuss the combustion and emission characteristics of a partially premixed natural gas engine. The results show that compared with the high pressure direct injection mode, partial pre-injection mode has higher peak in-cylinder pressure, peak heat release rate and maximum pressure rise rate. Increasing of pre-injection ratio will advance the engine combustion phase and shorten the combustion duration, thereby reducing the engine's indicated fuel consumption rate, but the addition of EGR will weaken this effect. The higher pre-injection rates coupled with moderate EGR can weaken the NOx-soot "trade-off" relationship. The 30% EGR rates coupled with 40% pre-injection can result in engine with lower indicated fuel consumption rates, lower methane, unburned HC and CO emissions, and better NOx and soot emission characteristics than direct injection solutions.
2024,46(5): 95-102 收稿日期：2023-03-15
DOI：10.3404/j.issn.1672-7649.2024.05.018
分类号：U664.121；TK402
基金项目：国家自然科学基金资助项目（51909154）；上海高水平地方高校创新团队（海事安全与保障）项目；上海船舶智能运维与能效监控工程技术研究中心项目（20DZ2252300）
作者简介：黄文庆(1996-),男,硕士研究生,研究方向为天然气双燃料发动机的性能与排放
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