在废气再循环（EGR）和稀燃策略下，以一台进气道喷射点燃式大功率甲醇发动机为试验对象，研究了两种稀释策略及复合稀释对甲醇发动机性能、燃烧及排放特性的影响。试验结果表明：在相同的稀释率下，稀燃比EGR能拥有更高的缸压峰值、更短的燃烧持续期、更低的燃油消耗率和更高的有效热效率。稀燃策略在降低HC和CO排放方面效果较为显著，而EGR策略能更为有效地降低NOx排放。在未燃甲醇和甲醛排放方面，稀燃策略效果都较好。与EGR单独稀释相比，复合稀释能显著提高甲醇发动机的有效热效率。复合稀释对HC排放的影响较小，在降低CO排放方面和过量空气稀释效果相似，优于EGR稀释，最大降低幅度高达80.3%；拥有更好的抑制NOx 排放的效果，最大降低幅度为97%。复合稀释时，未燃甲醇排放与EGR单独稀释时相当，高于过量空气单独稀释；高稀释程度复合稀释时，甲醛排放有所下降。
孟雨航
,
孙楠楠
,
张明泽
,
贾德民
,
张海燕
,
朱建军
. EGR和稀燃对甲醇发动机燃烧及排放特性的影响[J]. 车用发动机, 2023
, 0(6)
: 10
-18
.
DOI: 1001-2222.2023.06.00
Under the exhaust gas recycling (EGR) and lean-burn strategy, the effects of two strategies and compound method on performance, combustion and emission characteristics were studied based on a high-power methanol engine with injection ignition in the inlet port. The test results show that lean-burn can have higher cylinder pressure peak, shorter combustion duration, lower fuel consumption and higher effective thermal efficiency at the same dilution rate. Lean-burn strategy is more significant to reduce HC and CO emissions, but the EGR strategy can more effectively reduce NOx emission. In terms of unburned methanol and formaldehyde emissions, the lean-burn strategy has the better effect. Compared with EGR alone, compound dilution can significantly improve the effective thermal efficiency of methanol engine, has little influence on HC emission, can reduce CO emission by 80.3% at the largest that is similar to the excessive air dilution and better than EGR, can suppress NOx emission with a maximum reduction of 97%, but has an equivalent effect on unburned methanol emission that is higher than the excessive air dilution. When the compound dilution with a high degree is applied, formaldehyde emission will slightly reduce.
