The major objective of the presented work is to explore the effect of post injection (PI) strategy using neat diesel fuel (D100) blended with cetane number enhancer (CNE). The motive behind adding CNE in diesel fuel was to lower its self-ignition temperature and hence delay period subsequently. This can lead to more efficient combustion of post injected fuel which leads to lower incomplete combustion losses. The CNE used was Di-Tert-Butyl Peroxide (DTBP) which was blended with D100 in proportion of 1 % by volume. Initially experiments were conducted with D100 under various PI modes where variation of post injection timing (PIT) as well as post quantity (PQ) was considered. The experimental results showed that implementing PI resulted in lower smoke, unburned hydrocarbon (UHC), carbon monoxide (CO) and nitrogen oxides (NOx) emissions compared to single injection while affecting fuel consumption negatively. Then after similar experiments under various PI modes were repeated using blends of D100 and DTBP (D/DTBP) and results were compared with D100 case. It was found that addition of CNE in D100 resulted in more complete combustion of post fuel which further reduced CO and UHC emissions. The shorter delay period in case of D/DTBP blend compared to D100 case led to lower NOx emissions as well as higher smoke emissions. The obtained results revealed that PI mode with 3 mg PQ and 20° after top dead center (ATDC) PIT with D/DTBP blend offered 41.18 %, 17.55 %, 64 % and 62.5 % reduction in smoke, NOx, UHC and CO emissions respectively compared to single injection mode using D100 fuel.

中文翻译：

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柴油发动机中高十六烷值柴油与后喷射模式的结合：降低废气排放的途径


本工作的主要目标是探索使用与十六烷值增强剂 (CNE) 混合的纯柴油 (D100) 的后喷射 (PI) 策略的效果。在柴油中添加CNE的目的是降低其自燃温度，从而延迟周期。这可以使后喷射燃料的燃烧更加有效，从而降低不完全燃烧损失。使用的CNE是过氧化二叔丁基(DTBP)，其与D100以1体积％的比例混合。最初的实验是在各种 PI 模式下使用 D100 进行的，其中考虑了后喷射正时 (PIT) 和后喷射量 (PQ) 的变化。实验结果表明，与单次喷射相比，实施 PI 可以减少烟尘、未燃烧碳氢化合物 (UHC)、一氧化碳 (CO) 和氮氧化物 (NOx) 的排放，同时对燃油消耗产生负面影响。然后使用 D100 和 DTBP 的混合物 (D/DTBP) 在各种 PI 模式下重复进行类似实验，并将结果与​​ D100 情况进行比较。结果发现，在 D100 中添加 CNE 可使后燃料燃烧更完全，从而进一步减少 CO 和 UHC 排放。与 D100 情况相比，D/DTBP 混合物的延迟期更短，导致氮氧化物排放量更低，烟雾排放量更高。获得的结果表明，采用 3 mg PQ 的 PI 模式和采用 D/DTBP 混合物的上止点后 (ATDC) 20° PIT 分别可将烟雾、NOx、UHC 和 CO 排放量分别减少 41.18%、17.55%、64% 和 62.5%与使用 D100 燃料的单喷射模式相比。