Zhefeng Guo, Yu-Lun Hsieh, Sheng-Lun Lin, Yen-Yi Lee, Timothy H Lee
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引用次数: 0
Abstract
Nano-Al2O3 derived from recyclable sources emerges as a promising sustainable solution for enhancing diesel engine efficiency while mitigating emissions. However, a lack of an in-depth understanding of the health hazard aspect still challenges its commercial applications. To this end, nano-Al2O3/diesel (NAD) blends prepared via ultrasonic homogenization were experimentally and analytically investigated under various injection timings and excess air coefficients to explore the potential of nano-Al2O3 for balancing energy performance and emissions. Results revealed a synergistic effect between the NAD blends and optimized combustion control strategies. NAD blends presented enhanced heat release and pressure rise rates even under late injection or hypoxic conditions, indicating a faster and more complete combustion. Specifically, NAD blends promoted the partially premixed combustion phase and reduced postcombustion duration. While a slight increase in fuel consumption and a decrease in thermal efficiency were observed, potentially due to minor chamber compatibility issues, a significant improvement in emissions was identified. NAD blends effectively mitigated the well-known soot-particulate number-nitrogen oxide (NOx) trade-off inherent in diesel engines. NAD blends achieved lower NOx emissions through the even temperature distribution promoted by nano-Al2O3, minimizing the formation of NOx precursors. Simultaneously, NAD blends contributed to a reduction in soot emissions as well as an increment in nucleation mode particles, which are smaller and more harmful than conventional engine-out particulates. Notably, deposition modes highlighted that a higher nano-Al2O3 addition leads to an increase in nucleation mode particles, resulting in a higher alveolar deposition (dp = 5-100 nm) and lower nasal deposition (dp = 200-800 nm). These findings suggest that, by optimizing injection timing and excess air coefficients, NAD blends offer a promising approach to enhance combustion and achieve cleaner emissions simultaneously, making them a valuable contribution to the development of more sustainable diesel engine technologies.
从可回收来源中提取的纳米氧化铝作为一种有前途的可持续解决方案,在提高柴油发动机效率的同时减少排放。然而,缺乏对健康危害方面的深入了解仍然对其商业应用构成挑战。为此,通过超声波均质法制备的纳米al2o3 /柴油(NAD)共混物在不同的喷射时间和过量空气系数下进行了实验和分析研究,以探索纳米al2o3在平衡能源性能和排放方面的潜力。结果表明,NAD混合燃料与优化后的燃烧控制策略之间存在协同效应。NAD混合物即使在后期喷射或低氧条件下也表现出更强的热量释放和压力上升速率,表明燃烧更快、更完全。具体而言,NAD混合物促进了部分预混燃烧阶段,缩短了燃烧后持续时间。虽然观察到燃料消耗略有增加,热效率下降,可能是由于较小的腔室兼容性问题,但确定了排放的显着改善。NAD混合物有效地缓解了众所周知的柴油发动机固有的煤烟-颗粒-氮氧化物(NOx)权衡。通过纳米al2o3促进的均匀温度分布,NAD共混物实现了更低的NOx排放,最大限度地减少了NOx前体的形成。同时,NAD混合物有助于减少烟尘排放,并增加成核模式颗粒,这些颗粒比传统的发动机排出颗粒更小,更有害。值得注意的是,沉积模式强调,更高的纳米al2o3添加量会导致成核模式颗粒的增加,导致更高的肺泡沉积(d p = 5-100 nm)和更低的鼻沉积(d p = 200-800 nm)。这些研究结果表明,通过优化喷射时间和过量空气系数,NAD混合物提供了一种有前途的方法,可以同时增强燃烧和实现更清洁的排放,使其对更可持续的柴油发动机技术的发展做出宝贵贡献。
ACS OmegaChemical Engineering-General Chemical Engineering
CiteScore
6.60
自引率
4.90%
发文量
3945
审稿时长
2.4 months
期刊介绍:
ACS Omega is an open-access global publication for scientific articles that describe new findings in chemistry and interfacing areas of science, without any perceived evaluation of immediate impact.