Ramalingam Krishnamoorthy, Abdullah Mohd Zulkifly, Elumalai P V, Reddy M Venkateswar, Yafang Yan, Prabhakar S, Kamakshi Priya K
School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Penang, 14300, Malaysia.
Department of Mechanical Engineering, C.K. College of Engineering and Technology, Cuddalore, Tamil Nadu, India.
Sci Rep. 2025 Jul 17;15(1):25922. doi: 10.1038/s41598-025-08259-w.
The increasing global demand for cleaner energy solutions highlights the need to combine hydrogen with advanced biofuels for use in low-temperature combustion (LTC) engines. This study experimentally investigates the performance and emissions of an LTC engine fueled with six test fuels: Diesel, Citronella biofuel, three hydrogen-enriched blends (H20, H40, H60) and H40E (H40 + 10%R-EGR). Among the tested fuels, the H40 blend demonstrated the highest brake thermal efficiency (BTE), surpassing that of conventional diesel. Emission analysis showed notable reductions in hydrocarbons (HC) by 65%, carbon monoxide (CO) by 37%, carbon dioxide (CO₂) by 8%, NOx by 6%, and smoke opacity by 20.8% compared to diesel. Notably, H40E further lower NOx formation by 3% than H40 but HC and CO were higher by 2 to 5%. Combustion analysis revealed that hydrogen enhanced pre-mixed combustion, resulting in improved in-cylinder pressure and heat release rate. The experimental results were validated using Sankey diagram visualization, confirming improved energy distribution. The findings indicate that hydrogen-enriched biofuels, particularly the H40 blend offer a promising pathway for cleaner and more efficient engine operation, supporting the global transition away from fossil fuels.
全球对更清洁能源解决方案的需求不断增加，凸显了将氢气与先进生物燃料结合用于低温燃烧（LTC）发动机的必要性。本研究通过实验研究了一台LTC发动机使用六种测试燃料时的性能和排放情况：柴油、香茅生物燃料、三种富氢混合物（H20、H40、H60）和H40E（H40 + 10%废气再循环）。在测试的燃料中，H40混合物表现出最高的制动热效率（BTE），超过了传统柴油。排放分析表明，与柴油相比，碳氢化合物（HC）显著减少了65%，一氧化碳（CO）减少了37%，二氧化碳（CO₂）减少了8%，氮氧化物（NOx）减少了6%，烟度减少了20.8%。值得注意的是，H40E比H40进一步降低了3%的NOx生成，但HC和CO则高出2%至5%。燃烧分析表明，氢气增强了预混燃烧，导致缸内压力和热释放率提高。实验结果通过桑基图可视化进行了验证，证实了能量分布得到改善。研究结果表明，富氢生物燃料，特别是H40混合物，为更清洁、更高效的发动机运行提供了一条有前景的途径，支持全球从化石燃料的转型。
