Combustion characteristics analysis and performance evaluation of a hydrogen engine under direct injection plus lean burn mode

• Published in: Journal of cleaner production Vol. 470; p. 143323
• Main Authors: Chen, Wei, Lu, Chun, Zuo, Qingsong, Kou, Chuanfu, Shi, Rui, Wang, Hui, Ning, Dezhong, Shen, Zhuang, Zhu, Guohui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.09.2024
• Subjects: Hydrogen direct injection engine; Injection strategy; Lean burn; Performance evaluation; Zero carbon engine; Performance evaluation; Injection strategy; Zero carbon engine; Lean burn; Hydrogen direct injection engine
• ISSN: 0959-6526
• DOI: 10.1016/j.jclepro.2024.143323

Direct injection plus lean burn technology can effectively control combustion processes and reduce carbon emissions of hydrogen engines. Hence, hydrogen direct injection strategy optimization is a key means to improve engine performance and achieve low emissions. Thus, a three-dimensional transient calculation model coupled chemical reaction mechanism is established, and its reliability and accuracy are systematically evaluated using experimental data. Then, the effects of hydrogen direct injection strategies on the hydrogen-air mixing and combustion process are investigated. The results indicate that the ideal mixture stratification law is that the gas fuel concentration is gradually stratified from the ignition center to the periphery region. The maximum indicated work is obtained for the B-60° scheme which its injection position is near the intake side and 7.5 mm from the cylinder center on the X-axis. The optimal hydrogen injection angles vary with different injection positions by evaluating engine performance, specifically, 60° is optimal for injection position B, while 30° is best for injection position C which is between intake and exhaust and 40 mm from the cylinder center on the Y-axis. Finally, the achieved maximum thermal efficiencies of 41% and indicated power of 4.29 kW for the B-60° scheme, and its nitric oxide can meet the Europe V emission standards (7.5 g/kWh). This research can offer theoretical guidance for designing and optimizing fuel injection strategies for hydrogen energy engines, and it is relevant for promoting carbon neutrality and cleaner production.