Research on pre-ignition in hydrogen internal combustion engines based on characteristic parameters of hot spot.

When hydrogen internal combustion engine works using the intake manifold injection mode to provide the hydrogen, it has to face a contradiction between the abnormal combustion (preignition, backfire, etc.). Currently, most researches on abnormal combustion in hydrogen internal combustion engines have focused primarily on backfire and detonation, with limited investigation of pre-ignition, particularly when initiated by in-cylinder hot spots. In order to explore the relationship between the hot spot and the pre-ignition of hydrogen internal combustion engine, the influence of characteristic parameters of hot spot, such as hot spot area, initial temperature, duration of hot spot and temperature change rate, on pre-ignition of hydrogen internal combustion engines were analyzed. On the basis of using the isolated factor method to research the influence of each characteristic parameter on the occurrence time of pre-ignition of hydrogen internal combustion engines, the comprehensive effect of these characteristic parameters on the occurrence moment of pre-ignition in hydrogen internal combustion engines was also investigated with the orthogonal test method. It is found that the occurrence of pre-ignition of hydrogen internal combustion engines is the result of multi-factor interaction. Pre-ignition is most affected by hot spot area, and when the hot spot area is the same, the order of influence of pre-ignition timing is initial temperature > temperature change rate > duration of hot spot. The research results can promote the practical application of hydrogen fuel in internal combustion engines and provide guidance for the structural design of hydrogen internal combustion engines. • Hydrogen engine pre-ignition results from combined effects of several parameters such as the area, initial temp. • Strategies to control temp change rates could mitigate pre-ignition risks and optimize combustion performance. • Compared to initial temp, the moment of pre-ignition is more sensitive to changes in the area of the hot spot. • With equal hot spot area: initial temp > temp change rate > duration influence hydrogen engine pre-ignition. [ABSTRACT FROM AUTHOR]