International Journal of Hydrogen Energy | 2019
Effects of hydrogen addition on engine performance in a spark ignition engine with a high compression ratio under lean burn conditions
Abstract
Abstract In this study, the effects of hydrogen addition on the engine performance were investigated using spark ignition engine fueled gasoline with a compression ratio of 15\xa0at an air excess ratio (λ) of 1.8 and above. At λ\xa0=\xa01.8, the indicated thermal efficiency at the spark timing of the knock limit reached the maximum level under the conditions in which the hydrogen fraction was set to 4% of the heating value of the total fuel. Based on a heat balance analysis, the best hydrogen fraction was found as a balance between the improvement in the burning efficiency and the increase in heat loss. The lean limit was extended when the hydrogen fraction was increased from λ\xa0=\xa01.80 to λ\xa0=\xa02.28. The hydrogen addition achieved the maximum indicated thermal efficiency at spark timing of the knock limit was obtained at λ\xa0=\xa02.04, where the hydrogen fraction was 10%.