Performance and emission prediction of hydrogen addition to natural gas powered engine using 0/1 dimensional thermodynamic simulation


With the increase in global warming, the measures taken by the governments regarding the use of internal
combustion engines are also increasing. These measures, on the other hand, encourage the use of alternative fuels, both to reduce emissions and to research less use of petroleum-based fuels such as diesel and gasoline. Natural gas is one of the fuels that has been researched and used as an alternative fuel recently. However, the lower lean limit, high coefficient of variation (COV) of indicated mean effective pressure (IMEP), relatively lower diffusivity, requirement of high ignition energy and high flme quenching distance properties of natural gas compared to gasoline fuel have a limiting effect. However, these properties can be improved with the addition of a certain amount of hydrogen. In this study, a 3-cylinder diesel tractor engine was converted into a spark-ignition engine using natural gas. Then, by adding hydrogen at low rates between 1% and 5% by mass, its effects on performance, combustion characteristics, and emission values were examined. Despite the high compression ratio of the diesel engine, such as 17.5:1, it was observed that the addition of 5% hydrogen did not cause knocking. In addition, brake power (BP), brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), and brake mean effective pressure (BMEP) values improved with increasing hydrogen addition as 11.33%, 7.5%, and 0.49% respectively. In addition, in-cylinder temperature and pressure values increased due to increasing lower heating values and flame speed. While total hydrocarbon (THC) emission values decreased, nitrogen oxide (NOX) and carbon monoxide (CO) emission values increased slightly.

Fatih Aktaş