Investigation of Effects of changing hydrogen injection rate on combustion, environment and fuel economy parameters in a DI engine

Nowadays hydrogen fuel as a clean energy due to making much less emissions besides proper combustion effects in comparison to other usual fuels has been highly considered by research centers for using at various combustion systems. Nevertheless, effects of using hydrogen fuel under various operating conditions such as different engine speeds for meet the general balanced situation with taking into account most emissions and power parameters of engine need to further investigations. Unlike similar studies, in the present work, emphasis was on investigation of effects of injected hydrogen mass fraction at a wide range of engine speeds (from 1500 to 5000 rpm) and analyses have been performed with consider to most of emissions (CO2, CO, soot, HC, etc.) besides combustion and fuel economy parameters to yield a general balanced state at ISM370 HDÆengine. For constructing required geometries, simulation of different parts of the engine and numerical analyze, AVL Fire software has been used. Results of conducted studies show that air swirl in the cylinder is suitable before fuel injection and injecting more hydrogen fuel leads to increasing air turbulence. With study on the various rates of injected hydrogen (0.86%, 1.027%, 1.28% and 1.7%) in equivalence ratios specified, mass fraction of 1.027% hydrogen entered from intake port for meet to a balanced state between most of emissions, combustion parameters, etc. was known proper. Furthermore, it was determined that 2 deg BTDC injection timing makes doubles advantages of using 1.027% hydrogen mass fraction.