Analysis of Engine Performance Parameters with Hydrogen Enrichment in Premixed Spark Ignition Engine Using Fuel Blend

Hydrogen enrichment in internal combustion engines has been a topic of research interest to improve engine efficiencies and reduce carbon emissions. Hydrogen enrichment has garnered more interest than the pure hydrogen powered engines due to less complexity involved with the modifications of the engine and fuel system as well as the infrastructure required for it. Similarly, accurate chemical kinetics has proved to provide accurate results in terms of engine performance parameters, such as, in-cylinder pressure. The present study is an extension of study performed earlier with hydrogen enrichment in gasoline direct injection engine while using C8 H17 as a surrogate fuel for gasoline and assumes that an on-board electrolysis system installed on the vehicle produces hydrogen for the enrichment purposes. A mesh independent study is performed using 90% iso-octane (iC8 H18) and 10% n-heptane (nC7 H16) blend as a gasoline surrogate with hydrogen enrichment of 0%, 1%, 2% and 3% at equivalence ratios of 0.98 and 1.3, in a premixed spark ignition engine. Numerical simulations are performed to calculate and compare the thermal and combustion efficiencies of the engine using hydrogen-enriched fuel versus iso-octane and n-heptane blend. The study also predicts and measures the engine performance parameter of in-cylinder pressure, while comparing the iso-octane and n-heptane blend against the blend enriched with hydrogen. Based on the results obtained from smaller hydrogen enrichment concentrations, the study increases the hydrogen-enrichment of the fuel to 5%, 10% and 15% to analyse the effects of enrichment on the thermal and combustion efficiencies, as well as the in-cylinder pressure.