Abstract:
Energy efficiency and environmental impact have become dominant topics in internal combustion
engines development. Among many strategies to improve power and emissions outputs from diesel engines is the partial mix of hydrogen and air as fresh charge components to form extremely
lean and homogenous mixture, which resist the spontaneous combustion, while diesel fuel is injected directly inside combustion chamber using the conventional fuel injection systems. This
contribution presents an analytical and experimental investigation for the effects of adding hydrogen on diesel engines power output and the reduction of emissions. Parametric analysis is used
based on lamped parameters modeling of intake manifold to estimate in cylinder trapped charge.
The fuel energy flow to engine cylinders is compared for a range of loads and concentrations to
simulate relevant case studies. Diesel fuel reduction for significant range of part-load operation
can be achieved by introducing hydrogen, along with power improvement emission reductions are
affected positively as well. This is achievable without compromising the engine maximum efficiency, given that most engines are operated at small and part-load during normal driving conditions, which allow for introducing more hydrogen instead of large quantities of excess air during
such operation conditions that also can be further improved by charge boosting.
