Feasibility of hydrogen fuelled split cycle engine using multizone modelling

The environmental impact of fossil fuel combustion is driving the search for efficiency and sustainable propulsion systems. Questions remain on what source can meet the high energy requirements for heavy-duty propulsion and standalone systems. The recuperated split cycle engine (SCE) has shown potential for a step change in efficiency compared to conventional compression ignition heavy-duty engines. Combining this engine with hydrogen fuel would also reduce dependence on fossil fuels. This study uses Chemkin-Pro multizone homogeneous charge compression ignition (MZ HCCI) engine model to determine the feasibility of a hydrogen fuelled SCE. The MZ HCCI model represents the expansion cylinder of the SCE and is used to compare hydrogen and diesel in terms of performance and compatibility with the SCE at various valve timings. Results show that, though the IMEP generated by hydrogen is lower than diesel due to lower fuel mass density at higher initial temperatures, it delivers comparable thermal efficiency, with values approaching 60 %. Also, hydrogen shows characteristics well suited to the SCE architecture, indicating that hydrogen and the SCE is a feasible alternative to diesel CI heavy-duty propulsion systems.