Feasible route towards decarbonising marine transport with flexible, hydrogen – enriched, reactivity controlled compression ignition mid-speed engines

Abstract

Hydrogen (H2) admixing in Reactivity Controlled Compression Ignition (RCCI) technology engines is touted to enhance indicated efficiency (ITE>50%), optimize combustion and reduce greenhouse gas emissions. However, many pending issues remain regarding engine durability, nitrogen oxide (NOX) emissions and blending limits. These issues are addressed by employing a novel performance-oriented model which simulates under 3 min, combustion physics with similar predictivity (>95% accuracy) as computational fluid dynamic results. This so-called multizone model is parameterized to real-world operating cycles from a dual-fuel mid-speed marine engine. By considering port-fuel injected H2, the simulations show that combustion phasing advances at an average rate of 0.3⁰CA/% H2, accompanied by a peak reduction in methane slip of 80% achievable at 25% H2 energy share. Also, engine control oriented issues are addressed by demonstrating either intake temperature or diesel fuel share optimization to negate the drawbacks of combustion harshness and NOX emissions, while improving ITE 1–1.5pp over baseline operation.