4. Hydrogen Fueled Engine Technology, Adaptation, and Application for Marine Engines

In the last few years, there is a noteworthy increase in the number of ships that use alternative fuels apart from diesel as LNG, methanol, etc., to meet the carbon emission mitigation strategies. Hydrogen (H₂) is a contemporary promising fuel solution to cope with strict carbon emission limits. The adaptation of conventional to alternative fuels with a familiar technology, the internal combustion engine (ICE) technology, is a reasonable solution for near future carbon strategies because of being a relatively prevailing technology compared to other hydrogen sourced power generators. This chapter analyzes the potential transition of the H₂ fuel engines according to the combustion capability of hydrogen in marine engines. The lack of knowledge of hydrogen combustion and ignition in the reciprocating engines is still a main challenge of the hydrogen engines. Hydrogen combustion properties and induction into ICEs are evaluated considering advantages and challenges. The applications show that LNG-powered engines significantly have similarities with hydrogen engines and enable the transition of H₂ combustion in the marine engines. On the other hand, hydrogen engines suffer from low volumetric efficiencies and pre-ignition problems but they are capable of operate from ultra-lean to ultra-rich combustions. Thanks to the turbochargers, the stoichiometry levels are obtainable for engines to satisfy the high-power. Adding the hydrogen into the cylinder with liquefied/gas phase is the issue to be determined with ease of vaporization and the mixing. The combustion comes with near-zero CO₂ and soot advantages. However, neat H₂ combustion in marine engines is still far from the final product.