Boosting systems for hydrogen internal combustion engines

Environmental concerns are becoming increasingly critical, leading to the introduction of stringent emissions regulations. The European Commission is forcing the manufacturers toward net-zero CO 2 emissions. Conventional internal combustion engines are unable to meet these targets, thus requiring alternative propulsion system. While battery electric vehicles represent a viable solution, they are limited by cost, power-to-weight ratio, and charging constraints, particularly in heavy-duty applications. Hydrogen internal combustion engines offer a promising alternative, leveraging mature internal combustion engines technologies. However, hydrogen internal combustion engines operating under stoichiometric conditions produce significant NO x emissions. Ultra-lean combustion strategies can mitigate this issue, but they require advanced turbocharging systems capable of ensuring high air flow rates under both steady state and transient conditions. This article presents a review of boosting solutions for hydrogen internal combustion engines. The analysis includes turbine architectures, regulation systems, compressor technologies, and advanced boosting solutions, including multi-stage and electrically assisted systems.