Hydrogen Internal Combustion Engine Strategies for Heavy-Duty Transportation: Engine and System Level Perspective 2024-26-0175

Hydrogen internal combustion engines (H₂ICE) offer a cost-effective solution to decarbonize transport by combining a lower carbon intensity fuel with mature and established internal combustion engine technology. While vehicles running with hydrogen have been demonstrated over the years, this fuel's physical and chemical properties require modifications and upgrades on the vehicle from an engine and system-level perspective. In addition, market-specific regulatory and economic factors can also constrain the realization of optimal hydrogen powertrain architectures. Therefore, this paper reviews the impact of hydrogen use on combustion, injection, air management, and after-treatment systems, indicating the different strategies used to enable effective H₂ICE strategies from an efficiency, cost, and safety standpoint. Specifically, swirl and tumble-based combustion systems using port fuel injection, low-pressure, and high-pressure direct injection are discussed to review performance, cost, and maturity trade-offs. Additionally, a thorough overview of the possibilities enabled by clean sheet design versus development based on base diesel and natural gas engines is presented. Finally, Indian market-specific regulations and use cases are also discussed from a technology and total cost of ownership perspective to evaluate practical considerations such as ease of operation, payload reduction, and dwell time.