As a zero carbon power solution, hydrogen internal combustion engines are entering a period of technological explosion. This article analyzes from three aspects: technical principles, thermal efficiency improvement, and industrialization challenges.

1. Technical principle of hydrogen internal combustion engine

Combustion characteristics: The flame propagation speed of hydrogen is 8 times that of gasoline, and the ignition energy and injection timing need to be optimized. For example, a direct injection hydrogen engine with a pre chamber spark plug reduces the ignition energy requirement to 15mJ.

Knock suppression: By using lean combustion (λ=2.0) and water injection technology, the compression ratio is increased to 14:1. The peak power of a hydrogen internal combustion engine used in a certain heavy-duty commercial vehicle reaches 420kW, and the torque reaches 2600N · m.

2. Path to improving thermal efficiency

Dynamic intelligent combustion control: Real time adjustment of hydrogen injection amount and ignition angle based on cylinder pressure sensor, enabling the indicated thermal efficiency to exceed 50%. A certain passenger car uses a hydrogen internal combustion engine with a thermal efficiency of 46% under WLTC conditions.

Waste heat recovery system: using Rankine cycle to recover exhaust waste heat, the overall efficiency of the system is increased to 55%.

3. Challenges and Countermeasures of Industrialization

Cost optimization: Through modular design, the cost of hydrogen internal combustion engines is reduced by 40% compared to fuel cell systems. For example, a certain company shared the valve body between its hydrogen injection system and fuel injection system, reducing the number of components by 30%.

Infrastructure support: It is recommended that the government layout a network of hydrogen refueling stations in ports and logistics parks, and give priority to the right of way for hydrogen internal combustion engine vehicles.