Hydrogen Combustion Engine Technology: Systems and Safety

Acknowledgement: Lesson is derived from the transcript of video/s created by RMIT University/Organization
Learning Objectives
  1. Identify the core components of a hydrogen internal combustion engine powertrain.
  2. Compare the energy density and storage requirements of hydrogen versus petrol.
  3. Explain the function of pressure regulation systems in hydrogen vehicles.
  4. Describe the safety mechanisms designed to prevent hydrogen leaks during accidents.
  5. Understand the mechanical similarities between standard fuel injection and hydrogen injection.
Key Topics

The Hydrogen Powertrain and Injection System

The vehicle utilizes a Rotax Twin Cylinder motorcycle engine modified to run on hydrogen. Unlike fuel cells that generate electricity, this engine burns hydrogen directly. The hydrogen is delivered via twin injectors in a manner very similar to a standard fuel-injected petrol engine. The mechanical power is transferred through a drivetrain that includes a chain drive, a drive shaft, and a differential—components typically found in standard cars or quad bikes. This demonstrates that hydrogen technology can be adapted to work with existing internal combustion mechanical architectures.

Further Inquiry

Professional engineering bodies and automotive associations in Australia provide resources and standards regarding powertrain technology and alternative fuels.

Search Terms
  • "hydrogen internal combustion engine"
  • "automotive powertrain components"
  • "alternative fuel injection systems"

Hydrogen Storage and Energy Density

Hydrogen is a 'sparse' gas, meaning its density is very low at standard atmospheric pressure. To store a useful amount of energy in a vehicle, it must be significantly compressed. The tank in this lesson stores approximately one kilogram of hydrogen at 200 bar (200 times atmospheric pressure). Interestingly, this single kilogram of hydrogen contains an energy level equivalent to about three to four litres of petrol. This highlights the high energy-to-weight ratio of hydrogen, but also the challenge of the volume it requires compared to liquid fuels.

Further Inquiry

Australian scientific research institutions and industry councils are key sources for data on hydrogen properties, storage technologies, and energy comparisons.

Search Terms
  • "hydrogen energy density vs petrol"
  • "compressed hydrogen storage technology"
  • "properties of hydrogen gas"

Pressure Regulation and Safety Systems

Because the hydrogen is stored at a high pressure of 200 bar, it cannot be fed directly into the engine. It passes through a series of pressure reducers and check valves. By the time it reaches the engine injectors, the pressure is reduced to approximately 5 bar (five times atmospheric pressure). Safety is paramount; the system includes automatic safety shut-off valves located at the tank. If a collision occurs or piping becomes dislodged, these valves instantly cut off the hydrogen flow at the source to prevent explosions or leaks.

Further Inquiry

Government bodies and safety organizations in Australia regulate the handling, storage, and safety standards for high-pressure gases and dangerous goods.

Search Terms
  • "high pressure gas safety standards"
  • "hydrogen fuel system safety valves"
  • "pressure reduction in gas systems"
Knowledge Check
Quiz Progress Score: 0 / 10
1. What type of engine is used in the vehicle described?
2. How is hydrogen introduced into the engine?
3. What component is used to drive the wheels at the back of the vehicle?
4. approximately how much hydrogen does the storage tank hold?
5. One kilogram of hydrogen has a similar energy level to how much petrol?
6. What is the pressure inside the hydrogen storage tank?
7. To what pressure is the hydrogen reduced by the time it reaches the engine?
8. Why must hydrogen be significantly compressed in the tank?
9. What happens if the piping becomes dislodged during an accident?
10. Where are the pressure reducers located in the system flow?
Question 1 of 10