In simple terms, an HRS is a station to refill hydrogen. Hydrogen fuel cell vehicles can be refuelled quickly at a refuelling station – just like a petrol or diesel vehicle. However, its backend operations are entirely different, and these are supported by several key components that are critical for the safe and effective functioning of a refuelling station.
A regular HRS consists of hydrogen storage tanks, hydrogen gas compressors, a pre-cooling system and a hydrogen dispenser, which dispenses hydrogen to pressures of 350 bar, 700 bar or dual pressure dispensing, depending on the type of vehicle being refuelled. A typical hydrogen car will be refuelled in three minutes and a bus in seven minutes.
We are seeing great demand for hydrogen refuelling stations across the world; H2stations.org revealed that 142 stations went into operation globally in 2021. This demonstrates that the appetite is there and growing all the time, and we shouldn’t be waiting around for cost parity before building the right infrastructure to support further adoption worldwide.
1. Hydrogen inlet: Refuelling stations are configured for optimum performance based on the hydrogen inlet pressure. The hydrogen can be produced on site most commonly via electrolysis, delivered to site and fuelled directly from a tube trailer or via on-site storage.
2. Compression: The hydrogen is then compressed to increase the pressure, and reduce the volume, to enable a greater amount of hydrogen to be stored in the system and an efficient flow of gas for dispensing.
3. Heat exchanger (process gas chilling): The compressed hydrogen is then passed through a heat exchanger to remove the excess heat from the gas that was generated during the compression process. Specially designed hydrogen-resistant valves and fittings are used to control the highly pressurised hydrogen. These components utilise specific materials that are resistant to hydrogen embrittlement to prevent any cracking.
4. Hydraulic power unit and controls: The process is powered, monitored and controlled via the electronic control panel in the non-hazardous zone.
5. Dispensing chiller system: The hydrogen is then cooled to subzero temperatures for fast and efficient filling to ensure the hydrogen can be dispensed safely and to comply with filling protocols i.e. J2601.
6. Vent stacks: A safety feature to vent any escaped hydrogen safely. Hydrogen is lighter than air so dissipates quickly and safely, should an incident occur.
7. Storage: The high-pressure gas is then stored in the system until required for dispensing at the point of use. The storage is controlled by specially designed valves, fittings and electrical controls designed to regulate pressure and interact with the dispenser and vehicle as needed.
8. Dispenser: Designed to emulate traditional fuelling methods, the hydrogen is dispensed via a nozzle controlled by a smart valve which regulates the flow rate of the gas to fill the vehicle to the required pressure in accordance with the fuelling protocol.
At Haskel, we offer end-to-end refuelling solutions – from designing and manufacturing a station, to installing and maintaining it – with a legacy of having worked with compressed gases in mission-critical industries for 75 years.
To find out more about hydrogen refuelling worldwide, please get in touch: