Bluesky Hydrogen Refueling Station Equipment and System Solutions
The Process Flow Diagram of A Fixed Hydrogenation Station with a Daily Hydrogenation Capacity of 1,000 Kilograms ( 12 hours/day )
How do hydrogen refueling stations work with the Pipeline Hydrogen and Electrolysis Dual Supply System?
1. Entire Hydrogen Supply Chain
Based on the process flow arrows shown in the diagram, hydrogen supply is divided into two main sources:
Route 1: Pipeline gaseous hydrogen: municipal/industrial hydrogen pipeline → hydrogen refueling station. The mother station is split into two routes:
- Hydrogen is transported via tube trailers to the hydrogen supply station, and then supplied to transport tankers through pressure regulation and metering, forming a tanker station.
- Tube trailers deliver hydrogen directly to the terminal refueling station, where it is compressed to the required 35 MPa or 70 MPa and then dispensed to the corresponding vehicles.
Route 2: On-site water electrolysis hydrogen production: electrolyzer hydrogen production → gas-liquid separation → hydrogen purification → compressor boosting → hydrogen storage system → hydrogen dispenser directly refuels vehicles, achieving “on-site hydrogen production, on-site refueling”. The two hydrogen sources ultimately converge at the terminal refueling station, forming the two mainstream hydrogen supply modes: tube trailer external hydrogen supply and on-site electrolysis hydrogen production.
2. Route 1: Pipeline Hydrogen → Hydrogen Refueling Station
Pipeline Hydrogen Connection to Hydrogen Mother Station
- Pipeline hydrogen: low-pressure feed hydrogen (typically 1.6–4.0 MPa) from industrial by-product hydrogen pipelines or hydrogen production base transmission pipelines is delivered via high-pressure pipelines into the hydrogen refueling mother station, which serves as a regional hydrogen distribution hub.
- Core equipment of the mother station: the on-site compressor is the key pressurization unit, boosting low-pressure pipeline hydrogen to 20–30 MPa to meet the filling pressure requirements for tube trailer loading and pipeline export standards. Hydrogen output from the mother station is divided into two branches:
Branch A: Mother Station → Tube Trailer → Hydrogen Supply Station → Terminal Refueling Station
- Hydrogen loading/unloading column (mother station side): high-pressure hydrogen is filled from the mother station unloading column into tube trailers.
- Hydrogen transport via tube trailer to hydrogen supply station: fully loaded high-pressure hydrogen tube trailers arrive at the hydrogen supply station, which is equipped with a pressure regulating and metering skid and loading/unloading columns:
- pressure-regulating and metering skid: integrates pressure-regulating valves, flow meters, and safety valves to precisely control inlet hydrogen pressure. Accurately measures hydrogen usage and features automatic overpressure relief to protect the equipment.
- Hydrogen unloading column at supply station: connects to the trailer manifold interface to unload high-pressure hydrogen. Part of the hydrogen is directly supplied to the on-site hydrogen refueling equipment. In contrast, the remaining hydrogen is re-transported via short-distance trailers to other distributed terminal hydrogen refueling stations.
Branch B: Mother Station Tube Trailer Direct Delivery to Terminal Hydrogen Refueling Station
- The tube trailers filled at the hydrogen mother station do not pass through a hydrogen supply station; they are transported directly point-to-point to the unloading column at terminal hydrogen refueling stations.
3. Route 2: Full Process Principle of Water Electrolysis Hydrogen Production
The complete system operates in the sequence: electrolyzer → gas-liquid separation → purification → compressor → hydrogen storage → refueling. Functions and operating principles of each piece of equipment are explained as follows:
Electrolyzer (Core Hydrogen Production Unit)
Principle: Deionized water is added to the electrolyzer. When direct current is applied, water molecules undergo an electrochemical reaction at the electrolyzer’s electrodes. At the cathode, hydrogen is generated; at the anode, oxygen is generated.
Electrode Reactions (Alkaline Electrolyzer Commonly Used)
- Cathode (Hydrogen Production):2H2O+2e−=H2↑+2OH−
- Anode (Oxygen Production): 4OH−−4e−=O2↑+2H2O
PEM Proton Exchange Membrane (Acidic Environment)
- Cathode:2H++2e−=H2↑
- Anode:2H2O−4e−=O2↑+4H+
Mainstream electrolyzers are divided into two types: alkaline electrolyzers and PEM proton exchange membrane electrolyzers. They are the hydrogen production source of the entire hydrogen production system, generating crude hydrogen containing water vapor and trace electrolyte impurities, with a pressure of approximately 1.5–3 MPa.
Gas-Liquid Separation Equipment
The crude hydrogen from the electrolyzer contains liquid water and electrolyte droplets. The separated liquid water is returned to the electrolyzer for recycling, while most of the free water in the crude hydrogen is removed, significantly reducing the load on downstream purification equipment.
Purification Equipment
After gas-liquid separation, the hydrogen still holds minimal amounts of water vapor and oxygen impurities. The purification system uses molecular sieve drying and catalytic deoxygenation processes to deeply remove impurities. The final output is high-purity hydrogen with a purity of ≥99.999% (5N grade), meeting fuel cell-grade hydrogen standards and the requirements of GB/T 32744 for vehicle hydrogen quality. This is an essential process to ensure the safe operation of fuel cell vehicles.
Compressor
Purified low-pressure, high-purity hydrogen is fed into the hydrogen station compressor, which serves as the power core of the refueling station. The compressor boosts the ~3 MPa feed hydrogen in stages to high pressures of 42–90 MPa, with two mainstream pressure levels: 45 MPa (suitable for 35 MPa vehicle tanks) and 90 MPa (suitable for 70 MPa vehicle tanks), providing high-pressure hydrogen for storage and refueling.
Hydrogen Storage Cylinder Bank + Sequence Control Panel
1. Hydrogen Storage Cylinder Bank: Hydrogen pressurized by the high-pressure compressor is stored in the cylinder bank, which is divided into high-, medium-, and low-pressure tanks. This arrangement buffers peak-and-valley differences in hydrogen demand: excess high-pressure hydrogen is stored during low-demand periods and quickly supplied during peak vehicle refueling, reducing frequent compressor start-stop losses.
2. Sequence Control Panel: Intelligently controls the charging and discharge logic of the cylinder bank:
- Storage phase: Incoming hydrogen from the compressor fills the tanks sequentially from low → medium → high pressure, prioritizing filling the low-pressure tanks first, then medium, and finally high-pressure tanks.
- Refueling phase: The dispenser draws hydrogen preferentially from low-pressure tanks. When pressure is insufficient, it automatically switches to medium-pressure and finally to high-pressure tanks. This intelligent switching maintains stable hydrogen flow and pressure, improving refueling efficiency.
Hydrogen Dispenser (Terminal Refueling Equipment)
The hydrogen dispenser is connected to the sequence control panel and integrates a flow meter, hydrogen hose, breakaway coupling, temperature control module, and control system. After the driver connects the nozzle, the dispenser automatically adjusts the pressure to the vehicle’s onboard tank-rated pressure (35 MPa / 70 MPa) and controls the refueling process. It provides real-time measurement of hydrogen volume and cost, and is equipped with overpressure protection and leakage emergency shutdown functions. It directly completes hydrogen fueling for fuel cell vehicles and serves as the final interface for end users.
4. Comparative Analysis of Two Hydrogen Supply Modes in Hydrogen Refueling Stations
Mode 1: External Tube Trailer Hydrogen Supply (Pipeline Mother Station–Supply Station Chain)
- Gas supply route: Pipeline hydrogen → hydrogen mother station compression → tube trailer filling → supply station transfer/direct delivery → station unloading column → compressor → hydrogen storage cylinder bank → hydrogen dispenser
- Advantages: Short construction period and low initial investment.
- Limitations: Restricted by tube trailer transport radius (economically ≤150 km). Long-distance transportation causes higher logistics costs, and hydrogen costs fluctuate with fuel prices and freight.
- Applicable scenarios: Urban bus fleets, distributed heavy-duty truck filling stations、small-to-medium hydrogen stations with daily hydrogen demand ≤500 kg.
Mode 2: On-Site Water Electrolysis Hydrogen Production
- Gas supply route: Grid-supplied electricity / photovoltaic → electrolyzer hydrogen production → gas-liquid separation → purification → compressor → hydrogen storage cylinder bank → hydrogen dispenser
- Advantages: Powered by wind and solar renewable energy, enabling zero-carbon, eco-friendly hydrogen generation. No long-distance transportation losses.
- Challenge: Substantial initial equipment investment and larger land footprint. Electricity consumption cost for hydrogen production is a key variable.
- Applicable scenarios: Industrial park integrated hydrogen stations, wind/solar base integrated hydrogen production and filling stations, and large-scale comprehensive hydrogen stations with daily hydrogen demand above 1 ton.
5. Complete Equipment List and Functional Overview of a Hydrogen Station.
| Equipment Names | Installation Location | Core Functions |
| Hydrogen Unloading Column | Mother Station / Hydrogen Supply Station / Terminal Refueling Daughter Station | Hydrogen loading/unloading for tube trailers, enabling connection between trailers and station pipelines with pressure protection |
| Pressure Regulating & Metering Skid | Hydrogen Supply Station | Pressure regulation and stabilization, hydrogen flow measurement, and overpressure safety relief |
| Compressor | Hydrogen Mother Station + Terminal Refueling Daughter Station | Multi-stage hydrogen compression to meet high-pressure storage and refueling conditions |
| Electrolyzer | Integrated Hydrogen Production and Refueling Station | Electrolysis-based crude hydrogen production serves as the core unit of green hydrogen generation |
| Gas-Liquid Separator | Front End of Electrolyzer System | Removal of liquid water and electrolyte impurities from crude hydrogen |
| Purification Unit | After Gas-Liquid Separation | Deep purification of hydrogen to a 5N-grade vehicle fuel standard |
| Hydrogen Storage Cylinder Bank | Hydrogen Refueling Station Storage Area | Multi-level storage of high-pressure hydrogen for peak shaving and stable supply |
| Sequence Control Panel | Between the Hydrogen Storage Cylinder Bank and the Hydrogen Dispenser | Intelligent switching of hydrogen inlet and outlet between high-, medium-, and low-pressure storage banks |
| Hydrogen Dispenser | Hydrogen Refueling Station Refueling Area | Intelligent, metered, and pressure-controlled hydrogen fueling for vehicles |
6. Hydrogen Refueling Station Case
