🛡️ Module 7: Safety & Storage
Hydrogen Properties
| Property | Hydrogen | Gasoline |
|---|---|---|
| Flammability Range | 4-75% | 1-7.6% |
| Auto-ignition Temp | 585°C | 228-501°C |
| Density vs Air | 14× lighter (rises fast) | Heavier (pools) |
| Toxicity | Non-toxic | Carcinogenic |
Type IV Hydrogen Storage Tank
Construction: Polymer liner wrapped with carbon fiber
Pressure: 700 bar (10,000 psi) standard
Weight: 40-45 kg for 1 kg H₂ capacity
Capacity: 6-7 wt% gravimetric density
Safety: Pressure relief device (PRD), thermal protection
Lifetime: 15-20 years or 10,000-20,000 fill cycles
Safety Standards
| Standard | Title | Scope |
|---|---|---|
| UN ECE R134 | Hydrogen and Fuel Cell Vehicles | Vehicle-level safety |
| SAE J2579 | Fuel Systems in Fuel Cell Vehicles | Design and testing |
| ISO 19881 | Land Vehicle Fuel Containers | Tank certification |
| NFPA 2 | Hydrogen Technologies Code | Storage, handling, use |
Emergency Response
Hydrogen Leak:
- Sensor alarm triggers automatic H₂ valve closure
- Ventilate area (hydrogen rises rapidly)
- No ignition sources until concentration <1%
- Locate and repair leak before restarting