Figures (7)  Tables (5)

    • Figure 1. 

      4 hazard classes.

    • Figure 2. 

      Variation of peak pressure with combustion energy scale distance for different Mach numbers[31].

    • Figure 3. 

      Explosion threat zone of the vapor cloud for hydrogen storage tanks (Scenario -1)

    • Figure 4. 

      Google Earth image of the explosion threat zone of the vapor cloud for hydrogen storage tanks (Scenario -1).

    • Figure 5. 

      (a) Flammable threat zone of vapor clouds. (b) Toxic threat zone of the vapor cloud for hydrogen storage tanks (Scenario-1).

    • Figure 6. 

      Google Earth Image of the flammable threat zone of vapor clouds for hydrogen storage tanks (Scenario-1).

    • Figure 7. 

      Thermal radiation threat zone for hydrogen storage tanks (Scenario-2).

    • Physical state Gas
      Form Compressed gas
      Color Colorless
      Smell Odorless
      Melting point −259.2 °C
      Boiling point −253 °C
      Critical temperature −240.0 °C
      Flammability Flammable gas
      Flammability upper value 74.2% (V)
      Flammability lower value 4% (V)
      Vapor pressure 165,316.8 kPa (25 °C)
      Humidity 0.069
      Relative humidity 0.07
      Solubility in water 1.62 mg/L
      Auto-ignition temperature 560 °C

      Table 1. 

      Physical and chemical properties of hydrogen[29].

    • Parameter Value
      Nominal volume (L) 140
      Pressure (atm) 345
      Temperature (°C) 24
      Orientation Vertical
      Diameter (m) 4.03
      Length (m) 10.98
      Tank type Cylinder

      Table 2. 

      Hydrogen storage tank specifications[30]

    • Parameter Value
      Air temperature 24 °C
      Wind speed 3 m/s
      Wind direction Northwest
      Cloudiness Open
      Relative humidity 40%
      Surface roughness Low
      Atmospheric stability D

      Table 3. 

      Atmospheric conditions of Ankara province in June[32].

    • Flame expansion Reactivity Congestion
      Low Medium High
      2D High 0.599 DDT DDT
      Medium 0.47 0.66 1.6
      Low 0.079 0.47 0.66
      2.5D High 0.47 DDT DDT
      Medium 0.29 0.55 1.0
      Low 0.053 0.35 0.50
      3D High 0.36 DDT DDT
      Medium 0.11 0.44 0.50
      Low 0.026 0.23 0.34

      Table 4. 

      Mach numbers used in the B-S-T method[31].

    • Scenario Zone Red threat zone (m) Orange threat zone (m) Yellow threat zone (m)
      Scenario-1: No fire due to release Toxic threat zone 52 69 130
      Flammable threat zone 301 − 711
      Explosion threat zone − − 207
      Scenario-2: Jet fire due to release Thermal radiation threat zone 40 56 87

      Table 5. 

      All impact distances for scenarios used in the present study.