Hi all,
(Problem) Density drop significantly from operating condition to ambient condition for town gas (50mol% H2, 50mol% hydrocarbons). This result in a large very large zone distance (Zone 1, 9m) if used the calculation method in IEC 60079-10-1 (using density at ambient condition).
The result seems to be too conservative as the town gas is very light (0.58 kg/m3 at ambient condition), it will rise upward upon release rather than expand 9m around the release source suggested in the IEC 60079-10-1.
Can I use the density at operating condition (2.687 kg/m3 at 4 barg, 323K) to find the hazardous distance? I believe doing this will reflect the moment when the gas first release, rather than account for the expanding.
I also attached the detail information about the problem and results.
(Problem) Density drop significantly from operating condition to ambient condition for town gas (50mol% H2, 50mol% hydrocarbons). This result in a large very large zone distance (Zone 1, 9m) if used the calculation method in IEC 60079-10-1 (using density at ambient condition).
The result seems to be too conservative as the town gas is very light (0.58 kg/m3 at ambient condition), it will rise upward upon release rather than expand 9m around the release source suggested in the IEC 60079-10-1.
Can I use the density at operating condition (2.687 kg/m3 at 4 barg, 323K) to find the hazardous distance? I believe doing this will reflect the moment when the gas first release, rather than account for the expanding.
I also attached the detail information about the problem and results.
