Research Article
Influence of Gas from Long-Flame Coal Spontaneous Combustion on Gas Explosion Limit
Table 4
Gas volume fraction in different stages of coal spontaneous combustion and its lower limit of gas explosion and explosion pressure.
| The process of coal spontaneous combustion | Vapor volume fraction (%) | Explosion pressure (MPa) | CO | CH4 | C2H4 | C2H6 | CO2 | O2 | N2 | CH4 concentration (%) | 5.1% | 4.9% | 4.6% | 4.3% | 4.0% |
| Room temperature stage (with coal temperature 30°C) | 0.0005 | 0.0107 | 0 | 0 | 1.05 | 19.1 | 79.7 | 0.25 | NO | NO | NO | NO | Slow oxidation stage (with coal temperature 80°C) | 0.0281 | 0.0287 | 0.0002 | 0.0059 | 2.78 | 18.8 | 78.4 | 0.26 | 0.21 | NO | NO | NO | Rapid oxidation stage (with coal temperature 130°C, which is the change node of C2H6 production) | 0.2030 | 0.0619 | 0.0011 | 0.012 | 2.69 | 17.7 | 78.3 | 0.28 | 0.26 | 0.22 | NO | NO | Vigorous oxidation stage (with coal temperature 170°C) | 0.4350 | 0.1042 | 0.0071 | 0.1018 | 2.82 | 15.8 | 78.7 | 0.29 | 0.27 | 0.24 | 0.21 | NO |
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