In order to investigate the influence of air pressure and ventilation speed on the flashover critical conditions of cable fires in long-narrow confined spaces under plateau environments, a functional equation between the flashover critical ceiling temperature and air pressure and ventilation speed was derived based on dimensional analysis. A cable fire model in a long-narrow confined space was established using Fire Dynamics Simulator (FDS) to study the critical flashover temperature during fire development under different air pressures (101, 90, 77, and 65 kPa) and ventilation speeds (0, 0.5, 1.0, and 1.5 m/s). The results show that the flashover critical ceiling temperature of cable fires in long-narrow confined spaces is relatively high, ranging from 720.7 to 877.3 ℃. The flashover critical ceiling temperature follows a power-law relationship with air pressure and ventilation speed, while showing a decreasing trend with increasing pressure and ventilation speed. The established model provides reasonable predictions for the flashover critical ceiling temperature of cable fires in long-narrow confined spaces under both natural ventilation and longitudinal ventilation scenarios. The model prediction results agree well with the numerical simulation results.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |