To effectively prevent explosion hazards during propylene production, storage, and utilization, the explosion limits of propylene in air under varying initial temperatures (20 ℃–180 ℃) and initial pressures (0.1 MPa–0.9 MPa) were measured using 12L explosion limit tester. The study revealed that as the initial temperature and pressure increase, the upper explosion limit (UEL) of propylene rises significantly, while the lower explosion limit (LEL) decreases slightly, resulting in a marked broadening of the explosion limit range. At an initial temperature of 180 ℃, with the pressure increases, the carbon powder content in the explosive products significantly increases during the UEL test, and the LEL decline transitions from a linear to a sliding-curve pattern. Analysis using CHETAH 11.0 software revealed that the increase in carbon powder content is closely related to thermodynamic properties under high-temperature and high-pressure conditions. When the pressure rises from 0.1 MPa to 0.9 MPa, the carbon powder content in the explosion products surges from 3.82% to 25.88%. This significant growth primarily stems from two factors: first, high-pressure conditions promote the Boudouard reaction toward carbon formation; second, the increased total amount of reactants under high pressure leads to a multiplicative rise in product quantities.Using CHEMKIN software, the combustion characteristics of propylene under lower explosion limit conditions were investigated. In the fuel-lean region, propylene undergoes free radical chain reactions, ultimately generating CO2, which maintains the calculated adiabatic flame temperature (CAFT) above 1400 K. As pressure increases, CAFT gradually decreases. Meanwhile, with rising temperature, CAFT exhibits a pressure-dependent transition: at low pressures (<0.5 MPa), CAFT increases, whereas at high pressures, it decreases, with 0.5 MPa serving as the critical transition threshold. The coupling effects of initial temperature and pressure on explosion limits are far more pronounced than those of individual factors, with a stronger impact on the UEL than the LEL. The coupling effects caused a 108% increase in the UEL and an 18.05% decrease in the LEL. For individual factors, initial temperature alone led to a 3.8% UEL increase and a 3.41% LEL decrease, while initial pressure alone resulted in a 51.3% UEL increase and 2.44% LEL reduction.
| 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 |