
Pool fires are one of the most commonly encountered flame types in fire disasters, and the accurate and detailed modeling of pool fires is beneficial for the hazard analysis and assessment of liquid-related fire accidents. The radiation model is known to be the critical component in the accurate simulation of various fire scenarios. Therefore, to develop a proper radiation model, an LES study of a large-scale methanol pool fire was performed in this work by coupling four different radiation models into the open-source fire simulation code FDS and solving the radiation intensity transport equation using the discrete ordinates method. The impact characteristics of different radiation models are evaluated in detail with the NIST experiments, where the comparative analysis was carried out. Regarding the temperature calculations, the WSGG (weighted-sum-of-gray-gases)-based radiation model and Cassol’s model performed better. In addition, all models predict pulsation frequencies well. However, regarding the prediction of the radiative heat fluxes, Cassol’s two models and the FDS default model outperformed the other models, which indicates that the database for obtaining the spectral information of each species and the method to determine the WSGG coefficient of mixed gases are significant factors for the successful prediction of flame radiation.
By comparing the improved models, the WCassol model and Cassol model have the best performance.
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Entry | Catalyst |
T(°C) | Yieldb (g) | Activityb (106) | Mnc(104) | PDIc |
Branchd |
Tme(°C) |
1 | Ni1 | 0 | 2.65 | 3.18 | 38.2 | 1.8 | 7 | 128.2 |
2 | Ni1 | 30 | 5.43 | 6.51 | 33.6 | 2.1 | 21 | 118.0 |
3 | Ni1 | 60 | 2.52 | 3.02 | 21.9 | 2.0 | 40 | 114.4 |
4 | Ni1 | 90 | 2.01 | 2.41 | 16.6 | 2.1 | 41 | 114.0 |
5 | Ni2 | 0 | 2.35 | 2.82 | 37.6 | 1.8 | 15 | 120.2 |
6 | Ni2 | 30 | 4.11 | 4.93 | 29.7 | 1.9 | 26 | 117.0 |
7 | Ni2 | 60 | 2.76 | 3.31 | 17.3 | 2.1 | 46 | 113.6 |
8 | Ni2 | 90 | 0.90 | 1.08 | 14.8 | 2.1 | 61 | 80.9 |
9 | Ni3 | 0 | 1.10 | 1.32 | 16.2 | 2.3 | 36 | 115.1 |
10 | Ni3 | 30 | 1.94 | 2.33 | 12.8 | 2.6 | 51 | 106.1 |
11 | Ni3 | 60 | 0.80 | 0.96 | 11.9 | 3.1 | 72 | 69.1 |
12 | Ni3 | 90 | 0.02 | 0.02 | 11.5 | 3.2 | 94 | – |
a 1 μmol of catalyst in CH2Cl2 (2 mL), [Al]/[Ni] = 500. Vn-heptane = 20 mL, tpolymerization = 10 min, Pethylene = 8 atm. b Activity is in units of 106 g·mol−1·h−1. c Determined by Gel Permeation Chromatography (GPC) in 1,2,4-trichlorobenzene at 150 °C. d Branches per 1000 carbons, determined by 1H NMR. e Determined by differential scanning calorimetry. |