Zang Xiaowei 1,2,3, Yu Hao 1, LV Qishen 1, pan Xuhai 1,2,3, Jiang Juncheng 1,2,3
1. School of safety science and engineering, Nanjing University of technology, Nanjing, Jiangsu 211816
2. Fire and Fire Research Institute of Nanjing University of technology, Nanjing 211816, Jiangsu
3. Jiangsu Key Laboratory of intrinsic safety and control technology of hazardous chemicals, Nanjing University of technology, Nanjing 211816, Jiangsu
In order to prevent and control industrial spray and improve the testing method of spray and explosion, the spray droplet formation and explosion characteristics under different environmental pressure, injection pressure and concentration were experimentally studied in a 20 L spherical spray explosion test system. The results show that increasing the injection pressure is more likely to cause the methanol to break into tiny droplets. The range of the explosion limits of the methanol spray droplets is broadened. The increase of ambient pressure leads to the larger droplet size of the spray droplets and the narrowing of the explosion limit range of the spray droplets, which can effectively inhibit the secondary derivative accidents caused by methyl alcohol leakage to a certain extent. When the ambient pressure of the explosion vessel is 0.1 MPa, the injection pressure is 2.1 MPa, the spray concentration of methanol is 356.4 g/m3, and the droplet diameter of the methanol droplet is 2.5 m, the explosion characteristic parameters (the maximum explosive pressure, the maximum explosive pressure rise rate and the laminar burning rate) reach the maximum value at the above inflection points, and the small particle diameter (1~15) Under the action of external energy, the droplets of μ m) are more easily ignited, and the transient physical-chemical reaction is more rapid and violent in the process of explosion; the larger particle size (22 The ignition difficulty of droplets will occur when the droplets exceed m. However, after the ignition is successful, the characteristic parameters of explosion increase with the increase of spray concentration, showing an approximate linear rule. At this time, the influence of droplet size on the above explosive characteristic parameters can be neglected. The research results are helpful to understand the spray droplet explosion law, improve the corresponding test methods and safety design.
Key words: methanol, injection pressure, environmental pressure, droplet size, explosion characteristics
Citing this article: Zang Xiao Wei, Yu Hao, Lv Qishen, Pan Xuhai, Jiang Juncheng. Methanol droplet formation and explosion characteristics in confined space [J]. explosion and impact, 2020, 40 (3): 32201 doi: 10.11883/bzycj-2019-0128
Fig. 6 Effect of ambient pressure and concentration on spray and explosion characteristics of methanol
Table 3 Effect of ambient pressure on explosion limit of methanol droplet cloud
Table 4 Effect of injection pressure on explosion index
Table 5 impact of environmental pressure on explosion index
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