Numerical simulation of coal dust self–ignition and combustion under inclination conditions

• Published in: Energy (Oxford) Vol. 239; p. 122227
• Main Authors: Shi, Xueqiang, Chen, Xiaokun, Zhang, Yutao, Zhang, Yuanbo, Guo, Ruizhi, Zhao, Tenglong, Liu, Rui
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.01.2022; Elsevier BV
• Subjects: Coal; Coal dust; Combustion; Delay time; Dust; energy; Fire protection; Fire safety; gravity; Ignition temperature; Inclination angle; Mathematical models; Numerical models; Numerical simulation; Oxidation; Reaction mechanisms; Reliability aspects; Safety management; Self–ignition; temperature; time series analysis; Self–ignition; Numerical simulation; Combustion; Inclination angle; Coal dust
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.122227

In industries related to fossil energy, coal dust is often deposited at an angled position. A two–step parallel coal dust oxidation reaction mechanism is used to study the self–ignition and combustion characteristics of coal dust under inclination conditions. The consumption and transfer of multiple substances are considered. In addition, the gravity direction is used to simulate the influence of the inclination conditions on ignition characteristics of coal dust. Firstly, the reliability of the numerical model is verified, and the time series characteristics of the self–ignition and combustion of coal dust are studied. Then the characteristic parameters and evolution of self–ignition and combustion under different inclination are analyzed. The results show that under hot plate conditions, the ignition and combustion process of coal dust can be divided into five stages. The minimum ignition temperature of the coal dust layer (MITL) changes sinusoidally with the inclination angle. Coal dust deposited under the ceiling is easier to be ignited. As the temperature of the hot plate increases, the ignition delay time (IDT) is shortened. It is necessary to adjust the fire safety management according to the inclination conditions of the coal dust, especially in the area with an inclination angle of 150°–180°. [Display omitted] •Self-ignition and combustion characteristics of coal dust at different inclined angles are revealed.•MITLs change sinusoidally with the inclination angle.•Coal dust deposited under the ceiling is easier to be ignited.•Increasing of hot plate temperature leads to the advance of coal dust thermal runaway.•Hot spot moves from the inside to the surface, spreads on the surface, and moves from the surface to the inside.