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

Abstract

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°.