Abstract: A numerical simulation of the concentration distribution of coal dust in the silo during the feeding process was carried out in this paper by using Fluent software, and then on this basis, a numerical simulation of the process of coal dust explosion was carried out based on the OpenFOAM platform, to guide the layout of related safety facilities in the large coal silo. The results show that the smaller the vertical space in the silo is, the more obvious the vertical concentration gradient of coal dust is, and the greater the average concentration in the space is. The mass fraction of coal dust on the vertical geometric centerline of the silo under the empty and half-full silo conditions reaches above 30% and 40% respectively. The smaller the vertical space in the silo is, the greater the maximum explosion temperature in the silo is, but the smaller the maximum explosion overpressure is. Under the empty and half-full silo conditions, the maximum explosion temperature reaches 2 000 K and 3 000 K respectively, and the maximum explosion overpressure is 1 MPa and 0.82 MPa respectively. It is recommended to install the coal dust concentration monitoring and early warning devices on the top of the silo and the upper part of the side wall, and install effective explosion venting devices on the top of the silo, in order to effectively prevent the risk and reduce the loss of silo explosion.

Key words: coal silo, coal dust concentration, coal dust explosion, numerical simulation