Simulation of spontaneous combustion region in coal piles under multi-field coupling

ABSTRACT

Spontaneous combustion is one of the key threats to coal production, stockpiling, and transportation. It is difficult to study the process of spontaneous combustion of coal under different working conditions, which seriously restrict the development of coal spontaneous combustion prediction technology. To prevent the spontaneous combustion of coal in storage effectively, this research investigated the high-temperature area of the coal pile under different influencing factors through simulations and field experiments. The model was established on the coupling of oxygen field, temperature field, and velocity field utilizing COMSOL Multi-physics numerical simulation software. The results show that the high-temperature area gradually moves from both sides of the coal pile to the middle and upper part as the stacking time increases. Wind speed is an important factor affecting the position of the high-temperature area. The increase of the wind speed causes the high-temperature area to move gradually from the middle of the coal pile towards the leeward surface. The high-temperature area of the coal pile is within a depth of 0.60 to 2.10 m from the adjacent surface. These results provide a useful reference for monitoring the temperature and preventing spontaneous combustion of the coal pile.

KEYWORDS:

• Coal pile
• spontaneous combustion
• multi-field coupling
• numerical simulation

Notation

The following symbols are used in this paper:

d=day

α= coal stacking angle

Additional information

Funding

This work was supported by [National Natural Science Foundation of China][11174078],[National Key R&D Program of China][2016YFB0600701], and [Natural Science Foundation of Hebei Province, China][E2012502046].