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Spontaneous combustion of coal in stockpiles of power plants has a significant problem worldwide which leads to several health hazards, environmental pollution and coal loss. Spontaneous combustion...

Thermal power units are a major source of power generation in India. Belt conveyor is the leading transportation system in a thermal power plant. Belt conveyor fire in a thermal power plant breaks ...

Mine disasters occur predominantly due to methane or coal dust explosion or a combination of both. Among the top ten worst coal mine disasters in India, nine are due to coal dust explosion. The current paper describes a general overview of the parameters causing dispersion leading to coal dust explosion, and computational fluid dynamics (CFD) simulation study to observe the effects of particle size on dispersion in Indian coal mines. Turbulent kinetic energy (TKE) and velocity vector path of dust-air mixture and dust-free air were simulated to understand their effects on coal dust dispersion. The TKE contours and velocity vector paths for dust-free air were uniform and symmetrical due to resistance-free path available. The TKE contours and velocity vector paths for dust-air mixture shows the asymmetrical distribution of contours, due to entrainment of air with dust particles. Vortices were observed in velocity vector paths which gradually diminish on increment of time sequence. These vortices are dead centres where velocity and coal dust particles concentration are both zero.

Spontaneous combustion/fire and explosions occurring in the goaf area due to depillaring of thick coal seam (5–8 m) experiences significant loss to the mining industry. This ultimately causes destruction of natural resources and fatal accidents in India. Thus, it is threatening the safety of underground coal mines. This paper includes various laboratory studies to determine the cause of spontaneous combustion/fire during depillaring of panels in thick coal seams. The laboratory investigation comprises of proximate analysis, critical oxidation temperature study, differential scanning calorimetric analysis, fire ladder study, and goaf ignition temperature. The field investigation comprises of hygrometric survey to determine moisture loss and ventilation survey of the working seam to reveal that the goaf of the working panel is highly prone to spontaneous combustion/fire. The results of the above studies will help to develop suitable technique, i.e., partial stowing in goaf areas with the application of water mist spraying to prevent spontaneous combustion/fire during depillaring of thick coal seam. The above studies were carried out during depillaring panels (B2A and B2B) of a thick seam (5.4 m) at Khottadih Colliery, M/s Eastern Coalfields Limited of Raniganj coalfield of India.

Spontaneous combustion is one of the key issues in the blasting gallery (BG) method of coal mining. Earlier most of the BG panels have been sealed due to the occurrences of spontaneous heating duri...

Spontaneous combustion of coal in stockpiles depends on coal characteristics, stock geometry, ambient atmospheric condition, viz. wind speed, wind direction, and temperature. The study investigates the coal characteristics, using CFD simulation and field investigation to understand the spontaneous combustion phenomena of coal stockpiles; Fluent Ansys 16.2 was used in the study. 3D transient simulation with a time step of 86,400 s was carried out for thirty days. Three different cases, viz. one stockpile, two stockpiles side by side and four stockpiles were studied with ambient temperature at 27 °C, activation energy 4.8 * 107 J/kg mole, wind speed at 4.5 m/s and wind direction along the length of the stockpile. The rise in temperature is noticed at the base of the coal stockpile and the intensity of the temperature was found to be reduced with the increase in stockpile height. Thermal survey of coal stockpiles using infrared gun reveals that the temperature at the base (120–300 °C) is high as compared to the ones at the top (45–60 °C). This high temperature may be due to the stock of coal for a period more than a month. CFD simulation study thus corroborates the field and laboratory investigation data.