A study on the influence of liquid water and water vapour on the self-ignition of lignite coal-experiments and numerical simulations

Analysis of coal fire dynamics in the Wuda syncline impacted by fire-fighting activities based on in-situ observations and Landsat-8 remote sensing data

“…Spontaneous combustion of coal is influenced by a variety of factors (Song et al, 2014a;Wu and Liu, 2011) such as coal rank (Beamish, 2005;Wang et al, 2003;Wu and Liu, 2011), moisture content (Küçük et al, 2003;Smith and Glasser, 2005;Tahmasebi et al, 2014;Wang et al, 2003), sulfur content (Huggins and Huffman, 1989;Wang et al, 2003), volatile content (Smith and Glasser, 2005), ash content (Beamish and Blazak, 2005), particle size (Küçük et al, 2003;Wang et al, 2003), porosity (Akgun and Essenhigh, 2001;Krishnaswamy et al, 1996;Zhu et al, 2013), and volume-to-surface ratio (Lohrer et al, 2005). Underground and near surface coal fires can be the consequence of such self-ignition.…”

Numerical and experimental simulation of spontaneous combustion of coal

“…As is reported in Figure 2a-c, during the period when the temperature was between 50 and 100 o C, the simulated results are always lower than the measured results. The influence of moisture on heat release is neglected in the model, which is the main reason for this phenomenon [21]. Figure 2d showed the variations of the maximum temperature postions, it illustrated that when the temperature of the fire source was more than 50 o C, as the temperature rises, the position of the fire source changes correspondingly, and the tendency is to move towards the wind side.…”

On Thermal Stability Analysis for a Reacting Slab

“…It is well known that thermal decomposition of different materials is dependent on size, shape and surface or environ mental temperature as well as the physical properties of the material and environment. In other words for any given geo metry, there is a crit ical size and surface temperature above which the heat generation inside the solid exceeds the heat dissipation to the surroundings [1].…”

“…Theoretical study of transient heating in a slab of combustible material due to exothermic chemical react ion plays a significant ro le in many industrial app lications [1]. These include: heavy oil recovery, storage of cellulosic materials, the pyrolysis of bio mass and coal, the co mbustion of solids, waste incineration, coal gasification, etc.…”

“…Meanwhile, analytical solutions of the highly nonlinear part ial differential equations governing transient heating in a slab of co mbustible material due to exothermic reactions are usually impossible or extremely difficult to obtain. Hence in most cases, a numerical solution approach is adopted( [6], [7], [8], [9], [10], [1])…”