Experimental study on the minimum ignition temperature and combustion kinetics of coal dust/air mixtures

2017 ◽  
Vol 317 ◽  
pp. 154-161 ◽  
Author(s):  
Sen Xu ◽  
Junfeng Liu ◽  
Wei Cao ◽  
Yuyan Li ◽  
Weiguo Cao
Author(s):  
Di Sha ◽  
Yucheng Li ◽  
Xihua Zhou ◽  
Ruiqing Li

Abstract The ignition and explosion of coal dust are significant hazards in coal mines. In this study, the minimum ignition temperature and energy of non-stick coal dust were investigated empirically at different working conditions to identify the key factors that influence the sensitivity and characteristics of coal dust explosions. The results showed that for a given particle size, the minimum ignition temperature of the coal dust layer was inversely related to the thickness of the coal dust layer. Meanwhile, when the layer thickness was kept constant, the minimum ignition temperature of the coal dust layer decreased with smaller coal dust particle sizes. Over the range of particle sizes tested (25–75 μm), the minimum ignition temperature of the coal dust cloud gradually increased when larger particles was used. At the same particle size, the minimum ignition temperature of the coal dust layer was much lower than that of the coal dust cloud. Furthermore, the curves of minimum ignition energy all exhibited a minimum value in response to changes to single independent variables of mass concentration, ignition delay time and powder injection pressure. The interactions of these three independent variables were also examined, and the experimental results were fitted to establish a mathematical model of the minimum ignition energy of coal dust. Empirical verification demonstrated the accuracy and practicability of the model. The results of this research can provide an experimental and theoretical basis for preventing dust explosions in coal mines to enhance the safety of production.


2014 ◽  
Vol 84 ◽  
pp. 330-339 ◽  
Author(s):  
Dejian Wu ◽  
Frederik Norman ◽  
Filip Verplaetsen ◽  
Jan Berghmans ◽  
Eric Van Den Bulck

1995 ◽  
Vol 68 (2) ◽  
pp. 225-229
Author(s):  
A. V. Sal'nikov ◽  
B. S. Repič ◽  
P. T. Radulovič ◽  
L. L. Jovanovič

2019 ◽  
Vol 141 (2) ◽  
pp. 797-806 ◽  
Author(s):  
Tibor Szűcs ◽  
Pal Szentannai

AbstractThe utilization of challenging solid fuels in the energy industry is urged by environmental requirements. The combustion kinetics of these fuel particles differs markedly from that of pulverized coal, mainly because of their larger sizes, irregular (nonspherical) shapes, and versatile internal pore structures. Although the intrinsic reaction kinetic measurements on very small amounts of finely ground samples of these particles are mostly available, a bridge toward their apparent reaction modeling is not evident. In this study, a method is introduced to build this bridge, the goodness of which was proved on the example of an industrially relevant biofuel. To do this, the results of a macroscopic combustion measurement with real samples in a well-modelable environment have to be used, and for considering some not negligible effects, 3D CFD modeling of the experimental environment is also to be applied. The outcome is the mass-related reaction effectiveness factor as a function of the rate of conversion. This variable can be considered as the active fraction of the entire particle mass on its periphery, and it can be used as the crucial element in modeling the combustion process of the same particle under other circumstances by including the actual boundary conditions. Another advantage of this method is its covering inherently the entire combustion process (water and volatile release, and char combustion) and also its applicability for reactors utilizing bigger particles like fluidized bed combustors.


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