TY - JOUR
TI - Study on mass transfer property of oxygen molecules and kinetic regimes of pressured pulverized coal combustion
AU - Yue Fang
AU - Fu Peifang
AU - Liu Yang
AU - Zhang Bin
JN - Thermal Science
PY - 2016
VL - 20
IS - 3
SP - 973
EP - 978
PT - Article
AB - The effects of pressure on diffusion of oxygen molecules during the coal  combustion could not be ignored. The compressibility factor of real oxygen is  investigated to evaluate the deviation between real and ideal oxygen, and  obtain the mean free path of real oxygen. Comparing the Knudsen pore diameter  with the minimum pore diameter, it is found that with the increase of  pressure, Knudsen diffusion cannot exist at low pressure and may delay to  occur at higher temperature. When pressure exceeds 3.5 MPa, no Knudsen  diffusion occurs within the whole temperature range of our research.  Comparing the diffusion rate at 1 MPa with the burning rate, one can conclude  that the combustion mainly take place on the internal and external surfaces,  and the reaction is controlled by the chemical kinetics below 1400 K. When  themperature is between 1400 K and 1600 K, the reaction is controlled by both  the diffusion and the chemical kinetics. When the temperature is more than  1600 K, the combustion primarily happens on the external surfaces and is  controlled by the diffusion.