Coal spontaneous combustion is a complex procedure of physical and chemical changing, in which the macro characters is the reflection of micro changes of coal molecule structure in low temperature oxidation. In order to understand the essence of coal-oxygen composition, the Fourier transform infrared spectrum apparatus is used to test and analyze different kinds of coal samples in different oxidation temperature. According to main characteristic spectrum peaks, the activity of coal functional groups is studied. The difference and change of the type and quantity of functional groups in different kinds of coal sample in different temperature are analyzed. The relation between the macro structure change and spontaneous combustion property of coal in low temperature oxidation process is discussed.

Several tunnel fires were caused by the fire source loaded in moving vehicle. The physical model was designed based on real road tunnel to simulate the distribution of longitudinal temperature. Through fire dynamic simulation software FDS, the fire processes when moving vehicle stabilized and traveled at 10m/s and 15m/s in tunnel were simulated under natural ventilation of 2.7m/s. The purpose of research includes three aspects, first, the temperature field in the early stage when moving fire travels into tunnel; second, influence of moving fire on the longitudinal temperature distribution; third, explores the change of temperature peak and its influential factors when vehicles stops and combustion stabilizes. Simulation indicates that the airflow filed movement induced by moving fire to certain degree blocks the spread of heat released in the direction opposite to fire movement and it also entrains high temperature airflow into its movement. When ventilation direction is accordant with vehicle moving direction, the stabilized value of highest temperature point of ceiling tends to be higher than that when the directions are opposite.