Research On Heat Intensity And Combustion Period Under Low Temperature Oxidation Of Coal Controlling The Heating Temperature

At low temperatures, oxygen and coal will compounded. The generate heat of the reaction will cause coal warm up, and even lead to coal spontaneous combustion. In order to study coal oxidation and temperature rising regularities, this paper takes the linear heating experiment on the condition of program control. The experiment includes three parts: with different kinds of gases, with different coal sizes, with different coal weight. The gases are oxygen, air, nitrogen and without gases; the sizes are 0.5-1mm,2-5mm and 6-10mm; the weight is 500 g and 1000g; each coal sample will repeated heating to study the different temperature rising regularities of raw coal samples and oxidized coal samples.Coal temperature variation curves with time are obtained under various conditions.Because the difference of temperature diagram curves is very small, it is difficult to visually see the inherent law. In this paper, the temperature variations with time are analyzed by using temperature difference method, and then it can clearly see the variation rule of each curve in the temperature diagram. Studies have shown that: 1)with higher oxygen content in the gas, coal oxidation is more significant warming effect,heat release bigger, temperature changes faster; 2) too large or too small size isn’t conducive to coal oxidation temperature, and to some extent hinders the thermal effects of low-temperature oxidation of coal, heat release is reduced accordingly; 3) the weight of coal has less impact on the heating situation, including heat release or accumulation and the low-temperature oxidation of coal. Repeated heating of coal contrasts that: 1)temperature difference curves with oxidation exothermic are significantly higher than the curves without it, and the greater the heat release, the bigger temperature difference curves values; 2) the heat release rate grows with the temperature in the overall trend; 3)the more times oxidation heat, the smaller exothermic oxidation rate, and the smaller the values of temperature difference curves. The temperature difference curves effective react the strength of exothermic oxidation at the experiment conditions.Using the laws of thermodynamics and conservation of energy, it deduces the calculation model of heat release rate and spontaneous combustion. The calculation method of combustion period is based on experimental data of coal heat release rate ateach temperature, considers the case of the thermal in the corresponding conditions, and has good reference and promotion of significance. With the data of 14, 15# mine of ShiGang, calculates the heat release rate and spontaneous combustion of controlling heating process, counts the activation energy thermal gravimetric data.