نظم های توزیع و بررسی مطالعه شبیه سازی عددی در احتراق زغال سنگ خود به خودی "سه منطقه" بر اساس نوع تهویه از نوع تهویه Ч + J

Taking Wang Tai Coal Mine2304 working surface as the object of study, the gaseous components along with the advancing working face were examined through burying pipe sampling in the goaf, the change rule of oxygen volume fraction along with the depth of working face was investigated. According to the measure result of gas concentrations, this paper determined the distribution of coal spontaneous combustion oxidation “three zones” in Wang Tai Coal 2304 working face. At the same time, based on the Darcy law, the numerical simulation was performed for the single return air roadway by using the Fluent software, 80m, 160m and 240m away from the working surface respectively. In the three situations, the paper researched the distribution of flow field, the O2 concentration field and the CO concentration field, analyzed the change rule of oxidation zone along with the advancing working face. Wang Tai Coal 2304 working face contain spontaneous combustion “three zones”: cooling zone (0∼38m), oxidation zone (38m∼145m) and suffocation zone (> 145m); the width of oxidation zone along with single return air roadway from the face length approximately linearly increases.

In the process of mining, oxygen concentration emission reduced when the coal is oxidized and the gas was diluted in the gob, at the same time, because the air leakage can make the oxygen receive to supply, therefore, in the gob, it formed "three zones" with a cooling zone, an oxidation zone and a suffocation zone[1]. The extent and distribution patterns of the "Three zones" is not only the important genetic basic parameters for controlling the spontaneous combustion of the coal mine, the analysis of spontaneous combustion main basis for early growth, but also providing a strong basis for fire prevention and control [2]. At present, a large amount of research was carried out on the "three zones" in domestic and abroad[1,3-6], it mainly contain the extreme wind speed criteria method, the oxygen concentration method and temperature method. Based on the method of oxygen concentration, the 2034 surface mining of coal combustion distribution "three zones" was observed. According to the Darcy law, a single return air distance of working face about the 80m, 160m and 240m distribution of oxygen concentration, CO concentration field and the change flow under this three cases simulation were studied by using the FLUENT software.

The "three zones" partition and numerical simulation are carried out to the goaf of 2304. It can be obtained that: (1) The 2304 working face goaf three zones contain: cooling zone 0 ~ 38m, oxidation zone 38m ~ 145m, suffocation zone > 145m. (2) The dividing of the goaf three zones was affected by the area flow, the changes of air leakage volume and return air volume and other factors. Numerical simulation can provide the change of air leakage, gob oxygen concentration and CO concentration under the air leakage boundary conditions. It can help us to understand the early development of coal spontaneous combustion in the goaf, and put out coal spontaneous combustion in the bud. (3)When there is only a single return air roadway, the decay rate of the oxygen concentration will decrease along with the increase of the distance between the work face and the return air way. So, the width of oxidation zone in the gob would approximate increase linearly along with of the distance between the work face and the return air way.