Probability Study On Gas Accumulation In Mine Passageways

Through an extensive literature search in the field of coal mine gas accumulation and handling techniques in the past, the research topic of "Probability Study on Gas Accumulation in Mine Passageways" is brought forward, which is intended to explore a quantitative analysis technology on gas accumulation in underground coal mines.Mine safety, especially safety in gaseous coal mines, is highly emphasized all over the world and tremendous efforts have been put into this research field ever since the early days of the INDUSTRIAL REVOLUTION. Various techniques of reliability analysis, safety assessment and so forth have been adopted and developed for the analysis of data of gas emission, migration and accumulation, which in general require some kind of input from expertise in order to initiate a quantitative analysis. Due to the fact that the geological conditions, relevant productive systems, mining techniques, equipment adopted are quite different in coal mines, the risk assessment of gas accumulation in a mine may involve a substantial error when some general standard set by experts from a wide range of coal mines. In this aspect, research on quantitative analysis based on daily collected data needs a breakthrough to make the data more meaningful.A statistics risk model of gas accumulation and distribution in a mine ventilation system is established on the basis of characteristics of airflow, gas emission and migration in the airways. The analysis starts with the statistic characteristics of gas flow along specific airways;Mote Carlo simulation is then adopted to explore possible consequences of the uncertainties of gas flow in the system in a long run. At the same time, a model of stability analysis of airflow in the network is set up to characterize ventilation sensitivities when various disturbances were imposed to the system, and regions affected by gas migration and contamination can be marked even under the most unfavorable conditions. An INFO ENTROPY is introduced as the risk index of gas accumulation to complete the analysis process of the quantified risk assessment in the network. Data from Xiangshan Coal Mine wascollected and analyzed with the risk assessment model. INFO ENTROPY of airways in the network was obtained, and this index favorably shows the risk of gas problems in each airway of the mine, thus the feasibility of the INFO ENTROPY risk assessment model is confirmed.The INFO ENTROPY risk assessment model is established based on mine ventilation theory, calculating mathematics, computer simulation techniques and safety information technology. It offers a new way of rational thinking and can be used as a quantified tool to cope with gas safety risks in coal mines. Its potential usage shall be further explored.