COMPARISON STUDY OF "U+L " AND "Y+L " WORKING FACE VENTILATION PATTERNS ON GAS CONTROL IN A HIGHLY GASSY MINE

Original scientific paper A mine ventilation system is an important component of an underground mining system. We all know that the ventilation system design plays an important role in highly gassy mines, and the ventilation pattern is the primary factor in gob gas control in fully mechanized working faces. Because the gas emission rate is notably large in highly gassy fully mechanized working faces and the U ventilation pattern seriously restricts normal production, a new ventilation pattern is required. This paper uses a gas flow distribution numerical simulation method to analyze the gas controlling effect of U+L and Y+L patterns. The results indicate that the gas concentration of the U+L ventilation pattern is lower than that of Y+L pattern in a fully mechanized working face and its upper corner. Furthermore, the main ventilation factors that affect the gas drainage of U+L ventilation pattern are optimized through the orthogonal test and fuzzy evaluation method; it effectively reduces the gas concentration of the upper corner and the return airway. After the implementation of the optimal solution of the U+L ventilation pattern in No. 32212 (1) working face of Rujigou coal mine of Ningxia Hui Autonomou