1、翻译部分A new methane control and prediction software suite for longwall minesHeather N. Doughertyn,C.Ozgen KaracanNational Institute for Occupational Safety and Health, Office of Mine Safety and Health Research, Pittsburgh, PA 15236, USAAbstract：This paper presents technical and application aspects of
2、a newsoftware suite, MCP (Methane Control andPrediction), developed for addressing some of the methane and methane control issues in longwall coalmines. The software suite consists of dynamic link library (DLL) extensions to MS-AccessTM,written inC+.In order to create the DLLs, various statistical,
3、mathematical approaches, prediction and classificationartificial neural network (ANN) methods were used.The current version of MCP suite (version 1.3) discussed in this paper has four separate modules that(a) predict the dynamic elastic properties of coal-measure rocks, (b) predict ventilation emiss
4、ions fromlongwall mines, (c) determine the type of degasification system that needs to be utilized for givensituations and (d) assess the production performance of gob gas ventholes that are used to extractmethane from longwall gobs. These modules can be used with the data from basic logs, mining, l
5、ongwallpanel, productivity, and coal bed characteristics. The applications of these modules separately or incombination for methane capture and control related problems will help improve the safety of mines.Published by Elsevier Ltd.1.1 IntroductionLongwall mining is an underground mining method tha
6、t max-imizes coal production from coal beds that contain few geological discontinuities, such as faults, folds, and pinchouts. In longwalloperations, a mechanical shearer progressively mines a large blockof coal, calledapanel, which is outlined withdevelopment entries orgate roads. The location of m
7、ining along the panel is known as themining face. A schematic representation of a longwall panel is givenin Fig. 1. Longwall mining is a continuous process in an extensivearea, where the roof is supported temporarily with hydraulicsupports, called shields, which protect the workers and the faceequip
8、ment. As the coal is extracted, the supports automaticallyadvance and the roof strata are allowed to cave behind the supports.The caving of immediate roof strata results in a stress relief inoverlying formations, which fracture horizontally and verticallybased on their mechanical strength (Karacan e
9、t al., 2007a). Thiscavedor fracturedzone is called thegob.SinghandKendorski (1981)andPalchik (2003)analyzed the nature of strata disturbances due tolongwall mining and predicted that the gob created by the collapseof immediate roof rocks can reach four to eleven times the thickness of the mining hei
10、ght depending on the strength and porosity of the overlying rocks (Fig. 1).Fig. 1.Schematic representations of a longwall mine and the gob created behind the face (modified fromKaracan, 2008). Arrows show the direction of air leakage and themethane paths in the gob. Side view shows the location of a
11、 gob gas venthole above the mined coal seam.The gob created by longwall mining allows methane that was once confined within the overlying strata (or reservoir) to release after fracturing and find a path through gob to flow into the mine environment. Emissions of methane into the mine atmo-sphere an
12、daccumulation inaworking area in the minemay cause a dangerous mixture of methane and air, which could lead to an explosion. Therefore, it is critical to be able to predict the magni-tude of methane emissions and act with accurate and appro-priate methane control measures before the problems become
13、severe.Due to the large number of variables affecting potential emis-sion sources, accurate prediction of the rate of methane flow intothe working areas and eventually into the ventilation system is acomplex problem. Current prediction models depend on accuraterepresentation of the gob and the fract
14、ured strata that act as a gasreservoir in order to predict methane emissions, the amount ofmine-air leakage into the gob, and effective control methods. Thereservoir properties of the gob are extremely important, butdifficult to compile and interpret (Lunarzewski, 1998; Karacanet al., 2007a). This b
15、ehavior is a product of the challenges andunknowns related to the gob environment and its inaccessibilityfor direct measurements and inhomogeneity of the overburden.In this regard, knowledge of the dynamic elastic properties of roofrock and the overlying coal-measure formations is necessary toassess
16、 the size and thickness of the gob and fractured interval and to estimate methane flow in these zones (Whittles et al., 2006, 2007).Gob gas ventholes (GGVs) are commonly used to controlmethane emissions from the fractured strata (Fig. 1). They are aformof supplemental control that removes somemethane fromthegob, preventing it from entering the mine and increasing the load on the mine ventilation system. These ventholes are drilled from the surface to a depth tha
