1、翻译部分英文原文Determination of the most effective longwall equipment combination in longwall top coal caving (LTCC) method by simulation modelingFerhan Simsir*, Muharrem Kemal OzfiratMining Engineering Department, Dokuz Eylul University, 35160 Buca, Izmir, TurkeyReceived 12 January 2007; received in revis
2、ed form 2 November 2007; accepted 21 November 2007Available online 4 March 2008 1. IntroductionIn order to recover limited resources in underground efficiently, the most suitable production equipment and method must be applied to a colliery. Trying all alternatives and equipment combinations would b
3、e a very expensive challenge. Computer simulation, on the other hand, is a cost-effective tool for evaluating what-if scenarios in mine development and ore production. It is a useful tool for analysing complex systems such as factories, health care networks, logistics, and service-type operations. T
4、here are many different computer simulation types, such as discrete event, continuous, hybrid, and so forth. Discrete event simulations process discrete events that occur at random times through a central processing unit. In discrete event systems many events can occur simultaneously 1.Discrete even
5、t simulation languages, available since the 1960s, provide general facilities to model the operations involved in processing and manufacturing as discrete events occurring in time. The case under study, the fully mechanized longwall operation in Omerler, a colliery of the state-run Western Lignites
6、Corporation, is suitable for discrete event simulation since movements of shearerloader and roof supports are occurring simultaneously.In Turkey, caving methods are mostly employed in mining of thick coal seams as long as the roof strata are suitable for their use. Longwall with caving is always pre
7、ferred to stowing faces because of its simplicity, favourable economics, and high productivity. It is assumed that the upper bound of applying single-pass longwall (SPL) method as a mechanized system in thick coal seams is about 6m 2. If the thick coal seam cannot be mined by SPL, then multi slice l
8、ongwall (MSL) can be employed. However, for thick seams, MSL is less convenient, less economic, and requires more labour compared to longwall top coal caving (LTCC) method. When choosing which method to employ, the features of the seam also need to be considered.The LTCC method offers a viable means
9、 of extracting up to 7580% of seams in the 59m thickness range. Suitable geomining conditions in Europe and many other countries have led to a wide range of applications of caving coal mining faces during underground working including sublevel caving of thick seams. The LTCC method is increasingly u
10、sed in thick seam mining, for example, there are over 70 LTCC faces operating in China 3. In addition, in Australia, the LTCC method has successfully been used by several Chinese companies. The initial thickness, typically 3m, is cut and loaded conventionally with a shearer and front AFC. The remain
11、ing top thickness of coal, typically an additional 39 m, is allowed to cave into the rear AFC. By this way, coal recovery is increased to 85% from a 9m seam 4.In 1988, Senkal et al. found the coal loss to be 24.3% in the same underground mine. However, at that time, longwall equipment consisted of h
12、ydraulic props+steel roof bars as roof support, an AFC, and loosening blasting+pneumatic picks as winning method. The most important disadvantage of the LTCC method is that significant coal losses may appear when drawing the coal through the support window. Therefore, in this study, firstly the coal
13、 loss is figured out. After that, coal production sequence in the colliery is modelled dynamically by simulation. Real data collected from the system (i.e. the colliery itself) as well as the coal loss computed are used in the simulation model. The whole longwall operation is simulated using compute
14、r software, and daily production figures from face and the top are achieved.Here, the longwall, approx. 86m long, is set up on the floor part of the seam, and coal left on top is drawn through the roof support chute on the gob shield onto the front AFC. The thickness of the seam is variable due to l
15、ayer formation, but it is 8.5m on average (Fig. 1). Of this 8.5, 3m is mined from the longwall, the rest 5.5m caves in. The longwall equipment used consists of a double-ranging shearer-loader (Eickhoff EDW-150-2L), an AFC (SGZ-730/264, Chinese manufacture) and 56 roof supports(CMEC ZYD 4000/18/32, C
16、hinese manufacture) with chutes on the gob shield to draw the top coal. Fig. 2 gives the plan (a) and the cross-sectional views (b) of the longwall.In this study, equipment used in the longwall and effective on the whole panels operation have been changed in the simulation model one by one creating 320 distinct points to be executed. Sixty additional
