BURY, Alois
VSB - Technical University of Ostrava, tr. 17. listopadu, 708 33 Ostrava - Poruba, alois.bury@vsb.cz
Abstract: At present is very important to harmonise mining and transport in underground coal pits. Interactive programs that we have developed for this purpose and also for the coal quality control make possible a queue of goals, for example like capacity tests of the whole system, optimisation of the best possible blended coal mass and others. It has been necessary to introduce supervision into the mining and transport processes in order to carry out the equalisation of coal composition by a suitable order and capacity of system equipment. The basis of the system for the supervision of the whole homogenisation process consists in the computer models created by the built- in program packs for modelling, simulation and animation. The idea is that the computer simulation in the first phase should be used for operative planning of the process and then in the second phase the complete supervision in real time would be carried out. The interactive simulation programs use for the enter – data both describing the system structure and its object placement and current data of actual stage in individual objects. Then the interactive system provides also historical data with the possibility of their recording and another work. The interactive simulation programs are also widely used for an education support.
Keywords: simulation, quality control, selective mining, homogenisation
The process of optimisation a coal production and difficulties in its sales has brought a pressure on more effective utilisation of produced coal. In a situation of growing productivity the coal companies try to harmonise mining, transport and preparation processes. Automated control systems in the collieries and automated mining and driving machinery support the process.
Besides, more effective utilisation of produced coal within the multilevel system of automated control is, possible through selective mining of particular coal seams or through the best possible homogenisation of extracted product. This will enable adjustment of an exploitation process to the market conditions as to coal sales and prices
But the process of more effective utilisation of coal in a colliery faces several problems as:
The effective solution of presented problems is possible through the computer models realisation and simulation of particular variants. Therefore we, at our Institute of economics and control systems, have been interested in the solution of the project ”Analysis and research of possibilities of optimisation of coal extraction through selective mining and homogenisation”, in co-operation with ViP Ostrava. The project was submitted to the Grand Agency of the Czech Republic.(105/94/1119.)
The main goal of the project was to research possibilities of a more effective utilisation of coal produced in collieries in order to adjust the mining process to the market condition.
A complex research of solutions leading to optimum utilisation of produced coal through selective mining and homogenisation requires to solve the following partial assignments:
The final objective of the project, was to developed and design an application software for modelling and simulation the whole problems.
At present, the modelling and simulation are used above all as the most efficient tools for system analysing and system designing. Implementation of simulation models on a computer and testing of particular possibilities are the basic research methods. They are also the main components of the control system. Then the simulation models enable to optimise and predict the given technological process.
On the base of the analyses, and by means of simulation programs, it is possible to create models which present the actual attributes of the haulage system in the particular underground coal mine with respect to all aspects of optimal enhancement. For the purpose mentioned above, we decided to developed the special simulation program SIMDUL.The simulation program has been specifically based on a possibility to carry out a capacity analysis of belt conveyers lines, coal bunkers and a skip hoist system, regarding the above given problems of the selective mining and homogenisation possibility.
The program SIMDUL has been developed on base of object oriented design techniques. A computer model has been built then, bringing together interconnected objects. This is very important in mining transport application and mining in general, because mining conditions change permanently in time-spatial mining process with the all interaction among other underground coal mine subsystems. And the object oriented design methodology makes programming of all these aspects easy. The program uses the objects based on the underground mine transportation equipment and coal faces. From coal faces or from road heads is coal conveyed by the network of belt conveyors with transfer points, bunkers, to the shaft, where is coal then hoisted through the skip to the surface storage or directly is dispatched out.
In Fig. 1 is presented the main menu of simulation program (SIMDUL) we developed and that makes possible modelling and simulation.
Figure 1. SIMDUL menu
The user interface ensures communication between an user and the simulation program. It is formed by a menu system.
The particular work regimes are sorted to begin with, setting up the initial states (F1), saving the created model in disk memory (F2), loading the model which we want to test (F3), that had been created in regime F4 and at last using regime F5 for simulation (see Fig.1).
The display device of objects is a subroutine for a display of graphic symbols (conveyer, face, bunker, etc.) in the co-ordinate system in the branches of the haulage system in an underground coal mine.
The calculations are always implemented in both quantitative and qualitative parameters.
If it is necessary to have more detailed information concerning quantitative and even qualitative parameters of a coal flow in particular objects, the program there is, in regime F5, even a graphic animation of the movement of coal on belt conveyers and in bunkers.
It is made by a technique known as cell manipulation technique. This makes possible, among others, an evaluation of the delay time of particular conveyer lines and also the particular coal batches with certain qualitative attributes.
An user can also simulate breakdowns in the modelled haulage system and this way to analyse and evaluate various conditions for controlling the whole process.
In connection with MS Excel 7 then the simulation program will create some graphs.
It is generally known that the quality of the control and management of whatever process depends on the knowledge of the given process and the possibility of its prediction. Implementation of simulation models on a computer and testing various possibilities are the basic components of the system control. Computer models enable determine, checked respectively, the critical points in colliery transport system, bunkers and conveyers capacity demands, influence of different variants on the control strategy, evolution of qualitative parameters of coal blends in bunkers, influence of belt lines dead delays on it, etc. This all make possible to control such a complex problems as the optimal utilisation of extracted coal by the way of selective mining and homogenisation.
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BURY, A. 1996. Simulace dynamiky odtezeni pro ucely selektivni tezby a homogenizace uhli. In International Conference ´9.Hornická Ostrava´, 1996, s.D/21-26.
BURY, A. & HETTNER, M. 1997. Simulace procesu efektivnejsiho zhodnocovani tezeneho uhli. In 31th International Conference MOSIS´97. Hradec nad Moravici : MARQ, 1997, s. 331-336.