scholarly journals Comparison of the Efficiency of Various Flow Charts of Longwall Coal Mining

For increasing the efficiency of longwall coal mining a mathematical model and a simulation model of the longwall coal mining were developed. 2D and 3D visualizations of the execution of the simulation model were realized. The main goal of the modeling of coal mining in a fully-mechanized stoping face is the comparison of flow charts of Longwall coal mining, the evaluation of performance of a drum shearer depending on such factors as technical parameters of the drum shearer, size of a stoping face, flow charts of the drum shearer operation, changing geomechanical characteristics of the coal seam. As a result of simulation the dependences of the drum shearer performance and annual mine profits on the length of the stoping face and flow charts of the drum shearer operation such as one-way flow chart, shuttle flow chart and bench flow chart were obtained.

2018 ◽  
Vol 8 (3) ◽  
pp. 3060-3063
Author(s):  
V. Okolnishnikov

In the frames of simulation system, a specialized library of simulating models of mining equipment and coal seam (MTSS) was implemented. Using the specialized simulating model library of technological mining equipment an integrated model for technological processes of underground coal mining in stoping face was developed. The main goal of simulation for coal mining technological processes in stoping face is the evaluation of productivity of a cutter-loader depending on different factors like the technical parameters of the cutter-loader, size of the longwall face, geophysical state of the coal seam.


2018 ◽  
Vol 15 (1) ◽  
pp. 39-55
Author(s):  
V. B. Rudakov ◽  
V. M. Makarov ◽  
M. I. Makarov

The article considers the problem of determining the rational plans of the input sampling reliability and technical parameters of components of space technology, the totality of which is supplied to the Assembly plants for the manufacture of complex products of space technology. Problem statement and mathematical model based on the minimization of the economic costs of control and losses related to the risks of taking wrong decisions, are given in the article. The properties of the mathematical models are investigated, the algorithm for its optimization is developed. The result is an optimal plan for the sampling of sets of components, which includes: an optimal product mix subject to mandatory control of the aggregate and optimum risks of first and second kind, when acceptance number of statistical plan is zero. The latter circumstance is due to the high requirements of reliability and technical parameters of products of space technology.


Author(s):  
V. M. Makarov

We consider the problem of rational statistical control technical parameters of automatic spacecraft (AKA) in the process of their ground testing in autonomous and complex testing in a three-tier hierarchical structure: independent product testing, independent testing systems and comprehensive testing of the AKA in general. The mathematical model of control, the formalized statement of a problem and algorithm of optimization of statistical control of sets of products and their technical parameters on hierarchy of working off is given. At the same time, the model and algorithm allow you to select the optimal product range of each level of the hierarchy from the sets that are subject to mandatory control, take into account the specified requirements for technical parameters and the results of monitoring the technical parameters of the lower levels of products when planning and carrying out control of the parameters of the higher levels.


2022 ◽  
Vol 14 (4) ◽  
pp. 139-148
Author(s):  
Aleksandr Poluektov ◽  
Konstantin Zolnikov ◽  
V. Antsiferova

The mathematical model and algorithms of oscillatory movements are considered. Various factors affecting the oscillatory process are considered. Oscillatory movements are constructed in the MVSTUDIUM modeling environment. The schemes of three computer models demonstrating oscillatory processes are determined: a model of a pendulum with a non-movable suspension point, a model of a pushing pendulum with friction force and a model of a breaking pendulum. Classes are being built to execute models with embedded properties, as well as with the ability to export the created classes to other models, and embed classes created by the program developer into the model. Creation of 2D and 3D models of oscillatory processes, an experiment behavior map and a virtual stand.


2020 ◽  
Vol 12 (4) ◽  
pp. 1528 ◽  
Author(s):  
Ximin Cui ◽  
Yuling Zhao ◽  
Guorui Wang ◽  
Bing Zhang ◽  
Chunyi Li

Exhausted or abandoned underground longwall mining may lead to long-term residual subsidence on surface land, which can cause some problems when the mined-out land is used for construction, land reclamation and ecological reconstruction. Thus, it is important to assess the stability and suitability of the land with a consideration of residual surface subsidence. Assuming a linear monotonic decrease in the annual residual surface subsidence, the limit of the sum of the annual residual subsidence factor, and continuity between surface subsidence in the last year of the weakening period and the residual surface subsidence in the first year, we establish a model to calculate the duration of residual subsidence and the annual residual surface subsidence factor caused by abandoned longwall coal mining. The duration of residual surface subsidence increases with the increase in mining thickness as well as the factor of extreme residual subsidence. The proposed method can quantitatively calculate the annual residual subsidence, the accumulative residual subsidence, and the potential future accumulative residual subsidence. This approach can be used to reasonably evaluate the stability and suitability of old mining subsidence areas and will be beneficial for the design of mining subsidence land reclamation and ecological reconstruction.


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