CONSIDERATIONS REGARDING THE DEVELOPMENT OF AN ECONOMIC-MATHEMATICAL MODEL FOR OPTIMIZING THE TECHNOLOGICAL VARIANTS IN THE COAL MINE FACES

2014 ◽  
Author(s):  
Dolea Gheorghe Gabriel
Keyword(s):  
Mathematical Model ◽  
Coal Mine

Numerical Simulation on Water Invasion of Coal Mine

2013 ◽  
Vol 316-317 ◽  
pp. 1112-1117 ◽  
Author(s):  
Ai Jun Shao ◽  
Yuan Huang ◽  
Qing Xin Meng
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Groundwater Flow ◽  
Water Level ◽  
Coal Mining ◽  
Coal Mine ◽  
Mine Drainage ◽  
Model Verification ◽  
Mine Area ◽  
Hydrogeological Conditions

This paper presents the numerical simulation of groundwater flow and the prediction of drainage in the No.5 mine of the Feng-feng coal mine area, using the data from a water invasion. First of all, we build a mathematical model of groundwater flow according to the hydrogeological conditions. Then, the model is verified by the water invasion data. The measured and simulated water level fit well during the model verification. At last, the mine drainage was predicted using the established model. The results indicated that the coal mining below -100m would result in a large amount of drainage and relative high cost.

Optimal location of emergency stations in underground mine networks using a multiobjective mathematical model

2018 ◽  
Vol 25 (4) ◽  
pp. 264-272 ◽  
Author(s):  
Reza Lotfian ◽  
Mehdi Najafi
Keyword(s):  
Mathematical Model ◽  
Coal Mine ◽  
Emergency Services ◽  
Underground Mining ◽  
Optimal Location ◽  
Underground Mine ◽  
Underground Mines ◽  
Underground Coal Mine ◽  
Location Selection ◽  
The Right

Background Every year, many mining accidents occur in underground mines all over the world resulting in the death and maiming of many miners and heavy financial losses to mining companies. Underground mining accounts for an increasing share of these events due to their special circumstances and the risks of working therein. Thus, the optimal location of emergency stations within the network of an underground mine in order to provide medical first aid and transport injured people at the right time, plays an essential role in reducing deaths and disabilities caused by accidentsObjective The main objective of this study is to determine the location of emergency stations (ES) within the network of an underground coal mine in order to minimize the outreach time for the injured.Methods A three-objective mathematical model is presented for placement of ES facility location selection and allocation of facilities to the injured in various stopes.Results Taking into account the radius of influence for each ES, the proposed model is capable to reduce the maximum time for provision of emergency services in the event of accident for each stope. In addition, the coverage or lack of coverage of each stope by any of the emergency facility is determined by means of Floyd-Warshall algorithm and graph. To solve the problem, a global criterion method using GAMS software is used to evaluate the accuracy and efficiency of the model.Conclusions 7 locations were selected from among 46 candidates for the establishment of emergency facilities in Tabas underground coal mine.

scholarly journals Research on Clean Combustion Technology of EGR-based Flameproof Diesel Engine

2021 ◽  
Author(s):  
WANG Xiao
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
Coal Mine ◽  
Combustion Process ◽  
Weighted Average ◽  
Control Program ◽  
Operating Mode ◽  
Bench Test ◽  
Nox Emissions ◽  
Clean Combustion

Abstract In view of the serious pollution of NOx emissions from flame-proof diesel engines used in coal mines and its direct and indirect hazards that cannot be ignored, the combustion process of flame-proof diesel engines is analyzed and a combustion mathematical model is established. Subsequently, the clean combustion method based on exhaust gas recirculation (EGR) is adopted, and an EGR clean combustion device is designed, which meets the requirements of the coal mine standard Safety Regulations on Coal Mine . The design content involves: (i) Composition and structure design of EGR system meeting the requirements of flame-proof standards; (ii) The closed forced cooling cycle design of the EGR system. Specifically, the clean combustion process of flame-proof diesel engine based on EGR system is simulated and analyzed by fluid simulation analysis software, and the effects of EGR system on the performance and emission of flame-proof diesel engine under 15 operating modes of three rotational speeds and five loads are obtained. Then, the control strategy and control program of the EGR system of flame-proof diesel engine are compiled based on the mathematical model and simulation results. In addition, the bench test of the flame-proof diesel engine equipped with EGR device is carried out by using this control program in the laboratory, and the control program of EGR system is modified by analyzing the experimental data. Finally, the optimized bench test is carried out by selecting the control program that optimal matches the flame-proof EGR device and the flame-proof diesel engine. The test results suggest that: (i) Under the external characteristic working mode: after installing the EGR system, the power of the flame-proof diesel engine is 58.9kW under the optimized EGR opening, and the highest output torque is 252.3 Nm, and the power performance is slightly lower than that of the original engine; (ii) Under eight operating mode: after installing the EGR system, the weighted average CO emission of the flame-proof diesel engine under the optimized EGR opening is 0.0045%, and the volume concentration is increased by 0.0045% compared with that without the EGR system; the weighted average NOx emission of the flame-proof diesel engine under the optimized EGR opening is 93.35ppm, which is 56.17% lower than that without the EGR system, indicating that the EGR system technology has significantly improved the reduction of NOx emissions of the flame-proof diesel engine; (iii)Under eight operating mode: after installing EGR system, the HC emission of flame-proof diesel engine under optimized EGR opening is basically unchanged compared with that without EGR system, and the soot emission is slightly increased; and (iv) The EGR system meets the requirements of the coal mine standard, and this method and technology can improve the basis for reducing the NOx emission from the tail gas of the underground vehicles in the coal mine.

scholarly journals Mathematical Model of Maximum Commutation Half Cycle for Thermal Countercurrent Oxidation of Low-Concentration Gas in Coal Mine Ventilation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Kuan Wu ◽  
Shiliang Shi ◽  
Yong Chen
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Coal Mine ◽  
Mine Ventilation ◽  
Correction Coefficient ◽  
Design Calculation ◽  
Half Cycle ◽  
Factors Affecting ◽  
Low Concentration ◽  
Orthogonal Experiments

The Fluent computational fluid dynamics software was used to study the relevant factors affecting the maximum commutation half cycle for thermal countercurrent oxidation of low-concentration gas in coal mine ventilation. Based on orthogonal experiments, the maximum commutation half cycle for thermal countercurrent oxidation of the exhaust gas in the coal mine ventilation under 25 working conditions with the combination of different methane concentrations, inlet speeds, porosities, and oxidation bed filling lengths is investigated. SPSS data processing software was used to perform regression analysis on the numerical simulation data, and a mathematical model for predicting the maximum commutation half cycle under the influence of four factors was obtained. Through experiments, the mathematical model of the maximum commutation half cycle by the numerical simulation was verified. After introducing the wall heat loss correction coefficient, the complete prediction model of the maximum commutation half cycle was obtained. Comparing the experimental test value with the calculated value using the corrected model, the relative error was not more than 3%. The complete mathematical model corrected can be applied to the design calculation of the maximum commutation half cycle for thermal countercurrent oxidation of low-concentration gas in actual coal mine ventilation.

Mathematical model of hit phenomena and its application to movie advertisement

2008 ◽  
Author(s):  
Ishii Akira ◽  
Yoshida Narihiko ◽  
Hayashi Takafumi ◽  
Umemura Sanae ◽  
Nakagawa Takeshi
Keyword(s):  
Mathematical Model

The canary in the coal mine: Psychoanalysis and health

2007 ◽  
Author(s):  
Prudence Gourguechon
Keyword(s):  
Coal Mine
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