scholarly journals Optimization of mine ventilation network feature graph

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242011
Author(s):  
Jinzhang Jia ◽  
Bin Li ◽  
Dinglin Ke ◽  
Yumo Wu ◽  
Dan Zhao ◽  
...  

A ventilation network feature graph can directly and quantitatively represent the features of a ventilation network. To ensure the stability of airflow in a mine and improve ventilation system analysis, we propose a new algorithm to draw ventilation network feature graphs. The independent path method serves as the algorithm’s main frame, and an improved adaptive genetic algorithm is embedded so that the graph may be drawn better. A mathematical model based on the node adjacency matrix method for unidirectional circuit discrimination is constructed as the drawing algorithm may not be valid in such cases. By modifying the edge-seeking strategy, the improved depth-first search algorithm can be used to determine all of the paths in the ventilation network with unidirectional circuits, and the equivalent transformation method of network topology relations is used to draw the ventilation network feature graph. Through the analysis of the topological relation of a ventilation network, a simplified mathematical model is constructed, and network simplification technology makes the drawing concise and hierarchical. The rapid and intuitive drawing of the ventilation network feature graphs is significant for optimization of the ventilation system and day-to-day management.

2014 ◽  
Vol 962-965 ◽  
pp. 1095-1099
Author(s):  
Yu Wang

Based on the analysis of network theory and the airflow abnormal value of mine ventilation, the concept of sensitivity was introduced and a mathematical model to analyze the reason for the airflow abnormal values so as to realize the analysis for the airflow in all kinds of tunnels of ventilation system was put forward. By doing that, various reasons for the airflow abnormal value could be found so that possible predictions for the safety consequences could be made accordingly.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhenguo Yan ◽  
Yanping Wang ◽  
Jingdao Fan

The research analyzes and improves upon the concept of ventilation safety subregions in coal mines and proposes a partition method based on the breadth-first search algorithm for assessing the quality of the ventilation. This involves the analysis of the function of ventilation subregions and of ventilation gas-monitoring data. Then, using the so-called ventilation sensitivity matrix as the analysis method, we confirm the consistency of considering safety subregions, which are associated with air consumption places as the core concept and the objective positioning of the safety subregions within the ventilation analysis. This allows us to establish the validity and practicability of employing regional characteristic information of mine ventilation and gas concentrations in the mine’s air. Finally, based on the characteristics of the ventilation subregions, ventilation air quantity network maps with safety subregions are proposed and their application is demonstrated. The advantages and characteristics of using these maps to replace ventilation network maps for ventilation analysis are demonstrated.


Author(s):  

A nonlinear system, which consists of an inverted pendulum mounted on a cart with an electric drive, is considered. A mathematical model is created, its analysis and modeling of the investigated two-dimensional system operation is carried out. Keywords mathematical model; inverted pendulum; system analysis; state space


2011 ◽  
Vol 130-134 ◽  
pp. 1725-1729
Author(s):  
Ye Jian Yang ◽  
Ze Yi Jiang ◽  
Xin Xin Zhang ◽  
Peng Jin

With the aim of minimizing the energy consumption cost and taking the billet heating quality as the constraint condition, a mathematical model was established based on the billet heating model to solve the optimum heat institution of the reheating furnace. The tabu search algorithm was employed to solve the model. The results of the industrial production data optimization showed that the proposed mathematical model and the solving method could fully meet the practical production demand of the reheating furnace. In addition to satisfying the heating quality requirements, the energy consumption is reduced and the oxidation loss is decreased. Compared with the original one, the heating institution obtained from the mentioned model and algorithm had a better performance on energy efficiency.


2004 ◽  
Vol 8 (1) ◽  
pp. 83-94
Author(s):  
Angela Kalagasidis-Sasic

The movement of air in and through the building envelope often plays a leading role in the transport of heat and moisture into the building. It is caused by pressure and temperature variations around the building envelope inbuilt ventilation system, occupancy, etc. In order to improve the energy consumption, alternative designs for the ventilation systems are considered. One of them is a dynamically insulated wall as an inlet unit for the supplying air. In order to predict the performance of a dynamically insulated wall, it is necessary to make an analysis of the building as a system. This paper presents such system analysis which takes into account the interaction between the building components and indoor and outdoor climate, both in terms of the air leakage and heat and mass transfer to and from the building components. It is shown that, in the presence of air leakages (unintentional openings) in the enclosure of the building, the efficiency of the dynamic insulation is significantly decreased.


Power loss is the most significant parameter in power system analysis and its adequate calculation directly effects the economic and technical evaluation. This paper aims to propose a multi-objective optimization algorithm which optimizes dc source magnitudes and switching angles to yield minimum THD in cascaded multilevel inverters. The optimization algorithm uses metaheuristic approach, namely Harmony Search algorithm. The effectiveness of the multi-objective algorithm has been tested with 11-level Cascaded H-Bridge Inverter with optimized DC voltage sources using MATLAB/Simulink. As the main objective of this research paper is to analyze total power loss, calculations of power loss are simplified using approximation of curves from datasheet values and experimental measurements. The simulation results, obtained using multi-objective optimization method, have been compared with basic SPWM, optimal minimization of THD, and it is confirmed that the multilevel inverter fired using multi- objective optimization technique has reduced power loss and minimum THD for a wide operating range of multilevel inverter.


2018 ◽  
Vol 4 (7) ◽  
pp. 1521 ◽  
Author(s):  
Fang Lin

Construction ventilation system is divided into two stages based on completion status of shafts in the underground petroleum storage project in Jinzhou, China. With the help of theoretical analysis and numerical simulations by using FLUENT software, in the first stage, reasonable construction ventilation is designed and cases with different outside temperature are discussed to investigate the effect of ventilation performance. It is found that with temperature difference increases, peak value of CO concentration, exhausting time of dirty air and required time to meet the CO concentration qualification decrease, but the influence degree is quite limited. Gallery-type network ventilation technique (GNVT) refined from theories of operation ventilation for road tunnel and mining ventilation network, is proposed to conduct the second stage construction ventilation. Ventilation performance of different ventilation schemes with various shafts’ states and diverse arrangements of fans are also analyzed in this study. It turns out that Axial-GNVT with shafts taking in fresh air and access tunnel ejecting dirty air has much better performance than traditional forced ventilation from access tunnel. Improved energy saving scheme is finally adopted to guide the construction. In addition, it is worth mentioning that there is no need to build middle ventilation shafts and construct shafts as large and long as possible. Field test of wind speed, dust, poisonous gas, atmospheric pressure, temperature are performed to detect ventilation effectiveness. Reduction coefficient =0.69is obtained from the test results in consideration of super-large section and it also indicates that there is no difference if the axial fan is at the shaft mouth or in the bottom.


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