Computer simulations in the ventilation network of the Vulcan Mine

Maintaining safety and health conditions underground, especially where potentially explosive atmospheres are possible, depends mainly on how the ventilation system is built, applied and operated in the ventilation network. The ventilation networks of a mining unit for the exploitation of the useful mineral substance are mining works that aim to ensure optimal microclimate conditions in the underground. An ventilation network is built of nodes and branches, in order to establish its structure. In order to establish the optimal air flows at branch level, specialized programs are used, with the help of which the modeling, solving and optimization of the ventilation networks can be performed. Optimizing the management of the ventilation system involves in-depth and complex analyzes on the ventilation network that require a huge volume of data that can be processed only with the help of computing technology. The paper presents an analysis of the ventilation network of the Vulcan mine using the calculation technique to simulate situations that may occur in the ventilation system.

Update of the Ventilation Network Related to Livezeni Mine

The ventilation networks are associated with the set of underground mining works used for the extraction of useful mineral substances. Over time, the ventilation networks involve a change in the structure due to either the expansion or restriction of the mining works structure. For the establishment of air flows at the level of each active mining work, specialized programs are used at international level. These programs allow the modelling and solving of complex ventilation networks. The most advanced specialized programs are those from the VENTSIM range. The paper presents the updating of the ventilation network related to Livezeni mine, with the help of the VENTSIM program.

An Efficient Mine Ventilation Solution Method Based on Minimum Independent Closed Loops

In this paper, according to the analysis of optimum circuits, we present an efficient ventilation network solution based on minimum independent closed loops. Our main contribution is optimizing the circuit dividing strategy to improve the iteration convergence and the efficiency of a single iteration. In contrast to a traditional circuit, a minimum closed loop may contain one or more co-tree branches but fewer high-resistance branches and fan branches. It is helpful in solving the problem of divergence or slow convergence for complex ventilation networks. Moreover, we analyze the dividing rules of closed loops and improve the dividing algorithm of minimum independent closed loops. Compared with the traditional Hardy Cross iteration method, the improved solution method has better iteration convergence and computation efficiency. The experimental results of real-world mine ventilation networks show that the improved solution method converges rapidly within a small number of iterations. We also investigate the influence of network complexity, iterative precision, and initial airflow on the iteration convergence.

SOLUTION OF THE PROBLEM OF TRANSIENT AIR DISTRIBUTIONIN VENTILATION NETWORKS OF MINES, TAKING INTO ACCOUNT THERMODYNAMIC AIR FLOW PARAMETERS

This paper highlights the importance of calculating transient air distribution in mine ventilation networks, taking into account heat ventilation parameters of mine working atmosphere. The change in the temperature of an air flow as it moved along a working with a constant wall temperature was studied. For the network mathematical model of transient air distribution in a ventilation network of the mine, a new resolver was developed which takes into account the revealed regularities of change in air flow temperature from its velocity, temperature and cross-sectional area of mine workings, and allows calculating the change in air temperature as it moves along mine workings. The results of change in air temperature during its movement along the mine working were compared with analytical calculation method and in solving the problem by finite volume method. The obtained simulation results have good convergence. The deviation values obtained in the network model of transient air distribution from the finite volume method do not exceed 7 %.

The process of closing dynamics applied to the ventilation network of Paroşeni mine

The decision to begin the process of closing/preserving a mining objective requires the analysis of a complex of factors that interact and influence the efficiency of decision. Solving the ventilation networks with the help of computing is a huge step forward that allows optimization of the air management and real-time visualization of network changes. The method of solving the ventilation network with the help of the computation, allows the modeling and solving of the ventilation networks as well as any simulations of changes that may occur in the ventilation system regardless of its complexity, during the closing period. This paper will present the process of closing dynamics in a complex ventilation network.