The current paper is an overview on previous and ongoing research carried out by the authors concerning the use of Computational Fluid Dynamics for the accurate classification of hazardous Ex areas generated by flammable gases, for the optimization of computational simulation of air-methane mixture explosions by using ANSYS CFX and FLUENT and for calibrating computational simulations of gas explosions using the Schlieren effect. These research works containing analytic studies have led to the observation of basic principles which come to support the benefit of computational approaches for estimating gas dispersion within technological installations in which are handled or stored flammable materials and in which there are likely to occur explosive atmospheres. Preliminary results have led to the idea of developing a computational method for assessing the hazardous area extent in case of gas leak explosions in confined spaces. The computational method intended to be developed has to be validated in the lab using an experimental chamber as domain for analysing accidental flammable gas leaks from transportation installations and for studying the formation, ignition and burning of air-flammable gas mixtures in confined spaces. Results obtained from physical experiments will be used for calibrating the mathematical models. Further, verification and validation of computational simulations carried out based on physical experiments will be performed by a comparative analysis of virtual results with the experimental ones. In the end, the mathematical model will be implemented on a small-scale reproduction of a confined industrial area with explosion hazard.

Areas within which could arise explosive atmospheres having high concentrations, therefore requiring special precautions so as to guard the health and safety of concerned employees, are considered to be dangerous. If the electrical equipment used in these hazardous locations is not properly selected and installed for operating in explosive atmospheres, they are likely to generate an ignition and to result in explosion type events with significant environmental and material damages and, moreover, with human victims. Being an extremely difficult field to manage and having major importance, explosion prevention requires quality decisions. The reaching decision person must choose the best solution for putting into operation electrical apparatus in explosive atmospheres, taking into account certain factors, parameters, and the requirements for explosion protection and safety. Nowadays, special IT programs-decision support systems provide assistance for the reaching decision persons from a wide variety of domains. Explosion prevention shall not make an exception, especially because it firstly aims to improve the occupational health and safety of workers who operate within potentially explosive atmospheres. Taking into account the foregoing, the current paper presents the development and operation of a decision support system (DSS) for managing the selection and installation of explosion-proof electrical apparatus which are supposed to be used in atmospheres with explosion danger caused by burnable gases, liquids, vapours or mists.

This paper analyses the electrocution hazard in three-phase electrical networks that operate with the neutral point isolated from ground. The following cases are analyzed: short low-voltage electrical networks, long low-voltage electrical networks and highvoltage networks. In high voltage electrical networks, touching a phase is always dangerous even if the insulation resistances are considered to be infinitely high. The analyzed cases show that in three-phase electrical networks with ground-isolated neutral point, the value of the current which passes through the human body depends on its electrical resistance as well as on the insulation resistances of the phases to earth.

Nowadays, the transportation of hazardous substances required for various industrial works is a very common activity. In each national economy, safe transport of hazardous materials on land is an important issue. Much of these materials are either moved by trucks or trains. However, hazardous materials transportation is very likely to generate major accidents with irreversible consequences on surrounding population and on the environment along transportation routes. The current paper deals with analysis and simulation of the consequences of an explosion involving a truck transporting flammable gas cylinders materials. Consequence modelling involves the graphic representation or the calculation and estimation of numerical values which best describe the physical results of loss of containment scenarios which involve flammable/explosive/toxic materials with regard to their impact on surrounding assets or people. In the present study, state of the art software has been used for modelling and simulating the accident scenario, namely the initial fire and the subsequent explosion of the gas cylinders.

Worldwide, consumption of raw materials and especially coal is increasing. For underground coal mining there are necessary mine networks reaching higher and higher depths. Associated to mine networks, mine ventilation networks exist having vital role in ensuring optimal microclimate conditions. Presently, every field of industry is using the computers at every production stage. Mining or mineral industry is not an exception. Today, due the great extent of the underground networks and the amount of data involved, we are using computers in solving problems of planning and design, engineering and control of mine atmospheric environment. The solving of a complex ventilation network of a mine cannot be done manually, and usage of a specialized software and advanced IT equipment is a must. One of the most advanced specialized software is VENTSIM Visual Advanced, developed in Australia. The software has been used by the authors for modeling and solving of two complex ventilation networks related to Lupeni and Uricani Mines. The concrete result consists in the accurate solving of natural repartition of the air flows at the branch level, based on automatic calculation of their lengths. Another important advantage offered by the application consists in 3-D solid visualization, allowing user to obtain any technical detail, from any angle.