Environment, labor safety, fire and industrial safety
Oil refineries are a very likely source of man-made threats to humans and the environment. To avoid occurrence of emergency incidents, it is necessary to invest in the processing plants and other industries for industrial safety. When drawing up financing action plans, it is necessary to identify the most dangerous bottlenecks in the plant’s technological chain in terms of the risk of fire or explosion. Identification of the most critical parts of the technological process is possible by ranking the facilities according to the parameters of hazardous substances circulating in equipment and pipelines.
It is shown that the process of burning of a hazardous substance undergoes several stages – the occurrence of a fire, the development and spread of combustion, the identification of consequences and their elimination. At different stages of a fire or explosion, various indicators serve as hazard criteria. The article is devoted to the formation of a bank of parameters that determine the stage of a fire or explosion. The proposed method – decision making by the Saati method with a qualitative pairwise comparison of the parameters was realized using the example of one of the oil refineries in the Republic of Bashkortostan. In the process of refining the plant, about 20 types of hazardous substances are circulating with a total of about 366 thousand tons.
On the basis of the Federal Law «Technical Regulations on Fire Safety Requirements» dated 22.07.2008 No 123-FZ, a list of parameters from 16 items defining the fire hazard of technological flows in the liquid and gaseous aggregate state was formulated. The list obtained is optimized for the stage of a fire or explosion. With the help of the correlation analysis, the parameters in the single-valued pair relationship of significance level 95 % are excluded.
The generated sample of four independent parameters of hazardous substances is ranked by the method of paired comparisons and linear convolution. The importance of each independent parameter is established.
ANALYSIS OF METHODS FOR CALCULATING OF EXPLOSION AFTERMATH ON ESPECIALLY DANGEROUS INDUSTRIAL OBJECTS
Estimation methods of consequences to explosion of a fuel-air mixture are considered. Simulating of an air-fuel mixture explosion of real accidents and experiments was based on this methods by software products PV-Safety and TOXI+Risk has been performed. Zones of damage to buildings and structures because of explosions has been determined. A comparative analysis of the actual values of the explosion consequences in the event of accidents and experimental values with calculated data obtained by the programs TOXI+Risk and PV-Safety was completed. Based on this analysis it was concluded that the results of estimating the radii of damage zones of buildings and structures obtained by these software products are significantly overstated. The greatest deviation from the actual and the experimental values was revealed by using the PV-Safety program. Method based on fuel-air mixture explosion model does not consider the explosive transformation mode, the aggregate state of the hazardous substance, the characteristics of the surrounding space and the position of the point of initiation of the explosion. These deficiencies are lack in the method that used in TOXI+Risk for assessing the consequences explosions. Nevertheless, the radiuses of damage zones of buildings and structures obtained with TOXI+Risk exceed the values of the actual radii in the explosion by an average of 18 %. Thus, the methods for calculating the consequences of the explosion require further investigation.
The article is devoted to the issue of stimulating the operating personnel to improve the level of industrial safety. An analysis of the prevalent scheme of the accusation-repressive interaction of the supervisory bodies and the inspected enterprises showed its inconsistency. Increasing the effectiveness of incentives for enterprises to improve the level of industrial safety is proposed to be achieved by introducing a hierarchy of violations that provoke the emergence of dangerous situations. The results of the analysis of the activities of the supervisory bodies of the oil and gas industry in Alberta (Canada) are presented.
Approved and implemented supervision procedure «compulsory ladder» is presented, according to which inspectors of industrial safety supervisors operate at oil refineries. The system is a three-level vertical, at each stage of which there are certain inconsistencies, ranked by the scale of consequences for the population, the environment and the enterprise. In accordance with the rank of violation, inspection instructions and actions for eliminating violations are developed. Of particular importance are the consequences provided for the situation of non-compliance with the requirements of the supervisory authority.
As the first experience for the implementation of the Canadian system at Russian enterprises, a «compulsory ladder» was developed for the AVT-6 installation of one of the oil refineries in the Republic of Bashkortostan. The list of the basic technological equipment of AVT-6 is made, on the basis of the technological regulations, the deviation of the pressure and temperature values of the main process streams of the installation is done – a preliminary, insignificant, significant, critical excess of the prescribed values.
The transfer of Canadian experience to Russian enterprises provides an advantage in a unified system of industrial safety and labor protection, which is achieved by reducing the accident rate of oil and gas equipment up to 15% and increasing the overall culture in the field of industrial safety.
ELECTRICAL SOLUTION OF THE DIELECTRIC AND ITS INFLUENCE ON FLAME EMISSION WITH ELECTROMAGNETIC FIELD
Studies have been carried out on the effect of an electric breakdown of a dielectric on flame suppression by an electric field of high voltage. In the course of research in the event of electric breakdown of air, the quenching efficiency was reduced to zero. This effect occurs due to the drop in electrical tension between the electrodes. The electrical breakdown in dielectrics when extinguishing a flame is due to the presence of a certain number of ions and electrons, which under the action of the electric field move to the anode. It is established that the electrical strength of the material exerts the greatest influence on the outcome of experimental studies on extinguishing a fire by an electromagnetic field. Therefore, increasing the values of the electrical strength of the material (dielectric), it is possible to exclude the possibility of electrical breakdown.
If glass and electrotechnical porcelain are used as dielectrics on electrodes, the boundaries of the investigation flame process by an electric field of high tension will expand. Studies have shown that an electric breakdown has a negative effect on flame suppression by an electric field of high tension. The probability of electrical breakdown is influenced by such parameters as: the distance between the electrodes (the probability of breakdown increases with decreasing distance), atmospheric pressure, air humidity (the probability of electric breakdown decreases with decreasing air humidity), the strength of the material (with an increase in the strength of the material, the probability of breakdown decreases ) and voltage at the electrodes (with increasing voltage, the probability of breakdown increases).
In the course of the research it was established that an increase in the electrical strength of the electrodes will allow to conduct studies with a voltage of up to 20,000 kV without the occurrence of electrical breakdown.
The research of data in the field of industrial safety ensuring, and the reasons and actions for accident elimination at the enterprises of fuel and energy complex revealed the necessity for improvement of the scientific and methodical base existing at the moment. The techniques applied on hazardous production facilities according to risks and also the system of monitoring on risk management, unfortunately, do not consider the fact that productions have nonstationary casual character and constantly change in time. Besides they possess a weighable methodical error as in these techniques there is no step by definition of the quantitative assessment of risks. Introduction of methodology of the analysis of risk in a control system of the production safety allows to solve a problem of prevention of the contingency situations having nonstationary character and also to organize systems approach to the solution of multifactorial tasks, the bound to safety, the management information systems of monitoring and economic efficiency for accident prevention.