A comprehensive method for studying the degree of thermal damage to steel elements of vehicles using field methods

Introduction. Every year, the number of registered motor vehicles in Russia increases, with an increase of 30 % over the past 10 years. The desire to extend the service life of existing vehicles leads to an increase in breakdowns that lead to fire. The task of identifying places where there was an emergency situation that led to a fire is difficult, especially in the case of a complete burnout of the fuel load of the car. Goals and objectives. The purpose of the work is to create a methodology by which it is possible to conduct studies of cold-formed steel products of the vehicle body to determine the zone of the greatest thermal damage. Each method determines one of the characteristics that changes when the steel is exposed to high temperatures. The main task of the work is to test the possibility of applying these methods in a certain sequence to determine the zone that has undergone more annealing. Research methods. The complex method includes induction thickness measurement, which allows measuring the thickness of a layer of high-temperature oxide; a method for measuring the coercive force or demagnetization currents, as well as a method for measuring microhardness. The latter method will determine the decrease in the hardness of the vehicle body after exposure to high temperatures. Results and its discussion. The obtained data on the degree of thermal damage to cold-deformed steel products of the car body by three independent field methods will increase the reliability of the combustion start zone, which in turn will determine the search zone for the cause of ignition. Conclusion. Determining the specific cause of the fire during the maintenance, repair and operation of vehicles will allow you to exclude similar emergency modes in the future. The introduction of a comprehensive method for investigating the condition of an object after a fire will significantly increase the level of reliability of the results obtained when searching for a breakdown that led to a fire. Keywords: fire source, car body, thermal changes, field methods, complex technique, magnetic properties, scale thickness, microhardness

Probabilistic model of functioning of an automated control system for electrical equipment of industrial enterprises in Vietnam in the event of an accident

Introduction. Ensuring fire safety of industrial facilities depends on how correctly the automated systems for detecting and extinguishing a fire are selected, how quickly and efficiently the necessary preventive measures are taken to minimize the likelihood of a fire and damage from it. Assessment of the degree of risk of injury to people and damage caused by accidents is associated with the task of predicting the indicators of reliability and residual life of a functioning system. The most important issue is the establishment of the permissible periods for the further operation of residual current devices at a specific value of the risk of an accident. One of the features of industrial facilities is the presence of a large number of electrical equipment that creates the risk of major accidents accompanied by fires and explosions. Timely detection of the pre-fire state of electrical equipment is ensured through the use and development of an automated control system for electrical equipment. Goals and objectives. Assessment of the degree of risk of injury to people and damage to them in case of accidents when predicting reliability indicators in an automated control system for electrical equipment. Methods. To obtain the results, general scientific and special methods of scientific knowledge were used: analysis, synthesis, generalization, which were based on the provisions of the theory of probability, the theory of reliability. Research results. An assessment of the occurrence of an emergency is carried out based on elementary statistics and discrete Poisson distribution. Conclusions. The use of an automated control system for electrical equipment upon detection of leakage currents allows increasing the level of fire safety of industrial enterprises, as well as determining the life cycle of residual current devices during its operation. Keywords: accident, analysis, fire, explosion, risk, statistics, reliability, electrical equipment

Residential fire risk assessment and management

Introduction. The article analyzes statistical data for the period of 2006-2018 and presents an assessment of fire hazard levels in residential sectors of the constituent entities of the Russian Federation, which were determined on the basis of an integral socio-economic indicator of fire risk. It also considers the problems of assessing fire hazard in the residential sector as in a complex social and economic systems. The purpose of the study is to determine the levels of fire hazard and build a model for managing fire risks in residential sectors of the constituent entities of the Russian Federation. Research methods. To solve the research problems, the methods of system analysis, statistical analysis, mathematical statistics, etc. were used. Research results. A number of statistical dependencies of the fire situation in the Russian Federation have been analyzed and obtained. The indicators with the most fire hazardous level in the residential sectors of the constituent entities of the Russian Federation were determined by calculation. A block diagram of a model for managing fire risks in the residential sector using the integral socio-economic indicator of fire risk (ISEPPR) is built. Conclusion. The values of the fire hazard levels obtained in the work and the model of fire risk management in residential sectors of the constituent entities of the Russian Federation make it possible to improve management decisions in the field of supervisory activities and preventive work of the Federal State Fire Supervision Authorities. Keywords: residential sector, integral socio-economic indicator of fire risk, risk assessment, level of fire hazard

Comparative analysis of methods for studying soot sediments at fire places

Introduction. Smokes are aerosols that contain sublimating substances and condensing vapors, as well as products of chemical and photochemical reactions. In addition to solid and liquid particles, they contain gaseous products of both complete and incomplete decomposition during combustion process, as well as nitrogen and the remains of unreacted oxygen during combustion. The aerosol substance of smoke that has settled on any surface is called soot, which often acts as an object of fire-technical expertise, and the aggregate of soot particles that form zones of various configurations is called smokiness. Goals and objectives. The aim of the work is to study soot and its components for the development of a comprehensive methodology for the study of fires in determining both the focus and the cause of the fire, as well as the pathways of the spread of hazardous factors of fire at different stages of fire development. The main task of the work is to determine the dependence of the qualitative and quantitative indicators of soot and its component composition on the temperature conditions of combustion of various materials in order to establish the conditions for the course of a fire. Research methods. Field and laboratory methods for the study of soot are considered. Field methods include visual analysis of soot deposits (identifying the configuration of soot, color and intensity of the soot layer) and measuring the electrical resistance of the soot layer using a field contact probe. Laboratory methods include the method of microscopic morphological analysis, the method of thermal analysis, molecular spectroscopy and gas chromatography, which are indirect and direct methods for studying extracted organic components of soot. Results and its discussion. The modern methods of research of soot are analyzed. A scheme of laboratory methods is proposed. It allows carry out full morphological analysis, to evaluate the behavior of soot components during heating and composition of extracted components for solving the problems of studying fires. Regression dependences of the content of bituminous components on the logarithm of the electrical resistance of the soot layer were obtained, which showed that, regardless of the type of combustible material, a transition zone is observed on them, in which, with a relatively small change in electrical resistance, a significant increase in the content of bituminous components is observed. Conclusion. The paper considers an comprehensive approach to the study of extractable components of soot. The obtained dependences of the qualitative and quantitative indicators of soot and its component composition on the temperature conditions of combustion of various materials will improve the quality and level of reliability of information in the study of fires in order to determine the focus and cause of a fire, as well as the ways of spreading hazardous factors of a fire at different stages of its development. Key words: smoke, soot, extractable organic compounds, bitumen components, soot layer electrical resistance, molecular spectroscopy, Boltzmann function, fire investigation.

Laboratory method of determining the rate of burnout of liquid fuel

Introduction. In accordance with the provisions GOST 12.1.044-89 (ISO 4589-84) (Fire and Explosion hazard substances and materials. Nomenclature of indicators and metods of their determination) one of the important parameters of liquid combustion are the mass rate of liquid burnout and the influence of various conditions of the combustion process on the mass burnup rate. A laboratory method for determining the mass burnout rate of a combustible liquid has been developed. Goals and objectives. The aim of the study is to develop a laboratory method for determining the mass rate of liquid burn-up, which can be used in the educational process during laboratory work and to simulate the effect of combustion conditions on the mass rate of liquid burn-up. Methods. To implement this task, we used video recording of changes in the mass of the liquid during its combustion in vessels of different diameters, followed by graphical processing of the results of experiments for calculate the burn-up rate under different combustion conditions. Results and discussion. The method was tested on the example of the combustion of acetone. An example of computer-graphical result for calculating the mass rate of acetone burn-up is given. The empirical dependents of the acetone burn-up rate on the diameter of the liquid surface area is obtained. Conclusions. A laboratory method for determining the mass rate of burnout of a flammable liquid, which can be used in the educational process during laboratory work, has been developed. In contrast to GOST 12.1.044-89 (ISO 4589-84), the developed method can use vessels with a liquid diameter of more than 60 mm. Keywords: burnout rate, acetone, laboratory technique

Neural network modeling of the efficiency of response to emergency situations in a multi-level control system

Introduction. It is important to have models that adequately describe the relationship between the integral indicators of the functioning of the system with the particular indicators of the lower levels of management in complex control systems, in particular in RSChS. Traditional approaches based on normative models often turn out to be untenable due to the impossibility of covering all aspects of the functioning of such systems, as well as due to the high variability of the environment and the values of the set of target indicators. Recently, adaptive machine-learning models have proven to be productive, allowing build stable and adequate models, one of the variants of which is artificial neural networks (ANN), based on the solution of inverse problems using expert estimates. The relevance of the study lies in the development of compact models that allow assessing the effectiveness of the functioning of complex multi-level control systems (RSChS) in emergency situations, developing according to complex scenarios, in which emergencies of various types can occur simultaneously. Goals and objectives. The purpose of the article is to build and test the technology for creating compact models that are adequate to the system of indicators of the functioning of hierarchically organized control systems. This goal gives rise to the task of choosing tools for constructing the necessary models and sources of initial data. Methods. The research tools include methods for analyzing hierarchical systems, mathematical statistics, machine learning methods of ANN, simulation modeling, expert assessment methods, software systems for processing statistical data. The research is based on materials from domestic and foreign publications. Results and discussion. The proposed technology for constructing a neural network model of the effectiveness of the functioning of complex hierarchical systems provides a basis for constructing dynamic models of this type, which make it possible to distribute limited financial and other resources during the operation of the system according to a complex scenario of emergency response. Conclusion. The paper presents the results of solving the problem of constructing an ANN and its corresponding nonlinear function, reflecting the relationship between the performance indicators of the lower levels of the hierarchical control system (RSChS) with the upper level. The neural network model constructed in this way can be used in the decision support system for resource management in the context of complex scenarios for the development of emergency situations. The use of expert assessments as an information basis makes it possible to take into account numerous target indicators, which are extremely difficult to take into account in other ways. Keywords: emergency situations, hierarchical control system, efficiency, artificial neural network, expert assessments

Example of modeling the use of fire-fighting vessels

Introduction. The article considers a systematic approach to assessing the effectiveness of the preparation and use of fire-fighting vessels. Using the Pattern method, a study of the use of a fire-fighting boat for solving problems of extinguishing fires on water transport was conducted. Goal and objectives. The purpose of the study is to improve the methodology for determining the effectiveness of the preparation and use of fire-fighting vessels according to the selected evaluation criteria, with the determination of the impact of each criterion on the overall effectiveness of fire extinguishing. Methods. In the article, the process of evaluating the effectiveness of the preparation and use of fire-fighting vessels can be divided into two stages. At the first stage, a verbal presentation of the research task is carried out with the identification of the most "weak" training measures and during the application of fire-fighting vessels using the Pattern Method. At the second stage of the study, an assessment of the state of the identified "weak" measures is carried out with the definition of measures to improve the technical readiness of the material part or organizational and technical measures during the operation of fire-fighting vessels. Results and discussion. The author obtained a particular analytical solution for improving the efficiency of operation of fire-fighting vessels for the case of using a fire-fighting boat. A method for calculating the evaluation criteria is proposed. Conclusions. Thus, the proposed modification of the model of preparation and application of fire-fighting vessels consists in the representation of organizational and technical processes in the form of a logical "tree of goals". The directions of further research in terms of the development of the results obtained in the analysis of the operation of fire-technical equipment on fire-fighting vessels and fire-fighting vessels themselves are determined. Keywords: model, system approach, analysis, pattern method, diesel, special fire extinguishing means

Ensuring the sustainability of the operation of power facilities based on the protection of digital control systems

Introduction. The expansion of the range of threats of critical information impacts (attacks), all of which are difficult to foresee in the design and development of digital control systems, has actualized the development of new approaches, the use of which makes it possible to detect attacks, identify them and develop control commands to stabilize equipment operation, increase the resilience of energy facilities to critical information impacts (attacks). The purpose of the study is to solve the problem of protection against unauthorized interference in the operation of automatic and automated systems that control functional units of power equipment to achieve reliability and safety of power supply as an element of ensuring technosphere safety. Research methods. Within the framework of the study, general scientific and special methods of scientific knowledge were used, including analysis, synthesis, generalization, which were based on the main provisions and patterns of behavior of systems and information theory. Research results. It is proposed to create a system for monitoring the stability of energy facilities to critical information impacts (attacks), adapted to work in emergency situations and in a special period. The characteristics of the system, the main functions, components, key modules (subsystems), the main stages of development, implementation and ensuring the efficiency of work are formulated. Conclusion. The advantage of the system is its adaptation to abnormal behavior (including for unknown reasons) of functional units of equipment in order to achieve reliability and safety of power supply as an element of ensuring technospheric safety. The system allows you to reduce the workload and responsibility of operators, especially in situations where there is no, lack of reliable information or the presence of questionable technological information. Keywords: energy, digital control systems, threats, protection, security, intelligent elements, equipment

Voluntary fire squads and their participation in extinguishing fires in the Far North

Introduction. Extinguishing fires in remote areas of rural areas of the Republic of Sakha (Yakutia) is carried out not only by the State Fire Service, but also by volunteer fire brigades. The most important problem in extinguishing fires is the lack of fire stations in all rural settlements, which negatively affects the timely extinguishing of the fire. The problem that firefighters face when extinguishing is also considered. This is a shortage of water in the winter period of the year. Goals and objectives. The purpose of this article is to systematize the work of volunteer fire brigades (DPD), to give a clear idea of the significance of this formation. To achieve this goal, it is necessary to solve the following tasks: firstly, to describe the work and tasks of the organization of a volunteer fire brigade, and secondly, to assess the availability of knowledge, skills, and weapons with which the DPD can effectively affect the extinguishing of a fire. Methods. Volunteer fire brigades in the Far North with a shortage of water can use a method of mechanical impact on flames. Mechanical impact is understood as procedures aimed at limiting the spread and extinguishing a fire. Results and its discussion. To date, the formation of volunteer fire brigades in the regions of the Far North is developing, they focus on preventive measures to protect against fires, on rapid response and elimination of fire. Conclusions. A volunteer fire brigade (DPD) for settlements where there is no fire station is a rescue from fires and fires. The DPD can either independently participate in extinguishing a fire, or help the state fire service in extinguishing it. The DPD performs the same functions and tasks as the state fire service. The DPD has the means to cope with small fires. To extinguish large fires, DPD requires funding, which can be provided by entrepreneurs of the village, local residents, as well as the municipality of the district. Keywords: fires, volunteer fire brigade, water shortage, method of extinguishing fire

Management of personnel of fire and rescue garrisons taking into account radiation exposure

Introduction. At present, despite the efforts made by the state, the state of radiation protection does not reach the level at which there is no unacceptable risk of harm to the life or health of people, the environment, the property of individuals and legal entities, state and municipal property on the territory of the Russian Federation in the event of implementation of radiation treats. The readiness of management bodies, forces and means of fire and rescue garrisons to eliminate the consequences of radiation accidents is a very urgent problem. Goals and objectives. The aim of the work is to improve the management of the personnel of fire and rescue garrisons, taking into account the radiation exposure in preparation for liquidation and during the elimination of radiation accidents. Tasks include the creation and justification of a model that allows you to convert the exit risks of the deterministic effects into the risks of stochastic effects. Methods. To create a model for the management of fire and rescue garrisons’ personnel, taking into account the radiation exposure, we used the literature experimental data and used the probabilistic-statistical method and the method of least squares. Results and discussion. The calculated model of management of the fire and rescue garrisons’ personnel, taking into account radiation exposure in preparation for liquidation and in the course of liquidation of radiation accidents, is developed. The probabilistic mathematical model allows us to estimate the exit of stochastic and deterministic effects depending on the effective radiation dose. The excellent convergence of the predicted (calculated) value EAR1 = 0,000607 and the statistical value EAR0 = 0,000724 is due to the fact that the reference points LD10 = 2 Gy , LD50/60 = 4 Gy , LD90 = 6 Gy are based on repeatedly verified statistical data on radiation accidents and deaths of more than 1000 people in radiation accidents [1]. This indicates that the mathematical model adequately reflects the exit of stochastic and deterministic effects observed during the operation of nuclear facilities both in normal mode and in radiation accidents. Conclusions. The probability of exit of stochastic and deterministic effects depending on the radiation dose received by the personnel of fire and rescue garrisons is presented. The threshold of the stochastic effect for humans is in the vicinity of the equivalent dose of 10 mSv for radiation with low linear energy transfer. At the same time, the probability of a stochastic effect is 3 · 10-6 on average after 15 years. This model of radiation exposure management for the personnel of fire and rescue garrisons could be a good tool for the emergency response manager (fire extinguishing manager) during preparation for the elimination and during the elimination of radiation accidents. Keywords: management, personnel, fire and rescue garrison, radiation exposure, effective radiation dose, risk of death