DEVELOPMENT OF THE BASIS OF THE METHOD OF CONTROL OF THE EMERGENCY SITUATION RELATED TO FIRE AND EXPLOSION SAFETY OF LANDFILL

It is established that today there is no effective mathematical apparatus that adequately describes the process of preventing a dangerous event and preventing an emergency related to fire and explosion of solid waste disposal facilities close to settlements. The initial and boundary conditions of the existence of the mathematical apparatus are determined, which is the basis for the development of methods of counteracting the emergency. Humidity, the temperature of the landfill, the presence of oxygen at a certain point in time are factors that initiate the danger. The specific weight of the organic component, the value of the density of the array, the height of waste disposal affect the process of counteracting the danger.

MEASURES TO ENSURE THE EXPLOSION SAFETY OF THE DELAYED COK-ING UNIT FOR OIL RESIDUES

The article considers the main industrial safety requirements for the installation of delayed coking of oil residues. As well as the rules of industrial safety, which are important to observe at a dangerous production facility. Insufficient attention to this aspect of the activity can put the safety of work on the site at risk. And this, in turn, entails a threat to the health and life of persons working at this facili-ty.

Development of advanced explosion safety technology for hydrogen systems

A team of researchers from The University of Tokyo, Yamagata University and Hiroshima University, are working to understand phenomena related to large-scale hydrogen gas explosions. The team's research aims to develop a database of gas explosion behaviour through hydrogen gas explosion experiments. The hope is that this will deepen academic understanding, enable the building of a reliable simulation model and, ultimately, develop a practical and advanced explosion safety technology that can be used when designing, developing and implementing hydrogen systems. The findings will lead to improved safety and security for industries implementing hydrogen systems.

Methods of improving the fire and explosion safety of operation of liquefied hydrocarbon gas transportation tanks

Introduction. The problem of fire and explosion safety of liquefied hydrocarbon gas transportation arose in the 1970s. The task was set to design new generation tanks having improved technical and economic parameters and indicators to ensure fire and explosion safety. The co-authors have conducted the analysis of regulatory documentation covering the fire and explosion safety of hydrocarbon gas transportation tanks, which shows the absence of any unified policy in the design of cars designated for hazardous cargoes. Hence, a number of models, having no or insufficiently effective protective devices, are produced. Therefore, the issues of fire and explosion safety were understudied in the earlier research works on design of railroad cars, and the problem has not been resolved. Principal actions aimed at the fire and explosion safety of hydrocarbon gas transportation tanks were implemented by the Russian University of Transport (MIIT). Statistical information on fire hazardous failures and fleet tank accidents, as well as their detailed investigation has been collected. Tank barrel vulnerabilities have been identified; reliability and durability assessment methods have been developed. Priorities for improving the pressurized tank design are outlined. The following items of work have been performed: ● analysis of statistical data on hazardous cargo transportation accidents, ● development of fire hazard emergency scenarios; ● improvement of “Railroad car analysis and design regulations”, ● development of mathematical models designated for the analysis of tanks, ● identification of an unstable temperature field inside a tank barrel, if in the seat of fire, using non-linear heat conduction equations and the finite element method (FEM), ● identification of the stress-strain state of a tank barrel during a fire. Conclusions. Following the completion of the work performed by the Russian University of Transport (MIIT), hydrocarbon gas tanks have obtained a better barrel emergency impact protection. A unified policy in the design of cars for hazardous cargoes is needed and regulatory documentation requirements must be harmonized.

Analyzing and identifying the limits of 660V grid parameters to ensure electrical safety in underground coal mines

Purpose. To study the relation between leakage current and time, then to identify some limits of grid parameters to ensure electrical safety as well as explosion safety corresponding to all operating modes of leakage relay in Vietnam underground mines. Methodology. In underground coal mines of Vietnam, 660 V grids are characterized by ungrounded neutral point electric system. They require very serious and strict operation conditions including electrical safety and explosion safety. In daily operation, the earth leakage currents (earth fault currents) must be lower than the allowance limit. However, when utilizing many new power electronic devices such as variable speed drive (VSD), the quantity of connected equipment changes due to the change in capacitance current. After measuring the grid parameters, leakage currents are computed in terms of 3 compensating levels of earth fault relays. The resulting values of currents are used to build up limit curves. Findings. Curves of the graphs present the relation between the leakage current and the length of transmission cables associated with various connecting equipment. The curves may be used to operate the electric system safely and effectively. Originality. The proposed equations and simulation in Matlab may be applied to all underground mining grids with different input parameters. Practical value. Operating curves of the graphs are used to identify the most suitable grids parameters which could ensure electrical safety (keeping the leakage current within the allowance limits). It could help operators or technicians optimize the structure of grid and ensure its safety.

Features of modern circuitry of strain-resistive pressure sensors: fiber-optic pyrometric thermal compensation, optical radiation supply

The article discusses the issues of improving strainresistive pressure sensors (PS) for their joint use with modern achievements of fiber optics (FO). The possibilities of implementation and features of FO pyrometric compensation of the temperature error of semiconductor and resistive strain-resistor, optical and/or electrical heating of the strain gage for selfcalibration of the pyrometer, power supply by optical radiation transmitted through a light guide with galvanic isolation of the PS circuit, increased noise reduction and fire and explosion safety are considered. Noise properties of semiconductor and resistive strainresistor are also considered.

DEVELOPMENT OF TECHNOLOGICAL RECOMMENDATIONS FOR ENSURING FIRE AND EXPLOSION SAFETY DURING UNDERGROUND DEVELOPMENT OF PYRITE ORE DEPOSITS

The urgency of the problem of reducing the risks associated with spontaneous com-bustion of coal ores and sulfide dust explosions has now increased not only in Russia, but al-so abroad, as there have been significant changes in the mineral resource base of the world's leading metal producers. The oxidation of sulfide ores and rocks with air oxygen is an irre-versible and characteristic exothermic reaction that should be taken into account during the extraction and processing of sulfide-containing minerals to prevent spontaneous combustion of ores and explosions of sulfide dust. The article presents the developed technological measures and recommendations aimed at preventing the processes of oxidation and sponta-neous combustion of coal ores and sulfide dust explosions.

Fire safety of hydrogen filling stations

Introduction. The problem of greenhouse gas emissions from hydrocarbon-powered vehicles, polluting the air, makes consumption of hydrogen as an alternative motor fuel particularly relevant. Solutions to this problem are provided in a number of works written by foreign researchers. This article contains the analysis of these works in respect of fi re and explosion safety assurance at gaseous and liquid hydrogen filling stations (hydrogen fi lling stations).Features of hydrogen storage. Motor fuel storage is a main problem of hydrogen filling stations and their operation. Most advanced hydrogen storage methods (applicable to gaseous, liquid and adsorbed hydrogen, as well as metal hydrides that contain hydrogen) are analyzed in the work.Compressed hydrogen filling stations. Fire and explosion safety features of filling stations, where compressed hydrogen is stored, are considered by the author. As a rule, mobile fuel trucks, equipped with compressed gas tanks, are used there.Liquid hydrogen filling stations. Fire safety aspects of filling stations, where liquid hydrogen is stored, regasifi cation is performed, and vehicles are fi lled with compressed gas, are also analyzed.Hydrogen formation at filling stations. One of the ways to supply fuel to a hydrogen filling station is to produce it on site using dehydrogenation of methylcyclohexane, which is delivered in tank trucks. Hydrogen is compressed and stored in cylinders. Fire hazards arising at such stations are analyzed.Main provisions of NFPA 2 in terms of hydrogen filling stations. The requirements of the international standard NFPA 2 Hydrogen Technologies Code. 2016 Edition, that apply to compressed and liquefi ed hydrogen filling stations, are considered.Conclusions. The author has made a conclusion that hydrogen fi lling stations are intensively built in several countries. It has been proven that if necessary protective measures are taken, hydrogen fi lling stations can be as safe as those using hydrocarbon fuel. It is necessary to develop a domestic regulatory document containing fi re safety requirements applicable to hydrogen fi lling stations with account taken of the international experience.