Fire safety

There are presented the results of tests of fire protection samples of structures made of polymer composite (fiberglass) using an intumescent coating SGK-2 based on chlorosulfated polyethylene. There was compared the effectiveness of the coating applied on a 300х200 mm plate and two variants of combined fire protection, where as an intermediate layer the SGK-T composition with phenolic microsphere filler was used instead of heat-expanding graphite in SGK-2 or a layer of basalt fibre material MBOR-F. The temperature of the fiberglass plate was recorded, as well as the temperature between the layers of fireproofing and on the surface of the bulging layer. Standard and other modes of exposure were reproduced under heating by a packet of halogen incandescent lamps. Regulation was carried out using surface thermocouples.

It has been confirmed that only when using the SGK-2 coating, it is practically impossible to ensure the fire resistance limit of load-bearing structures made of polymer composites even during 15 minutes. The option of combined fireproofing with an intermediate SGK-T layer provides the fire resistance limit of structures for 15 minutes or more, but when using a layer of MBOR-F, a significantly higher fire resistance limit is achievable. During additional tests of SGK-2 on steel plates, the possibility of reproducing various exposure modes on the stand was demonstrated. Change in the thickness of the intumescent layer was recorded; information was obtained on the temperature of the onset and bloating rate, as well as other characteristics affecting the effectiveness of fire protection. The temperature level of the beginning of bloating of the SGK-2 coating turned out to be about 195 °C, which is higher than previously indicated. It was noted that, when applying softer than standard exposure modes, their effect on the plate heating level was reduced by the reduction of the bloating rate.

Such studies undoubtedly contribute to the adoption of reasonable technical solutions for fire protection and ensuring the required fire resistance limits for structures made of polymer composites and other materials.

The article presents studies of the hydraulic resistance of fire plugs using diaphragms.

The purpose of the scientific article was to determine the hydraulic resistance and capacity of fire plugs.

The methodology of the scientific article is based on the basic principles of hydrodynamics. There was conducted an experiment excluding inaccurate measurement of the parameters to determine the hydraulic resistance and capacity of fire plugs.

The scope of the article results lies in the field of improving measures in the design of internal fire water supply systems in order to ensure fire safety of buildings and structures.

The authors proposed and substantiated the solutions to the problem of measuring the hydraulic resistance of fire plugs with diaphragms.

The paper publishes the results of studies of pressure losses and capacity of a fire plugs both with and without a diaphragm. The use of diaphragms was evaluated in terms of pressure reduction solutions to meet regulatory requirements for reactive recoil at the fire branch and firefighting costs. Proposals have been prepared to improve the regulatory requirements of Code of Rules SP 10.13130.2020 and to increase fire safety of buildings and structures when designing internal fire water supply systems. The article reveals the prospects for performing more accurate calculations when designing internal fire water supply systems based on the adjustment of the standards of the requirements of SP 10.13130.2020.

A detailed analysis of the combustion process of titanium, zirconium and magnesium powders was carried out in the experimental study. The reasons that allow metals to burn in nitrogen, carbon dioxide, and water have been identified and explained.

At the first stage of the study, there were conducted the experiments to evaluate the effect of powder layer parameters on the burning rate over their surface. It was found that the size of the metal powder layer does not affect the burning rate on the surface of this layer. However, there is a critical layer thickness at which combustion stops.

Experiments have also been conducted on the propagation of combustion inside the metal powder layer. It was determined that the mass of the burning electrolytic powders on the surface area of the Ti and Zr layers does not depend on this area and is directly proportional to the height of this layer. The burning rate over the surface determines the rate of fire development in a layer of metal powder.

Visual examination of the combustion products revealed that the upper layer always consists mainly of metal oxides ((TiO₂, ZrO₂, MgO), and the lower layer, which is much larger (for Ti and Zr), contains metal nitrides (TiN, ZrN, Mg₃N₂).

The document discusses the components of an isothermal fire tank: a shut-off device, refrigerating units, a weighing device and control devices. There was carried out the review of references concerning the use of an isothermal fire tank as part of an automatic gas extinguishing system.

The draft interstate standard « Automatic gas fire extinguishing installations. Isothermal fire tanks. General technical requirements. Test methods» describes the test methods of a key component of an automatic gas fire extinguishing system — an isothermal fire tank and a shut-off device. Isothermal fire tanks use carbon dioxide in a liquefied state under saturated vapour pressure as a gas extinguishing agent. This draft standard has been developed on the basis of the Russian State Standard GOST R 53282-2009 «Automatic fire extinguishing systems. General technical requirements. Test methods».

The interstate standard is intended for the countries of the Eurasian Economic Union. Its implementation will ensure compliance with the requirements of the technical regulations of the EAEU TR 043/2017 «On requirements for fire safety and extinguishing equipment». In addition, the standard unifies a common approach to test methods for isothermal fire tanks, which will contribute to improving their quality and reliability.

The provisions of regulatory documents in the field of fire safety provide requirements for limiting the spread of fire from the windows of burning premises to the windows of staircases. At the same time, the practice of fire protection of objects requires the development of additional fire-fighting measures, which are necessary both if it is impossible to comply with these regulatory requirements, and in the absence of the necessary set of detailed requirements that take into account the wind speed in the area of object location, the functional fire hazard class of the room adjacent to the staircase, the need to ensure the rescue of people along the staircase or devices in the staircase of a fireproof zone. The development of these measures is based on the results of the analysis of the spread dynamics of fire hazards into the windows of the staircase with different sets of initial data.

As part of the study, a computational analysis of the dynamics of the spread of fire hazards into the windows of an ordinary staircase of a residential building was carried out. The purpose of the analysis was to study the possibility of deviation from the requirements of regulatory documents in terms of the size of the walls between the windows of the premises and the windows of the staircase, as well as the need to supplement them and substantiate the missing regulatory requirements.

To carry out the calculations there is used the field modeling of the dynamics of the spread of fire hazards. In particular, fire scenarios were considered, in which the worst conditions for ensuring human safety are implemented.

During the simulation, parameters such as the wind speed, the class of functional fire hazard of a burning room, the size of the walls and the area of the window sashes in the staircase were changed. Calculations were carried out for three fire scenarios: in the apartment, in the store and in the library storage.

The research results can be used as the basis for the development of new approaches to predict the risk of fire, taking into account its spread.

The paper discusses the environmental implications of rising global temperatures due to the adoption of various international environmental agreements. The accumulation of greenhouse gases in the atmosphere has been shown to have negative consequences for the global climate. The paper also examines the legal framework for regulating the use of ozone-depleting substances, as well as the role of greenhouse gas emissions in increasing average annual temperatures. It is noted that the rate of increase in greenhouse gas emissions is higher than that of ozone-destroying substances, due to their widespread use in industry. It has been shown that the adoption of the Kigali Amendment to the Montreal Protocol on Substances Depleting the Earth’s Ozone Layer has led to specific challenges related to the fire safety of refrigerants. This is because greenhouse gases have been replaced primarily by marginal hydrocarbons (propane, butane, and isobutane), as well as some hydrofluorinated olefins. According to the requirements of the amendment, greenhouse gas emissions should be reduced by 85 % by 2036. This poses challenges for a safe transition to alternative substances. Due to the fact that it is not feasible to completely eliminate the use of fluorinated alkanes as refrigerants due to their greenhouse gas properties, the rationality of developing non-flammable mixtures becomes justified. One of these mixtures should contain a substance with high global warming potential, such as one of the R-23, R-125 or R-227 series refrigerants, which acts as an inhibitor of gas-phase combustion. The other component of the mixture should be a chemical compound that has a short lifetime in the atmosphere. Examples of the efficacy of this approach have been demonstrated, allowing for compliance with environmental regulations while ensuring the fire safety of equipment utilizing these refrigerants.

Currently, the wooden house construction industry is developing, particularly the construction of residential and public buildings with a height of three or more floors made of  CLT-panels. If a fire occurs in such a building, there is a threat of rapid flame spread throughout the entire volume and area of the building. In this regard, it becomes necessary to verify compliance with the current regulatory requirements for automatic sprinkler fire extinguishing systems (AUP) and confirm the water supply standards.

The article is devoted to the application of automatic sprinkler fire extinguishing systems for the protection of wooden house construction. The article provides an analysis of the possibility of using sprinkler fire extinguishing systems, taking into account the small areas of residential protection. The study clarified the methodology for determining the intensity of spray water supply when extinguishing fires of combustible substances and materials in rooms using the express method. This technique is adapted to sprinkler-drencher fire extinguishing systems in terms of the type of flammable liquid for igniting a stack of glued wood and its required quantity. Fire tests were conducted to determine the mass rate of burnout of a model hearth made of glued wood bars, and tests to extinguish model fires. In addition, full-scale fire tests of the fire extinguishing system in the layout of the office space were carried out, and a conclusion was made about the possibility of using a sprinkler fire extinguishing system in the development of fire protection of multi-storey buildings made of CLT-panels. The results of the research can be useful for future developments to improve fire extinguishing systems in wooden houses.

Climatic conditions of the arid territories of the south of Russia contribute to the occurrence and spread of steppe fires. The pyrogenic situation on the territory of the Republic of Kalmykia and the subjects of Volgograd and Rostov regions, as well as the Republic of Dagestan and Stavropol Krai, requires comprehensive control. The purpose of this study is to monitor natural and anthropogenic fires on the territory of Kalmykia and adjacent areas. There were studied the statistical data on the number and scale of steppe fires in the arid regions of the south of Russia. Data on the number and area of steppe fires for 2020–2023 in the study areas are presented. It was revealed that the cause of steppe fires in most cases is the human factor, since the largest number of fires was recorded in areas with the most developed infrastructure, where the population exceeds the average one. There is also a clear seasonal dependence in the distribution of the number of fires, as the greatest number of fires is recorded in the summer months, the least ones – in winter. Thus, arid territories are subject to the action of steppe fires, due to natural and climatic factors and anthropogenic influence.