Review of an experiment to study the propane discharge in a closed production area

В статье представлены результаты экспериментальных исследований истечения пропана в различных направлениях в закрытом помещении. Рассматривался случай, когда источник истечения находился в багажнике автомобиля - имитация нахождения автомобиля с газомоторным топливом на станции технического обслуживания. Целью эксперимента являлось изучение механизма пространственного распространения газа в закрытом помещении для валидации математических моделей, используемых в программном комплексе ANSYS Fluent при моделировании поступления пропана в закрытое помещение. This scientific work describes a test conducted in a multidisciplinary test box on the testing training ground of the Orenburg branch of the All-Russian Research Institute for Fire Protection of EMERCOM of Russia. For the experiment there was built a room to simulate a service station (or parking box) for two cars. The frame was made of wooden bars and a plastic film was used to isolate the internal volume. The experimental installation consisted of a gas source with an internal diameter of 5 mm, located in the center of the room, and a system for gas supply and registration of experimental data from six gas analyzers SGOES-2 with a measurement range of pre-explosive concentrations from 0 to 100% of the lower concentration limit of flame propagation (NKPR) or a volume fraction from 0 to 1.7% with absolute ± 5% NKPR (in the range from 0 to 50% NKPR) and relative ± 10% NKPR (in the range from 50 to 100% NKPR) errors. In the center of the experimental room there was placed a car with the gas source in the trunk. All openings to the interior were insulated with plastic film and mounting foam. Natural cracks were left between the trunk lid and the body. The gas source is located in the trunk of the car and is directed towards the wide part of the trunk at an angle of 30 degrees relative to the floor (simulating the location of the gas cylinder used in cars). The gas analyzers were located along the wall, where the outflow is directed along the perimeter of the trunk, and one gas analyzer was located directly in the trunk behind the gas analyzer to control gas contamination. Propane has been released into the trunk with a constant flow rate of 2.8 m/h for 5 minutes. There were 8 test starts of the gas supply system (the flow vertically down), and then there were carried out 3 experiments per 3 series of tests in each. The purpose of the test was to study the mechanism of spatial gas propagation in an confined space for validation of mathematical models used in the ANSYS Fluent software package when modeling the propane intake into the confined space

Integral method for evaluating the activity results of main offices of EMERCOM of Russia for the subjects of the Russian Federation

Предложена математическая модель и рассчитаны значения риска причинения вреда (ущерба) в результате пожаров в субъекте Российской Федерации. Субъекты Российской Федерации распределены по категориям уровня обеспечения пожарной безопасности в зависимости от расчетного значения риска причинения вреда (ущерба) в результате пожаров в субъекте Российской Федерации. Предложены оценки результатов деятельности ГУ МЧС России в зависимости от риска причинения вреда (ущерба) и категории уровня обеспечения пожарной безопасности, к которому отнесены субъекты Российской Федерации. The regulatory legal acts of the Russian Federation establish that the criteria for assigning objects of control to the categories of damage risk should be formed based on the results of the damage risk assessment. In the developed countries of the world, as a rule, the distribution of objects of control by risk categories is used to justify the frequency of their inspections and is carried out depending either on the point risk assessment or on the number and seriousness of violations of mandatory fire safety requirements identified during the inspection of the object of control. In the literature sources there are no mathematical models for determining the damage risk as a result of a fire in buildings for evaluating the activity results of fire authorities (Main offices of EMERCOM of Russia). The purpose of this work was to develop and test a mathematical model for evaluating the activity and rating of the Main offices of EMERCOM of Russia for the subjects of the Russian Federation based on the category of fire safety level. As a criterion for assigning the subjects of the Russian Federation to different categories of fire safety level it is proposed to use the damage risk as a result of a fire in buildings located on the territory of the corresponding subject of the Russian Federation. The mathematical model has been developed to determine the damage risk of causing harm (damage) as a result of a fire in a building and there is given its assessment for buildings on the territory of each subject of the Russian Federation. There was carried out the distribution of the subjects of the Russian Federation according to the categories of fire safety based on the calculated value of damage risk. It is shown that such distribution significantly depends on the objectivity of statistical information on fires and the number of buildings on the territory of each subject of the Russian Federation. The assessment of the activity results for each of 86 EMERCOM of Russia Main offices was made and they were rated based on the category of fire safety level of the corresponding subject of the Russian Federation.

Submersible pumps - application practice, technical requirements, development paths

Проанализировано применение погружных (плавающих) насосов в насосно-рукавных комплексах. Рассмотрены их преимущества перед центробежными насосами, устанавливаемыми в мобильной пожарной технике. На основе практики применения и технических характеристик погружных насосов, производимых ведущими зарубежными фирмами, сформулированы технические требования для разработки отечественного погружного насоса. Кроме того, технические требования могут стать основой разработки национального стандарта для этого типа пожарно-технической продукции. The article analyzes the results of operation of a relatively new type of centrifugal pump - a submersible (floating) centrifugal pump with a hydraulic drive. These pumps have a number of significant advantages over centrifugal pumps installed on mobile fire fighting equipment - they can be used to pump liquid from a mark up to minus 30 m. Since the suction pipe of such a pump is located directly in the pumped liquid (below the liquid mirror level), the phenomenon of cavitation is practically excluded. Submersible pumps are used to supply water in case of fire and for water disposal during the elimination of hazardous hydrological phenomena, both independently and in conjunction with centrifugal pumps installed on mobile fire fighting equipment (supply to pumping). All submersible pumps included in the set of hose-pumping complexes are of foreign production. The demand for such pumping units causes the need to develop domestic samples in order to get away from import dependence in the manufacture of pumping and hose systems and their operation. Based on the practice of using submersible pumps and the technical characteristics of submersible pumps produced by leading foreign companies, the following technical requirements for the development of a domestic submersible pump have been formulated. Pump delivery is 170-180 l ∙ s from the mark to minus 30 m. Water intake is possible both in equipped (adapted) and unequipped (unsuitable) places. In addition, the requirements for the hydraulic drive, weight and size characteristics, and some components have been formulated. In conclusion, some directions for the further development of pumping and hose systems and submersible pumping stations are considered.

Application of numerical modeling to assess the influence of the longitudinal slope in a road tunnel on the fire hazards spread

Рассмотрено влияние продольного уклона автодорожного тоннеля на распространение в нем опасных факторов пожара при возникновении загорания. Для оценки этого влияния использован полевой метод моделирования. Проведен анализ полученных результатов. Сделан вывод о том, что «классическое» понимание картины пожара, основывающееся на принципе «чем больше уклон тоннеля, тем быстрее происходит блокирование», при определенных условиях может не соответствовать действительности. При этом большое влияние на результат расчетов может оказывать постановка граничного условия постоянства давления. One of the important issues in the design and construction of tunnels is to ensure their fire safety. To take into account the characteristics of a particular object and make decision on its effective fire protection, it is necessary to study the influence of various factors on the dynamics of a possible fire. Conducting field tests in this case is expensive and time-consuming. Therefore, one of the most effective methods in this case is numerical modeling. In this paper there is considered the issue of the influence of the longitudinal slope value of a road tunnel on the dangerous factors spread in case of fire. The assessment was carried out by simulating a fire in a model tunnel using the field method. A model tunnel of rectangular cross-section was chosen for conducting numerical experiments. The SOFIE software package was used to implement the model. To evaluate the results obtained there were created the fields of optical smoke density in the central longitudinal section at various time points. This dangerous fire factor is the determining factor because it reaches critical values most quickly. As a result of calculations in the work there was established the influence of the tunnel slope value on the fire hazards spread. It is found that the nature of fire hazards spread in a tunnel without a slope significantly differs from their propagation pattern in an inclined tunnel. If there is a slope, the blocking of tunnel sections (escape routes) up the slope during the first minutes of fire occurs much faster than down, so it is preferable to evacuate people in case of an emergency down the slope. Under certain conditions the principle “the greater the slope of the tunnel, the faster the blocking occurs” can be untrue. At the same time, the obtained result depends on the setting of the boundary condition of pressure constancy during the calculation and can differ from the real fire performance, however, in general, it is not an underestimation of fire danger and can be used in engineering calculations.

About some directions of creation and operation of first aid fire trucks

Рассмотрены основные концептуальные направления создания пожарных автомобилей первой помощи (АПП). Проанализирован проведенный управленческий эксперимент с использованием АПП в рамках обсуждения в 2003 году на совещании-семинаре по теме «О результатах эксперимента по применению новых технологий пожаротушения с целью определения оптимальных решений по их применению». Сформулирован ряд замечаний по конструкции и функциональным возможностям эксплуатации этого типа ПА. Приведен рейтинг потребности АПП с учетом вместимости их цистерны для воды. Представлены данные из литературных источников, отражающие направления их создания и эксплуатации. The main conceptual directions in the creation of first aid fire trucks (APP) are considered. The standards for their creation and testing are presented. The importance of the presence of first aid in the fleet of fire trucks (PA), taking into account adaptation to operating conditions, is shown. The data on conducting a management experiment using the APP are presented as part of a discussion in 2003 at a meeting-seminar on the topic “On the results of an experiment on the use of new fire extinguishing technologies in order to determine optimal solutions for their application”. A number of remarks on the design and functionality of this type PA are made. The need rating in APP is given, taking into account the capacity of their water tank. Data from literature sources reflecting the directions of their creation and operation are presented.

Explanations of some technical requirements for fire lanterns

В статье отражены результаты обсуждения наиболее актуальных вопросов, возникших при формировании технических требований к фонарям пожарным при разработке межгосударственного стандарта «Техника пожарная. Фонари пожарные. Общие технические требования. Методы испытаний». Предложения, требующие подробных разъяснений, касаются количества циклов применения фонаря, обоснования принятого уровня освещенности и разработки требований к нормированию светового потока источника света фонаря. На основании качественных испытаний четырех наиболее распространенных моделей групповых фонарей в подразделениях противопожарной службы Российской Федерации, проведенных испытательной лабораторией института в период с 2010 по 2018 год, сформулированы основные их эксплуатационные показатели. This article contains some comments and suggestions that caused a discussion during the consideration of the draft of the interstate standard provisions “Fire fighting equipment. Fire lanterns. General technical requirements. Test methods”. The proposals that require detailed explanations include issues related to the cycle life of lamp, the justification of the accepted level of illumination and the development of requirements for the normalization of the luminous flux of the lamp light source. As a reference point for determining the cycle life of the flashlight there was selected the battery. Based on the standard indicators of the resource of different types batteries the value of cycle life of the flashlight is equal to 400. On the base of the qualitative tests on the four most common models of group lamps in the divisions of the fire service of the Russian Federation, conducted by the testing laboratory of the Institute for the period from 2010 to 2018, the main operational indicators are formulated as the following: “The time of continuous illumination of the lamp under normal conditions according to GOST 15150, excluding the time of triggering the warning alarm (FPG), should be at least 5 hours; the illumination of the working surface with the lamp must be at least 1500 lux during the entire glow time”. The introduction of requirements for the normalization of the luminous flux of the light source of the lamp is not provided.

Methodology for studying the combustion products composition from various materials

Изложены методология и принципы лабораторного исследования состава продуктов горения различных материалов с использованием таких инструментов, как газовая и газожидкостная хроматография, масс-эффузио-спетрометрия. Большое внимание уделено применяемым в хроматографических колонках сорбентам и их температурным режимам, а также способам приготовления образцов для исследований. Рассмотрены вопросы детектирования различных компонентов в смеси продуктов горения. Результаты исследований продуктов горения разных материалов представлены в табличной форме, при этом в скобках указаны рассчитанные индексы токсичности С, оцененные по литературным данным (смертельная для человека концентрация при получасовой экспозиции). The article discusses the issues of determining the qualitative and quantitative composition of the combustion products from synthetic and natural materials. Multicomponent mixtures of volatile combustion products contain compounds of inorganic and organic origin. To determine the composition of the combustion products from various materials there is proposed the methodology and principles of laboratory research using such instruments as gas and gas-liquid chromatography, mass spectrometry, infrared and ultraviolet spectroscopy, and visible-field spectroscopy. These methods make it possible to identify certain chemicals. For example, organic compounds are analyzed by chromatography. Inorganic substances are determined by converting them into colored compounds and by analyzing their spectrum in the visible and ultraviolet regions. When developing methods of chromatographic and spectrophotometric studies, it is proposed first of all to identify the qualitative composition of combustion products based on information about the composition of polymer molecules of the studied natural or synthetic materials. Such an assessment, as an example, was made by studying the combustion products of polyethylene. The molecular weights were determined using the MX-1312 chromatomassefusiometer. To determine the molecular weight of a substance, a mathematic formula was obtained based on mathematical processing of experimental data. A special method has been developed to reduce the processing time of effusiograms (by 10-15 times). Much attention is paid to the sorbents used in chromatographic columns, their temperature conditions, and methods of preparing samples for research. Methods of identification of various components in a mixture of combustion products using various detectors are considered. The results of studies of the combustion products from different materials are presented in tabular form, with the calculated toxicity indices, С, estimated according to the literature data (lethal concentration for humans at half-hour exposure) are indicated in parentheses.

Numerical simulation of fire in road tunnel. Selection of calculation grid

Рассматривается вопрос выбора расчетной сетки при моделировании пожара в тоннеле с помощью полевого метода и проводится оценка возможного влияния размеров ячеек сетки, а также граничного условия постоянства давления на результаты расчета. Выполнено моделирование пожара для четырех размеров расчетной сетки. Обоснована возможность применения наиболее грубой из используемых сеток с точки зрения инженерных расчетов, в том числе с оговоркой относительно постановки граничного условия. The issue of fire safety of road tunnels is currently an urgent task. Road tunnels are usually not standard typical facilities, but the unique structures. Therefore, it is necessary to study the influence of various parameters on the development of fire in order to take into account the characteristics of a particular object and make decisions on its effective fire protection. Implementation of field tests in this case is expensive and time-consuming. In this regard, numerical modeling is one of the most effective methods of such research. Field models are the most common and currently used for numerical calculations. These models are based on the numerical solution of the system of conservation equations for small control volumes of the calculation grid. This paper examines the issues of selection the calculation grid when modeling a fire in tunnels using the field method is considered and the possible influence of the size of the grid cells is estimated. The mathematical model used in this work is based on a set of differential equations of hydrodynamics, heat transfer, as well as the equation of conservation of the masses of components. Four computational grids were selected for a horizontal (without slope) model tunnel to determine the optimal cell size. As a result of conducted calculations it was established the following: the size of calculated grid is not fundamental for the initial stage of the fire; the use of smaller grid may be preferable at further development of fire, accompanied by increase of combustion capacity to the maximum; the maximum temperature values, especially in the far sections, are obtained on the coarsest grid. The use of such a grid for estimated engineering calculations can be allowed.

Laboratory plant for evaluation of burnout rate of various materials

Описана методика исследования скорости выгорания различных материалов. Для реализации методики создана лабораторная установка. Экспериментально установлено, что процесс выгорания материалов зависит от температуры реактора и скорости воздушного потока. Кривая выгорания имеет S-образный вид и три характерных участка: индукционный период, линейный участок и участок реакции, где происходит выгорание углеродистого остатка. В табличной форме представлены результаты исследования некоторых широко распространенных материалов. The article describes a method for studying the burnout rate of various materials. There was created the laboratory plant for implementation of the method. It is experimentally established that the process of burnout of materials depends on the temperature of the reactor and the air flow rate. The burn-up curve has an S-shape and three characteristic sections: the induction period, the linear section, and the reaction section where the carbon residue burns out. The article presents the results of study of some widely distributed materials in tabular form. The mass burn rate of beech wood is 1.5 times higher than that one of pine. Perhaps this is due to the impregnation of beech with furniture varnish, since the sample was part of the furniture lining. It is noteworthy that significant discrepancy in the burn-up rates was obtained during combustion of samples of different brands of polyurethane foams. So, for hard polyurethane foam - “izolan 2”, which has a flame retardant in its composition, burnout curves with longer induction period are obtained (as a result of flame retardant action). However, the burnout rate is higher in comparison with soft polyurethane foam without flame retardant (foam rubber). The composition of the material “isolan-2”. Rubber also has a long induction period, but a high burnout rate.

Issues of ensuring timely evacuation of people from buildings of educational organizations

Статья посвящена проблеме противопожарной защиты объектов просвещения с учетом требований Федерального закона «Технический регламент о требованиях пожарной безопасности», постановления Правительства Российской Федерации, которым утверждены Правила проведения расчетов по оценке пожарного риска. Рассмотрены вопросы определения необходимого времени эвакуации людей из общеобразовательных организаций при пожаре. Проанализированы требования нормативных правовых документов в области пожарной безопасности. The article is devoted to the actual topic of providing conditions for the safe evacuation of people from educational institutions. The analysis of the requirements of regulatory legal documents in the field of fire safety and statistical data on fires is carried out. The issue of improving the level of fire protection of educational facilities was planned to consider at the meeting of the Government Commission for the Prevention and Elimination of Emergency Situations and Ensuring Fire Safety during the Board Meeting on the results of the Ministry’s work on the main areas of activity in 2020 and on the tasks for 2021 of EMERCOM of Russia. Moreover, the President of the Russian Federation instructed the Government of the Russian Federation to introduce a unified approach to ensuring the security and anti-terrorist protection of educational organizations in the very near future in May of this year. The supervisory authorities of the EMERCOM of Russia conduct practical training on evacuation of people regularly, but for their successful implementation it is necessary for each head of educational organization to know what time is allocated for organizing and conducting the necessary evacuation of people during fire at the facility. Article 53 of Federal Law No. 123 of 22.07.2008 “Technical Regulations on fire safety requirements” defines that the safe evacuation of people from buildings and structures in case of fire is provided if the time interval from the moment of fire detection to the completion of people evacuation to a safe area does not exceed the required time for evacuation of people in case of fire. The buildings of educational organizations were designed at different times, respectively, the objects have different layouts, number of floors, and degree of fire resistance. Therefore the individual approach to each object of protection is necessary to determine the essential evacuation time. Determining the time of people evacuation from buildings and premises will have a positive impact on the effectiveness of practical training, will help to determine whether people have time to evacuate from the building at prescribed time. The Rules for conducting calculations on fire risk assessment is approved by the Decree of the Government of the Russian Federation No. 1084 dated July 22, 2020. The Methodology for determining the calculated values of fire risk in buildings, structures and fire compartments of various classes of functional fire hazard is approved by the Order of EMERCOM of Russia No. 382 dated June 30, 2009 (as amended by Order of EMERCOM of Russia No. 632 of 02.12.2015). This Methodology establishes the procedure for determining the necessary time for the people evacuation from the objects of protection. The implemented work will allow the bodies of the state fire supervision of EMERCOM of Russia to increase the quality index of administration of control and supervisory functions at the objects of protection of this category.