The aim of this work was to investigate the explosion of propane-air mixture in a cylindrical tube with 20 cm in diameter and 150 cm in length, closed at both ends and having hole on the lateral surface, dimensions and position of which were varied according to conditions of experiments. The study was conducted by numerical simulation within 3D CFD (Computational Fluid Dynamics) models based on a system of fundamental conservation equations applied to problems of gas dynamics, which supplemented by equations describing the propagation of a flame. System of approximating equations was solved by the large-particle method (LPM) developed by Belotserkovskiy O. M. and Davydov Yu. M. This method involves applying the rigid grid, placed in the calculated area and formed from about 90 thousands of the so-called “particles”, through which move the gas flows. Comparison of the results of numerical experiments and previously conducted physical experiments show the adequacy of the mathematical model. As a result of studies it was confirmed the known dependence between the explosion pressure and the diameter of a hole. Furthermore, it was shown that the dependence of explosion pressure on size and position of a hole on the lateral surface is ambiguous. Decrease of the distance between the hole of a smaller size and the source of ignition leads to rising explosion pressure (while increase of the distance leads to its lowering). The abnormal development of explosion in the form of self-oscillation with large amplitude in a certain range of size and position values of a hole was revealed during experiment. This effect is very similar to the “singing flame” phenomenon of Higgins. In conditions of pressure oscillations there were observed the fluctuations of position and size of the flame front. Oscillations lead to significant increase in pressure compared to explosions without oscillations. It should be noted that the possibility of appearance of the self-oscillation mode of explosion is known from the data of physical experiments, but such mode was modeled for the first time. It is known that previous attempt to create such mode using FLACS software was unsuccessful.

Experience of modern multistory wooden buildings has shown that as the main structural schemes there are used frame and volumetric-modular technology with the use of cross-laminated timber (CLT) panels. It is a steady tendency to increase the number of stories of buildings. In the article the analysis of normative requirements in the field of fire safety of high-rise buildings of wooden structures is presented. In the Russian Federation the construction of one- and two-storey wooden residential houses are allowed with maximum floor surface of 800 and 500 m², respectively. In this case, the limits of fire resistance of building structure are not standardized. It’s allowed the construction of three-storey houses of the class of constructive fire danger of the C2 and fire resistance of building structures not less than REI 15 (E 15). Basic regulatory requirements for wooden houses in Europe and North America are associated with the number of floors, the fire resistance rating of load-bearing structures and the application materials of wood finishes and facades. As a rule, the construction of two-storey wooden residential buildings has no limitations. With increasing number of stories there are used various fire protection system: fire detection, automatic fire extinguishing system, etc. Special attention is paid to the creation of fire compartments and limit the use of combustible materials in interior and exterior decoration. However, in some countries (Sweden, France, Netherlands) the construction of eight-story buildings of wooden structures without the use of automatic fire suppression systems is allowed. Results of fire tests of wooden constructions from laminated veneer lumber are presented. It is shown that wooden structures have a fire-resistance required for use in the construction of multi-storey buildings of different functional purpose. The parameters of the speed of charring of different wood structures are given. The main directions of research and development of the regulatory framework in the field of fire safety of buildings of wooden structures are defined. Special attention is paid to the further conduct of fire tests for evaluating the fire resistance of wooden structures using new composite materials and technologies, and conducting full-scale fire tests of wooden buildings and constructions in order to simulate the development of fires.

The aim of this work was to create the mathematical model for calculation of the carboxyhemoglobin concentration in the human blood in case of fire. Tests were conducted in conditions of variable CO density, typical for the initial stage of indoor fire, and increased pulmonary ventilation rate. It is offered the criteria for determination of the critical values of fire duration under the terms of safe evacuation and people rescue. The methods of theoretical analysis of the content of carboxyhemoglobin in the human blood and calculation of the carbon monoxide (CO) concentration, in conditions of fire in premises, were used during the experiment. The mathematical model was created taking into account the concentration of CO in the inhaled air, the mass of hemoglobin in the blood, the pulmonary ventilation rate, the volume of respiratory dead space and the CO exposure time. Critical time of safe evacuation for people under the effects of CO is accepted when the content of carboxyhemoglobin in the blood reaches the 20 % by mass (minor poisoning). Critical time from the initial stage of fire and until the moment when people, which stay in premises without protection means against CO (respirators, gas masks, self-rescuers, etc.), and, with high probability, are unable to leave the premises independently, is accepted when the concentration of carboxyhemoglobin in the blood reaches the 50 % by mass (moderate poisoning). The model premises were in the form of parallelepiped with dimensions (m): 4´5´3, 4´5´6 and 24´12´3. As combustible materials there were used the wood building materials, PVC sheath of cables and transformer oil. The results of numerical experiments on determination of the carboxyhemoglobin concentration using the analytical solution of the integral calculation model for the thermal and gas dynamics of fire are presented. The estimated values of CO exposure intervals prior to various degrees of human intoxication are obtained. The comparison of critical durations of fire (considering CO effects), obtained using proposed model and existing approach, is made. The critical duration of fire, obtained using proposed model, was significantly greater than the corresponding value determined by existing methods (for example, in case of burning of the transformer oil in the room with dimensions of 4´5´3 m). The main conclusion is that existing scientific and regulatory literature contains the calculation methods for critical duration of fire, considering CO effects, which may lead to qualitatively and quantitatively wrong results. The proposed criteria for determination of the critical values of CO exposure time and the calculation methods for the content of carboxyhemoglobin allow defining the time of safe evacuation and people rescue more reasonably than existing approach.

Providing required (statutory) parameters of fire resistance of R 60-R 180 steel beam structures involved in ensuring the overall sustainability of buildings and structures is not possible without the use of structural fire protection. Widespread method of structural fire protection involves the use of plate materials. The use of this type of fire protection allows for the production of works without the use of “wet processes”, which is very important for the Far North with a short period of time of positive temperatures. Fire-retardant treatment of steel structures with plate materials may also be carried out without stopping the production process in the reconstruction of buildings and structures. One of the members of the group of fire retardant materials are slabs PYRO-SAFE AESTUVER T, whose composition as a filler includes perlite, glass fiber, and as a binder - cement. The article describes current research aimed at obtaining baseline data to determine fire retardant efficiency of slabs PYRO-SAFE AESTUVER T and features of the calculation of fire resistance of coated steel rod elements in order to ensure regulatory requirements for fire resistance. The studies of fire resistance performance of coatings for steel structures allowed us to obtain the variation of thermal conductivity and heat capacity of fire retardant material, when impacted by fire. To obtain these dependencies, fire tests of steel-lined columns were conducted on the bench equipment for fire tests of building structures on the experimental base of VNIIPO of Emercom of Russia (All-Russian Research Institute for Fire Protection of Ministry of Russian Federation for Civil Defense, Emergencies and Elimination of Consequences of Natural Disasters). Parameters of cladding, such as density, humidity, emissivity, thermal conductivity and thermal capacity under normal conditions were taken from reference literature. Then, in the presence of experimental data, thermo-physical characteristics (thermal conductivity and heat capacity) of the material at elevated temperatures were calculated with a computer program by solving the inverse heat conduction problem. The obtained parameters of the thermal characteristics for a given flame retardants, allowed to construct warm-up nomograms of unlimited steel plates, depending on the thickness of the steel and the thickness of cladding with PYRO-SAFE AESTUVER T slabs. As a result of the research, the obtained nomograms of fire resistance of steel structures with PYRO-SAFE AESTUVER T fire protection plates may be used for the design of passive fire protection systems at construction sites. In combination with the calculation method, these nomograms allow to reduce the usage of fire-retardant material in cladding thereby increasing the economic efficiency of fire protection of this type. In Federal State Budgetary Establishment VNIIPO the “Instruction on the calculation of the actual limit of fire resistance of steel structures with fire-retardant frameless facings made of PYRO-SAFE AESTUVER T slabs” was developed.

The problem of building of mathematical models which describe indicators of fire service activities with parameters of fire safety is considered. Inadequate development of such models is marked. Both information support statistical bases of Vietnam and the territory differing significantly in various fire situations are used. Exponential analytical dependences between the relative characteristics reflecting specific loads of firefighters on the number of fires and specific parameters of an economic damage as well as a death toll and the injured people in the fires are received. These dependences can effectively be applied in the solution of tasks in the field of short-term forecasting of fire safety; evaluation of dead and injured peoples in fires; optimal territorial and dynamic allocation of fire service staff resources to minimize the economic damage caused by fires, as well as minimizing number of peoples dead and injured in the fires. Besides authors suggest to use in the solution of specified tasks models and methods developed in the active systems theory. The received analytical dependences with a sufficient accuracy (74-89 %) describe empirical data. A process of the fire service staff subsystems activity is represented in terms of entrance - resources - results . The formulation of tasks is performed and criteria of optimal fire service staff resources management in dynamic and territorial aspects are discussed. It is indicated that further modeling directions should focus on the development of integrated staff resource management criteria for fire service, allowing assessing its activities under stable operating conditions, and in cases of significant changes in fire situation. In addition, it is concluded that the implementation of the system approach fire service activities must take into account not only the work on the fire, but also the prevention of fires, including a large-scale advertising and educational activities, interaction with insurance companies related to fire risk and other aspects of combating fires.

Within Russia and out its boarder it is problem of protection for cash dispenses, payments terminals and for other values vaults against crime attacks by using special electrical tools, gas cutting devices, hand-made explosive devices. Accounting the number of cases of cash dispenses breakages by explosion of their safes cellular with cash we can allocate Italy, Brazil, Argentina and some other states. Now the main way of protection explosion of cash dispenses is its technical engineering provision for strengthening to burglary after explosion. However, decisions of mechanical protection for such cash units against burglary by gas explosion are not enough effective and they do not provide full protection of cash dispenses against such crime threats. The one of provision directions of security for values vaults is increasing of efficiency of detection and transmission of alarm about out-law actions of intruders during early stage for organization of measures of operate responding. There are results of experience researches of processes and signals, which occur during burglary by gas (oxygen-acetylene) cutting torch of cash dispense and payment terminals of different manufactures and grades. It is shown that the most effective part of spectral characteristics of a signal is in a range of frequencies from 3.5 to 11.0 kHz. Thus inside safes compartment (bottom chamber) fast growth of air temperature with rate 123 °C/min is observed. Other direction of security provision for cash dispenses is designing of complex unit of explosion protection. In this article there are considered the comparable carried out in august 2016 tests of experience samples of advanced automatics protection cash dispenses systems against explosion, including detection means of explosive gas preset concentration (gaseous alarms) and units of neutralization of explosive danger mixture for explosion formation prevention during attempt to initiate it. Present results of tests have allowed to plan the directions of future investigations and designing in the field following modernization of explosion suppression accounting constructions characteristics of cash dispenses and possible intruder’s actions. In conclusion there is analysis of normative-methodological provision of such problem in Russia.

Available cases of emergence and development of fires with participation of products show need of assessment of heat release when burning electric isolation of wires and comparisons according to this characteristic the electrocable products of different types. Definition of these characteristics possibly using different types of test equipment. Use of rated methods of determination of combustion heat or its direct definition by means of adiabatic bomb calorimeter is recognized inexpedient as in the conditions of fire there is no complete combustion of combustible component. Besides, these methods does not allow to receive information on kinetics of process of heat production. The cone-calorimeter widely applied abroad in different industries and working with using principle of oxygen consumption can give essential mistake depending on types of used fire retardants. In the aircraft manufacturing industry for heat release assessment at burning is used the OSU calorimeter (ASTM E906, type A) working with using the thermopair method. At carrying out researches the decision to use this type of the equipment and test method is made. Seven brands of the electricity cables differing both by structure of outer jacket, and the size of cross-section and quantity of current carrying veins have been tested. Tests of samples are carried out at heat flux on the sample of equal 35 kW/m². The standard defined characteristic (the maximum intensity of heat release rate (kW/m²) has been counted for comparison not only the conditional square of sample, but also at wire length, the area of exterior surface, mass of cable. The total quantity of heat release has been defined for different intervals of time (1, 2 and 5 minutes) as in standard form for aircraft (kW·min/m²), and in metric system of measures (MJ/100 rm). Essential influence of structure and cable size on registered characteristics of heat release and prospects of use of this method for assessment of fire safety of electricity cables is shown.

Fires of electrical reasons, make up around 20-25 % of total number of fires in the world. The most flammable (more than 60 % of the total number of electrical fires) are cable products. In the operation of the power plant possible an emergency mode is parallel or serial arc fault. It causes a fire due to the high temperature of the arc up to 7000 °C. It was found that fire arises primarily as a result of the electric arc. An arc fault is often a consequence of damage of electrical insulation. AFDD/AFCI is fairly new relay device for fire safety. Standard of Russian Federation for these devices is identical to the International standard IEC 62606:2013 “General requirements for arc fault detection devices”. The standard requires limits of response time of device depending of arc fault current. A time-current characteristic is one of the most important indicators of AFDD/AFCI performance. Late trip of emergency circuit with arc fault are most likely to cause a fire of insulation. Thus, to ensure the fire safety of cable it is necessary to know and use in design of electrical networks the maximum allowable time-current characteristics of the arc fault protection device. The case of a serial arc fault by fracture of cable conductor is considered. In practice, the most frequent reasons of this are rupture of cable wire due to metal fatigue or excessive tension and damage by external object. In the damaged conductor arises the small gap which punches by operating voltage. Thus, the current on this cable continues, and remains close to the nominal value. The gap arises the arc discharge accompanied by intense heating causes further degradation of the cable insulation and arises a fire. Determination of fire risk parameters of ignition energy of an arc fault is practical and is related to the fire safety of wire and electric cable networks. By the heat balance equation in the proposed model we obtained the expressions relating the general thermophysical parameters of the process are obtained. In particular, the formula of maximum allowable time-current characteristics of AFDD/AFCI is obtained. Furthermore we done the evaluation of termophysical parameters and time-current characteristics. Then given the comparison of these results with the values of the standard GOST R IEC 62606. Conformity of the standard values and the calculated data is found. Thus, we identified the model by which the standard values are calculated.

In the article the analysis of the climatic zones of the Russian Federation is performed. The analysis showed that the areas with cold climates having factors having a negative impact on technical means of fire extinguishing are identified. It all started from extinguishing tube with a furnace, which is also mounted on horse-drawn wagons. However, over the last century it was intensive development of technical means of fire fighting. The advent of the internal combustion engine contributed to the mechanization of fire fighting equipment. First of all, with horse traction the water pumps moved to the car chassis, which allowed to improve pump-hose system. There is a need of protection from the negative impact of more items of pump-hose systems. Initially, for fire vehicles to ensure the thermal stability of individual elements of a pump-hose system it’s used the energy of the exhaust gases of the engine. Analyzing all technical solutions, it can be noted that they protect from low temperatures only the individual elements of a fire truck. A comprehensive solution for security of fire equipment from the negative effects of low air temperatures to 2010 was not available. Using nearly 200 years experience in the use of technical means to extinguish fires in conditions of low temperatures, State Fire Academy of Emercom of Russia in 2010 formed and proposed the concept of creation North of the fire truck. In 2011, scientists of the State Fire Academy of Emercom of Russia jointly with the engineering staff of JSC “Vargashinsky factory fire and special equipment”, with the participation of the Yakut branch of RAS designed and developed fire-rescue vehicle in a climatic design CL PSA-S-6,0-40(6339). Thus, it is possible to say that technical means of fire control, adapted for operation in low temperatures, have a history stretching over 200 years. During the period, the development of technologies for firefighting, there are solved particular problems of protection of individual elements of mobile fire fighting equipment, and the complex task of creating a fire rescue vehicle in North version.