Demonstration of compliance with the parameters of portable fire extinguishers is provided in the form of certification testing for reliability and fire extinguishing capacity. Reliability testing is performed on 32 randomly selected from the batch extinguishers, and the acceptance number of failures should be zero. Fire extinguishing capacity is determined by fire test, and type of tested fire extinguishers considered successfully passed test if 2 of 3 extinguishers have extinguished model fire site (MFS) of specified class and rank, i. e. the acceptance number of failure is one. Those sample arrays aren’t aligned to each other, to quality control normative documents and to reliability estimation procedure. To determine the size of sample array of fire tests sequential analysis method is used. Allowable risk in this case is determined from the requirement that the probability of rejection of batch of extinguishers p does not exceed predetermined value a ( p £ p₀), in which p₀ is the upper limit of the probability of failure, and the probability of passing the test of the batch doesn’t exceed b, in case p₁ £ p . At every m-numbered test number of defective products d_m is counted. Compliance with MFS rank of tested extinguishers batch is determined by results of every test extinguishing MFS ( d = 1 or d = 0). Option of passing the test of all of the 32 extinguishers is economically inexpedient, so the size of sample array should be reduced without reducing product quality. The size of sample array depends on value of lower limit of failure probability firstly, so physico-chemical processes of MFS extinguishing were analyzed to substantiate the size of sample array. According to combustion theory fire stops if heat removal from burning area exceeds evolution of heat from combustion focus. Heat absorption of extinguishing powder, operator actions and constructive features of fire extinguisher have influence on extinguishing effect. Numeric value of heat removal from combustion focus will vary from test to test of extinguishers from even one batch respectively. In this case amount of heat absorbed by extinguishing powder will be found in between values corresponding to MFS of lower and higher rank. It is known in theory that the probability of random value to be found in the interval between standard deviations is rated 0.67. So, the probability of excess or lack of heat taking place is rated 0.165. That’s why value 0.165 is taken as lower limit of probability of failure for determining the size of sample array for fire tests. With this in mind limit amount of samples is determined by sequential analysis method (with b = a = 0.2 and p₀ = 0.004) and equals 8 extinguishers in case of zero amount of defective units. Advantage of this model is based on possibility to continue test with increased amount of extinguishers in case of failure of one. For example in case of failure at first iteration of test whole batch will be considered valid if 22 following extinguishers won’t be rejected, i. e. amount of samples should be 30. In case of failure at subsequent iteration sample array should be extended to 52 extinguishers. The novelty of this method lies in the differentiated approach to the testing of fire extinguishers.

Municipal emergency services (fire, ambulance, police and others) are indispensable, and at the same time quite expensive elements of the city infrastructure. That is why issues related to justification of the required headcount, technical equipment, deployment locations, appraisal of these services’ capabilities remain extremely relevant. An administration of any city will constantly face these challenges when generating a municipal development plan or when optimizing a municipal budget. Computer simulation systems remain a reliable tool, and, as a matter of fact, the only tool that can be used to assess consequences of reducing or increasing headcount of these services and of changing their parameters. This article contains a short summary of the simulation system called KOSMAS, which was developed by the authors of the article (an international project team) and derived from work experience gained through designing such systems over the last 25 years. This system provoked a great deal of interest among specialists of various emergency services operating in many countries of the world. This system was used to solve tasks of designing and restructuring fire-fighting, ambulance and gas services in Russia, Germany, Turkey and Croatia.

The most characteristic examples of accidents with the fires in the main buildings of thermal power plants (the fires at Reftinsky and Uglegorsk power plants) are presented. Reasons and consequences of these accidents are considered. It is established that potentially high fire danger in the main buildings is caused availability of oil under pressure in lubrication systems and regulations of turbine units, hydrogen in the cooling system, and at the coal power plants, availability of dust-air mix in systems of fuel feeding and a dust preparing. There are noted the main types of damage (loss) considered at accidents on the generating objects of power such as: direct expenses; the missed benefit; losses from deterioration of technological parameters at input of reserve capacities; losses at the consumer because of short-reception of the electric power; ecological and social damage. The main attention is paid to an assessment of irrevocable losses of means of production and costs of rescue and recovery operations - the main components of a direct loss. In some cases this type of damage can be defining. There are analyzed more than hundred accidents with the fires in engine rooms of the main buildings of thermal power plants and their consequences, including about seventy accidents at condensation stations. Dependence between the amount of losses and layout solutions of the main buildings of thermal power plant is defined. It is shown that with increase in number of the power units based in one building the damage increases. The probability and damage rate of the equipment, construction designs of each power unit in the zone captured by the fire depending on distance to epicenter are defined. Losses were estimated on the basis of actual data with attraction of expert estimates of experts. The technique for an assessment of irrevocable losses of means of production and costs of rescue and recovery operations at potential accidents is proposed. Expenses on elimination (localization) and investigation of accident are estimated according to requirements of the existing leading standard documentation. In the conclusion it is recommended to consider possible accidents and the corresponding damage in the course of development of the project of thermal power plant and a technical and economic assessment of alternative layout solutions of the main buildings.

Over the past three decades there are worked out the general principles of flexible standardization fire protection facilities, taking into account material losses in fires. However, practical implementation of this approach is hampered by the absence of reliable data on the effectiveness of fire prevention measures and estimated effects of fire material. Often this is done expertly, at best - for statistical data on fires. The reasons for this state of affairs were the following factors: 1) the random nature of the process of real fires and fighting them, spreads of building structures parameters and characteristics of fire protection engineering; 2) lack of engineering tools to evaluate and compare the performance of individual fire protection measures, allowing to set the sound application of the relevant measures. In this connection, the article seeks to develop theoretical foundations of engineering method of choice of rational variants of objects of protection with economic responsibility. This will be used probabilistic approach (analysis), allowing not only to more adequately take into account the physics of the processes, but slightly lower requirements for accuracy of data than the deterministic analysis. The theoretical foundation of engineering method of calculation of rational fire protection options premises of buildings, including fire barriers and automatic fire suppression system is worked. It’s proposed an analytical approach to assessing the reliability of building structures, taking into account both the stochastic parameters of designs and parameters of the premises in which they are used, as well as the characteristics of the fire load in the premises. The proposed engineering method implements the criterion of reduced costs, economic feasibility criteria, which in conjunction with the criterion of individual fire possible to obtain a rational way to protect the object. If necessary, the content of the criterion of reduced costs can easily be expanded by taking into account indirect losses from fires, detailing the damage on buildings, equipment via loss ratios, etc. Analytical approach to the evaluation of stochastic parameters of the equivalent length of a fire on an example of local fires can be extended to constructions in terms of volume fires, fires developing freely, by using the results of numerical experiments. In principle, the introduction of simulated fire simulation systems using random input parameters and field model of fires, yield more valid results for the rational choice of protection options. However, due to the complexity of such an approach for the engineering protection of the parameter estimates in the practice of scientific research and design organizations can currently be used in these analytical assessments.

The aim of this work is to carry out experimental researches on revealing the features of behavior of the people with various physical capacities in the course of preparation for evacuation from buildings of specialized institutions for disabled people, hostels of higher educational institutions and residential buildings. To collect the empirical data it was used approved methods of carrying out experiments on research of pedestrian flows with application of the modern video recording devices - “DOD F900LS” - with frame frequency of 30 f/s. The obtained results were theoretically generalized by means of methods of mathematical statistics. As a result of work it was determined the numerical parameters which have impact on formation of the pre-movement time value for evacuation of the people of various ages and groups of mobility from specialized institutions for disabled people, hostels of higher educational institutions and residential buildings. The realized investigations allow creating the significant database containing values of the pre-movement time of evacuation from buildings with difficult functional contingent. The database is based on the verified methods of full scale tests and methods of statistical analysis.

Major fires, that occurred in the UAE this year, revealed the incapability of existing systems to prevent the spread of fire on the facade of the building. Thus, the main aim to prevent the spread of fire is the location of the fire inside the building and prevention of fire spreading outside the building through the translucent constructions. The most difficult task, solving this problem, is to confirm the necessity of sufficient fire resistance of the translucent constructions, which do not allow spread the fire outside and spread through the building. The existing methods of high-rise building assessment do not fully reveal the actual fire resistance state. One of the factors that may reduce the fire resistance of translucent constructions is water spraying, if the system is incorrectly installed. At the present time, there is no data on the effect of water spraying on the fire resistance of translucent constructions with fire-resistant filling and not enough information on the reaction of constructions with laminated glass. In this regard, in order to determine the influence of water spraying on the fire resistance of fire-resistant glass, we have conducted fire testing of the samples of translucent constructions on large-scale setup, which consisted of two stages. At the first stage, the samples of TC without water spraying were tested, and at the second stage, the samples of TC with water spraying on the unheated side. Conducted large-scale fire testing of the fire-resistant glass showed, that the presence of water spraying on the unheated surface leads to the glass cracking, to the violation of the mechanism of dehydration and foaming of the fire retardant gel and its water washout. Ultimately, all this contributes to premature destruction of the fire-resistant glass. Laminated glass testing revealed that water spraying of the unheated side does not significantly increases the fire resistance of laminated glass “3-1-3”, it was only 9 minutes in standard fire temperature conditions. The greatest efficiency was shown by water spraying the heated surface of the laminated glass. In this case, the water spraying prevents the heating and melting of the protection layer and helps to preserve the integrity of the sample. Another necessary condition is to ensure even water spraying the entire heated surface of laminated glass. Thus, the conducted tests allow make following conclusions. 1) water spraying the unheated side of the fire-resistant glass with a water soluble fire retardant gel can cause loss of fire resistance and premature destruction of translucent constructions; 2) water spraying the unheated side of the laminated glass model of “3-1-3” does not significantly increase the fire resistance of the TC, due to inadequate protection for lamination from warming up and melting; 3) the most effective way to improve the fire resistance of TC is continuous and even water spraying the heated side of the laminated glass. In this case, the melting of the polymer film is excluded. The use of the obtained results of this research in practice will improve the fire safety of buildings with translucent designs.

The experimental investigations of temperature, varying in a trace of water droplets, water flow masses and aerosol flows, moving through high-temperature combustion products, were conducted. The temperature values of vapor-gas mixture in an area, corresponding to the trace of water droplets, moving through high-temperature combustion products (initial temperature values were 450-950 K) were measured by quick-response thermocouples (time of thermal delay was less than 1 sec). The objects of investigations were aerosol flows with droplet sizes, equal to R_d » 0.04÷0.40 mm, and droplet concentration, equal to g_d » 3·10^-5÷12·10^-5 m³ of droplets/m³ of gas; single droplets with R_d » 1.5÷2.5 mm, and significant water flow masses with characteristic size of 22-30 mm. Application of the quick-response thermocouples allowed defining the ranges of maximal reduction of gaseous medium temperature T_g in a trace of extinguishing liquid according to a group of factors, such as a method of supplying of water into the combustion zone, characteristic size of the elements of liquid flow R_d , droplet concentration in a water flow g_d , temperature of the combustion products T_g . The variation of combustion product temperature in a trace of motion of atomized flow, droplets and liquid flow masses was determined in the analysis of temperature trends, ranged from 15 K to 140 K. The values of preservation time t of low temperature of vapor-gas mixture in a trace of droplet flow, single droplets and significant liquid flow masses were determined relative to initial gas temperature: t » 4÷28 sec. It was experimentally defined that maximum values of time t correspond to supplying the atomized water, with characteristic sizes of elements, equal to R_d » 0.15÷0.30 mm, and concentration, equal to g_d » 3·10^-5÷12·10^-5 m³ of droplets/m³ of gas, into the standardized fire. The conditions when the characteristics of temperature and concentration traces have significant influence on processes of evaporation and heat exchange between gases and moving liquid (with accumulation of liquid energy) were determined. The ascertained experimental data prove the earlier made theoretical hypothesis about sufficiently long periods of preservation the temperature traces of water droplets, even if they are small. The obtained experimental information become the basis for developing the method of the effective reduction of fire temperature (flame and combustion products) in the technologies of polydisperse aerosol fire extinguishing.

This article describes the results of laboratory tests on determination of conditions of the thermal self-ignition of sediments of vapors of various combustible liquids inside air pipes of ventilating systems. On the basis of tests there were calculated the values of critical thickness of sediments at regular and emergency operating modes of ventilating system taking into account the unsymmetrical heat exchange of the formed layer. In such conditions the temperature of opposite surfaces of sediments are different, and heat exchange of the accumulated layer with environment is unsymmetrical. To determinate the critical parameters of self-ignition of sediments on the surface of various equipment, in conditions of unsymmetrical heat exchange of the material layer, it was used the calculation method with the Frank-Kamenetsky parameter d in oxidation reaction of the combustible substance, considering convective heat exchange at both opposite surfaces of the sediment. For calculation it was accepted that the maximum average daily temperature in regions of Russia during the warm season doesn’t exceed 40 °C. Influence of the temperature inside air pipe on the critical thickness of sediment was determined at temperature values of external air of 40 and 20 °C. Presence of the temperature difference on opposite surfaces of a sediment layer leads to growth of its critical thickness by several times in comparison with requirements of the Russian State Standard 12.1.044-89. Our calculations show that if the temperature of air-gas environment ( T_g ) inside air pipes is equal to 70-80 °С, then the self-ignition of sediments become impossible because of significant growth of their critical thickness. Apparently, ignition of sediments, which thickness is less than 0.05 m, can occur as a result of penetration of the smoldering particles into air pipe or uncontrolled growth of the temperature of air-gas environment higher than 210 °C. Noticeable reduction of the critical thickness of sediments become possible also in air pipes with thermal insulation, if the temperature of external surface of the sediment (contacting with the pipe surface) approximate values of T_g . Influence of the cross section diameter of air pipe, as well as the rate of motion of air flow inside the pipe, on conditions of self-ignition is unobserved in comparison with influence of increase of the sediment layer thickness. The results of estimation of the induction period of self-ignition of the sediment with critical thickness (when T_g = 127.5 °C) inside air pipe with section diameter of 0.5 m and rate of motion of 1.5 m/s, in conditions when the temperature in production room is about 40 °C, indicate that self-ignition of sediments can occur within 1 hour, i. e. during one working shift. Despite the fact that features of heat exchange of sediments can significantly increase the induction period, the process of accumulation of the sediment layers up to critical thickness (taking into account regular and emergency conditions of operation) should be considered as the major limiting factor.