Pozharovzryvobezopasnost/Fire and Explosion Safety最新文献

{"title":"Robotic fire-fighting systems using advanced fire suppression technologies with Russian priority","authors":"Y. Gorban, S. Tsarichenko","doi":"10.22227/0869-7493.2022.31.05.54-66","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.05.54-66","url":null,"abstract":"Introduction. Fire suppression systems are stationary technical means designed for fire extinguishing. Their evo- lution relies on the general level of technological development. At present, automatic fire suppression systems (AFSS) are most widely used; they include sprinkler AFSSs, patented in 1864 by Harrison, UK, as well as new robotic fire suppression systems (RFSS). The purpose of the article is to analyze the trends in the development of fire extinguishing systems, and substantiate Russia’s priority in the development of advanced fire extinguishing technologies on the basis of robotic fire suppression systems (RFSS).Fire suppression systems: from manually operated to robotic ones. Sprinkler fire extinguishing has significant drawbacks; they are low sensitivity and high inertia. Fire monitors are among the main most powerful means of firefighting. Fires are extinguished by firefighters who are in extreme life-threatening environments. The issue of replacing a person during fire extinguishing was studied. Mobile firefighting robots appear in many countries. In practice, stationary firefighting robots are widely used. The first stationary firefighting robot was invented in Russia in 1984 to protect the Kizhi Museum. It was also applied to liquidate the consequences of the accident at the Chernobyl nuclear power plant. The first RFSS was introduced at the Leningrad NPP in 1989. Acting in close cooperation with the VNIIPO EMERCOM of Russia, FR Engineering Centre conducted research to improve the design and control system, establish the regulatory framework for the RFSS. As a result, Russia has become the first country in the world where a new type of automatic fire extinguishing systems, or robotic fire suppression systems, was introduced by the law. RFSS requirements are established by the Federal law No. 123-FZ, GOST R and Codes of Practice. Russia’s priority right for the invention of RFSS is protected by a number of patents.Conclusions. In our country, long-term research and development have been carried out to design new fire extin- guishing technologies named robotic fire suppression systems. Regulatory and technical frameworks have also been established, and a firefighting robot plant has been built. Now new fire extinguishing technologies, involving firefighting robots, are widely spread; they protect thousands of significant facilities of the country.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128357287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle size influence on the aluminum combustion dynamics in 1-m3 chamber","authors":"N. Poletaev","doi":"10.22227/0869-7493.2022.31.05.6-13","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.05.6-13","url":null,"abstract":"Introduction. The results of a standard study of the explosibility of aluminum air suspensions (AAS) can contribute to the development of AAS combustion physics. In particular, a complex of information about the polydispersity and of the AAS low explosion limit values in a 1-m3 chamber made it possible to determine the maximum particle size of the explosive fraction of a polydisperse sample d*m,t ≈ 40–50 µm (Poletaev, 2014). In the present work, a relationship is established between the AAS combustion dynamics in a 1-m3 chamber and persion. The dispersity of sample particles is described by the mass-average particle size of its explosive fraction (d*50), in contrast to the works of other researchers who use the mass-average size of all particles (d50).Initial data. Known information about the dispersity and explosion parameters of 15 aluminum samples studied in a 1-m3 chamber was used. The continuous particle size distribution functions necessary for calculating d*50 were represented by the Rosin – Rammler distributions filling the gaps between the discrete data of the sieve analysis of the samples.Combustion dynamics. The dynamics of AAS turbulent combustion in a 1-m3 chamber is represented by the maximum air suspension burn-up rate Ub. Ub was calculated using the formula (Kumar, 1992) intended for gas-air mixtures by substituting the AAS explosion parameters into this formula.Results and its discussion. A plot of the d*50 Ub complex versus d*50  is shown. The average value of the complex (≈ 33 µm·m/s) is constant in the range 10 ≤ d*50  ≤ 35 µm. The latter is typical for the product of the particle size and the normal velocity of the laminar flame in AAS (Ben Moussa, 2017) and indicates the similarity of the effect of particle dispersion on the dynamics of turbulent and laminar combustion of AAS.Conclusions. The dispersion of an explosive polydisperse aluminum sample is determined by the average particle size of the explosive fraction of the sample d*50. The similarity of the combustion patterns indicates a relationship between the mechanisms of laminar and turbulent flame propagation in AAS.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134546145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the possibility of using various fire extinguishing means in high-rise buildings","authors":"M. Aleshkov, O. Dvoenko, A. Gumirov, A. Sokovnin, M. V. Seregin, I. O. Semenyuk, S. Tsarichenko","doi":"10.22227/0869-7493.2022.31.04.65-75","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.04.65-75","url":null,"abstract":"Introduction. To date, fires in high-rise buildings are one of the significant problems faced by fire protection units. Unique objects require a special approach in terms of fire safety and fire extinguishing. The most important task is to ensure the supply of extinguishing agents to the height using modern fire-fighting equipment and installations.Materials and methods. In September 2021, to conduct experimental scientific and tactical exercises on the roof of the Neva Towers tower, a program and methodology for supplying fire extinguishing agents in various ways to the height were developed. The following methods of feeding to height were considered: deployment using the equipment of a container for high-altitude firefighting, feeding from an installation with compression foam technology, feeding using a waterjet cutting unit “Cobra”.Theoretical bases. A theoretical assessment of the possibility of supplying extinguishing agents to a height with the help of new fire-rescue equipment confirmed the need for experimental scientific and tactical exercises on the roof of the Neva Towers tower.Results and discussions. As a result of the scientific and tactical exercises, the effectiveness of the use of new fire extinguishing systems with compression foam supply, as well as installations with waterjet cutting technology “Cobra” was proved. It was possible to provide a feed to a height of 350 m.Conclusions. To date, with the help of new fire extinguishing technologies, it has been experimentally proven that their use is most effective compared to “traditional” methods of supplying extinguishing agents. In the future, it is necessary to conduct more detailed studies of the hydrodynamic parameters of pumping and bag systems in order to develop recommendations for preliminary planning of the actions of forces and means of fire and rescue units.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130078588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Approval of a computational method for determining thermal loads during accidents accompanied by fireballs","authors":"R. R. Shangaraev","doi":"10.22227/0869-7493.2022.31.04.16-26","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.04.16-26","url":null,"abstract":"Introduction. Large fires are quite often accompanied by the formation of fireballs (OSH), which create significant thermal loads. As a result of the fire coverage of a container containing an overheated liquid, a physical explosion occurs, which releases a significant amount of fuel forming a fireball. This phenomenon is dangerous because, with a short lifetime, it is capable of causing thermal injuries over considerable distances. The existing methods of predicting the consequences of a fireball, set out in various domestic regulatory documents and foreign literature, do not fully reflect the possible values of thermal loads. In this regard, a computational method for determining thermal loads was developed, taking into account the movement of the fireball.Goals and objectives. The purpose of this study is to test the developed computational methodology for determining thermal loads, which takes into account the kinematic characteristics of the fireball. The following tasks were solved in the study:● check the operability of the fireball lifting model;● to conduct a comparative analysis of thermal loads according to the developed methodology with the results of calculation of domestic and foreign methods;● conduct a computational experiment on the effect of air mobility (wind effect of 7 m/s) on thermal loads.Research methods. To check the operability of the OSH lifting model, footage of the formation of a fireball was used. According to the shooting frames, the position of the fireball in space and its kinematic characteristics were tracked. Using kinematic parameters, thermal loads were determined. To assess the adequacy of calculations of thermal loads, a comparative analysis of the results of calculations of the developed computational methodology with the results of calculations using existing domestic and foreign methods was used. To substantiate the application of the developed computational methodology for determining thermal loads, taking into account the kinematic parameters of the fireball, a computational experiment was conducted using the MATLAB software and computing complex.Results and their discussion. The results of the calculation of kinematic parameters are satisfactorily correlated with the results of mathematical modeling. The obtained values of thermal loads according to the developed computational methodology are in satisfactory agreement with the results of calculations according to existing domestic and foreign methods. Based on the calculations performed in the article, it is shown that a change in gas dynamic flows (wind demolition) leads to a significant change in the damaging factors of fireballs that are formed during fires in emergency situations.Conclusions. The results of the research made it possible to assess the adequacy of the performance of the improved computational methodology for determining thermal loads in accidents accompanied by fireballs, as well as to justify the relevance of the application of the","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128637580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrolysis of hybrid polyurethane inorganic thermal insulation: thermogravimetric analysis and FTIR spectra","authors":"A. Kobelev, Yu.K. Naganovskiy, E. Kruglov, R. Aseeva, E. M. Shapikhov","doi":"10.22227/0869-7493.2022.31.04.5-15","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.04.5-15","url":null,"abstract":"Purpose. The purpose of this work is to study the process of thermal decomposition (pyrolysis) of two samples of a hybrid organic-inorganic (OIH) heat-insulating material based on data obtained by thermogravimetric analysis and IR-Fourier spectrometry.The goal set predetermined the following research tasks: to find out the basic chemical structure of the OIH samples (by functional groups), to study the order of processes in materials when heated in nitrogen, to calculate the activation energy, the pre-exponential factor, to determine the pyrolysis mechanism.Methods. The methods of thermogravimetric analysis and IR-Fourier spectrometry were used in the work. Samples for spectrometric analysis were prepared in the process of thermogravimetric tests using the “freezing” experiment method.Results and discussion. The paper studies the structural features of two samples of hybrid polyurethane inorganic (OIH) thermal insulation material and traces the physicochemical processes that occur when they are heated under dynamic conditions in a nitrogen atmosphere up to 750 °C.The multi-stage nature of the pyrolysis of the OIH material is shown. The pyrolysis of the first sample is a threestage process. For the second sample, decomposition proceeds in two stages. All stages are endothermic. This indicates the predominance of energy costs for breaking bonds between the organic and inorganic parts and other conclusions.It has been established that the pyrolysis of OIH samples at all stages is carried out according to the mechanism of nucleation and the growth of nuclei (active centers of destruction). Analysis of the IR spectra of the samples showed that both samples were prepared using Desmodur aliphatic isocyanates.Conclusions. The paper studies the chemical structure and physicochemical changes when heating the new group of materials — hybrid organic-inorganic (OIH) heat-insulating materials. The article is a continuation of a team of authors systematic study of a thermal behavior of modern types of polymer thermal insulation.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115686320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of methods used to identify combustible gas and vapour-related factors contributing to explosions in the context of assigning explosion and fire safety categories to premises","authors":"G. T. Zemskiy, L. P. Vogman, N. Kondratyuk, D. Korolchenko","doi":"10.22227/0869-7493.2022.31.04.27-37","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.04.27-37","url":null,"abstract":"Introduction. The authors have classified numerous publications, addressing the assignment of explosion and fire safety categories to premises, buildings and outdoor facilities, into the three groups: 1) sources of information that are in effect (including in-house and region-wide documents), sources that were in effect; 2) manuals and guidelines on category assignment; 3) publications that confirm (refute) or clarify some provisions, specified in regulatory sources. This article can be included into the third group of publications.Goal. Analysis of different methods, used to identify the value of Z factor; identification of strengths and weaknesses of each method, development of recommendations on the application of these methods.Objectives. The objective is to identify the substance-related factor contributing to explosions, use particular cases to demonstrate the efficiency of this or other identification method.Results and discussion. The analysis of Z factor identification methods, describing the contribution of vapours of highly flammable liquids to an explosion, has proven that three types of procedures can be used to find the Z factor value:the method of tables (that uses the maximal possible tabular value of Z = 1; for gases and aerosols Z = 0.5; for vapours of highly flammable liquids Z = 0.3);the computational method based on a pattern of three-dimensional gas and vapour spreading on the premises; however, this method, if applied, may involve a high probability of errors due to numerous conditions limiting its applicability; hence, the unexplainable value of Z may exceed 1. Besides, the computational method is extremely laborious. Its application requires the clarification of conditions for its use;the graphical method (based on the dependency graph of Z on the X parameter). This method is the simplest and the most reliable one. When the graphical method is used to find the value of Z, the excess oxidant ratio must be taken as being equal to one, and the Х parameter must be calculated according to the following formula: Х = 0.99 Рs.v/Сst.c.Conclusions. The graphical method, used to find the value of Z, is simple and reliable. When the Х parameter is identified, the excess air ratio is used: φ = 1.9, which leads to the underestimation of Z, the vapour-related factor contributing to explosions. To prevent the unreasonable underestimation of Z, the excess air ratio must be disregarded or taken as being equal to 0.99.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128078924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Researches of the pre-evacuation time of people in residential multi-storey buildings without fire warning systems","authors":"D. A. Samoshin, R. Istratov, M. M. Sharanova, V. A. Kochetygov, S. V. Tomin, A. Frolov","doi":"10.22227/0869-7493.2022.31.04.38-55","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.04.38-55","url":null,"abstract":"Introduction. According to statistics, the greatest loss of life from fires in Russia occurs in residential buildings with a height up to 28 m. At the same time, most fire protection systems are not provided in such type of buildings. In particular, in residential buildings of mentioned above height fire alarm system maybe not. That is why the real values of the pre-evacuation time (PET) in the buildings are not known, because domestic research still has not been conducted.Goals and objectives. The aim of the work was to establish the values of the PET of people in a residential building that is not equipped with a fire alarm system.The main tasks were to study the time to warn building occupants about a fire and to research the time of people’s reaction to a fire warning.Methods. The method of scientific research in this work is a full-scale experiment. In the first set of experiments focus were on warning time — it was investigated how much time it took to warn all building occupants by 1, 2 and 3 notifiers. The second set of experiments were aimed to study of people’s reaction time to a fire alarm — it was determined how long it took to start evacuating from their apartments.Results and their discussion. Studies have shown that the value of the alert time of a nine-storey building by one, two and three notifiers averaged was 20.0, 11.6 and 7.2 min, respectively. Based on the data obtained, a mathematical model was built that allows predicting the optimal number of notifiers depending on the number of storeys in the building. Studies of people’s reaction time to a fire alarm have shown that during the daytime, on average, people need less time to realize and prepare for evacuation (72 s) than at night (112 s). Combining the results obtained allowed us to determine the optimal number of notifiers to warn all people in residential building.Conclusion. Comparison of the experimental values of the PET with the data of the current Methodology of fire risk calculation for a nine-storey house showed a discrepancy of 2.6 times.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124014039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of computational grid cell size and heterogeneity of computing area for estimated fire detection time","authors":"S. Kalmykov","doi":"10.22227/0869-7493.2022.31.04.56-64","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.04.56-64","url":null,"abstract":"Introduction. In Russia, based on the provisions of the current regulatory documents, the time for the start of evacuation for a room in which a fire broke out is determined depending on the area of the room. According to some authors, the time of the start of the evacuation of people is a combination of “technical”, which includes the time of detection of a fire, and “psychophysical”, determined by the behavioral and organizational characteristics of the people who make it up. The fire detection time is currently not taken into account.Purpose. Evaluation of the influence of the size of the cells of the computational grid and the inhomogeneity of the computational domain on the estimated time of fire detection.Aims. 1. Establish the qualitative nature of the influence of the size of the cells of the computational grid and the inhomogeneity of the computational domain on the estimated time of fire detection.2. Offer recommendations for determining the estimated time of fire detection.Methods. For research, computer simulation methods were used using the Fire Dynamics Simulator software package.Results and discussion. The use of grids with different cell sizes can significantly reduce the number of cells in the computational domain and, as a result, the computation time. However, this leads to rather contradictory results. The minimum time values are reduced by almost 3–4 times compared to a homogeneous computational grid, and the maximum time increases by 2 times.Conclusions. 1. The size of the cells of the computational grid and the inhomogeneity of the computational domain have a significant impact on the time of fire detection.2. A sufficiently large spread in the values of the estimated fire detection time may indicate an unreliable estimate of the total time for the start of evacuation and incorrect conclusions about the safe evacuation of people and/or the probability of evacuation of people.3. For a correct estimate of the evacuation start time, taken into account the estimated fire detection time, it is recommended to use homogeneous computational grids with cell sizes not exceeding 0.25 m.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127569150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of venting structures on overpressure caused by an indoor explosion","authors":"V. Gorev, A. Korolchenko","doi":"10.22227/0869-7493.2022.31.03.12-23","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.03.12-23","url":null,"abstract":"Introduction. The article considers an accidental indoor gas explosion on condition of pressure relief through openings in which venting structures were installed.A solution to this problem can protect residential buildings from consequences of explosions due to the fact that the volume of premises in residential buildings is small compared to industrial buildings, and it determines more stringent pressure relief conditions at the initial moment of the explosion development. The article shows that pressure can reach critical values in a small space during the motion of a venting structure in the opening before the onset of pressure relief.Goals. The authors aim to identify the pattern of blast load development from the moment of explosion to the attainment of the maximum pressure value with account taken of the properties of venting structures and patterns of their opening. This goal is relevant due to the fact that until now at this stage pressure development has been considered without any account taken of how deeply the venting structure is installed in the wall opening. Much attention was focused on the selection of the opening size.Methods. The methods of the theory of dimensions, numerical and analytical modeling of explosion processes, patterns of gas escape and rigid body motion were applied to obtain dimensionless groups describing the development of an explosive load until maximum values. These dimensionless groups allow identifying explosive loads for rooms having different volumes, which is also a new result.Results. In this work, the influence of individual factors on the ultimate result has been identified. These factors are the room volume, the pressure at which the venting structure starts moving, the mass and position of the venting structure in the opening, the opening perimeter and the rate of explosive combustion.Conclusions. The results, obtained in the course of this work, allow identifying the dynamic load of an explosion at the stage of its growth. This value can be used to set more reliable bearing characteristics of structures for cases of accidental explosions in living accommodations.","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116642584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theory and practice of diagnostics of fire hazardous modes of operation of catalytic converters","authors":"V. Lozhkin","doi":"10.22227/0869-7493.2022.31.03.65-74","DOIUrl":"https://doi.org/10.22227/0869-7493.2022.31.03.65-74","url":null,"abstract":"Introduction. The wide-scale use of catalytic converters and particulate filters in automobile engines has aggravated the problem of their ignition and updated the research and methodological framework for the examination of causes of fire emergency modes (FEMs) of operation of fuel catalytic units (FCUs). The relationship between the FEMs of the FCU operation and failures of the fuel equipment, wear of the cylinder-piston group of engines and deviations in fuel compositions was confirmed. The goal was to develop a diagnostic method for fire hazardous modes of operation of FCUs of vehicles.Methodology. A model of oxidative catalysis underway in the FCU has been proven rational. The model is used to calculate the thermo-catalytic efficiency and heat generation in the active layer of the γ-Al2O3 platinum catalyst depending on the temperature of exhaust gases (EG), concentrations of CO, CH and soot. It has been found out that catalysis can theoretically develop in four limit domains: internal kinetic domain, internal diffusion domain, external diffusion domain, and external kinetic domain.Results and discussion. Experimental and computational studies have shown the probability of emergence of breakdown vehicles with a multiple excess of soot emissions and thermal stresses. A 10‑fold increase in CO, CH and soot in EG rises the thermal performance of the catalytic reaction from 17,282 to 491,907 kJ/h, creating a fire hazard in a KamAZ engine. To identify a FEM, the diagnostic method based on the «free acceleration» (FA) mode according to GOST 33997–2016 is proposed. The procedure is supplemented with maximum revolutions and restrictions (0.5 s) of the FA mode time. The latter is necessary for the guaranteed operation of the engine in the «full load mode». The method was applied in the course of the fire engineering studies on a Ford Mondeo car having a TDCi (Common Rail System) diesel engine and a catalytic particulate filter. Laboratory examination and analytical studies have found that the main reason for the operation of FCU in emergency (due to environmental and fire hazards) modes is the corrosion of precision parts of the fuel equipment accumulated during its long-term operation. Progressive corrosion is caused by excessive sulfur and moisture content in fuel and oil.Conclusions. It’s been proven that the emergency heating of a catalytic converter causes a sharp rise in the car combustion risk. The authors have proposed an original method for the diagnostics of fire-hazardous modes of operation of catalytic converters based on procedures set in GOST 33997–2016 (ТР ТС 018/2011).","PeriodicalId":169739,"journal":{"name":"Pozharovzryvobezopasnost/Fire and Explosion Safety","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126061129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}