Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.08
V. Kovalchyk, R. Kindzer, S. Yemelyanenko
After analyzing the presence of fire and technical equipment, in particular fire extinguishing devices, on the fire and rescue engines of the SES of Ukraineunits, we have suggested, developed and constructed a nozzle for obtaining low-frequency air-mechanical foam. This nozzle can serve as a combination of water and foam extinguishing agents to extinguish fires that have not developed into significant areas and sizes.It is preferable to eliminate the fire at the initial stage of its occurrence, preventing the influence of the effects of its dangerous factors on living creatures and the environment. Given the above problem, the authors designed a nozzle with the ability to completely cease the supply of extinguishing agents, using an overhead crane with a handle.At the exit from the fire nozzle, a metal mesh consisting of 1,5 x 1,5 mm tubes is installed. The shell of the nozzle is equipped with rubber overlays on both sides, which will protect arescuer from possible electric shock. The use of such nozzle allows for more efficient elimination of fires and more economical use of extinguishing agents. The technical characteristics are acceptable for the subsequent successful use of the device as intended. Additionally, one of the advantages is the possibility of ceasing the delivery of extinguishing substances in case of changing the position of a rescuer during the elimination of fire, reducing the flow of water and foam, as well as protection against possible electric shock.
在分析了乌克兰SES单位的消防和救援发动机上的消防和技术设备，特别是灭火装置的存在后，我们建议，开发并构建了一种用于获得低频空气机械泡沫的喷嘴。这种喷嘴可以作为水和泡沫灭火剂的组合，以扑灭尚未发展到重要区域和规模的火灾。最好在火灾发生初期就将其扑灭，防止其危险因素对生物和环境的影响。鉴于上述问题，作者设计了一种能够完全停止灭火剂供应的喷嘴，使用带手柄的高架起重机。在消防喷嘴出口处安装由1.5 x 1.5 mm管组成的金属网。喷嘴的外壳两侧装有橡胶保护层，这将保护救援人员免受可能的电击。使用这种喷嘴可以更有效地消除火灾和更经济地使用灭火剂。该技术特性对于后续设备的成功使用是可接受的。此外，其优点之一是在灭火过程中，如果救援人员的位置发生变化，可以停止灭火物质的输送，减少水和泡沫的流动，并防止可能的电击。
{"title":"DEVELOPING OF BLOCKING NOZZLE FOR COMPLEX EXTINGUISHING ON THE INITIAL STAGE OF FIRE","authors":"V. Kovalchyk, R. Kindzer, S. Yemelyanenko","doi":"10.32447/20786662.33.2018.08","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.08","url":null,"abstract":"After analyzing the presence of fire and technical equipment, in particular fire extinguishing devices, on the fire and rescue engines of the SES of Ukraineunits, we have suggested, developed and constructed a nozzle for obtaining low-frequency air-mechanical foam. This nozzle can serve as a combination of water and foam extinguishing agents to extinguish fires that have not developed into significant areas and sizes.It is preferable to eliminate the fire at the initial stage of its occurrence, preventing the influence of the effects of its dangerous factors on living creatures and the environment. \u0000Given the above problem, the authors designed a nozzle with the ability to completely cease the supply of extinguishing agents, using an overhead crane with a handle.At the exit from the fire nozzle, a metal mesh consisting of 1,5 x 1,5 mm tubes is installed. The shell of the nozzle is equipped with rubber overlays on both sides, which will protect arescuer from possible electric shock. \u0000The use of such nozzle allows for more efficient elimination of fires and more economical use of extinguishing agents. The technical characteristics are acceptable for the subsequent successful use of the device as intended. Additionally, one of the advantages is the possibility of ceasing the delivery of extinguishing substances in case of changing the position of a rescuer during the elimination of fire, reducing the flow of water and foam, as well as protection against possible electric shock.","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"121 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89431359","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.04
V. Hudym, O. Nazarovets, T. Shpak
According to statistics, one of the most common causes of vehicle fires is the fire hazard of operating onboard electrical networks - 35%. The most common causes of vehicle fires, during their operation, are malfunctions of electrical equipment (short circuit and overload of on-board electrical wiring) and fuel systems. In this regard, the problem arose to identify the cause and establish the involvement of the ignition of the on-board electrical system and the electrical equipment of the vehicle by studying the microstructures of the conductive elements of the power grid. Microstructures were studied using a method of metallographic and X-ray spectral analysis, using a scanning electron microscope with an X-ray microanalysis system. The microstructure of the reference model of the wire is a copper polycrystal, which is elongated in the direction of deformation. It should be noted that after etching the microstructural heterogeneity is detected, it is observed on both longitudinal and transverse slices. The passage of a direct current through a wire significantly changes its microstructure: in it there are local areas of the globular shape, indicating the melting and subsequent rapid crystallization, resulting in the formation of separate sections in the form of round inclusions. It should be noted that under the influence of short-circuit currents, the gullet form is formed on the surface of the wires, and the dimensional characteristics of the melting regions become larger. In the complex action of the short-circuit of the direct current and the open flame of the model focus on the regions of the melting it becomes noticeable that from the action of the current, due to the sharp heating of the metal formed fine-grained structure, and with the subsequent action of the open flame in the wires formed a large-grained structure, and the action of the flame It is manifested in the fact that the oxidation of the grain boundaries occurs, which results in the destruction of the material of the wire along the grain boundaries. Performing research using the method of local X-ray spectral analysis enables us to determine the oxygen content of copper conductors by the principle of individuality of the spectra and provides sufficiently accurate data on its content in the structure of the conductor, depending on the heating conditions, which confirms the expediency of its use to detect the involvement of the conductors of the onboard electrical grids prior to the occurrence of fires.
{"title":"MICROSTRUCTURAL PHASE ANALYSIS OF COPPER WIRE SAMPLES HEATED BY DIRECT CURRENT","authors":"V. Hudym, O. Nazarovets, T. Shpak","doi":"10.32447/20786662.33.2018.04","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.04","url":null,"abstract":"According to statistics, one of the most common causes of vehicle fires is the fire hazard of operating onboard electrical networks - 35%. The most common causes of vehicle fires, during their operation, are malfunctions of electrical equipment (short circuit and overload of on-board electrical wiring) and fuel systems. \u0000In this regard, the problem arose to identify the cause and establish the involvement of the ignition of the on-board electrical system and the electrical equipment of the vehicle by studying the microstructures of the conductive elements of the power grid. \u0000Microstructures were studied using a method of metallographic and X-ray spectral analysis, using a scanning electron microscope with an X-ray microanalysis system. \u0000The microstructure of the reference model of the wire is a copper polycrystal, which is elongated in the direction of deformation. It should be noted that after etching the microstructural heterogeneity is detected, it is observed on both longitudinal and transverse slices. \u0000The passage of a direct current through a wire significantly changes its microstructure: in it there are local areas of the globular shape, indicating the melting and subsequent rapid crystallization, resulting in the formation of separate sections in the form of round inclusions. \u0000It should be noted that under the influence of short-circuit currents, the gullet form is formed on the surface of the wires, and the dimensional characteristics of the melting regions become larger. \u0000In the complex action of the short-circuit of the direct current and the open flame of the model focus on the regions of the melting it becomes noticeable that from the action of the current, due to the sharp heating of the metal formed fine-grained structure, and with the subsequent action of the open flame in the wires formed a large-grained structure, and the action of the flame It is manifested in the fact that the oxidation of the grain boundaries occurs, which results in the destruction of the material of the wire along the grain boundaries. \u0000Performing research using the method of local X-ray spectral analysis enables us to determine the oxygen content of copper conductors by the principle of individuality of the spectra and provides sufficiently accurate data on its content in the structure of the conductor, depending on the heating conditions, which confirms the expediency of its use to detect the involvement of the conductors of the onboard electrical grids prior to the occurrence of fires.","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83964134","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.10
P. Pastuhov, O. Lavrenyuk, B. Mykhalitchko, V. Petrovskii
Introduction. Inflammation susceptibility and the nature of combustion are one of the most important characteristics for the parametrization of the fire hazard of polymer materials. Because ignition is the occurrence process of the persistent flame near the surface of the material, which is preceded by the process of propagation of the flame front on its surface, the predisposition to ignition of the polymer materials plays an important role in the aspect of initiation of fires. A comparative evaluation of inflammation susceptibility of substances of different nature was carried out basing the determination of the ignition point and self-ignition point. Purpose. The work aims to determine the peculiarities of the influence of copper(II) carbonate on the increase of ignition point and self-ignition point of epoxy-amine composites. Metods. The experimental determination of the ignition point and self-ignition point was carried out according to all-Union State Standard 12.1.044-89 (4.7, 4.9 items). Toward this end, three samples of the test material were prepared with a weight of 3 g. Before testing, samples were conditioned in air. Results. Data on the effect of copper(II) carbonate on the value of ignition point and self-ignition point of the epoxy-amine composites indicate that the epoxy-amine-based composite, cured by the traditional amine hardener (PEPA), has lowest temperature of the ignition and self-ignition. The temperture values of ignition and self-ignition increase as the content of copper(II) carbonate increases in the composite, measuring up a maximum value at 80 g of CuCO3 per 100 g of binder. It is proved that the reason for the increase of the ignition temperature and self-ignition temperature of the modified epoxy-amine composites is the appearance of strong coordination bonds that are formed due to the chemical binding of the combustible polyethylenepolyamine with the non-combustible inorganic salt (with copper(II) carbonate). The measured values of the ignition point and self-ignition point of the amine hardener (PEPA) of the epoxy-diane oligomer indicate that it is able to ignite at temperature 136ºC, and self-ignite at temperature 393ºС. After forming the chelate complex, the coordinated PEPA turns into a practically non-combustible substance. Conclusion. Consequently, the main factor that affects to make difficulty of ignition of organic nitrogen-containing substances is the efficient chemical binding N atoms of the combustible amine molecules with d-metal atom of the non-combustible inorganic salt, which is accompanied by the formation of sufficiently strong coordination bonds of the Cu(ІІ)¬N type. The resistance to ignition of the modified polymeric composites will depend on the binding strength of the copper(II) salt with an amine hardener. The mechanism of the fire retardant influence of the d-metal salts on combustion of the epoxy-amine-based composites consists in this. So, copper(II) compounds, in particular copper
{"title":"FEATURES OF THE COPPER(II) CARBONATE INFLUENCE ON AN INFLAMMABILITY OF EPOXY-AMINE COMPOSITES","authors":"P. Pastuhov, O. Lavrenyuk, B. Mykhalitchko, V. Petrovskii","doi":"10.32447/20786662.33.2018.10","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.10","url":null,"abstract":"Introduction. Inflammation susceptibility and the nature of combustion are one of the most important characteristics for the parametrization of the fire hazard of polymer materials. Because ignition is the occurrence process of the persistent flame near the surface of the material, which is preceded by the process of propagation of the flame front on its surface, the predisposition to ignition of the polymer materials plays an important role in the aspect of initiation of fires. A comparative evaluation of inflammation susceptibility of substances of different nature was carried out basing the determination of the ignition point and self-ignition point. \u0000Purpose. The work aims to determine the peculiarities of the influence of copper(II) carbonate on the increase of ignition point and self-ignition point of epoxy-amine composites. \u0000Metods. The experimental determination of the ignition point and self-ignition point was carried out according to all-Union State Standard 12.1.044-89 (4.7, 4.9 items). Toward this end, three samples of the test material were prepared with a weight of 3 g. Before testing, samples were conditioned in air. \u0000Results. Data on the effect of copper(II) carbonate on the value of ignition point and self-ignition point of the epoxy-amine composites indicate that the epoxy-amine-based composite, cured by the traditional amine hardener (PEPA), has lowest temperature of the ignition and self-ignition. The temperture values of ignition and self-ignition increase as the content of copper(II) carbonate increases in the composite, measuring up a maximum value at 80 g of CuCO3 per 100 g of binder. It is proved that the reason for the increase of the ignition temperature and self-ignition temperature of the modified epoxy-amine composites is the appearance of strong coordination bonds that are formed due to the chemical binding of the combustible polyethylenepolyamine with the non-combustible inorganic salt (with copper(II) carbonate). The measured values of the ignition point and self-ignition point of the amine hardener (PEPA) of the epoxy-diane oligomer indicate that it is able to ignite at temperature 136ºC, and self-ignite at temperature 393ºС. After forming the chelate complex, the coordinated PEPA turns into a practically non-combustible substance. \u0000Conclusion. Consequently, the main factor that affects to make difficulty of ignition of organic nitrogen-containing substances is the efficient chemical binding N atoms of the combustible amine molecules with d-metal atom of the non-combustible inorganic salt, which is accompanied by the formation of sufficiently strong coordination bonds of the Cu(ІІ)¬N type. The resistance to ignition of the modified polymeric composites will depend on the binding strength of the copper(II) salt with an amine hardener. The mechanism of the fire retardant influence of the d-metal salts on combustion of the epoxy-amine-based composites consists in this. So, copper(II) compounds, in particular copper","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74195742","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.06
I. Dadashov
Extinguishing of flammable liquids is one of the most difficult problems of firefighting. Especially great difficulties are caused by fire extinguishing of oil and oil products, in tank farms. The best results when extinguishing flammable liquids are provided by means air-mechanical foams. For various types of foams, there are common drawbacks: low foams stability under the action of intense heat fluxes from the flame of a burning liquid, their rapid destruction upon contact with polar liquids, difficulties with feeding over long distances, high cost of a number of foaming agents, the presence in their composition of environmentally hazardous substances, contamination of flammable liquids, high cost of foam supply systems . To eliminate the disadvantages of air-mechanical foam, it is proposed to use granular foam glass as one of the components of the fire extinguishing system for extinguishing flammable liquids. It has been previously established that the foam glass layer slows down the evaporation of combustible liquids. In addition, filling the foam glass leads to the cooling of the burning liquids. Cooling is one of the most important mechanisms for stopping combustion. Due to the cooling of flammable liquids, the vapor pressure is lowered over their surface and, accordingly, the intensity of combustion decreases. To determine the conditions for combustion of flammable liquids need to know the temperature of liquids after exposure to them extinguishant substances.
{"title":"EXPERIMETAL INVESTIGATION OF USING GRANULATED FOAMGLASS FOR COOLING THE COMBUSTIBLE LIQUID","authors":"I. Dadashov","doi":"10.32447/20786662.33.2018.06","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.06","url":null,"abstract":"Extinguishing of flammable liquids is one of the most difficult problems of firefighting. Especially great difficulties are caused by fire extinguishing of oil and oil products, in tank farms. The best results when extinguishing flammable liquids are provided by means air-mechanical foams. For various types of foams, there are common drawbacks: low foams stability under the action of intense heat fluxes from the flame of a burning liquid, their rapid destruction upon contact with polar liquids, difficulties with feeding over long distances, high cost of a number of foaming agents, the presence in their composition of environmentally hazardous substances, contamination of flammable liquids, high cost of foam supply systems . \u0000To eliminate the disadvantages of air-mechanical foam, it is proposed to use granular foam glass as one of the components of the fire extinguishing system for extinguishing flammable liquids. It has been previously established that the foam glass layer slows down the evaporation of combustible liquids. In addition, filling the foam glass leads to the cooling of the burning liquids. \u0000Cooling is one of the most important mechanisms for stopping combustion. Due to the cooling of flammable liquids, the vapor pressure is lowered over their surface and, accordingly, the intensity of combustion decreases. To determine the conditions for combustion of flammable liquids need to know the temperature of liquids after exposure to them extinguishant substances.","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84631935","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.03
P. Hashchuk, S. Nikipchuk
The general principles of model reflection of working processes in the internal combustion engine are investigated. Like that intramolecular (chemically effective), molecular (thermodynamically active) or macroscopic (ordered by external manifestation) motion in substances causes mass transfer - diffusion, impulse transfer - viscosity, as well as they form the transfer of energy of disordered motion - heat-exchanging. By tying the phenomena of mass, momentum and energy transfer with molecular, intraocular and ordered motions, respectively, the leading, radial and convection components of each of these phenomena can be distinguished. Due to the common condition, diffusion, viscosity, heat transfer are interconnected phenomena and play a decisive role in processes passing through cylinders of the internal combustion engine. Therefore, they together should have been subject to some general harmonious theory of motion and energy exchange, which is based on the uniform physical and mathematical principles of environmental reflection. However, today such a theory does not exist. Because of this, in the study of heat exchange processes in the internal combustion engines we have to move, relying heavily on the principles of empiricism. In spite of the extremely complex phenomenon of heat transfer, the internal combustion engine in the working space of the engine is such that it allows us to rely on relatively simple model descriptions based on the principles of empiricism. The purpose of the work — based on the principles of the theory of similarity, to justify the possibility of adequate reflection and formalized generalization of experimentally identified information about the laws of the flow of heat transfer processes in the engines of Otto (the engine of rapid internal combustion). The main object of empirical research is the coefficient of heat transfer. Only meaningful transparency and ease of use can be explained by the fact that so far this concept is widely used, although it is completely motivated can be replaced by a more general dimensionless characteristic. A great deal of empirical dependencies are proposed for calculating this coefficient. Each of them has own level of universality and it is applicability limits for adequacy. Generally, universality and adequacy are not mutually conductive characteristics of the quality of empirical relationships. That is why studying a certain set of engine operating modes, it is desirable to involve in the mathematical and experimental apparatus of research, such analytically displayed empirical relationships, which within this set remained unchanged by the structure and values of its main parameters. Heat transfer in the cylinder of the engine of rapid internal combustion between the gas and the wall of the combustion space occurs mainly due to forced convection. Actually in the engine operating on the Otto cycle, the heat transfer as a result of radiation in the course of fueling is generally neg
研究了内燃机工作过程模型反映的一般原理。就像物质中的分子内运动(化学有效)、分子运动(热力学活跃)或宏观运动(由外部表现有序)引起的传质-扩散、脉冲传递-粘度，以及它们形成的无序运动的能量传递-热交换。通过将质量、动量和能量传递现象分别与分子运动、眼内运动和有序运动联系起来，可以区分每种现象的前导、径向和对流分量。由于共同的条件，扩散、粘度、传热是相互联系的现象，在内燃机汽缸内的过程中起着决定性的作用。因此，它们一起应该服从某种运动和能量交换的一般和谐理论，这是基于环境反射的统一物理和数学原理。然而，今天这样的理论并不存在。正因为如此，在内燃机的热交换过程的研究中，我们不得不采取行动，严重依赖于经验主义的原则。尽管传热现象极其复杂，但在发动机工作空间内的内燃机使我们可以依靠基于经验主义原理的相对简单的模型描述。这项工作的目的-基于相似理论的原则，证明了充分反映和形式化推广的可能性实验确定的信息关于奥托(快速内燃发动机)的热交换过程的流动规律。实证研究的主要对象是换热系数。迄今为止，这个概念被广泛使用，只有有意义的透明度和易用性才能解释这一事实，尽管它完全可以被更普遍的无量纲特征所取代。提出了大量的经验依赖关系来计算这个系数。它们都有各自的通用性水平和充分性的适用范围。一般来说，普遍性和充分性并不是经验关系质量的相互传导特征。这就是为什么在研究某一组发动机工作模式时，需要涉及数学和实验装置的研究，这种分析显示的经验关系，在这一组内，它的主要参数的结构和值保持不变。在快速内燃发动机的气缸内，气体与燃烧空间壁面之间的传热主要是由于强制对流而发生的。实际上，在奥托循环上运行的发动机中，由于加油过程中的辐射而产生的传热通常可以忽略不计，因为(与柴油发动机不同)，在燃烧的抛射中，没有大量燃烧的烟尘颗粒，并且本身，气体作为排放者，与强迫湍流对流相比，可以容忍相对少量的热量，这在一般情况下不太可能被考虑在内。强迫对流方程传统上基于准则Nusselt (Nu)、Reynolds (Re)、Prandtl (Pr)之间的相似关系;C n m -常数。G.Woschni发现功率度的数值是可以接受的，但总的来说，根据发动机气缸内压力流动和平均温度的实验信息，可以得到很好的模拟结果。对发动机的每一种工作方式，从范围上取其含义。给出了在不同负荷下，由电机轴的转动角度引起的热输出系数变化的模型再现的例子。
{"title":"MODELING OF HEAT EXCHANGE PROCESSES EXPECTING IN CYLINDERS OF THE INTERNAL COMBUSTION ENGINES","authors":"P. Hashchuk, S. Nikipchuk","doi":"10.32447/20786662.33.2018.03","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.03","url":null,"abstract":"The general principles of model reflection of working processes in the internal combustion engine are investigated. Like that intramolecular (chemically effective), molecular (thermodynamically active) or macroscopic (ordered by external manifestation) motion in substances causes mass transfer - diffusion, impulse transfer - viscosity, as well as they form the transfer of energy of disordered motion - heat-exchanging. By tying the phenomena of mass, momentum and energy transfer with molecular, intraocular and ordered motions, respectively, the leading, radial and convection components of each of these phenomena can be distinguished. Due to the common condition, diffusion, viscosity, heat transfer are interconnected phenomena and play a decisive role in processes passing through cylinders of the internal combustion engine. Therefore, they together should have been subject to some general harmonious theory of motion and energy exchange, which is based on the uniform physical and mathematical principles of environmental reflection. However, today such a theory does not exist. Because of this, in the study of heat exchange processes in the internal combustion engines we have to move, relying heavily on the principles of empiricism. \u0000In spite of the extremely complex phenomenon of heat transfer, the internal combustion engine in the working space of the engine is such that it allows us to rely on relatively simple model descriptions based on the principles of empiricism. \u0000The purpose of the work — based on the principles of the theory of similarity, to justify the possibility of adequate reflection and formalized generalization of experimentally identified information about the laws of the flow of heat transfer processes in the engines of Otto (the engine of rapid internal combustion). \u0000The main object of empirical research is the coefficient of heat transfer. Only meaningful transparency and ease of use can be explained by the fact that so far this concept is widely used, although it is completely motivated can be replaced by a more general dimensionless characteristic. A great deal of empirical dependencies are proposed for calculating this coefficient. Each of them has own level of universality and it is applicability limits for adequacy. Generally, universality and adequacy are not mutually conductive characteristics of the quality of empirical relationships. That is why studying a certain set of engine operating modes, it is desirable to involve in the mathematical and experimental apparatus of research, such analytically displayed empirical relationships, which within this set remained unchanged by the structure and values of its main parameters. \u0000Heat transfer in the cylinder of the engine of rapid internal combustion between the gas and the wall of the combustion space occurs mainly due to forced convection. Actually in the engine operating on the Otto cycle, the heat transfer as a result of radiation in the course of fueling is generally neg","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82399257","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.09
B. Kopchak, A. Kushnir, I. Kravets
Introduction. The attempt to get the best dynamic and static characteristics of the basket turn angle complicates the tasks performed by the automatic control system (ACS) basket turn drive. The ACS of the basket turn should meet the following requirements: high speed, smooth acceleration and breaking of the motor, static and dynamic accuracy of the reproduction of tasks trajectories, no overregulation in transition modes, required stability reserve, low sensitivity to coordinate and parametric disturbances, etc. A number of fundamentally different ACSs and methods for their synthesis have been analyzed to provide these requirements. As a result of the analysis, there has been selected a two-loop feedback control system (FCS) of the basket turn with regard to the elastic properties of the arrow, which is synthesized by the method of the generalized characteristic polynomial. Studies have shown that this system allows to provide an aperiodic transition process of the basket turn angle with a given speed and low sensitivity in steady state to the perturbation effect. However, the synthesized FCS transfer functions of the controllers of angular velocity of the motor and the basket have a high order and turned out to be quite complicated in terms of practical implementation. Purpose. In the article it is proposed to replace these controllers, by approximating them through evolutionary methods, with more compact fractional PІλDμ-controllers or fractional order controllers. Results. The studies carried out in this work have shown that fractional order controllers are quite advantageous in comparison with the over classical ones, particularly in the case of their application for optimization of electromechanical systems with the following features of their control objects: two masses, including those with the presence of impact; backlash viscosity of the drive friction; nonlinear load and so on. Replacement of the high-order motor and basket angular speed controllers with more compact PІλDμcontrollers or fractional order controllers has been performed using Optimization Toolbox optimization package in the MATLAB package. This software has been developed for approximation of classical parts with high-order transfer functions by fractional order parts, using a genetic algorithm or a particle swarm optimization for their transition functions. Conclusion. The conducted research on digital models has confirmed the efficiency of the replacement of high-order motor and basket angular velocity controllers with PІλDμ-controllers or fractional order controllers, whose transfer functions are determined by approximating the transition functions of the controllers by the genetic algorithm method.
{"title":"SYNTHESIS OF FRACTIONAL ORDER CONTROLLERS FOR MULTI-LUPP CONTROL STRUCTURE OF FIRE LIFT BASKET TURNING","authors":"B. Kopchak, A. Kushnir, I. Kravets","doi":"10.32447/20786662.33.2018.09","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.09","url":null,"abstract":"Introduction. The attempt to get the best dynamic and static characteristics of the basket turn angle complicates the tasks performed by the automatic control system (ACS) basket turn drive. The ACS of the basket turn should meet the following requirements: high speed, smooth acceleration and breaking of the motor, static and dynamic accuracy of the reproduction of tasks trajectories, no overregulation in transition modes, required stability reserve, low sensitivity to coordinate and parametric disturbances, etc. A number of fundamentally different ACSs and methods for their synthesis have been analyzed to provide these requirements. As a result of the analysis, there has been selected a two-loop feedback control system (FCS) of the basket turn with regard to the elastic properties of the arrow, which is synthesized by the method of the generalized characteristic polynomial. Studies have shown that this system allows to provide an aperiodic transition process of the basket turn angle with a given speed and low sensitivity in steady state to the perturbation effect. However, the synthesized FCS transfer functions of the controllers of angular velocity of the motor and the basket have a high order and turned out to be quite complicated in terms of practical implementation. \u0000Purpose. In the article it is proposed to replace these controllers, by approximating them through evolutionary methods, with more compact fractional PІλDμ-controllers or fractional order controllers. \u0000Results. The studies carried out in this work have shown that fractional order controllers are quite advantageous in comparison with the over classical ones, particularly in the case of their application for optimization of electromechanical systems with the following features of their control objects: two masses, including those with the presence of impact; backlash viscosity of the drive friction; nonlinear load and so on. \u0000Replacement of the high-order motor and basket angular speed controllers with more compact PІλDμcontrollers or fractional order controllers has been performed using Optimization Toolbox optimization package in the MATLAB package. This software has been developed for approximation of classical parts with high-order transfer functions by fractional order parts, using a genetic algorithm or a particle swarm optimization for their transition functions. \u0000Conclusion. The conducted research on digital models has confirmed the efficiency of the replacement of high-order motor and basket angular velocity controllers with PІλDμ-controllers or fractional order controllers, whose transfer functions are determined by approximating the transition functions of the controllers by the genetic algorithm method.","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76567323","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.14
D. Smolyak, Y. Baran
Introduction. The main task of the SNSS rescue units is to provide emergency assistance and rescue of the population in case of occurrence of events that threaten their life and health or may cause material damage. The success of rescuing people by fire brigades depends on several factors. First of all, it is the presence of special fire fighting equipment for rescue operations at the altitude and the technical possibility of its use. Today, the rescue of the victim from a sewage well, a water collector - a phenomenon is still quite widespread. Such cases come from the fault of the victim, yes, and due to negligence of the relevant utilities. Purpose. In rescuing people from multistory buildings, rescuers use motorbikes, but if the motorway can not arrive at an emergency, and manual fire ladders do not reach the required height, fire and rescue units use fire ropes and evacuate people with them.Rescue works in wells of underground communications are divided into the following stages: • Preparation of the necessary equipment and place of the event for the execution of works; • Emergency rescue directly into the well; • Preparation of the victim for lifting to the surface and transportation; • lifesaving on the surface. Methods. For descent from the floors or lifting from the underground well, the survivors of the survivors knit a double rescue loop from the fire rope and put it on the victim. But there is a better alternative to the double rescue loop - this is a rescue triangle. Results. Characteristics of the rescue triangle: time of dressing, comfort of dressing, durability, care of the rescue triangle.Conclusion. Equipping at least fire trucks equipped with rescue tripods, rescue triangles will greatly simplify the work and increase the efficiency of rescue works from the floors of the house or underground collectors (wells).
{"title":"THE METHOD OF USING THE LIFTING TROUBLESHOOT FOR CONSUMPTION OF SATISFACTORIES FROM UNDERGROUND MANIFOLDS (WELLS)","authors":"D. Smolyak, Y. Baran","doi":"10.32447/20786662.33.2018.14","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.14","url":null,"abstract":"Introduction. The main task of the SNSS rescue units is to provide emergency assistance and rescue of the population in case of occurrence of events that threaten their life and health or may cause material damage. The success of rescuing people by fire brigades depends on several factors. First of all, it is the presence of special fire fighting equipment for rescue operations at the altitude and the technical possibility of its use. Today, the rescue of the victim from a sewage well, a water collector - a phenomenon is still quite widespread. Such cases come from the fault of the victim, yes, and due to negligence of the relevant utilities. Purpose. In rescuing people from multistory buildings, rescuers use motorbikes, but if the motorway can not arrive at an emergency, and manual fire ladders do not reach the required height, fire and rescue units use fire ropes and evacuate people with them.Rescue works in wells of underground communications are divided into the following stages: • Preparation of the necessary equipment and place of the event for the execution of works; • Emergency rescue directly into the well; • Preparation of the victim for lifting to the surface and transportation; • lifesaving on the surface. Methods. For descent from the floors or lifting from the underground well, the survivors of the survivors knit a double rescue loop from the fire rope and put it on the victim. But there is a better alternative to the double rescue loop - this is a rescue triangle. Results. Characteristics of the rescue triangle: time of dressing, comfort of dressing, durability, care of the rescue triangle.Conclusion. Equipping at least fire trucks equipped with rescue tripods, rescue triangles will greatly simplify the work and increase the efficiency of rescue works from the floors of the house or underground collectors (wells).","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86917977","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.02
O. Bashynskyi, M. Peleshko, S. Vovk, O. Pazen
In the article the influence of binder hardening of concrete processes and changes in the phase composition of cement by heating to 1000 °С. It was established that the presence of active mineral adds in cement composite increases the strength of concrete at ordinary temperatures as well as when heated in a fire. Damage of structures, accompanied by loss of strength characteristics of concrete under the influence of high temperatures of the fire due to the decomposition of water-containing crystalline hydrates, which are formed when locked up with water. The analysis of the results of physical and mechanical investigations of portland cement with applications of meadow waste has shown that their loading allows to significantly increase the strength of this cement stone, due to the formation of an additional amount of sodium sulfate or potassium. Their influence as activators of hardening is most noticeable in the initial terms and gradually decreases with age of hardening. It has been shown that use in the composition of the binder of meadow-based additives and hydrosilics makes it possible to increase the strength of the cement stone by 1.5 times, which is essential for the development of effective composite binders on its basis for work in high temperatures. In this, the presence of fluoride aluminium in hydrosilic in a quantity of 3.3% by weight determines its plastisizing effect on cement. It has been experimentally stated that during the heating of concrete above 500°C, the destruction of hydrated components of cement stone with the destruction of structural bonds between individual particles with a significant decrease in strength characteristics. In this case, the use of applications provides a partial coupling of CaO in the process of solid phase reactions during heating. It is proved that the use of composite cement, as a binder, due to the presence of its composition of a meadow-based application - accelerates hardening and improves strength characteristics, hydrosilics - increases residual strength at a pressure of up to 1000°С by 2.4 MPa .
{"title":"INFLUENCE OF THE CEMENT COMPOSITION ON THE PROPERTIES OF REINFORCED CONCRETE STRUCTURES WORKING IN HIGH TEMPERATURE CONDITIONS","authors":"O. Bashynskyi, M. Peleshko, S. Vovk, O. Pazen","doi":"10.32447/20786662.33.2018.02","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.02","url":null,"abstract":"In the article the influence of binder hardening of concrete processes and changes in the phase composition of cement by heating to 1000 °С. It was established that the presence of active mineral adds in cement composite increases the strength of concrete at ordinary temperatures as well as when heated in a fire. \u0000 Damage of structures, accompanied by loss of strength characteristics of concrete under the influence of high temperatures of the fire due to the decomposition of water-containing crystalline hydrates, which are formed when locked up with water. \u0000The analysis of the results of physical and mechanical investigations of portland cement with applications of meadow waste has shown that their loading allows to significantly increase the strength of this cement stone, due to the formation of an additional amount of sodium sulfate or potassium. Their influence as activators of hardening is most noticeable in the initial terms and gradually decreases with age of hardening. It has been shown that use in the composition of the binder of meadow-based additives and hydrosilics makes it possible to increase the strength of the cement stone by 1.5 times, which is essential for the development of effective composite binders on its basis for work in high temperatures. In this, the presence of fluoride aluminium in hydrosilic in a quantity of 3.3% by weight determines its plastisizing effect on cement. \u0000It has been experimentally stated that during the heating of concrete above 500°C, the destruction of hydrated components of cement stone with the destruction of structural bonds between individual particles with a significant decrease in strength characteristics. In this case, the use of applications provides a partial coupling of CaO in the process of solid phase reactions during heating. It is proved that the use of composite cement, as a binder, due to the presence of its composition of a meadow-based application - accelerates hardening and improves strength characteristics, hydrosilics - increases residual strength at a pressure of up to 1000°С by 2.4 MPa .","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"116 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84449634","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.13
M. Semerak, D. Kharyshyn, N. Ferents, T. Berezhanskyi
Currently, in Ukraine and abroad for the construction of high-rise buildings and structures using pipe-like structures. Wide application of pipe concrete columns is due to their high carrying capacity at relatively smaller overall dimensions due to the blocking of cracking in concrete by a steel clasp. The advantages of concrete columns should include more simplified conditions of technology of manufacturing and installation on their basis of bearing structures of floor covering. Piping constructions consist of steel shells and concrete core. Since the steel pipe mainly provides the bearing capacity of the concrete column, its failure or reduction of stiffness, which is characteristic of the fire under the influence of its thermal factors, leads to destruction. Investigation of fire resistance of concrete structures, which are not protected by flame retardant coatings, showed that a steel clasp during a fire after 15 minutes is heated to a critical temperature of 500 ° C.The use of flame retardant coatings is an effective method of fire protection of concrete constructions, which prevents the rapid heating of steel welds and provides a normalized fire resistance limit for such structures. In this work, studies were carried out on the effectiveness of fire protection of concrete columns with different types of fire-retardant materials - mineral wool slabs, special flame retardants and flame-retardant coatings. For fire protection mineral wool materials were used ROCKWOOL plates of the series "Conlit SL150". Mineral wool plates "Conlit SL 150" consist of fibers of rocks of a basalt group, they can withstand, without melting, temperature more than 1000 ° С. The silica-based adhesive "Conlit Glue" can withstand temperatures above 900 ° C, has good adhesion when bonding Conlit SL 150 mineral wool slabs with protective structures. From the second type of fire-retardant materials, the fire-proof composition "Naktresk" was chosen on the basis of gypsum. The coating is formed in the process due to hardening of the mixture on protected surfaces. The third type of flame retardant materials is the flame-retardant intumessent coating "Pyro-Safe Flammoplast SP-A2".It has been established that with the use of fire protection systems on the basis of mineral wool plates "Conlit SL150" and fire retardant "Nutresc", the fire resistance class of reinforced concrete columns increases from R 15 to R 180. The fire protection system on the basis of the painted paint "Pyro-Safe Flammoplast SP-A2" »Increases fire resistance from R 15 to R 75
{"title":"INVESTIGATION OF THE EFFICIENCY OF THE STEEL TUBE CONFINEMENT CONCRETE PILLARS PROTECTION BY FIRE-RETARDANT MATERIALS","authors":"M. Semerak, D. Kharyshyn, N. Ferents, T. Berezhanskyi","doi":"10.32447/20786662.33.2018.13","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.13","url":null,"abstract":"Currently, in Ukraine and abroad for the construction of high-rise buildings and structures using pipe-like structures. Wide application of pipe concrete columns is due to their high carrying capacity at relatively smaller overall dimensions due to the blocking of cracking in concrete by a steel clasp. The advantages of concrete columns should include more simplified conditions of technology of manufacturing and installation on their basis of bearing structures of floor covering. \u0000Piping constructions consist of steel shells and concrete core. Since the steel pipe mainly provides the bearing capacity of the concrete column, its failure or reduction of stiffness, which is characteristic of the fire under the influence of its thermal factors, leads to destruction. Investigation of fire resistance of concrete structures, which are not protected by flame retardant coatings, showed that a steel clasp during a fire after 15 minutes is heated to a critical temperature of 500 ° C.The use of flame retardant coatings is an effective method of fire protection of concrete constructions, which prevents the rapid heating of steel welds and provides a normalized fire resistance limit for such structures. In this work, studies were carried out on the effectiveness of fire protection of concrete columns with different types of fire-retardant materials - mineral wool slabs, special flame retardants and flame-retardant coatings. For fire protection mineral wool materials were used ROCKWOOL plates of the series \"Conlit SL150\". Mineral wool plates \"Conlit SL 150\" consist of fibers of rocks of a basalt group, they can withstand, without melting, temperature more than 1000 ° С. The silica-based adhesive \"Conlit Glue\" can withstand temperatures above 900 ° C, has good adhesion when bonding Conlit SL 150 mineral wool slabs with protective structures. From the second type of fire-retardant materials, the fire-proof composition \"Naktresk\" was chosen on the basis of gypsum. The coating is formed in the process due to hardening of the mixture on protected surfaces. The third type of flame retardant materials is the flame-retardant intumessent coating \"Pyro-Safe Flammoplast SP-A2\".It has been established that with the use of fire protection systems on the basis of mineral wool plates \"Conlit SL150\" and fire retardant \"Nutresc\", the fire resistance class of reinforced concrete columns increases from R 15 to R 180. The fire protection system on the basis of the painted paint \"Pyro-Safe Flammoplast SP-A2\" »Increases fire resistance from R 15 to R 75","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91192321","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}
Pub Date : 2018-12-31DOI: 10.32447/20786662.33.2018.01
V. Balanyuk, N. Kozyar, Yu. Kopystynskyi, A. Kravchenko
In order to increase the efficiency and the rate of extinction, it was proposed to use extinguishant aerosols to extinguish. Extinguishant aerosols are more comfortable in operation and cheap compared to gas, foam and water fire extinguishing. As for the phlegmative concentrations, it is apparent that all of these substances have different values of phlegmative concentration. The lowest levels of phlegmatic concentration are for extinguishing aerosols, which, due to the developed surface, effectively interrupt chain reactions and perform explosive action. The work substantiates that quenching of alcohols with volumetric extinguishants is of interest from the standpoint of efficiency, cost, speed and the possibility of explosive depletion of alcohol-air mixtures, and the creation of new effective gas-aerosol mixtures is an urgent issue to be addressed. The following main results were obtained in the work, namely, the process of extinguishing polar liquids is not perfect at present and in almost all cases, the polar fuel-emitting native suffers quality losses. In addition, the amount of foaming agent is much higher than the amount required for alcohols, and the cost of this type of foaming agent is several times higher than the cost of a general purpose foaming agent. In addition, extinguishing with extinguishants of volumetric action is much more effective than foam quenching as the extinguishing agent of the volume action extinguishes 3 D fires. For further increase of extinguishing efficiency and reduction of liquid losses during extinguishing, it is relevant to further study gas-aerosol mixtures in their various combinations.
{"title":"EXTINGUISHING FIRES OF ALCOHOLS AND THEIR MIXTURES","authors":"V. Balanyuk, N. Kozyar, Yu. Kopystynskyi, A. Kravchenko","doi":"10.32447/20786662.33.2018.01","DOIUrl":"https://doi.org/10.32447/20786662.33.2018.01","url":null,"abstract":"In order to increase the efficiency and the rate of extinction, it was proposed to use extinguishant aerosols to extinguish. Extinguishant aerosols are more comfortable in operation and cheap compared to gas, foam and water fire extinguishing. As for the phlegmative concentrations, it is apparent that all of these substances have different values of phlegmative concentration. The lowest levels of phlegmatic concentration are for extinguishing aerosols, which, due to the developed surface, effectively interrupt chain reactions and perform explosive action. The work substantiates that quenching of alcohols with volumetric extinguishants is of interest from the standpoint of efficiency, cost, speed and the possibility of explosive depletion of alcohol-air mixtures, and the creation of new effective gas-aerosol mixtures is an urgent issue to be addressed. The following main results were obtained in the work, namely, the process of extinguishing polar liquids is not perfect at present and in almost all cases, the polar fuel-emitting native suffers quality losses. In addition, the amount of foaming agent is much higher than the amount required for alcohols, and the cost of this type of foaming agent is several times higher than the cost of a general purpose foaming agent. In addition, extinguishing with extinguishants of volumetric action is much more effective than foam quenching as the extinguishing agent of the volume action extinguishes 3 D fires. For further increase of extinguishing efficiency and reduction of liquid losses during extinguishing, it is relevant to further study gas-aerosol mixtures in their various combinations.","PeriodicalId":12280,"journal":{"name":"Fire Safety","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78708540","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：