scholarly journals Research into the physical and chemical properties of fire-retardant materials of structural elements of trucks running on gas engine fuel with the aim of increasing their fire-retardant efficiency

2021 ◽  
Vol 2061 (1) ◽  
pp. 012098
Author(s):  
V Konoplev ◽  
A Zhukov ◽  
Z Melnikov ◽  
V Sarbaev

Abstract The fire load is an integral part of the fire hazard definition. Reducing this load is one of directions to fight fires in transport. To study the physicochemical processes and thermal effects occurring as a result of thermal decomposition of wood fire-proofed by retardants like BAN, OK-GF, OK-DS (OK-GFM), SPAD-0 and their chemical compositions, we used the methods of differential thermal analysis, thermogravimetry, and derivative thermogravimetry. In addition, to study the intensity of physicochemical combustion processes, tests to control changes in woodwork masses and temperature at the top of pipe depending on the duration of combustion of the samples and the consumption of fire retardants were conducted. Fire retardant compositions like OK-GF, OK-DS, Pirilax biopyrene at the consumption of 0.1 kg / m2 ensure flame and combustion resistance of the wood. The analysis of the research results confirmed the possibility of assigning to wood structures of a lorry’s body of the group 1 of flame and combustion resistance. Using the above fire retardants and their compositions in the treatment of lodgment elements and runners significantly affects the possibility and duration of the combustion process of a lorry. This was tested by means of an artificial fire source method (without chemical treatment, the burning time does not exceed 50 minutes). This significantly improves post-collision safety of vehicles with an increased fire load in terms of fire resistance because of using the natural gas as a motor fuel.

2020 ◽  
pp. 102-112
Author(s):  
Алексей Юрьевич Шебеко ◽  
Евгений Евгеньевич Простов ◽  
Евгений Николаевич Простов ◽  
Денис Михайлович Гордиенко

Представлено краткое описание автомобильных топливных систем, включающих в себя газобаллонное оборудование (ГБО) различных поколений, рассмотрена эволюция систем ГБО. Проанализированы статистические данные по автомобилям с ГБО, количество и причины пожаров на газобаллонных автомобилях (ГБА), рассчитана средняя частота возникновения пожаров для легковых, грузовых ГБА и автобусов с ГБО. A brief description of automotive fuel systems, including gas cylinder equipment (GCE) of various generations is presented. The evolution of gas cylinder equipment systems is considered. The safety of a gas cylinder is analysed depending on a wide range of factors. The statistics of FGBU VNIIPO on the number of fires in the Russian Federation by types of gas equipment (installations, devices, units), which became the source of the fire, as well as the statistics on causes of fires are presented and reviewed. There are presented the results of calculations concerning the frequency of fire occurrence per year per one vehicle that is in service and operates with CNG or LPG as a motor fuel in Russia due to violation of the rules for design and maintenance of gas equipment. The separate data on vehicles powered by CNG and LPG are not presented, since the existing statistical base on fires does not imply separation of vehicles by types of used gas engine fuel. The specified data are representative for enterprises for storage and maintenance of gas motor fuel vehicles and characterize the fire hazard of GCE, since such causes of fire as arson, violation of the rules for design and maintenance of vehicles, etc. are not actually implemented at the abovementioned enterprises. The data of the National Transportation Statistics of the USA in terms of the ratio of the total number of various vehicles to the number of running on gas engine fuel are considered. Conclusions on the causes of fires on gas cylinder automobile (GBA) are drawn.


2021 ◽  
Vol 2 (55) ◽  
pp. 81-87
Author(s):  
H.M. Kukharonak ◽  
◽  
D.G. Hershan ◽  
A.S. Klimuk ◽  
◽  
...  

The article presents the results of computer modeling and experimental research of the effect of butanol content in the fuel on the specific power, fuel-economic and environmental performance of 4ЧН 11/12.5 (4ChN 11/12.5) diesel engine at various cycle fuel supplies and exhaust gas recirculation rates. The research has been carried out at crankshaft speeds of 1,000, 1,200, 1,400, 1,600, 1,800, 2,000 and 2,200 rpm with 25, 50, 75 and 100 % load. Fuels with butanol content of 5, 10, 15, 20, 25, and 30 % by volume have been investigated. The computer model of the diesel working process has been developed that takes into account the physical and chemical properties of the fuel, the characteristics of the fuel flow in the nozzle tip and the development of fuel sprays in the combustion chamber. Based on the results of computer modeling, dependencies have been determined that make it possible to assess the effect of the percentage of butanol in mixed fuel on the mean indicator pressure, specific fuel consumption, indicator efficiency, emissions of nitrogen oxides and dynamic indicators of the combustion process when choosing the composition of mixed butanol-containing fuel. Based on the conducted research, the following composition of mixed fuel has been selected: 85 % diesel fuel and 15 % butanol. Comparative tests of the diesel engine have been carried out when working on the external speed characteristic on diesel fuel and its mixture with 15 % butanol. It is obtained that when using mixed fuel, the character of the power change remains unchanged, the exhaust smoke decreases, nitrogen oxides emissions decrease at crankshaft speeds of 1,400, 1,600, 1,800, and 2,200 rpm, and the effective engine efficiency remains practically unchanged.


2018 ◽  
Vol 27 (9) ◽  
pp. 17-25
Author(s):  
N. I. Konstantinova ◽  
T. Yu. Eremina ◽  
E. A. Nikolaeva ◽  
M. M. Almenbaev

Introduction. In order to reduce the fire hazard of textile materials (TM), scientific research is being carried out for the development of various methods of their fire protection. One of the directions in the field of decorative finishing TM with reduced flammability is their surface treatment with fire retardant compositions. Along with the development of fire retardants for TM, it is quite legitimate to study the effects of tissue on human skin, when in contact.Methods. At the stage of development of fire retardant compositions for surface treatment and the choice of the technology of their application, it is necessary to take into account the functional purpose of the TM, the scope of application and operational requirements.Discussion. In developing a fire retardant composition for surface treatment of TM that are in contact with human skin, the authors proposed the use of a number of phosphorus-containing compounds, which are effective fire retardants. However, a significant disadvantage of such compounds is their instability, decomposition and dissociation over time, which leads to irritation of the skin in direct contact with the material. Therefore, research has been carried out and optimal chemical compositions of stabilizers, buffer solutions and their ratios in the fire retardant have been selected. Their use for surface treatment of TM on acellulosic basis makes the TM resistant to ignition and does not adversely affect the skin of a person in direct contact.Conclusions. Based on the experimental data obtained, it follows that one of the possible ways to solve the problem of developing effective fire protection means that meet the requirements of normative documents in the field of fire safety and sanitary hygiene may be modification of compounds based on carbamide compounds with the selection of appropriate stabilizers and buffer solutions.


2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110352
Author(s):  
Wenjing Xia ◽  
Suying Fan ◽  
Tao Xu

The objective of this study is to quantitatively evaluate inhibitory action of halogen-free fire retardants (HFR) on combustion properties and volatile emission of such bituminous components as saturates, aromatics, resins, and asphaltenes (SARA). Thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR) tests were performed on SARA fractions containing matched fire retardants, respectively, and thermal kinetics parameters based on TG curves and functional and structural indices from FTIR spectra were calculated, respectively. The selected fire retardants have not affected the combustion process of SARA fractions, but the combustion temperature intervals are elevated and combustion progresses are retarded. Also, the char yields of SARA fractions are obviously increased by the matched fire retardants, improving their heat stability. The activation energy is elevated because of the added fire retardants, indicating combustion resistance of SARA fractions become larger. Additionally, the matched fire retardants inhibit the toxic gas emission in the combustion process of SARA fractions, but have few effects on gaseous product constituents. H2O and CO2 are identified as two typical released gases in various combustion phases of each SARA fraction. Finally, the added hydroxide play a role of fire retardants through cooling, dilution, adsorption, and neutralization, and the generated active oxide facilitates the expandable graphite (EG) and matrix to form densified and thick carbon layer. These suppress the volatile emission, and hinder the heat conduction and oxygen supply. Fire retardant composite exhibits the synergistic effect of fire retardancy and smoke inhibition in the combustion process of SARA fractions.


2021 ◽  
Vol 1 (10 (109)) ◽  
pp. 45-52
Author(s):  
Sergii Zhartovskyi ◽  
Olexander Titenko ◽  
Oksana Kyrychenko ◽  
Ievgen Tyshchenko ◽  
Roman Motrichuk ◽  
...  

To develop appropriate measures and means of fire protection at facilities, it is relevant to form an idea of the phenomenology of the processes of the occurrence, evolution, and termination of combustion. This paper proposes procedures for building mathematical models of the energy component of those physicochemical processes that occur in wood under the influence of fire, which make it possible to determine the time from the beginning of such an impact to the onset of the phase of flame combustion. The adequacy of mathematical modeling was tested experimentally at a standardized installation for studying flame propagation over the surface of wood. The samples used for the reported theoretical and experimental studies were the specimens of unprotected wood made from 20-mm-thick pine sapwood with a density of 400‒550 kg/m3. The samples of fireproof wood (of the same variety, thickness, and density) were impregnated with a fire retardant based on diammonium phosphate and ammonium sulfate (at consumption of 168.2 g/m2 of dry fire-retardant components). The modeling employed the results from the experimental determining of the ignition temperature of unprotected and fire-proof wood, specifically: 235 °C – for unprotected wood, 410 °C – for fire-proof wood, respectively. The results of mathematical modeling and experimental studies confirm the possibility of significant lengthening of time from the onset of fire exposure to the ignition of fire load from wood when nitrogen-phosphorus impregnating agents are used for fire protection. Procedures of mathematical modeling have been proposed to build models for determining the cooling effect from the use of impregnating fire retardants to protect the wood on the prolongation of the stage of a fire start. Mathematical modeling data could be applied when making impregnating fire retardants


2017 ◽  
Vol 68 (11) ◽  
pp. 2676-2681
Author(s):  
Mihaela Gabriela Dumitru ◽  
Dragos Tutunea

The purpose of this work was to investigate the physicochemical properties of watermelon seeds and oil and to find out if this oil is suitable and compatible with diesel engines. The results showed that the watermelon seeds had the maximum length (9.08 mm), width (5.71mm), thickness (2.0 mm), arithmetic mean diameter (5.59 mm), geometrical mean diameter (4.69 mm), sphericity (51.6%), surface area (69.07), volume 0.17 cm3 and moisture content 5.4%. The oil was liquid at room temperature, with a density and refractive index of 0.945 and 1.4731 respectively acidity value (1.9 mgNaOH/g), free fatty acid (0.95 mgNaOH), iodine value (120 mgI2/100g), saponification value (180 mgKOH/g), antiradical activity (46%), peroxide value (7.5 mEqO2/Kg), induction period (6.2 h), fatty acid: palmitic acid (13.1%), stearic acid (9.5 %), oleic acid (15.2 %) and linoleic acid (61.3%). Straight non food vegetable oils can offer a solution to fossil fuels by a cleaner burning with minimal adaptation of the engine. A single cylinder air cooled diesel engine Ruggerini RY 50 was used to measure emissions of various blends of watermelon oil (WO) and diesel fuel (WO10D90, WO20D80, WO30D70 and WO75D25). The physic-chemical properties of the oil influence the combustion process and emissions leading to the reduction of NOX and the increase in CO, CO2 and HC.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qinghong Zeng ◽  
Shengbo Chen ◽  
Yuanzhi Zhang ◽  
Yongling Mu ◽  
Rui Dai ◽  
...  

AbstractWe report on the mineralogical and chemical properties of materials investigated by the lunar rover Yutu-2, which landed on the Von Kármán crater in the pre-Nectarian South Pole–Aitken (SPA) basin. Yutu-2 carried several scientific payloads, including the Visible and Near-infrared Imaging Spectrometer (VNIS), which is used for mineral identification, offering insights into lunar evolution. We used 86 valid VNIS data for 21 lunar days, with mineral abundance obtained using the Hapke radiative transfer model and sparse unmixing algorithm and chemical compositions empirically estimated. The mineralogical properties of the materials at the Chang’E-4 (CE-4) site referred to as norite/gabbro, based on findings of mineral abundance, indicate that they may be SPA impact melt components excavated by a surrounding impact crater. We find that CE-4 materials are dominated by plagioclase and pyroxene and feature little olivine, with 50 of 86 observations showing higher LCP than HCP in pyroxene. In view of the effects of space weathering, olivine content may be underestimated, with FeO and TiO2 content estimated using the maturity-corrected method. Estimates of chemical content are 7.42–18.82 wt% FeO and 1.48–2.1 wt% TiO2, with a low-medium Mg number (Mg # ~ 55). Olivine-rich materials are not present at the CE-4 landing site, based on the low-medium Mg #. Multi-origin materials at the CE-4 landing site were analyzed with regard to concentrations of FeO and TiO2 content, supporting our conclusion that the materials at CE-4 do not have a single source but rather are likely a mixture of SPA impact melt components excavated by surrounding impact crater and volcanic product ejecta.


2011 ◽  
Vol 382 ◽  
pp. 372-374
Author(s):  
Yong Jiang ◽  
Zhi Bin Jiang ◽  
Guo Jie Shao ◽  
Dong Cheng Guo ◽  
Yu Tian ◽  
...  

Purpose: The purpose of this study was to study the compositions of the polygonaceae medicinal plants called rumex root. Methods: Solvent method and chromatography was used to purificate the chemical compositions of Rumex, and the molecular structure of the compound was identified by physical and chemical properties and spectral data. Results: Two compounds were obtained from the ethanol extract of rumex root, which were identified as Chrysophanol and Physcione. Conclusions: Experimental basis was provided for the further study of the active ingredients of rumex root and the development and utilization of medical resources.


2021 ◽  
Vol 30 (4) ◽  
pp. 36-47
Author(s):  
O. S. Lebedchenko ◽  
S. V. Puzach ◽  
V. I. Zykov

Introduction. The reliable operation of safety systems, that allows for the failure of no more than one safety system component, entails the safe shutdown and cool-down of an NPP reactor in the event of fire. However, the co-authors have not assessed the loss of performance by an insulating material, treated by intumescent compositions and used in the power cables of the above safety systems exposed to the simultaneous effect of various modes of fire and current loads.Goals and objectives. The purpose of the article is the theoretical assessment of the application efficiency of intumescent fire-retardant coatings in power cables used in the safety systems of nuclear power plants having water-cooled and water-moderated reactors under fire conditions. To achieve this goal, the temperature of the outer surface of the insulation and the intumescent fire-retardant coating was analyzed depending on the mode of fire. Theoretical foundations. A non-stationary one-dimensional heat transfer equation is solved to identify the temperature distribution inside the multilayered insulation and the fire-protection layer of a conductive core.Results and their discussion. The co-authors have identified dependences between the temperature of the outer surface of the insulation and the fire retarding composition of the three-core cable VVGng (A)-LS 3x2.5-0.66, on the one hand, and the temperature of the indoor gas environment for three standard modes of fire and one real fire mode. It is found that before the initiation of the process of destruction of the insulation material, the intumescence of the fire-retardant coating occurs only in case of a hydrocarbon fire. Under real fire conditions, the maximal insulation melting time before the initiation of intumescence of the fire-retardant coating at the minimal temperature of intumescence is 4.75 minutes, while the maximal time period from the initiation of destruction of the insulation material to the moment of the insulation melting is 6.0 minutes.Conclusions. An experimental or theoretical substantiation of parameters of intumescent fire retardants, performed using standard modes of fire, has proven the potential loss of operational properties by insulating materials of power cables, used in the safety systems of nuclear power plants, in case of a real fire. Therefore, it is necessary to establish a scientific rationale for the efficient use of fire retardants in the above cables with regard for the conditions of a real fire.


2011 ◽  
Vol 32 (4) ◽  
pp. 423-433 ◽  
Author(s):  
Aneta Magdziarz ◽  
Małgorzata Wilk ◽  
Monika Zajemska

Modelling of pollutants concentrations from the biomass combustion process This paper presents possibilities for of numerical modelling of biomass combustion in a commercially available boiler. A sample of biomass was tested with respect to its physical and chemical properties. Thermogravimetry studies of biomass were carried out. Computer simulation makes it possible to analyse complex phenomena which are otherwise difficult to observe. The aim of this work was to model biomass combustion to predict the amount of pollutants generated (NOx, CO, SO2) in the exhaust gases coming out from boilers The calculations were made using the CHEMKIN program. Results of calculations were performed taking into account the influence of temperature, pressure and residence time.


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