25 results on '"GAS explosions"'
Search Results
2. The using of ATmega 2560 micro-controller for LPG leakage detection.
- Author
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Evalina, Noorly, Pasaribu, Faisal Irsan, Aziz, H. Abdul, and Gultom, Z. Arifin
- Subjects
LEAK detection ,GAS leakage ,GAS detectors ,GAS explosions ,RESIDENTIAL areas ,COMPUTER equipment - Abstract
Gas leakage is a problem that can occur in residential areas, this paper provides a solution so that the house is safe from gas leaks, The design of gas leak detection equipment is very important as an early warning system, so there are no accidents and fires due to gas canister explosions, and residences can be protected from gas leaks, MQ-6 gas sensors as gas leak detection inputs. LCD as display output, bell as sound output, relay as solenoid gas valve controller as gas line safety when gas leakage. All of these components are connected to the main regulator ATmega 2560 Microcontroller, When the Gas Sensor Detects a Gas Leak, Then the Sensor Will Give The Command To Turn on the Bell, Show Warning On the LCD screen, And Relay works ordered Solenoid Gas Disconnected, And Gas Line Closed, when the voltage on the sensor is 2.33 volts, the sensor will detect gas leakage and will transmit to the microcontroller ATmega 2560 Microcontroller to set the LCD and Buzzer to work, and Solenoid will close the gas line, and if the sensor voltage below 2.33 sensor will not detect gas leakage, automatically the LCD and Buzzer will stop working. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Review on "Progressive collapse analysis of multi-storey RCC building".
- Author
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Lilhare, Pawankumar and Nardey, Abhijeet
- Subjects
BUILDING failures ,PROGRESSIVE collapse ,GAS explosions ,COLUMNS - Abstract
Progressive collapse is the result of a local failure of one or more structural member mostly column due to blast, internal gas explosions, vehicular collision, earthquake, Man Made disasters etc. The failure of main load carrying Members i.e. column and beams leads to redistribution of forces to the adjacent members and if redistributed load exceeds beyond member capacity it fails. This process continues in the building and eventually the building collapse. Progressive collapse of building is very dangerous for human life, so it is necessary to Analysis the building for progressive collapse before design and construction starts. This review shows the different aspects of progressive collapse analysis studies done by researches. This review also focuses on the different platform, methodology to be used by researchers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. IGNITION OF METHANE AND ITS BURNING, IN PROXIMITY OF THE SOURCE OF INITIATION.
- Author
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Vlasin, Nicolae-Ioan, Cioara, Cristian, Florea, Gheorghe Daniel, Simon-Marinica, Adrian Bogdan, and Vass, Zoltan
- Subjects
PARTICLE image velocimetry ,FLAMMABLE materials ,FLAME ,GAS explosions ,NATURAL gas ,EXPLOSIVES - Abstract
The use of natural gas as a home heating source has, unfortunately, generated a number of gas explosion events, most of which have as their main cause the accidental leakage of combustible gas. The dynamic effects generated by the explosion pressures differ from case to case, depending on the concentrations of combustible gas accumulated in the chambers from the time of the occurrence of the gas leak to the occurrence of the source of initiation. Often, these dynamic effects involve concentrations close to the stoichiometric one, the destruction consisting of breaking windows, breaking walls and even slabs between floors. But often, events of this type are followed by fires, the dynamic effects being much reduced, in these cases the thermal effects predominate. The subject is lightly approached in the literature and, therefore, this paper presents the physical experiments performed in the laboratory and the results obtained, highlighting both the process of forming the explosive atmosphere and the mechanism of ignition of methane at concentrations far from the stoichiometric, its burning time giving the possibility to ignite the combustible materials with which the flame front comes in contact. The recordings were made through a PIV (Particle Image Velocimetry) system and are useful for calibrating computational simulations and preparing technical expertise reports for this type of events. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. FLUID-STRUCTURE INTERACTION IN GASEOUS EXPLOSION SIMULATIONS.
- Author
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Manea, Florin, Ghicioi, Emilian, Munteanu, Laurențiu, and Șimon-Marinică, Bogdan Adrian
- Subjects
FLUID-structure interaction ,FLOW velocity ,GAS explosions ,BLOOD flow ,BLOOD pressure - Abstract
According to ANSYS - developer of the Multiphysics platform for computer simulations - the FSI (Fluid-Structure Interaction) model can be used in all cases where a fluid encounters a solid structure, for example, wind gusts rotating a turbine, air washing the surface of a moving car etc. This method finds applications especially in the aeronautical and automotive industries, but also in medical research, such computer simulations track the influences of blood pressure and blood flow velocity in the veins. This paper deals with an extension of applying this method in a lesser field, namely in investigating gas explosion events through computer simulations. For this, in the virtual domain, a geometry similar to a house was built, in which an explosive atmosphere generated by an accidental natural gas leak was simulated. Following the source of initiation, the process of rapid combustion of combustible gas takes place, the dynamic effects produced by the pressures generated by the expansion of the gases being calculated and quantified by the FSI model. The results obtained by applying this method in the simulations help in the decision-making process to adopt the most effective measures to prevent explosion-type events of air-fuel mixtures, being useful in the development of explosion risk assessment studies, for identifying the worst-case scenario. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. IMAGING RESEARCH FOR THE FORMATION OF EXPLOSIVE ATMOSPHERES.
- Author
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Tuhut, Ligia Ioana, Vlasin, Nicolae-Ioan, Simon-Marinica, Adrian Bogdan, Florea, Gheorghe Daniel, and Babut, Andrada
- Subjects
PARTICLE image velocimetry ,EXPLOSIVES ,GAS explosions ,GAS leakage ,VECTOR fields ,SUSPENDED solids - Abstract
n the investigation of gas explosion events resulting from combustible gas leakage, often the formation of the explosive atmosphere at the location of the ignition source is less highlighted, usually being calculated the concentration of combustible gases at the entire volume affected by the explosion; depending on the distance between the gas source and the ignition, the complexity of the geometry (volumes occupied by various solid bodies) and the air currents in that volume (convective currents generated by heat sources, air currents formed between two space openings, etc.), the concentrations of combustible gases may differ locally, reaching the explosive range. To study this phenomenon, a transparent, semi-closed stand was made, in which controlled amounts of methane gas were introduced together with very small mass particles. The diffusion of methane carrying particles was recorded by PIV (Particle Image Velocimetry) techniques. The principle underlying these techniques is the position comparison of the suspended solid particle, located in a transparent and homogeneous fluid environment, a comparison made between two staggered images, with a known time frame. The results of the high-speed camera recordings are then transferred to the Insight 4G application, through which the vector fields of velocities, turbulences and the behaviour of the explosive gas cloud can be highlighted, until the explosive conditions at the location of the initiation source are met. The process of mixing fuel gases with air has usually been explained by the application of diffusion formulas and / or by the calculation of hazardous gas concentrations from accidental leaks or releases. In this context, by visualizing in real time the process of mixing a combustible gas with air, a new field of study is born that can bring a surplus of knowledge in combating explosion events and the development of appropriate protection measures. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
7. Blast wave dynamics caused by explosion of toroidal cloud of propylene-air mixture.
- Author
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Valger, S. A., Fedorova, N. N., Fomin, P. A., Cheng, Wang, Zhongqi, Wang, and Fomin, Vasily
- Subjects
BLAST waves ,EULER equations ,GAS explosions ,INTERNAL waves ,TRANSPORT equation ,EXPLOSIONS ,SHOCK waves ,DETONATION waves - Abstract
In the paper, a physical and mathematical model is proposed, and the corresponding numerical algorithm is developed to calculate the shock-wave flow, generated by the explosion of a complex-shaped cloud. As an example, we simulate the atmosphere blast of the propylene-air mixture above a flat horizontal surface. The cloud has a shape of tor, which axis makes the 30 degrees angle with the normal to the substrate. Similar clouds can be formed during powerful emergency jet emissions of explosive gas into the atmosphere. Numerical simulation of the problem based on solving of a system of 3D transient Euler equations, supplemented by the transport equations for a two-component gas medium and the energy conservation equation. Gas explosion assumed to be instantaneous. After the explosion, the reaction products are supposed to be in a "frozen" state, and their thermodynamic parameters are calculated by explicit algebraic formulas depending on pressure and temperature. Based on the results of numerical simulation, a complex shock-wave structure of the flow and dynamics of pressure profile in the vicinity of the explosion zone and near the horizontal surface are obtained. Flow picture includes two non-concentric ring shocks and internal expansion wave. Based on the computation results, the complex wave structure is analyzed, and pressure loads on the substrate are evaluated. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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8. IDENTIFICATION OF SPATIAL OBJECTS WITH THE SAME TOPOLOGICAL STRUCTURE IN IMAGES FROM DIFFERENT TIMES OF THE YEAR.
- Author
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Andrianov, Dmitriy, Eremeev, Sergey, and Kovalev, Yuri
- Subjects
REMOTE-sensing images ,SUMMER ,GAS explosions ,SEARCH algorithms ,FOREST fires ,CHEMICAL spills - Abstract
Currently every day the need for obtaining information from satellites and quadcopters is increasing. Various services and ordinary users have a need for automated processing of received information from satellites. However, automated processing raises a number of problems: different illumination of objects, their difference in different times for example at different times of the year, soil changes, river spills and forests before and after fires etc. However, topology allows you to preserve the shape of feature data.The article sets the task of developing an algorithm for searching for spatial objects with the same topological structure for different seasons. Thespatial objects identification algorithm based on topological features,which using barcodes formed using simplicial complexes and persistent homology. The search takes place on various satellite images. The result of the algorithm is the detection of objects in images for different time intervals based on the obtained three-dimensional barcodes.The analysis of various approaches to the search for spatial objects in satellite images is carried out the advantages and disadvantages are identified.In the work images of rivers and lakes were studied for different years and in the spring, winter, autumn and summer seasons. Plots of topological characteristics of these objects are constructed. Similarities and differences of topological characteristics are displayed.The developed algorithm allows you to find spatial objects with an accuracy of 90%. In the future the algorithm can be improved by introducing additional topological features and the accuracy of determination can be about 95%. This algorithm can be applied not only to rivers and to lakes but when searching for changes in soils, forests or when gas explosions appear in the Arctic. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. VIRTUAL SIMULATION OF INITIATING EXPLOSIVE ATMOSPHERES DUE TO METHANE LEAKES.
- Author
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Florea, Gheorghe Daniel, Vlasin, Nicolae Ioan, Ghicioi, Emilian, Simon Marinica, Adrian Bogdan, and Vass, Zoltan
- Subjects
GAS leakage ,GAS explosions ,METHANE ,GAS as fuel ,DUST explosions ,ATMOSPHERE - Abstract
Most of the time, in assessing a situation where a leakage of combustible gas is involved, the volume of the room where the release occurs and the volume of the released gas is taken into account, thus resulting in an average concentration of the fuel gas applied to the entire volume of the room. In some cases, when the source of combustible gas is close enough to the source of initiation, or when air currents converge at the location of the source of initiation carrying amounts of combustible gas, the explosive mixture formed in the vicinity of the source of ignition may be initiated even if the minimum explosive concentration in the entire volume is not reached / exceeded.This paper explores the release of methane gas inside a closed space and the initiation of the mixture at different concentrations reached at the spark location. The experiments are virtually performed through CFD techniques. Computational modeling of gas explosion phenomena in closed-space involves simulating the movement of some areas in response to event-generated pressures, the deformation by translation and/or rotation of these areas, or even the transformation of their boundary conditions from walls into open frontiers to release explosion pressures. A very important aspect regarding computational modeling is the source of initiation of the methane air mixture.As a result of virtual tests, some differences were observed between the simulation results and the calculation currently used for the determination of methane concentrations in enclosed spaces in case of accidental leakages of combustible gases. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. THE USE OF MODERN TECHNOLOGIES IN RESCUE ACTIVITY.
- Author
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Irimia, Alin, ilie, Cosmin, Pupăzan, Daniel, Gireadă, ndrei, and Kovacs, Izabella
- Subjects
FLAMMABLE gases ,RESCUE work ,INDUSTRIAL capacity ,RESCUES ,GAS explosions ,RAILROAD stations - Abstract
Bothsurface but especially underground rescue activities in industrial environments presentingrisk of explosive / flammable or toxic gases, are difficult because ofmajor risk of fires or explosions in a veryshort time. Dense smoke can make rescue work even more difficult and time becomes an extremely important factor, especially when workers are caught in the affected area and it is assumed that they could be alive. The technological development of last years has allowed the miniaturization of equipmentand occurrence of new technologies whose implementationin rescue activitiesfacilitates searching in damaged areasand locating theworkers. The purpose of the paper is to present a series of equipment that can become useful in order to fit outrescue stations and train rescuers on how to use them. Industrial environments with potential toxic / explosive / flammable gases are very different both in terms of technology and intervention methodsthat rescuers will have to use in the event of a fire, explosion or toxic gas. However, there is a wide range of equipment and devices of recent emergence, usable in many industries, which can increase the safety ofrescue teams and help reduce the response time to restoresafety. Modern equipment also influences the structure of intervention teams by the fact that it sometimes requires specializations for exploitation. For this reason, knowledge of adequate equipment requires the co-optation in the rescue station of individualswith a certain degree of qualification necessary for operating equipment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. PHENOMENOLOGICAL MODELING OF GAS EXPLOSION IN CLOSED VESSEL.
- Author
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MIKÁCZÓ, Viktória and SZEPESI, Gábor L.
- Subjects
GAS explosions ,PHENOMENOLOGY ,WORK-related injuries ,COMPUTER simulation ,PROPANE ,FLAMMABLE materials - Abstract
Gas explosions come out at a significant part of industrial accidents. Many of protection methods can be used to prevent them, from eliminating the causes (like disabling ignition source, displacing the oxidizing atmosphere, preventing the formation of dangerous concentrations) to suppressing the occurring explosion, and reducing damages. One type of the possibilities of protection is to reduce evolving pressure with rupture devices and vent ducts. However, their design methods are given in standards with limited equipment sizes and geometries, but further solutions are necessary in practical approaches. Derogation from recommendations of standards can only be allowed with proper technical justification. Problem can be solved with validated numerical simulations. In this paper, a mathematical model of unvented gas-phase deflagration is presented. The model based on numerical model of Chippett (1984.) and tested against propaneair explosions at initial temperature of 293 K and initial pressure at 1 bara in a vessel with 0.02 m³ volume. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
12. Kömür Madenlerindeki Jeolojik Riskler ve Önlemleri, Soma, Amasra, Elbistan ve Karaman Örnekleri.
- Author
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Toprak, Selami
- Subjects
OIL field flooding ,GAS explosions - Abstract
Copyright of Abstract of the Geological Congress of Turkey / Türkiye Jeoloji Kurultayı Bildiri Özleri is the property of TMMOB JEOLOJI MUHENDISLERI ODASI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
13. Preliminary Result on Unconfined Vapor Cloud Explosion using Vertical Tube on Hot Surface.
- Author
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Yurismono, Hari, Sumarsono, Danardono A., and Nugroho, Yulianto S.
- Subjects
LIQUID honing ,VAPORS ,EXPLOSIONS ,GAS explosions ,FLAME ,COMBUSTION - Abstract
The unconfined vapor cloud explosion (UVCE) is fire accidents that could cause severe damage and it sometimes leads to high potential of casualties. Severity caused by UVCE is due to its wide spread fire explosion and that the source mostly comes from a relatively small amount of gasoline or gas leak that has happened long enough leading to the occurrence of an explosion. Since the awareness to this situation relatively low. Research on flammability levels from various liquid and gas fuels has been conducted extensively and it has even been shown in MSDS which ease users in utilizing fuel handling and the selection of safety factors. There have been many studies completed on discovering the cause of fire occurrence especially after the incident of several UVCE-related accidents. Similarly, many dispersion models of fuel leakage and liquid followed by evaporation process have been developed at an applicable level. UVCE still leaves some questions related to the initiation of the explosion. Some research on the phenomenon of explosions on UVCE has been carried out to find out the conditions so as to enable an explosion. Moreover, there is still one question unanswered on UVCE concerning on how do high velocity of deflagration arises in the conditions of an open space explosion. From an accident evaluation so far, it can be believed that the obstacle in the flame path will make the escalated flame velocity reach the Deflagration to Detonation Transition (DDT) level. This was supported by the results of a large scale experimental study conducted by several researchers whose results were reported in line with these assumptions. In addition, some researchers believe that the explosion of UVCE is sequential, beginning with the initial fire. The flame formed will generate heat quickly through radiation heat transfer to the unburned vapor cloud section. This phenomenon is considered responsible for the occurrence of a larger explosion and covers a large area on several accidents.This paper presents preliminary results from lab scale research to characterize the deflagration velocity of vapor cloud flame which is affected by the temperature of the environment. Visual observation is processed from the camera record on deflagration in an open vertical tube with a hot plate. By using gasoline as a vapor cloud source, tests were carried out in three conditions: lean mixture, stoichiometric mixture and rich mixture. In experiments with lean mixture does not occur or it is difficult to fire. For stoichiometric mixture, deflagration occurs quickly and causes an explosion sound. In rich mixture conditions a loud explosion occurs. Especially for the 1.8 stoichiometric concentration, two fires were produced and with the loudest explosion sound. On first fire combustion occurs quickly with a large fireball, after which a second explosion is followed which depletes the rest of the unburned vapor cloud. In experiments with very rich mixture (concentrations of 2 x stoichiometric conditions) occur fire with a slow flame velocity and form soot significantly. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
14. VERIFICATION OF PERFORMANCE REQUIREMENTS AND TECHNICAL PARAMETERS OF PLASTIC EXPLOSIVES WITH CIVIL AND MILITARY USE.
- Author
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Ciprian Jitea, Ilie –, Vasilescu, Gabriel, Laszlo, Robert, Kovacs, Attila, and Rădeanu, Cristian
- Subjects
EXPLOSIVES ,DETONATION waves ,CHEMICAL energy ,GAS explosions ,CHEMICAL stability ,COMMERCIAL product testing ,TECHNICAL specifications - Abstract
Substances that have chemical energy are known under the generic name of explosives. The chemical energy resulting from the decomposition of explosive substances has constituted and will continue to be one of the main forms of energy used in many sectors of the economy as well as in the military field. The technical experience accumulated so far has demonstrated that it is very difficult for a simply characterization of the explosion. Thus, in order to achieve this it is necessary to know the thermo-chemical characteristics (oxygen balance, temperature, explosion heat, gas volume of explosion, specific pressure and energy level), ballistic (detonation speed, sensitivity to transmission of detonation, brisance, working capacity, power in TNT equivalent), physico-chemicals (loading density, humidity, chemical stability) and safety (impact and friction sensitivity, sensitivity to extreme temperatures or heat resistance). The paper highlights the results of the researches undertaken in order to evaluate the technical and functional parameters, specific to plastic explosives with dual use (civil and military). In this regard, in the laboratory for explosives and pyrotechnic articles accredited by Romanian Accreditation Body, a number of relevant tests have been carried out on samples taken from this type of explosive, namely: determination of density according to PI-26 test procedure; determination of impact sensitivity according to PI-84; determination of friction sensitivity according to PI-83; modalities of initiation according to PI-75; determination of sensitivity to the transmission of detonation according to PI-71; determination of brisance by Hess method according to PI-80; The product tested is intended for use for special applications such as main load or buster (load of amplification and transmission of detonation), being a powerful, malleable explosive capable of taking different forms as well as placing on various targets, for performing various requests shockwave. These qualities were also confirmed by the results of the experimental tests carried out using the appropriate INSEMEX testing infrastructure. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
15. EVALUATION THE SECURITY DEGREE OF THE HIGH QUALITY SAFE HAVING RESISTANCE GRADE V BASED ON THE RESULTS OF GAS EXPLOSION TEST.
- Author
-
Rădeanu, Cristian, Gabriel, Vasilescu, Kovacs, Attila, Robert, Laszlo, and Claudia, Miron
- Subjects
GAS explosions ,BURGLARY ,TESTING - Abstract
In order to be framed in security classes, safes for keeping money and valuables are subject to various tests that involve hitting them with tough tools. The security class of an anti-burglary safe indicates its resistance to mechanical action, and practically indicates the time in which partial or total access to the protected goods from the inside can be obtained. A anti-burglary safe has been specially developed to protect its contents or to be resistant to external attacks. The degree of burglary resistance is determined by the thickness of the metal and the number and type of latches used, plus other burglar-resistance factors, which are included in the construction of the door and the walls of the seif. These degrees are set according to burglar-resistance tests. Intrusion resistance test, in accordance with EN 1143-1, takes into account the amount of time it takes to have partial and complete access the safe and the type of tools used to penetrate into the vault. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
16. PHENOMENOLOGICAL MODELING OF GAS EXPLOSION IN CLOSED VESSEL.
- Author
-
MIKÁCZÓ, Viktória and SZEPESI, Gábor L.
- Subjects
PROPANE ,GAS explosions ,WORK-related injuries ,PHENOMENOLOGY ,NUMERICAL analysis - Abstract
Gas explosions come out at a significant part of industrial accidents. Many of protection methods can be used to prevent them, from eliminating the causes (like disabling ignition source, displacing the oxidizing atmosphere, preventing the formation of dangerous concentrations) to suppressing the occurring explosion, and reducing damages. One type of the possibilities of protection is to reduce evolving pressure with rupture devices and vent ducts. However, their design methods are given in standards with limited equipment sizes and geometries, but further solutions are necessary in practical approaches. Derogation from recommendations of standards can only be allowed with proper technical justification. Problem can be solved with validated numerical simulations. In this paper, a mathematical model of unvented gas-phase deflagration is presented. The model based on numerical model of Chippett (1984.) and tested against propaneair explosions at initial temperature of 293 K and initial pressure at 1 bara in a vessel with 0.02 m³ volume. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
17. Research on the Analytical Method about Influence of Gas Leakage and Explosion on Subway.
- Author
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Wendong Ji, Ligong Yang, and Lin chen
- Subjects
GAS leakage ,GAS explosions ,LEAKAGE ,SUBWAY accidents ,EXPLOSIONS - Abstract
With the construction and development of city subway, the cross impact of underground rail transit and gas pipe network is becoming more and more serious, but there is no analytical method for the impact of gas explosions on the subway. According to this paper, the gas leakage is equivalent to the TNT explosion equivalent, based on which, the calculation of the explosive impact load is carried out. On the basis of the concrete manifestation of gas explosion, it is more convenient to carry out the subsequent calculation by equivalently treating the explosive impact load as a uniform load within a certain range. The overlying soil of the subway station has played a protective role for the subway, making the displacement of the subway structure in the explosion process significantly reduced. The analysis on the actual case shows that this method can be successfully applied to the quantitative analysis of such accidents. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
18. ADVANCES IN MODELLING THE RISKS ASSOCIATED WITH GAS EXPLOSIONS IN CONFINED SPACES.
- Author
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Pasculescu, Vlad Mihai, Vlasin, Nicolae Ioan, Suvar, Marius Cornel, Florea, Gheorghe Daniel, and Vass, Zoltan
- Subjects
GAS explosions ,FLAMMABLE gases ,EXPLOSIVES ,HAZARD mitigation ,GAS leakage - Abstract
Process and plant design need to be continuously improved, the use of new safety concepts to a full extent being one of the key parameters leading to their sustainable improvement. Accidents occurred over time in industrial facilities where explosive gas or vapor atmospheres may be present have put the explosion risks high on the agenda of regulators, operators, accident investigators or researchers in the field. Accidental flammable gas leaks in mixture with air may generate explosive atmospheres which once ignited lead to explosion type events resulting in large overpressures causing significant damages to process installations or even fatalities. Harmful effects converted into fatality rates, referred to as vulnerability modeling is of significant importance for process quantitative risks assessment. The paper deals with data and research which lay ground for computational modelling for assessing the hazardous area extent and risks associated with gas leak explosions, taking into account computational investigations on the behavior of accidental flammable gas releases and on the effects of the generated explosive atmosphere's explosion in confined spaces. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
19. RESEARCHES REGARDING GAS EXPLOSIONS BY COMBINED IMAGISTIG METHODS.
- Author
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Vlasin, Nicolae-Ioan, Ghicioi, Emilian, Florea, Gheorghe Daniel, Vass, Zoltan, and Chiuzan, Emeric
- Subjects
GAS explosions ,MINES & mineral resources ,NATURAL resources ,FLAME ,EXPLOSIONS - Abstract
Methane gas, one of the underground mine atmosphere, is the main hazard for the workers in this field. The risk of occurrence of an explosive atmosphere and the consequences are different from one mine to another, based on the mine type, its configuration, the extracted coal and the probability of the methane and coal dust occurrence. With every prevention measure taken, the potential risk of an explosion cannot be excluded from the firedamp mines, just reduced as much as possible. The controlled researches regarding the gas mixtures explosions are not a novelty in the field. However, the modern recording methods with high speed cameras combined with Schlieren techniques for density gradients visualization bring extra information. This paper purpose the recording of ga explosions in a transparent media, with the help of two high speed camera, using both Schlieren and conventional techniques. The results obtained by overlaying the recording are aiming the flame front in different situations. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
20. FIRST ROMANIAN COMPUTATIONAL SIMULATION OF AIR-METHANE MIXTURE EXPLOSION.
- Author
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Vlasin, Nicolae-Ioan, Pasculescu, Vlad-Mihai, Suvar, Marius Cornel, Florea, Daniel, and Chiuzan, Emeric
- Subjects
MINERAL industries & the environment ,MINE explosions ,FIREDAMP ,NATURAL gas consumption ,GAS explosions - Abstract
Regarding the mining industry, the risk of an explosive atmosphere occurrence and the consequences differ from one mine to another, depending on the configuration of the mine and on the type of the coal extracted. Although preventive measures are taken, the potential risk of explosion cannot be excluded from firedamp mines, but only reduced as much as possible. Therefore, where the possibility of forming these explosive atmospheres exists, the explosion risk assessment is required by developing scenarios that considers the existence, in the same location and at the same time, of the source of ignition, the combustible gas and the oxygen. In this regard, CFD techniques can be very useful tools for risk assessors. Due to the large field of natural gas consumers, the benefits resulted from the development of the virtual simulation models of gas explosions are found not only in the security state of the staff of coal underground mining. It can beneficially effect an area much wider, from big industries to small consumer appliances, from urban center activities to environmental protection. In the field of computational modeling of gas explosion, the global concerns in this area are very low. So far, in Romania there are no known works in virtual simulations of gas explosion, this domain being totally uncovered. This paper presents the first Romanian success of this kind, respectively the computational simulation of a stoichiometric airmethane mixture explosion in a closed, equipped with obstacles space. This could be achieved by changing the parameters and indices inside the models of ANSYS FLUENT application, customizing these data for gas explosion specific domain. The results are presented in form of spatial charts of the flame front development and by graphics that represent the time evolution of characteristic parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
21. ASPECTS ON PROFICIENCY TESTING FOR SPARK IGNITION TEST.
- Author
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Darie, Marius, Burian, Sorin, Csaszar, Tiberiu, Moldovan, Lucian, and Colda, Cosmin
- Subjects
GAS explosions ,SPARK tests ,PROBABILITY theory ,REPRODUCIBLE research ,GEOMETRIC distribution - Abstract
This paperwork represents a following of the conducted research based on statistical analysis of the probability of ignition resulting from the experimental data obtained with the purpose of highlighting the aspects related to the reproducibility of the results. In the first part of the paper it was presented the experimentation test rig (spark test apparatus) and the results of the statistical analysis of experimental data obtained during the tests with air-hydrogen explosive mixture. On this occasion it was examined the possibility of choosing the probability distribution of the results by using Cullen and Frey diagrams. In the second part it was proposed and presented the theoretical model for the geometric distribution density of the number of revolutions to which the ignition of the explosive mixture test has occurred. The third part was dedicated to considerations regarding the probability of ignition and reproducibility of the spark ignition test results. On this occasion it was found that tests for validating the test rig imposed by the standard had high probabilities of compliance but the tests of an electrical circuit considered safe in terms of explosion protection had unexpectedly low values of probability in passing the test. Thus, it was deduced that the retesting of an equipment that successfully passed a previous test will present very low reproducibility probabilities. [ABSTRACT FROM AUTHOR]
- Published
- 2016
22. RESEARCH OF AIR-METHANE EXPLOSIONS USING HIGH SPEED IMAGERY ANALYSIS.
- Author
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Vlasin, Nicolae-Ioan, Păsculescu, Vlad-Mihai, Şuvar, Marius Cornel, Cozma, Eugen, and Florea, Daniel
- Subjects
METHANE ,GAS explosions ,SHOCK tubes ,TUNNELS ,APPROXIMATION theory - Abstract
Gas explosions phenomenology analysis has been mainly performed in shock tubes of circular or rectangular sections, in spherical vessels, experimental galleries or tunnels. Usually, these constructions dispose of opaque walls and are possibly provided with one or more viewing windows, and sensors for pressure and temperature. The advantages of these experimental stands consist especially in large pressure values supported. But the main drawback is that important parameters can be measured only on predetermined points. Thus, the volumes of the two consecutive points are assigned average values of gradients or of parameters, missing the precise information on when and where the change appeared, and the speed with which it takes place is an approximation. In order to remove this constraint, the paper proposes a transparent model of a testing stand which should allow the imagery analysis of gas explosions by highlighting the Schlieren effect. Based on this model, two transparent explosion rooms have been designed, in which have been tested ignitions of explosive air-methane atmospheres at different concentrations, the phenomena being recorded using high speed video cameras. The results of these tests - consisting of video materials - allow postprocessing and determining the values (e.g. flame propagation velocity) between any two very close points, significantly increasing the measurement accuracy. Also, by make use of the high-speed video recordings, the times at which major changes of the parameter values occur can be measured with accuracy, and consequently, a thorough analysis of the phenomenology in temporary ranges of milliseconds or even shorter can be carried out. [ABSTRACT FROM AUTHOR]
- Published
- 2016
23. A study on the development of GIS-based smart disaster prevention system using real time monitoring of city gas leak & explosion.
- Author
-
Jong-Tak Park and Chang-Soo Kim
- Subjects
GEOGRAPHIC information systems ,EMERGENCY management ,GAS leakage ,GAS explosions ,NATURAL gas pipelines ,ACCIDENTS - Published
- 2016
24. FEM analysis of escape capsule suffered to gas explosion.
- Author
-
Li, Chang-lu, Mei, Rui-bin, Li, Chang-sheng, Cai, Ban, and Liu, Xiang-hua
- Subjects
GAS explosions ,COAL mining ,FINITE element method ,DEFORMATIONS (Mechanics) ,STRAINS & stresses (Mechanics) ,MECHANICAL loads ,PRESSURE - Abstract
Escape capsules are new devices for underground coal mines that provide air, water, food and supplies in the event of an emergency in where miners are unable to escape. It is difficult to carry out the experiments of explosion and safety because the danger and nonrepeatability of explosion. The structure deformation and distribution of equivalent stress has been investigated under different impact pressure conditions including unimodal and bimodal loads based on the FEM and software LS-DYNA. The results show that the distribution of deformation and equivalent stress has the same trend on the same surface with the increment of explosion pressure. The deformation and stress are larger with side impact pressure compared with that of the same front impact pressure. Furthermore, the maximum equivalent stress is 246MPa and 260MPa on the front and sides of capsule with five times for national standard impact pressure 1.5MPa. Under these conditions, the deformation is less than about 9.97mm and 10.47mm, respectively. When the front impact pressure is 2.0MPa, the deformation of capsule still belongs to elasticity but the less plastic deformation occurs on the Ushape stiffening channels with the same side impact pressure. However, it is safe for capsule structure because the equivalent stress 283MPa is much less than the tensile strength. It is noted that bimodal load accelerates the capsule deformation so that it is more dangerous compared with unimodal load. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
25. DIRECT APPROACH TO EXPLOSIVE HYDROGEN BURNING PROCESS WITH CRIB.
- Author
-
Kubono, S., Teranishi, T., Notani, M., Yamaguchi, H., Saito, A., He, J. J., Wakabayashi, M., Fujikawa, H., Amadioa, G., Baba, H., Fukuchi, T., Shimoura, S., Michimasa, S., Nishimura, S., Nishimura, M., Gono, Y., Odahara, A., Kato, S., Moon, J. Y., and Lee, J. H.
- Subjects
HYDROGEN ,STELLAR radiation ,GAS explosions ,NUCLEAR astrophysics ,NUCLEOSYNTHESIS ,X-ray bursts - Published
- 2005
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