The Influence Of Vessel Volume And Equivalence Ratio In Vented Gas Explosions

2012 ◽  
Author(s):  
R.M. Kasmani ◽  
G.E. Andrews ◽  
H.N. Phylaktou
Keyword(s):  
Key Words ◽  
Enhancement Factor ◽  
Equivalence Ratio ◽  
Hot Spot ◽  
Gas Explosion ◽  
Gas Explosions ◽  
Vessel Volume ◽  
Main Factor

Experiments of vented gas explosions involving two different cylinder vessel volumes (0.2 and 0.0065 m3) were reported. It was found that self–acceleration and larger bulk flame trapped inside the vessel are the main factor enhancing the overpressure attained in 0.2 m3 vessel. There was about 2 to 7 times increase in ratio of pressure and flame speeds on both vessels at the same equivalence ratio and K which can be considered as turbulent enhancement factor, β. The comparison with previous work has shown over–prediction results as compared to the present study. Key words: Vented gas explosion; self acceleration; turbulent enhancement factor; hot spot

Vented Gas Explosion In A Cylindrical Vessel With A Relief Pipe

2012 ◽  
Author(s):  
Rafiziana Mohd. Kasmani ◽  
G. E. Andrews ◽  
H. N. Phylaktou ◽  
S. K. Willacy
Keyword(s):  
Key Words ◽  
Equivalence Ratio ◽  
Cylindrical Vessel ◽  
Burst Pressure ◽  
Gas Explosion ◽  
Sonic Flow ◽  
Vented Explosion

Kajian tentang letupan gas/udara di dalam tangki silinder dengan panjang/garis pusat adalah 2, dilaporkan di mana tangki silinder bersambung dengan paip dengan panjang/garis pusat ialah 6. Kajian ke atas kesan tekanan koyakan penutup ventilasi dan kedudukan pencucuh dijalankan untuk mengetahui nilai tekanan maksimum di dalam tangki, halaju nyalaan gas serta halaju gas tak terbakar. Gas propana dan metana di dalam udara digunakan dalam kajian ini dengan kadar persamaan gas/udara antara 0.8 hingga 1.6. Keputusan kajian menunjukkan bahawa tekanan dan halaju nyalaan udara di dalam tangki silinder adalah lebih tinggi jika kedudukan pencucuh berada jauh dari ventilasi berbanding jika pencucuh berada pada bahagian tengah tangki. Selain itu, sebelum gas dialirkan keluar ke bahagian paip, aliran gas dihalang untuk memasuki bahagian paip disebabkan oleh aliran sonik yang terbentuk pada bukaan paip. Kata kunci: Letupan gas; tekanan koyakan penutup ventilasi; kedudukan pencucuh; aliran sonik A study of vented explosions in length/diameter (L/D) of 2 of cylindrical vessel with a duct pipe (L/D = 6) is reported. The influence of vent burst pressure and ignition locations on maximum overpressure generated inside the vessel, flame speeds and unburnt gas velocities ahead of the flame were systematically investigated. Propane and methane–air mixtures with equivalence ratio, Φ of 0.8 to 1.6 have been used. Results show that rear ignition exhibits higher maximum overpressures and flame speeds in comparison to central ignition. It is confirmed that prior to the flame entry to the duct, the flow is chocked due to the sonic flow created at the duct entrance. Key words: Vented explosion; vent burst pressure; ignition location; sonic flow

scholarly journals Analysis of repair works to remove the effects of structural failure after a gas explosion

2019 ◽  
Vol 284 ◽  
pp. 02002
Author(s):  
Aleksandra Bąk ◽  
Ryszard Chmielewski
Keyword(s):  
Residential Buildings ◽  
Residential Building ◽  
Technical Condition ◽  
Structural Elements ◽  
Structural Failure ◽  
Gas Explosion ◽  
Gas Explosions ◽  
Construction Supervision ◽  
Bearing Structure ◽  
Construction Works

The article presents the issues of repair works in a multi-family residential building, whose structural and non – structural elements have been damaged and destroyed by a gas explosion and the fire. Gas explosions in residential buildings constitute a small percentage of the total number of building disasters, however, due to the relatively large number of injured people, these incidents are very dangerous [1]. Moreover, the gas explosion often leads to significant material losses and fatalities. Proper assessment of the load-bearing structure after such incident requires an extensive knowledge of the behaviour of structures. The first authority, that issues a decision regarding further use is Construction Supervision Inspector. Until the demolition of the object is ordered, the next step is to provide expert report made by an authorized construction expert, whose aim is to assess the technical condition of the elements of the structure and to determine the scope of necessary repair works. Construction expert, who give such opinion during the assessment of objects immediately after such incident, often has limited access to structural elements, moreover these elements often are covered. Hence, the recommendations contained in these reports often do not include all of required construction works.

scholarly journals Analysis of the results of a survey on a residential building after a gas explosion and fire

2020 ◽  
Vol 164 ◽  
pp. 08014
Author(s):  
Dmitry Panfilov ◽  
Alexander Zaitsev ◽  
Evgeny Yudin
Keyword(s):  
Fire Resistance ◽  
Residential Building ◽  
Theoretical Studies ◽  
Building Structures ◽  
Gas Explosion ◽  
Foreign Experience ◽  
Residential Sector ◽  
Gas Explosions ◽  
Experimental And Theoretical Studies

The paper analyzes the statistics on household gas explosions and subsequent fires in the residential sector. The results of a survey of a residential building after a gas explosion and a real fire are presented in order to determine the possibility of its restoration and further operation. The results of the necessary experimental and theoretical studies are presented. Examples of the use of foreign experience in the study of fire resistance of building structures are given. The results obtained were used in the development of recommendations for the possibility of restoration of the house and during the necessary construction and finishing works.

Explosions in Gas Turbine Lube Oil Reservoir Result in Installation of Dry Gas Seal System

1989 ◽  
Author(s):  
Lawrence R. Ferrill ◽  
N. Daryl Ronsky ◽  
Tim A. Harris
Keyword(s):  
Gas Turbine ◽  
Oil Reservoir ◽  
Oil Consumption ◽  
Gas Explosion ◽  
Dry Gas Seal ◽  
Gas Leakage ◽  
The North ◽  
Gas Explosions ◽  
Seal Oil ◽  
The North Sea

Mechanical dry gas seal systems were retrofitted into two centrifugal natural gas compressors which are located offshore in the Norwegian sector of the North Sea. The project was initiated after a fire and several gas explosions had occurred in the gas turbine lube oil reservoir. These incidents were a result of gas leaking from the compressor’s seal oil system and then migrating via the lube oil lines into the reservoir. The dry gas seal systems have eliminated gas leakage into the turbine lube oil reservoir, eliminating the hazard of gas explosion. The retrofits have also provided additional benefits including reductions in space and weight, reduced power usage, reduced maintenance, and elimination of seal oil consumption which had been up to 440 gal./day (2000 liters/day).

scholarly journals Process of Natural Gas Explosion in Linked Vessels with Three Structures Obtained Using Numerical Simulation

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 52 ◽  
Author(s):  
Qiuhong Wang ◽  
Yilin Sun ◽  
Xin Li ◽  
Chi-Min Shu ◽  
Zhirong Wang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Time Pressure ◽  
Combustion Products ◽  
Gas Explosion ◽  
Spherical Vessel ◽  
Flame Acceleration ◽  
Physical Experiments ◽  
Gas Explosions ◽  
Simulation Results

Combinations of spherical vessels and pipes are frequently employed in industries. Scholars have primarily studied gas explosions in closed vessels and pipes. However, knowledge of combined spherical vessel and pipe systems is limited. Therefore, a flame acceleration simulator was implemented with computational fluid dynamics software and was employed to conduct natural gas explosions in three structures, including a single spherical vessel, a single spherical vessel with a pipe connected to it, and a big spherical vessel connected to a small spherical vessel with a pipe. These simulations reflected physical experiments conducted by at Nanjing Tech University. By changing the sizes of vessels, lengths of pipes, and ignition positions in linked vessels, we obtained relevant laws for the time, pressure, temperature, and concentrations of combustion products. Moreover, the processes of natural gas explosions in different structures were obtained from simulation results. Simulation results agreed strongly with corresponding experimental data, validating the reliability of simulation.

Numerical study of external explosion characteristics induced by indoor natural gas vented explosion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lei Pang ◽  
Qianran Hu ◽  
Kai Yang
Keyword(s):  
Natural Gas ◽  
Design Methodology ◽  
Large Scale ◽  
Numerical Study ◽  
Outdoor Environment ◽  
Gas Explosion ◽  
Content Type ◽  
Gas Explosions ◽  
Explosion Overpressure ◽  
Vented Explosion

Purpose The purpose of this paper is to ascertain the harm to personnel and equipment caused by an external explosion during natural gas explosion venting. The external explosion characteristics induced by the indoor natural gas explosion are the focal points of the investigation. Design/methodology/approach Computational fluid dynamics technology was used to investigate the large-scale explosion venting process of natural gas in a 6 × 3 × 2.5 m room, and the characteristics of external explosion under different scaled vent size (Kv = Av/V2/3, 0.05, 0.08, 0.13, 0.18) were numerically analyzed. Findings When Kv = 0.08, the length and duration of the explosion fireball are 13.39 and 450 ms, respectively, which significantly expands the degree and range of high-temperature hazards. The suitable flow-field structure causes the external explosion overpressure to be more than twice that indoors, i.e. the natural gas explosion venting overpressure may be considerably more hazardous in an outdoor environment than inside a room. A specific range for the Kv can promote the superposition of outdoor rupture waves and explosion shock waves, thereby creating a new overpressure hazard. Originality/value Little attention has been devoted to investigating systematically the external explosion hazards. Based on the numerical simulation and the analysis, the external explosion characteristics induced by the indoor large-scale gas explosion were obtained. The research results are theoretically significant for mitigating the effects of external gas explosions on personnel and equipment.

Explosion Relief Panels and Their Effect on Gas Explosion Overpressure

2004 ◽  
Author(s):  
Jan Roar Bakke ◽  
Per Erik Skogrand
Keyword(s):  
Working Environment ◽  
Gas Explosion ◽  
Improve Working ◽  
Medium Scale ◽  
Arctic Regions ◽  
Offshore Installations ◽  
Gas Explosions ◽  
Explosion Overpressure ◽  
Solid Walls ◽  
Explosion Risk

Explosion relief panels are commonly used on offshore installations to improve working environment and at the same time allow venting of gas explosions to control explosion risk. This is very important particularly in arctic regions where requirements for acceptable working environment may easily conflict with requirements for low explosion risk. Explosion relief panels have been tested in low congestion, medium scale explosion tests, and based on such tests it has been concluded that replacing solid walls with relief panels reduces explosion loads significantly. It is not clear whether this conclusion can be extended to real offshore modules, which are significantly larger and more congested. In the present paper the gas explosion simulator FLACS is therefore used to investigate the effect of different wall configurations (e.g. open, solid or relief panels) on explosion overpressure in a large, highly congested offshore module. The objective is to assess whether in reality similar benefits from using relief panels as seen in the experiments can be expected.

scholarly journals http://www.kscnet.ru/journal/kraesc/article/view/639

2020 ◽  
Vol 4(48) ◽  
pp. 36-48
Author(s):  
A.A. Shaikhullina ◽  
◽  
E.P. Dubinin ◽  
A.A. Bulychev ◽  
M.S. Baranovsky ◽  
...  
Keyword(s):  
Continental Crust ◽  
Continental Margin ◽  
Hot Spot ◽  
Linear Structure ◽  
Passive Margin ◽  
Western India ◽  
Continental Lithosphere ◽  
Field Modeling ◽  
Thinned Continental Crust ◽  
Main Factor

The Chagos-Laccadiv Range is a linear-elongated structure adjacent to the passive margin of western India. The ridge consists of three segments: northern — Lakkadiv ridge, central — Maldives ridge and southern — bank (archipelago) Chagos. The ridges are separated by depressions and have different manifestations in morphology and anomalous gravitational field. Modeling of the density structure of the Chagos-Lakkadive Ridge tectonosphere showed that the Lakkadive and Maldive segments, most likely, represent submerged blocks of thinned continental crust, partially separated from the continental margin of India by a riftogenic basin. Along with the assumption that the Chagos Bank may contain fragments of the continental crust, the main factor in its formation is apparently the active magmatic activity of the Reunion hot spot, leading to an increase in the thickness of the crust due to underplating. Physical modeling showed that the formation of such a linear structure is possible in the presence of thermal (hot spot) and structural (faults and cracks) inhomogeneities in the model continental lithosphere, which within the continental margin led to a jump (jumping) of the spreading axis towards the young margin and partial separation from it narrow linearly elongated microblocks (ridges).

scholarly journals ASSESSMENT OF THE STATE OF OPTIMAL CONTROL OF SURFACE MOISTURE AS THE MAIN FACTOR FOR OBTAINING ENVIRONMENTALLY FRIENDLY AGRICULTURAL PRODUCTS

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Prof. Akademian RAS B.H. Aliyev ◽  
Prof.RAE Z.H., Aliev
Keyword(s):  
Optimal Control ◽  
Key Words ◽  
Environmentally Friendly ◽  
Clean Technology ◽  
Agricultural Products ◽  
Agricultural Product ◽  
Surface Moisture ◽  
Current Information ◽  
Managerial System ◽  
Main Factor

Abstract: The current information on moisture and the temperature of the ground in managerial system by production to agricultural product necessary, in the first place, for taking the operative decisions at development ecological clean technology irrigation under growing agricultural cultures to achieve the maximum harvest. Key words: aerospace methods, COW, moisture, moisture test, arable, soil, ecology, vafer humidity, drill, graduation, tool, etc.

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