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

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

Experiments on duct-vented explosion of hydrogen–methane–air mixtures: Effects of equivalence ratio

Fuel ◽  
2022 ◽  
Vol 308 ◽  
pp. 122060
Author(s):  
Chunhua Wang ◽  
Jin Guo ◽  
Kai Zhang ◽  
Saifeng Du ◽  
Hao Chen ◽  
...  
Keyword(s):  
Equivalence Ratio ◽  
Vented Explosion

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.

Solution of Gas Explosion Load and Simulation of Dynamic Response of Multilayer Structures

2012 ◽  
Vol 557-559 ◽  
pp. 2401-2405
Author(s):  
Hua Dong Liu ◽  
Wei Qiang Wang
Keyword(s):  
Dynamic Response ◽  
Multilayer Structure ◽  
Radial Direction ◽  
Burst Pressure ◽  
Multilayer Structures ◽  
Gas Explosion ◽  
Explosion Pressure ◽  
Structure Strength ◽  
Explosion Load ◽  
Chemical Explosion

Chemical explosion may occur in urea reactor. The explosion load and the dynamic response of the multilayer structure are analyzed. Based on Russel model, the maximum explosion loads were calculated by thermodynamic methods. Dynamic response was simulated by Ls-dyna software. The result shows that the explosion pressure is smaller than the burst pressure; the stress distribution along the radial direction and the effective stress history are obtained and they both show some new features. The results may offer some reference significance for similar structure strength design and safe protection.

scholarly journals Vent burst pressure effects on vented gas explosion reduced pressure

2015 ◽  
Vol 36 ◽  
pp. 429-438 ◽  
Author(s):  
Bala M. Fakandu ◽  
Gordon E. Andrews ◽  
Herodotus N. Phylaktou
Keyword(s):  
Pressure Effects ◽  
Burst Pressure ◽  
Gas Explosion ◽  
Reduced Pressure

Numerical simulation on structure effects for linked cylindrical and spherical vessels

SIMULATION ◽  
2018 ◽  
Vol 94 (9) ◽  
pp. 849-858
Author(s):  
C Yan ◽  
ZR Wang ◽  
F Jiao ◽  
C Ma
Keyword(s):  
Structural Changes ◽  
Flame Temperature ◽  
Cylindrical Vessel ◽  
Gas Explosion ◽  
Spherical Vessel ◽  
Airflow Velocity ◽  
Monitoring Point ◽  
Explosion Pressure ◽  
Simulation Results ◽  
Peak Value

This paper presents a simulation study on the methane–air mixture explosions through using the eddy-dissipation concept (EDC) model in FLUENT. The aims are to investigate the structure effects of methane–air mixture explosions in a spherical vessel, cylindrical vessel and different systems of cylindrical vessels connected with pipe. Meanwhile, in order to study the characteristics of methane-air mixture explosions in the linked vessels, changes of flame temperature and airflow velocity in the linked vessels are simulated and analyzed. The results suggest that the effect of structural changes of a single vessel on the gas explosion intensity is clear, and the explosion intensity of a spherical vessel is greater than that of a cylindrical vessel. The simulation results of different structural forms of a cylindrical vessel connected with pipelines show that the time to reach the peak value of explosion pressure is the shortest in the linked vessels, and the explosion pressure rising rate is highest at the vessel’s center. For the linked vessels, after ignition, the airflow ahead of the flame propagates to the secondary vessel, and the maximum airflow velocity of every monitoring point in the linked vessels increases. The detonation occurs when the flame propagates to the secondary vessel, which leads to a severe secondary explosion in the secondary vessel. The studies can provide an important reference for the safe design of industrial vessels.

Effect of burst pressure on vented hydrogen-air explosion in a cylindrical vessel

2015 ◽  
Vol 40 (19) ◽  
pp. 6478-6486 ◽  
Author(s):  
Jin Guo ◽  
Quan Li ◽  
Dongdong Chen ◽  
Kunlun Hu ◽  
Ke Shao ◽  
...  
Keyword(s):  
Cylindrical Vessel ◽  
Burst Pressure ◽  
Air Explosion
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