scholarly journals Investigation on the characteristics of single-phase gas explosion and gas-coal dust coupling explosion in bifurcated tubes

2020 ◽  
pp. 337-337
Author(s):  
Guoxun Jing ◽  
Shaoshuai Guo ◽  
Yulou Wu
Keyword(s):  
Shock Wave ◽  
Bifurcation Point ◽  
Single Phase ◽  
Coal Dust ◽  
Straight Tube ◽  
Gas Explosion ◽  
Distribution Law ◽  
Tube Section ◽  
Bifurcation Angle ◽  
Gas Coal

In order to deeply understand the overpressure propagation characteristics of explosion shock wave of single-phase gas explosion and gas-coal dust coupling explosion in bifurcated tube, this paper makes a comprehensive and in-depth study on the change and distribution law of explosion shock wave overpressure of single-phase gas explosion and gas-coal dust coupling explosion in bifurcated tube by means of experimental research, the results show that: The explosion shock wave overpressure of single-phase gas explosion and gas-coal dust coupling explosion is all affected by the bifurcation angle of the tube, the larger the bifurcation angle of the tube is, the greater the explosion shock wave overpressure is. In terms of explosion shock wave overpressure distribution, single-phase gas explosion and gas-coal dust coupling explosion show a similar overall development trend, and the maximum explosion shock wave overpressure is obtained in front of the bifurcation point. The mutation coefficients of explosion shock wave overpressure of single-phase gas explosion and gas-coal dust coupling explosion before and after the bifurcation point of the tube are all affected by the bifurcation angle of the tube. In the straight tube section, the mutation coefficient of explosion shock wave overpressure increases gradually with the increase of the bifurcation angle of the tube, while the situation in the inclined tube section is just the opposite. Under the condition of the same bifurcation angle, the shock wave overpressure mutation coefficient of gas-coal dust coupling explosion is smaller than that of single-phase gas explosion.

The Solid Barrier Explosion Device of the Gas Recoil Type of the Extracting Coal Face of the Coal Mine

2011 ◽  
Vol 121-126 ◽  
pp. 3015-3019 ◽  
Author(s):  
Chun Rong Wei ◽  
Min Qiang Xu ◽  
Jian Hua Sun ◽  
Xian Wei Zhang
Keyword(s):  
Shock Wave ◽  
High Temperature ◽  
Coal Mine ◽  
Coal Dust ◽  
Structure Design ◽  
Dust Explosion ◽  
Gas Explosion ◽  
Coal Face

Aiming at the limitation of the roadway-type barrier explosion device which is being used in the coal mine, this paper suggests to establish the gas recoil type barrier explosion device. Using the mechanism of the gas recoil type, it made the structure design of the solid barrier explosion device of the circle-arch roadway. The device has the better effect on the elimination of the damage and the influence of the high-temperature flame of the gas and coal dust explosion and the overpressure damage of the shock wave. Especially, it can have a more realistic function for the secondary explosion or multiple explosions of the underground gas explosion.

Coupling effects of foam ceramics on the flame and shock wave of gas explosion

2012 ◽  
Vol 50 (4) ◽  
pp. 797-800 ◽  
Author(s):  
Jinfeng Zhang ◽  
Zhongqiang Sun ◽  
Yanmin Zheng ◽  
Zhaogui Su
Keyword(s):  
Shock Wave ◽  
Gas Explosion ◽  
Coupling Effects

scholarly journals Explosion disaster distribution characteristics and outlet open-close effect of turning roadway

2020 ◽  
Author(s):  
Pengfei Lv ◽  
Minghua Ju ◽  
Jiaxu Zhang ◽  
Lei Pang ◽  
Kai Yang
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Human Body ◽  
Nonlinear Dynamic Analysis ◽  
Distance Effect ◽  
Distribution Law ◽  
Destructive Effect ◽  
Bending Angle ◽  
Finite Element Program ◽  
Minimal Impact

Abstract In this study, under the open-close conditions of a roadway outlet, the nonlinear dynamic analysis finite element program ANSYS/LS-DYNA was used to build models of explosions on roadways with 0˚ and 90˚ bending angles, to compare and analyse the shock wave propagation characteristics and variation laws. Moreover, the destructive effect of the explosion on the partition was analysed based on the level of damage caused to the human body by shock wave overpressure. The results show that the bending angle has an impact on the space-time distribution law of the explosion shock waves on the roadway. As the bending angle increases, the peak overpressure attenuation of the shock waves becomes prominent, and the arrival time for the same distance increases. The closure of the roadway outlet has a distance effect on the peak overpressure of the shock waves. The explosion shock waves cause the peak overpressure to rise sharply owing to the reflection and stacking effects near the closure. In the far zone of the outlet, the attenuation of the shock waves is too fast and has minimal impact on the peak overpressure. Additionally, overall, the closure of the roadway outlet increases the damage range of the explosion shock waves and the severity of their effect on the human body. With an increase in the bending angle, the damage range and severity decrease. These results can provide a reference for explosion disaster evaluation and prevention.

Effect of low-concentration coal dust on gas explosion propagation law

2020 ◽  
Vol 367 ◽  
pp. 243-252 ◽  
Author(s):  
Chaowei Guo ◽  
Hao Shao ◽  
Shuguang Jiang ◽  
Yajun Wang ◽  
Kai Wang ◽  
...  
Keyword(s):  
Coal Dust ◽  
Gas Explosion ◽  
Low Concentration ◽  
Propagation Law

Theoretical and Numerical Investigation of Supersonic Multiphase Gas Injection

2021 ◽  
Author(s):  
Da Zhu ◽  
Mohan Sivagnanam ◽  
Ian Gates
Keyword(s):  
Shock Wave ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Single Phase ◽  
Gas Injection ◽  
Continuous Phase ◽  
Solid Particles ◽  
Gas Flows ◽  
Theoretical Derivation ◽  
The Impact

Abstract Supersonic gas injection can help deliver gas uniformly to a reservoir, regardless of reservoir conditions. This technology has played a key role in enhanced oil recovery (EOR) and in particular, thermal enhanced oil recovery operations. Most previous studies have focused on single phase gas injection whereas in most field applications, multiphase and multicomponent situations occur. In the research documented in this paper, we report on results of evaluations of compressible multiphase supersonic gas flows in which gas is the continuous phase is seeded with dispersed liquid droplets or solid particles. Theoretical derivation and numerical simulations with and without relative motions between continuous and disperse phases are examined first. The results illustrate that the shock wave structures and flow properties associated with the multiphase gas flows are different than that of single-phase isentropic flows. The existence and importance of relaxation zones after the normal shock wave in multiphase flow is described. Numerical computational fluid dynamics (CFD) simulations are conducted to show how the multiphase multicomponent flow affects gas phase injection under different conditions. The impact of solid/liquid mass loading on flow performance is discussed. Finally, the practical application of the findings is discussed.

scholarly journals Theoretical Analysis on the Attenuation Characteristics of Strong Shock Wave of Gas Explosion

2011 ◽  
Vol 24 ◽  
pp. 422-425 ◽  
Author(s):  
Bingyou Jiang ◽  
Baiquan Lin ◽  
Shulei Shi ◽  
Chuanjie Zhu ◽  
Ziwen Li
Keyword(s):  
Shock Wave ◽  
Theoretical Analysis ◽  
Strong Shock ◽  
Strong Shock Wave ◽  
Gas Explosion ◽  
Attenuation Characteristics

Numerical Analysis of Shock Wave Propagation Law of Internal Gas Explosion

2011 ◽  
Vol 105-107 ◽  
pp. 299-302
Author(s):  
Xiu Hua Zhang ◽  
Yan Yan Wu
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Initial Energy ◽  
Shock Wave Propagation ◽  
Coupling Method ◽  
Frame Structure ◽  
Gas Explosion ◽  
Fluid Structure ◽  
Explosion Pressure ◽  
Propagation Law

The purpose of this paper is to research on shock wave propagation law of internal gas explosion. The multi-material Eulerian and Lagrangian coupling algorithm was adopt. Using ANSYS/LS-DYNA dynamic analysis software to build frame structure, air and gas explosion models. Multiple ALE elements for simulating air and gas explosion material the analysis of blast shock wave propagation in a three-story steel frame structure and the characteristics of explosion pressure using fluid-structure coupling method are carried out. The conclusions show that fluid-structure coupling method can well simulated shock wave propagation of internal gas explosion, and the pressure peak of blast shock wave increased with the increasing of the blast air initial energy. Locality is the characteristic of explosion pressure in sealed space, and the pressure pass weakly when it propagates in solid.

Characterization of Injection Nozzles for Gas-Solid Flow Applications

1991 ◽  
Vol 113 (3) ◽  
pp. 469-474 ◽  
Author(s):  
F. T. Dodge ◽  
S. T. Green ◽  
J. E. Johnson
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Cone Angle ◽  
Stokes Number ◽  
Velocity Profiles ◽  
Particle Mass ◽  
Straight Tube ◽  
Turbulence Level ◽  
Free Jet ◽  
Combustion Systems

Laser phase-doppler velocimetry measurements have been used to characterize the particle-gas sprays produced by straight-tube nozzles that simulate idealized fuel injectors for solid fuel combustion systems. Tests were conducted on two nozzle sizes, for two particle sizes, two loading ratios, and two gas velocities. The Reynolds numbers was varied from 9500 to 19000, and the Stokes number from 1.9 to 61.4. It was found that the velocities of the particles in the spray decelerate more slowly, and the velocity profiles are generally more narrow, than for a single-phase free-jet. The turbulence level of the particles in the sprays was found to be less than half the turbulence level of a single-phase free-jet, and the turbulent velocity profiles were not yet fully developed at X = 40D. The hydrodynamic characteristics of the nozzles that are the most important for combustion systems were found to be: (a) the particle spray expands radially at a cone angle of 2° (measured at the radius corresponding to the peak of the particle mass flux distribution); and (b) the nozzle pressure drop and particle mass flow can be related by a correlation that depends on loading ratio, Reynolds number, Stokes number, and the pressure drop coefficient of the nozzle for a single phase flow.

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