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 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.

scholarly journals Analysis of the Characteristics and Influencing Factors of Gas Explosion in Heading Face

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xue-bo Zhang ◽  
Jian-liang Gao ◽  
Jing-zhang Ren ◽  
Chun-xia Wang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Influencing Factors ◽  
Geometric Model ◽  
Great Influence ◽  
Ignition Energy ◽  
Gas Explosion ◽  
Step Size ◽  
Time Step ◽  
Time Space

In order to accurately grasp the characteristics and influencing factors of gas explosion in heading face, the mathematical model of gas explosion was determined. According to the actual size of a heading face of a coal mine, a 3D geometric model with a length of 100 m was established, and the effects of ignition energy and gas explosion equivalent on the gas explosion characteristics of the heading face were analyzed. The results show the following. (1) The mathematical models for numerical simulation of gas explosion can accurately simulate the gas explosion and its propagation process. The time-space step size has a great influence on the simulation results. The grid spacing for numerical simulation of mine gas explosion is determined to be 0.1 m and the time step length is determined to be 0.001 s. (2) The ignition energy has a limited effect on gas explosion characteristics. It only has a certain influence on the gas explosion process, but has little influence on the overpressure of shock wave. The larger the ignition energy is, the faster the explosion reaction speed is, and the maximum overpressure increases slightly. When the ignition energy increases to a certain value, the time of peak shock wave and the maximum overpressure both tend to be stable. The ignition energy has little effect on gas explosion characteristics when an explosion accident occurs underground with a large amount of gas accumulation. (3) The gas explosion equivalent has a great influence on the overpressure of gas explosion shock wave. The higher the explosion equivalent is, the greater the pressure is, and the peak value of the shock wave overpressure increases with the explosion equivalent as a power function. The research results have important guiding significance for the research and development of new technology for prevention and control of gas explosion.

scholarly journals Study on Inhibitory Effect of Cavity on Gas Explosion Propagation

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhuo Yan ◽  
Shujie Yuan ◽  
Zhongqing Li ◽  
Shicheng Gu ◽  
Chaomin Mu
Keyword(s):  
Shock Wave ◽  
Experimental Study ◽  
Vacuum Chamber ◽  
Wave Attenuation ◽  
Inhibitory Effect ◽  
Pipeline System ◽  
Gas Explosion ◽  
Explosion Suppression ◽  
Cavity Structure ◽  
Single Cavity

It is pointed out in the literature that the vacuum chamber has the effect of explosion suppression. The effect of explosion suppression depends on the volume of the vacuum chamber, while the vacuum degree has little effect on the performance of explosion suppression. Inspired by this, to explore a new method of gas explosion suppression, a rectangular steel cavity with a wall thickness of 10 mm, a length of 500 mm, a width of 800 mm, and a height of 200 mm was designed. The cavity was installed in a pipeline system to carry out experimental research and to investigate the law of attenuation of gas explosion flames and shock wave overpressure after passing through the cavity. The results show that the single cavity has the function of flame-out and wave attenuation, which attenuates the explosion flame and shock wave overpressure by 42.5% and 11%, respectively, and that the dual cavity further improves the performance of flame-out and wave attenuation, which attenuates flame and shock wave overpressure by 75.4% and 26.7%, respectively. On the basis of the experimental study, a numerical model was established, and a numerical simulation was carried out under the same conditions as the experimental study. The results show that the single cavity inhibits the propagation of the shock wave and attenuates the shock wave overpressure by 10.61%. The dual cavity further improves the suppression performance and attenuates the shock wave overpressure by 28.88%. Finally, by simulating the propagation process of the gas explosion shock wave and flame in the cavity, the mechanism of inhibiting gas explosion propagation by the cavity structure is analyzed.

scholarly journals Influence of Roadway Cross-Section Shape on Gas Explosion Shock Wave Law in U-Type Ventilation Working Faces

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jiajia Liu ◽  
Mengqi Shen ◽  
Shouqi Chen ◽  
Ming Yang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Simulation Study ◽  
Simulation Software ◽  
Effective Length ◽  
Shaanxi Province ◽  
Gas Explosion ◽  
Cross Sectional ◽  
Working Face ◽  
Tunnel Section

In U-shaped ventilation working face, different tunnel section shapes are one of the important factors affecting the propagation of gas explosion shock wave. In order to study the propagation law of gas explosion shock wave in working face, the numerical simulation study was carried out by using Fluent simulation software combined with the actual situation of gas explosion in #415 working face of Chenjiashan Coal Mine in Shaanxi Province. By constructing a three-dimensional mathematical and physical model, a simulation study of the upper-corner gas explosion was carried out. The results are described as follows. (1) After the gas explosion shock wave propagates 40 m, the overpressure peak equidistant difference tends to be stable and attenuates and propagates in the form of a single shock wave. The study determines that the effective length of the U-shaped ventilation inlet/return tunnel is 40 m. (2) When the tunnel section is trapezoidal, the initial overpressure of the gas explosion shock wave propagating to the inlet/return airway is the highest, followed by rectangular and semicircular arches, but the internal overpressure attenuation trend of different cross-sectional shapes is the same. (3) The gas explosion shock wave propagates radially along the working face section during the working face propagation. The farther away the location is from the upper corner of the tunnel during a gas explosion with different cross-sectional shapes, the closer the cutoff overpressure peak is. The attenuation trend of overpressure with the propagation distance conforms to the power function law. The research results provide an important theoretical direction for the numerical simulation of gas explosions in coal mining faces.

scholarly journals Effect of Different Bend Pipes on the Propagation Characteristics of Premixed Methane-Air Explosion in Confined Spaces

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jinwei Qiu ◽  
Bingyou Jiang ◽  
Mingyun Tang ◽  
Liang Zhou ◽  
Bo Ren
Keyword(s):  
Shock Wave ◽  
Attenuation Coefficient ◽  
Propagation Characteristics ◽  
Gas Explosion ◽  
Bending Angle ◽  
Pipe System ◽  
Confined Spaces ◽  
Air Explosion ◽  
Gas Volume ◽  
Initial Peak

To explore the effect of different bend pipes on the propagation characteristics of premixed methane-air explosion, the experimental explosion pipe system and numerical model were established. By adopting the comparative analysis of experiments and numerical modeling, it conducted researches on the overpressure evolution of gas explosion shock wave in pipes with different bends and obtained the expressions of attenuation coefficient of shock wave overpressure. The results showed that the change of pipe direction accelerated the attenuation of gas explosion shock wave. The propagation attenuation of gas explosion in the bend pipe was mainly affected by the bending angle and initial peak overpressure before bending. With the increase of the bending angle, the attenuation coefficient of gas explosion shock wave gradually increased. For the same bending angle, the attenuation coefficient of gas explosion shock wave increased with the increase of gas volume. The obtained coupling relationships between attenuation coefficient, bending angle, and initial peak overpressure before bending were useful for estimating the overpressure value after the bend. The results presented in this paper have important significance for the assessment of structures that have been damaged in the mine laneway of gas exploration accidents, further enriching the gas exploration spread theory.

Study on Hazard Effects of Gas Explosion in Coal Laneways

2011 ◽  
Vol 402 ◽  
pp. 846-849
Author(s):  
Lei Pang ◽  
Tong Wang ◽  
Yu Shu Xie ◽  
Wei Yao ◽  
Qi Zhang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Temperature Field ◽  
High Temperature ◽  
Flame Front ◽  
Axial Distance ◽  
Distribution Characteristics ◽  
Gas Explosion ◽  
Flame Region ◽  
Air Explosion

Methane-air explosion is one of the main accidents in coal mines. In this paper, the hazard effects of the gas explosion in a long straight coal laneway were studied by virtue of numerical simulation. Distribution characteristics of the shock wave overpressure, the flame speed and the temperature field were obtained. Along the increasing axial distance, shock wave overpressure increases in original methane-air area and decreases beyond the original methane-air area. Range of flame exceeds original methane-air area. Flame accelerates continually in original methane-air area and decelerates beyond the original methane-air area. The temperature attenuates slowly along the increasing distance in the flame area by virtue of flame front, and attenuates quickly along the increasing distance beyond the flame region. High temperature hazard involves farther area beyond original methane-air area.

Numerical Modelling of Gas Explosion Overpressure Mitigation Effects

2020 ◽  
Vol 1006 ◽  
pp. 117-122
Author(s):  
Yurii Skob ◽  
Mykhaylo Ugryumov ◽  
Yuriy Dreval
Keyword(s):  
Mathematical Model ◽  
Shock Wave ◽  
Computer Technology ◽  
Solid Wall ◽  
Three Dimensional ◽  
Probit Analysis ◽  
Gas Explosion ◽  
Compression Phase ◽  
Damage Probability ◽  
Fueling Station

The main aims of this study are to assess numerically the mitigation effects caused by the solid wall installed at the fueling station in order to protect personnel from the consequences of the emergent gas explosion, evaluate the optimal location of the wall and choose the appropriate material the wall have to be made of in order not to be destructed. A three-dimensional mathematical model of an explosion of hydrogen-air cloud is used. A computer technology how to define the personnel damage probability fields on the basis of probit analysis of the explosion wave is developed. The mathematical model takes into account the complex terrain and three-dimensional non-stationary nature of the shock wave propagation process. The model allows obtaining time-spatial distribution of damaging factors (overpressure in the shock wave front and the compression phase impulse) required to determine the three-dimensional non-stationary damage probability fields based on probit analysis. The developed computer technology allows to carry out an automated analysis of the safety situation at the fueling station and to conduct a comparative analysis of the effectiveness of different types of material the protective facilities made of.

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.

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