Influence of Cavity Width on Attenuation Characteristic of Gas Explosion Wave

Abstract

This study aimed to investigate the influence of cavity width on the attenuation characteristic of gas explosion wave. Attenuation mechanism of gas explosion wave through cavity was obtained by numerical simulation. The gas explosion shock wave energy can be greatly attenuated through the cavity structure in five stages, namely, plane wave, expansion, oblique reflection, Mach reflection, and reflection stack, to ensure that it is eliminated. Cavities with various width sizes, namely, 500 ∗ 300 ∗ 200, 500 ∗ 500 ∗ 200, and 500 ∗ 800 ∗ 200 (length ∗ width ∗ height, unit: mm), were experimented to further investigate the attenuation characteristics through a self-established large-size pipe gas explosion experimental system with 200 mm diameter and 36 m length. Results showed an evident attenuation effect on flame duration light intensity (FDLI) and peak overpressure with increasing cavity width. Compared with 300 mm, the overall FDLI decreased by 83.0%, and the peak overpressure decreased by 71.2% when the cavity width was 800 mm. The fitting curves of the FDLI and peak overpressure attenuation factors to width-diameter demonstrated that the critical width-diameter was 2.19 when the FDLI attenuation factor was 1. The FDLI attenuation factor sharply decreased at the width-diameter ratio range from 1.5 to 2.5 and basically remained steady at 0.17 at the width-diameter ratio range from 2.7 to 4.0. The peak overpressure attenuation factor gradually decreased with the increase of width-diameter ratio and changed from 0.93 to 0.28 with width-diameter ratio from 1.5 to 4.0. The research results can serve as a good reference for the design of gas explosion wave-absorbing structures.

Impact of Comminution Kinetic Energy: First Mathematical Modeling of Fragmentation Dynamic Fractures Per Millimetre of Coal

“…The calculation of kinetic energy impact for coal comminution with linear momentum can be complex and depends on various factors such as the velocity of the coal particles, the mass of the coal particles, the velocity of the impacting object, and the type of impacting object. However, some basic principles can be used to estimate the kinetic energy impact of coal comminution with linear momentum [42][43][44]. One approach to calculate the kinetic energy impact of coal comminution with linear momentum is to use the formula for kinetic energy in Eq.…”

“…For example, researchers are exploring the use of electromagnetic pulse technology to generate high-speed impacts that can break up coal particles, as well as the use of high-pressure water jets to break up coal particles. The application of kinetic energy impact application of coal comminution with linear momentum in industry is still in the early stages of development, but it has the potential to offer significant benefits in terms of reducing energy consumption and environmental impact, as well as improving the efficiency and effectiveness of the coal comminution process [40][41][42][43][44].…”

“…For example, researchers are using computational fluid dynamics simulations to model the impact of high-speed particles on coal particles, which can help to optimize the design and operation of comminution equipment. The recent research on kinetic energy impact application of coal comminution with linear momentum is focused on developing new technologies and processes that can improve the efficiency and effectiveness of the comminution process, while also reducing energy consumption and environmental impact [41][42][43][44].…”

Design and Development of Explosion-Proof Cavity of Hydraulic System Power Unit Applied in Explosion-Proof Area

“…The construction of the cavity has a critical impact on the gas explosion. The cavity width of the gas explosion wave attenuation characteristics of the impact is particularly significant, so the construction of the explosion-proof cavity should focus on the construction and size of the cavity [12,13].…”