Numerical Analysis of Effect of the Number of Nozzles on Water Mist Flow Field for Gas Explosion Suppression

2011 ◽  
Vol 301-303 ◽  
pp. 478-482
Author(s):  
Fan Mao Meng ◽  
Zhi Chao Liu
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
New Technology ◽  
Water Mist ◽  
Theoretical Research ◽  
Gas Explosion ◽  
Explosion Suppression ◽  
Coal Mine Gas ◽  
Mist Flow ◽  
The Relationship

Explosion suppression by water mist is a new technology for the control of coal mine gas explosion with the three elements in the gas explosion at the same time. By building the physical model of the horizontal laneway in mine, and using the method of theoretical research and numerical simulation, this paper studies the relationship between the number of nozzles and H2O percentage and the distance for stable percentage of H2O, and provides a reliable for the design of water mist system for gas explosion suppression in the horizontal laneway in mine.

Numerical Analysis of Water Mist Flow Field for Gas Explosion Suppression in Upper Corner

2011 ◽  
Vol 71-78 ◽  
pp. 4848-4851
Author(s):  
Fan Mao Meng ◽  
Zhi Chao Liu ◽  
Zhi Zhong Liu
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Coal Mine ◽  
Water Mist ◽  
Gas Explosion ◽  
Gas Concentration ◽  
Methane Gas ◽  
Gas Accumulation ◽  
Explosion Suppression ◽  
Mist Flow

The water mist is an economical and environmental agent for gas explosion suppression. It can be applied in the commonly gas concentration zones and the gas accumulation zones which is difficult to reduce the concentration of methane gas. By numerical analysis, this paper studies the effect of the direction and the number of the nozzles, and the distance form the nozzles to the wall at X direction in upper corner in coal mine. For gas explosion suppression in upper corner, it can use one nozzle which direction is same as the wind and the distance is 2m.

Effect of Wind Speed to Water Mist in Coal Mine Laneway

2011 ◽  
Vol 71-78 ◽  
pp. 4935-4938 ◽  
Author(s):  
Zhi Chao Liu ◽  
Fu Wei Sun ◽  
Fan Mao Meng
Keyword(s):  
Numerical Analysis ◽  
Wind Speed ◽  
Coal Mine ◽  
Water Mist ◽  
Gas Explosion ◽  
Explosion Suppression ◽  
The Status ◽  
The Relationship

There are many factors which affect the effectiveness of the gas explosion suppression by the water mist in the coal mine laneway. This paper studies the relationship between the wind speed and the status of the water mist by numerical analysis. The results shows, for gas explosion suppression in coal mine laneway, the water mist system must be arranged in the region that the wind speed is 5m/s or slower.

Evaluation of propane explosion with applied water mist

2021 ◽  
Vol 39 (6) ◽  
pp. 443-454
Author(s):  
Ping-Jung Li ◽  
Chao-Shi Chen ◽  
Cheng-Yu Weng ◽  
Hsin-Hsiu Ho
Keyword(s):  
Water Mist ◽  
Experimental Results ◽  
Gas Explosion ◽  
Applied Water ◽  
Occurrence Time ◽  
Fuel Concentration ◽  
Explosion Suppression ◽  
Explosion Limit ◽  
Air Speed ◽  
Entrained Air

This article discusses the overpressure of a gas explosion and the performance of applying water mist for explosion suppression. According to the experimental results, the larger the opening area, the more difficult it is for pressure to accumulate, resulting in lower overpressure of a gas explosion. When the opening was opened under a high air speed environment, the amount of entrained air was greater. Consequently, the occurrence time of the explosion was shorter than at a low air speed. Despite the water mist nozzle being installed outside the enclosure, a propane gas explosion still occurred regardless of the amount of water mist used, failing to suppress the explosion. However, the water mist nozzle installed inside the enclosure supplied an adequate amount of water mist that could wash a part of the propane, resulting in the fuel concentration dropping below the lower explosion limit, hindering the occurrence of an explosion.

scholarly journals Research on explosion suppression technology of low-concentration gas transmission pipeline

2021 ◽  
Vol 267 ◽  
pp. 01057
Author(s):  
Weizheng Wu
Keyword(s):  
Coal Mine ◽  
Water Mist ◽  
Inert Gas ◽  
Practical Significance ◽  
Low Concentration ◽  
Explosion Suppression ◽  
Coal Mine Gas ◽  
Transmission Pipeline ◽  
Mine Gas ◽  
Transmission Pipelines

In order to effectively control the explosion accident disasters of low-concentration gas transmission pipelines and improve the safety of low-concentration gas transmission and utilization process, the paper has summarized and analyzed the current three types of low-concentration gas transmission pipeline explosion suppression technologies and devices used in the field, including powder suppression, inert gas suppression and fine water mist suppression, and put forward the problems of coal mine gas transmission pipeline explosion suppression technologies. It is of great practical significance to pipeline transmission and utilization of low-concentration gas.

scholarly journals Numerical Simulation of Impact Loads of Main Fan Blades in Gas Explosion

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jianliang Gao ◽  
Jingzhang Ren ◽  
Xuebo Zhang ◽  
Jiajia Liu ◽  
Chunxia Wang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Radial Direction ◽  
Three Dimensional ◽  
Time Interval ◽  
Impact Loads ◽  
Gas Explosion ◽  
Occurrence Time ◽  
Fan Blade ◽  
The Relationship

The shock wave generated by a severe gas explosion accident can damage the main fan, and the toxic and harmful gases in the well cannot be discharged in time, leading to the expansion of disaster accidents. Therefore, it is meaningful to study impact loads of main fan blades in gas explosion. In this paper, a full-scale three-dimensional numerical simulation model has been established based on No. 2 Yangchangwan Coal Mine in China. The propagation of shock wave in shaft and air tunnel and the dynamic process of main fan blade subjected to shock load when gas explosion of different volume occurs in heading face have been simulated. The overpressure on the blade at different times, the overpressure distribution on the blade, and the relationship between the overpressure and the explosion intensity have been obtained. The results showed that the time when the explosion shock wave reached, each blade of the wind turbine was basically the same, and the time when each blade reached, the maximum overpressure was basically the same. With the increase of gas explosion volume, occurrence time of overpressure and maximum overpressure time on the fan blade were shortened, and the time interval between them was also shortened. There is a little difference in the overpressure of each blade. Fan blade directly above the hub was subject to the highest overpressure, and fan blade directly below the hub was subject to the lowest overpressure. The overpressure of the maximum overpressure blade was 5.44% to 6.77% higher than that of the minimum overpressure blade. The distribution of overpressure on each fan blade was uneven, and the overpressures on blade edges were the lowest. The overpressure on the fan blades showed a corrugated distribution along the radial direction. There was 12.06% to 15.40% difference between the maximum and minimum overpressure section on the fan blade.

Damage Effect of Shock Wave on Ventilation Structures during Gas Explosion

2010 ◽  
Vol 29-32 ◽  
pp. 118-124
Author(s):  
Zhi Ming Qu
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Low Cost ◽  
Ventilation System ◽  
Experimental Studies ◽  
Mine Ventilation ◽  
Damage Effect ◽  
Main Task ◽  
Gas Explosion ◽  
The Relationship

When the gas accumulation position, volume and concentration are basically determined, the gas explosion is ignited with the minimum ignition power. The main task is to study the damage effects by explosion shock wave on the roadway structures or barriers within the roadway. That the roadway and its ventilation structures are damaged will have an important impact on some lanes, mine ventilation system as well as the whole mine, which will influence the decision-making during disasters relief. As the experimental studies of damage effect by gas explosion is more difficult, therefore, the numerical simulation and analysis is important and useful. In conclusion, simulation can not only use low-cost way to reproduce gas explosion shock wave propagation and the damage of roadway structures, but also obtain the relationship between explosion damage effect and the volume and concentration.

scholarly journals Influences of the Workpiece Pose Errors on Gear Skiving Accuracy

2021 ◽  
Author(s):  
Xiaochuan Lin ◽  
rongjing hong ◽  
Yawen Wang ◽  
Yun Peng ◽  
Xiaolei Ren
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Machine Tool ◽  
Coordinate Transformation ◽  
Inverse Kinematics ◽  
Kinematic Chain ◽  
Pso Algorithm ◽  
Cutting Depth ◽  
Tooth Flank ◽  
The Relationship

Abstract This paper investigates the influence of the workpiece pose errors on gear skiving accuracy. First, based on the theory of homogeneous coordinate transformation, the mapping relationship between the tooth flank of the workpiece and the skiving tool is established according to the principle of gear skiving. Second, the workpiece pose errors are defined, and the relationship between each workpiece pose error and cutting depth is analyzed. According to the kinematic chain of the machine tool, a method for measuring the workpiece pose errors based on actual inverse kinematics is proposed. Third, the tooth deviations from individual workpiece pose errors, and the coupling workpiece pose errors are studied. The sensitive errors are obtained from the tooth deviation by numerical simulation. Finally, the numerical analysis is verified by gear skiving experiments, and the proposed method can be used to identify the possible workpiece pose errors. Furthermore, the PSO algorithm is introduced to guide the workpiece setting pose errors in the gear skiving process.

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