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.

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.

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.

Application of Fault Tree Analysis Method in Gas Explosion Accident

2013 ◽  
Vol 709 ◽  
pp. 340-343
Author(s):  
Xiu Wang
Keyword(s):  
Coal Mine ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Gas Explosion ◽  
Minimal Path ◽  
Tree Analysis ◽  
Gas Concentration ◽  
Coal Mine Gas ◽  
Mine Gas ◽  
Minimal Path Sets

According to the gas explosion theory and the investigation of occurred gas explosion, the basic events that lead to coal mine gas explosion are summarized and the fault tree is worked out. Besides, the fault tree analysis is used for qualitative analysis. The minimal cuts sets, minimal path sets and structure importance are solved. Accordingly, the reasons of gas explosion are obtained, which can provide references for the prevention of coal mine gas explosion. The study showed that: the minimal cut sets of gas explosion is much(165) and the minimal path sets is small(4), and it is the major dangerous and harmful factors in coal mine. It that gas concentration must be strictly controlled and all sources of ignition should be eliminated is the basic and fundamental way to prevent mine gas explosion.

scholarly journals Early Warning of Gas Concentration in Coal Mines Production Based on Probability Density Machine

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5730
Author(s):  
Yadong Cai ◽  
Shiqi Wu ◽  
Ming Zhou ◽  
Shang Gao ◽  
Hualong Yu
Keyword(s):  
Probability Density ◽  
Coal Mine ◽  
Early Warning ◽  
Learning Algorithms ◽  
Class Imbalance ◽  
Gas Explosion ◽  
Concentration Data ◽  
Gas Concentration ◽  
Imbalance Learning ◽  
Class Imbalance Learning

Gas explosion has always been an important factor restricting coal mine production safety. The application of machine learning techniques in coal mine gas concentration prediction and early warning can effectively prevent gas explosion accidents. Nearly all traditional prediction models use a regression technique to predict gas concentration. Considering there exist very few instances of high gas concentration, the instance distribution of gas concentration would be extremely imbalanced. Therefore, such regression models generally perform poorly in predicting high gas concentration instances. In this study, we consider early warning of gas concentration as a binary-class problem, and divide gas concentration data into warning class and non-warning class according to the concentration threshold. We proposed the probability density machine (PDM) algorithm with excellent adaptability to imbalanced data distribution. In this study, we use the original gas concentration data collected from several monitoring points in a coal mine in Datong city, Shanxi Province, China, to train the PDM model and to compare the model with several class imbalance learning algorithms. The results show that the PDM algorithm is superior to the traditional and state-of-the-art class imbalance learning algorithms, and can produce more accurate early warning results for gas explosion.

Research on the SDS + Castor Oil Aqueous Solution Used as Methane Absorption and Gas Explosion Suppression Material

2011 ◽  
Vol 685 ◽  
pp. 264-271
Author(s):  
Zeng Zhi Zhang ◽  
Hong Mei Xu ◽  
Na Gu
Keyword(s):  
Aqueous Solution ◽  
Coal Mine ◽  
Castor Oil ◽  
Volume Fraction ◽  
Explosion Chamber ◽  
Gas Explosion ◽  
Methane Absorption ◽  
Explosion Suppression ◽  
Water Based ◽  
Mine Gas

A kind of water-based material which can absorb mine gas and suppress gas explosion was designed for the purpose of keeping the coal mine safe. The anionic surfactant sodium dodecyl sulfate (SDS) was used as the main gas absorbent according to the micelle solubilization of surfactant, and castor oil was used as absorption enhancer in this material. Methane was regarded as a model of mine gas. The volume fraction of methane absorption was measured by head space gas chromatography. The state of the aggregates in the material was observed by transmission electron microscopy. The explosion suppression effect was tested by self-made explosion chamber which can simulate gas explosion. Also the methane absorption rate of the water-based material was tested in practice of coal mine. The results showed that the maximum volume fraction of methane absorption of the SDS + castor oil aqueous solution can reach up to 12.65%; with the addition of castor oil, the structure of aggregates in SDS aqueous solution system changed from spherical to lamellar, so it can provide greater non-polar microenvironment for methane; the water-based material can lower the maximum explosion pressure to some extent when it was sprayed into the explosion chamber in atomization condition before ignition; field test on methane absorption showed that the methane absorption ratio can reach up to 16.7%, which is much higher than the experimental value.

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.

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