Analysis of Distribution Law of Fire Gas Concentration in Underground Cable Tunnel of Substation

2020 ◽  
Author(s):  
Zhiping Song ◽  
Xiaolong Wang ◽  
Zhenyu Tan ◽  
Xingshun Miao ◽  
Liang Zou
Keyword(s):  
Distribution Law ◽  
Gas Concentration ◽  
Underground Cable

Gas Concentration Distribution Law in the Roadway after Coal and Gas Outburst

2015 ◽  
Vol 713-715 ◽  
pp. 314-318
Author(s):  
Chun Li Yang ◽  
Yi Liang Zhao ◽  
Xiang Chun Li ◽  
Yang Yang Meng ◽  
Fei Fei Zhu
Keyword(s):  
Concentration Distribution ◽  
Correlation Coefficients ◽  
Coal And Gas Outburst ◽  
Gas Emission ◽  
Distribution Law ◽  
Gas Concentration ◽  
Research Results ◽  
Gas Outburst ◽  
Whole Process ◽  
Secondary Disasters

Gas emission happens after coal and gas outburst, and it could cause secondary disasters in the roadway. Therefore it is necessary to research gas concentration distribution law in the roadway after coal and gas outburst, and theoretical basis for avoiding the occurrence of secondary disasters could be provided. Based on the above, Fluent is used to simulate gas concentration distribution law in the roadway during outburst. The research results show that gas velocity of the initial stage is larger in the whole process of gas outburst and gas emission impacts opposite walls in the form of jet in the roadway intersection. The flow changes direction and moves along the main airway and return airway. It produces countercurrent along the main airway. Because the pressure in the main airway is high, gas migration velocity becomes zero after a certain distance and is "back" to return airway. The higher the outburst velocity is, the longer the flow length is. Gas concentration variation with two kinds of different outburst intensities and position are regressed and it shows that correlation coefficients of power function are the highest. The research results have a certain theoretical value to prevent the occurrence of secondary disasters after coal and gas outburst.

scholarly journals Study on Rock Burst Early Warning in the Working Face of Deep Coal Mines Based on the Law of Gas Emission

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Qinghua Zhang ◽  
Shudong He
Keyword(s):  
Rock Burst ◽  
Early Warning ◽  
Critical Value ◽  
Gas Emission ◽  
Distribution Law ◽  
Deep Mine ◽  
Gas Concentration ◽  
Research Results ◽  
Working Face ◽  
The Law

This study is aimed at predicting rock burst disasters in high gas mines. First, the distribution law and correlation of gas and stress in the F15-17-11111 working face of Pingdingshan No. 13 Mine were analyzed based on the coupling relationship between gas emission and stress in the working face. Next, the relationship between gas emission and stress distribution was revealed, and an early warning method of rock burst in the deep mine working face based on the law of gas emission was proposed and applied to the F15-17-11111 working face. Finally, the critical value of the gas concentration indicator for rock burst early warning in the F15-17-11111 working face was determined as 0.05%. The following research results were obtained. The gas emission and the mining stress in the F15-17-11111 working face are negatively correlated. Mechanically, their correlation satisfies the typical coupling. Besides, the critical value of the gas concentration indicator determined by the proposed early warning method boasts high accuracy in predicting rock burst disasters. It can be used as an early warning method for underground rock burst disasters to promote the safety of working face mining. The research results provide reference and guidance for the monitoring and early warning of rock burst disasters in deep high gas mines.

Study on Distribution of Gas Concentration on the Upper Corner by Thermal Imaging Equipment and Swirling Jet

2014 ◽  
Vol 608-609 ◽  
pp. 811-815
Author(s):  
Xiu Feng Zhang ◽  
Sheng Qiang Yang
Keyword(s):  
Thermal Imaging ◽  
Similarity Theory ◽  
Gas Migration ◽  
Distribution Law ◽  
Gas Concentration ◽  
Coal Gas ◽  
Gas Accumulation ◽  
Swirling Jet ◽  
Infrared Thermograph ◽  
Thermal Imaging Equipment

The gas accumulation is often mine hidden danger and has become a hotspot recently. in order to analysis the coal gas distribution law, the paper determines the heat transfer and temperature distribution using infrared thermograph and swirling jet device. Based on similarity theory, it can simulate the gas concentration distribution and gas migration. Based on an experiment result, the gas accumulation can be dissipated effectively and the distribution of gas concentration becomes uniform as the time, it can be provided as a reference of rotation fan design.

scholarly journals Numerical Simulation of Gas Ventilation Mode in Highway Gas Tunnel

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jihua Zhang ◽  
Yun Dong ◽  
Yadong Chen ◽  
Huasheng Sun ◽  
Jingke Wu ◽  
...  
Keyword(s):  
Effective Means ◽  
Ventilation System ◽  
Normal Operation ◽  
Distribution Law ◽  
Airflow Velocity ◽  
Gas Combustion ◽  
Gas Concentration ◽  
Ventilation Modes ◽  
Fluent Software ◽  
Mountain Tunnel

When the mountain tunnel projects passing through the complex formation with coal, it happened along with disaster accidents such as gas outburst, gas combustion, and gas explosion. These disasters should seriously threaten the safety and life of the construction personnel and affect the normal operation of the tunnel construction. Ventilation is the most effective means to control gas, fire, dust, heat, and other disasters. To study the effects of different ventilation modes in highway gas tunnels, Fluent software was used to simulate forced ventilation, exhaust ventilation, and mixed ventilation in a high gas tunnel of a highway in Hunan. The distribution law of the airflow velocity and gas concentration of these three ventilation modes were obtained to determine the optimal ventilation system. It was shown that vortex zones of different ranges formed in the tunnel for all three ventilation modes, and the gas concentration was higher in the vortex zone than in other regions. Mixed ventilation of them is superior to the other two modes, showing the best ventilation effect with regard to airflow velocity and gas concentration.

ANALISIS PENGUKURAN KONSENTRASI KARBONMONOKSIDA (CO) PADA BREATHING ZONE PETUGAS PARKIR BASEMENT MALL KOTA BANDUNG

2019 ◽  
Author(s):  
Gede H Cahyana
Keyword(s):  
Air Pollution ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Sampling Method ◽  
Breathing Zone ◽  
Gas Concentration ◽  
Average Value ◽  
Co Concentration ◽  
Personal Dosimeter ◽  
Co Gas

Indoor air pollution in closed room is one of the air pollution that gives serious threats to human health. One of them come from vehicle gas emissions in closed parking area. This research identifies and analyses CO concentration measured in Mall X parking man’s breathing zone with closed parking area and in Mall Y semi-opened parking area. CO measurement carried out by passive sampling method using Personal Dosimeter Tubes. Measurement result of CO gas concentration to parking man’s breathing zone in Mall X was 25 – 81,25 ppm with average value in 50 ± 26,15 ppm. Meanwhile CO gas concentration in Mall Y gave result 3,13 – 12,5 ppm with average value in 7,88 ± 4,36 ppm. Correlation value between CO concentration and its intake in Mall X area was 0,9983, meanwhile correlation value between CO concentration and its intake in Mall Y area was 0,9903. It was concluded that CO gas concentration measured in parking man’s breathing zone influenced the differences of CO intake value in significance value.

Guaranteed values – the basis of the analysis of the quality of individual products

2019 ◽  
pp. 20-33
Author(s):  
D. N. Kalacheva
Keyword(s):  
Frequency Distribution ◽  
Distribution Law ◽  
Basic Characteristics ◽  
Definition Of

Herein, the main features and rules of using guaranteed values when analyzing the quality of rocket - space equipment products are considered. The definition of the guaranteed value and the form of its presentation is given. It is indicated that guaranteed value is distributed and is characterized by the frequency distribution law. The main methods of representation and conversion of guaranteed values are statistical. Examples of determining the basic characteristics of guaranteed values are given.

METHOD FOR ESTIMATING PARAMETERS OF GENERALIZED MODEL OF LUMINOSITY OF SPACE OBJECTS BASED ON DATA FROM DIFFERENT RANGES

2018 ◽  
pp. 57-62
Author(s):  
E. I. Gundrova ◽  
A. P. Lukyanov ◽  
A. V. Pruglo ◽  
S. S. Ravdin
Keyword(s):  
Phase Angle ◽  
Real Data ◽  
Model Data ◽  
Space Object ◽  
Distribution Law ◽  
Generalized Model ◽  
Measurement Results ◽  
Space Objects ◽  
Reference Distance

Previously, the authors have proposed a generalized model for estimating the distribution law parameters of luminosity of space objects, assuming that not only successful but also unsuccessful measurement results are taken into account. Estimation was done on the data of observations under similar conditions: phase angle, range, sensibility of the telescope. The algorithm under such limitations was tested on model data and real measurements. Therefore, obtained results showed that algorithm did not fit for cases of changing range of space objects. In this work, the new algorithm, that allows to merge information from different ranges to the observed space object, is proposed. In this case, luminosity values are reduced to the ones at a reference distance of 1000 km considering sensibility of the telescope. To obtain estimates of the parameters the Cramer-Mises-Smirnov criterion is used. This algorithm was tested on model data and results of its work on real data were obtained. The data showed correct work of the algorithm and also confirmed the practicability of organization the registration of unsuccessful measurements.

scholarly journals Research on road engineering detection method based on GPR technology

2020 ◽  
Vol 165 ◽  
pp. 04014
Author(s):  
Liu Tao ◽  
Li Jia ◽  
Zheng Zhi-gang ◽  
Huang Zhi ◽  
Jiang Jian ◽  
...  
Keyword(s):  
Parameter Setting ◽  
Non Destructive Testing ◽  
Practical Application ◽  
Distribution Law ◽  
Destructive Testing ◽  
Road Engineering ◽  
The Road ◽  
Image Optimization ◽  
Testing Technology ◽  
Non Destructive

GPR is an effective non-destructive testing technology. This paper introduces its composition principle and operation method, explains the process of parameter setting and image optimization, obtains the dielectric constant of 10000 points, compares it with the density, and then obtains the uniformity distribution law of construction quality based on image. By calibrating the thickness of the road surface, the effective detection of road diseases can be realized, and the theoretical basis and practical application conditions of GPR technology can be clarified.

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