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Research on time structure characteristic of gas concentration sequence in the working face

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Journal of Coal Science & Engineering(China) 2011年第3期17卷 311-315页

作者： HE Li-wen SONG Yi SHI Shi-liang LI Xi-bin School of Energy Engineering Xiangtan University Xiungtan 411100 China School of Resource and Safety Engineering Centeral Southern University Changsha 410083 China School of Energy and Safety Engineering Hunan University of Science and Technology Xiangtan 411201 China

In the procedure of coal industry production, the losses of the persons and economy caused by the gas explosion accidents are most serious, therefore, prevention and control of the gas explosion accident of the coal mines is an important issue needed to be solved urgently in the safety production work of our coal mines. The characteristic of time structure variation index characteristic was analyzed about gas concentration sequence of three measure points in the NO. 1I 1024 working face. It was found that the value of time variation about three measure points was mostly 1〈δ≤1.5, and gas emission presented consistently strong-clustering state twice, and the value of time variation presented continuous variation state in the active stage of gas concentration. Complex characteristics of the value indicated gas emission was continuously variable in time or space and presented the complex nonlinear characteristics. So the characteristic about gas emission system was correctly depicted and analyzed to gas emission system according to the relation of its state variation and essential of nonlinear system. The result also provided reliable warranty for its continued nonlinear research on gas emission.

关键词： time structure gas concentration sequence working face nonlinear

A review on effects of different factors on gas explosions in underground structures

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Underground Space 2020年第4期5卷 298-314页

作者： Ying Xu Yimiao Huang Guowei Ma School of Civil and Transportation Engineering Hebei University of Technology5340 Xiping RoadBeichen DistrictTianjinChina Department of Civil Environmental and Mining EngineeringUniversity of Western Australia35 Stirling HighwayCrawleyWAAustralia

Underground structures are normally located in highly-confined and congested spaces,which may lead to severe gas explosion accidents,with significant human and economic *** accurately evaluating the consequences of these explosions,a variety of influencing factors need to be considered,including concentrations of gas mixtures,vent conditions,obstacles,and ignition ***,a good review on these influencing factors is important for a better understanding of explosion behavior,e.g.,the deflagration to detonation *** this study,some critical influencing factors for gas explosions in underground or confined spaces are investigated,and the effects of the factors on such gas explosions are *** results are discussed,along with findings from *** present study provides a reference for future studies on safety management and consequence mitigation for underground gas explosions.

关键词： gas explosion gas concentration Ventilation Obstacle Ignition feature Detonation

Combustion Characteristics of Solid Refuse Fuels from Different Waste Sources

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Journal of Renewable Materials 2020年第7期8卷 789-799页

作者： Jong Seong Chae Seok Wan Kim Tae In Ohm Department of Civil and Environmental Engineering Hanbat National UniversityDaejeon34158Korea Department of Fire and Environmental Safety Daegu Haany UniversityDaegu38610Korea

In the production(as co-fuel or alone)of solid refuse fuel(SRF),knowledge about the characteristics of the raw materials is required for an ecofriendly and effective combustion *** are commonly produced by drying combustible waste and removing incombustible matter,resulting in a higher combustibility as compared to the original ***,the characteristics of SRFs may highly vary depending on where and from which materials they were ***,we investigated the characteristics of various SRFs using thermogravimetric analysis(TGA).As a TGA sample is commonly small,on the scale of milligrams,and,unlike homogeneous fuels,SRFs are heterogeneous,individual SRF samples analysed with this method may not represent the bulk material,and sample properties may vary significantly between ***,we further performed combustion experiments using a small-scale combustor and sample sizes from 1 to 10 *** optimise SRF combustor design and determine the SRF characteristics,proximate,elemental,heating value,TG,and differential thermogravimetric analyses were conducted,and weight losses and gas concentrations at different temperatures were measured upon *** lower heating values of the three analysed SRFs were 20,976,16,873,and 19,762 kJ/kg,and their Cl contents were 0.89,0.95,and 1.27 wt.%(legal criterion[Cl]<2.0 wt.%).TGA and small combustor experiments showed that complete weight loss was achieved below 500°***,CO was detected until 620°C.

关键词： Solid refuse fuel small-scale combustor thermogravimetric analysis waste gas concentration

Radiative Forcing of SO_2 and NO_x: A Case Study in Beijing

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Advances in Atmospheric Sciences 2006年第2期23卷 317-322页

作者：孙治安王晓云曾宪宁 Bureau of Meteorology Research Centre GPO BOX 1289K Melbourne 3001Australia Beijing Regional Meteorological Centre Beijing Nanjing University of Information Science and Technology Nanjing 210044

A case study was performed in Beijing in 2000 to observe concentrations of SO2 and NOx in the atmosphere and to evaluate their radiative impact. It was found that the concentrations of these gases are usually high in the morning due to a temperature inversion in the boundary layer. The average concentrations obtained from the observations are much higher than those used in the McClatchey reference atmosphere. The radiative impacts of these gases are calculated using a line-by-line radiative transfer model. The results show that the radiative forcing at the surface due to SO2 is 0.0576 W m^-2 and that due to NOx is 0.0032 W m^-2. These figures are almost compatible with that due to CFC11.

关键词： air pollution radiative forcing gas concentration greenhouse effect

维普期刊数据库

Investigation of a semi-empirical load model of natural gas explosion in vented spaces

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Journal of Safety Science and Resilience 2021年第3期2卷 157-171页

作者： Shigang Yang Jiongwei Cai Ya Yang Qin Fang Qi Bao Senpei Wang National Defense College of Engineering Army Engineering University of PLANanjing 210007China 73021 Troop of PLA Hangzhou 310012China Naval Command College of PLA Nanjing 210016China

Due to the influence of many factors,the overpressure-time history load model of vented gas explosions is difficult to describe and is not conducive to further structural *** on vented gas explosion test data,this paper obtains three typical overpressure-time history curves and puts forward a new semi-empirical model-double hump model that considers gas concentration and venting pressure,and gives a formula for peak pressure and overpressure-time history *** scientificity of the model is then verified by the total impulse in the *** model is able directly reflect the load characteristics,provide reference for calculating key parameters of a vented gas explosion and provide information on the structural response under the *** model thereby has the potential to help reduce the impact of gas explosion disasters.

关键词： Vented gas explosion Load model Overpressure-time history gas concentration Venting pressure

A Precise Sensor for SF_6 Based on Piezoelectric Ultrasound

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稀有金属材料与工程 2006年第A03期35卷 157-158页

作者： Changping Zhu Minglei Shan Hongping Zhang Xiaohua Zhang Peng Zhen Yuanyun Tao Department of Computer ＆ Information Engineering Hohai University Changzhou 210032 China State Key Laboratory of Hydrology-water Resources And Hydraulic Engineering Hohai University Nanjing 210098 China Data Division of ZTE Corporation Nanjing 210012 China East China University of Science ＆ Technology Shanghai 200237 China

Based on piezoelectric ultrasound technology,the paper theoretically analyses the determination of gas concentration and presents a norm-contrast method,which is realized by high-speed chip CPLD (Complex programmable logic device),to determine the concentration of SF_6 accurately with air as *** is proved that this sensor can determine the concentration of SF_6 with the precision of 50μg/*** sensor is in the process of producing.

关键词： ultrasound detection gas concentration CPLD

A Precise Sensor for SF6 Based on Piezoelectric Ultrasound

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稀有金属材料与工程 2006年第S3期 157-158页

作者： Changping Zhu~(1,2) Minglei Shan~1 Hongping Zhang~1 Xiaohua Zhang~1 Peng Zhen~(1,3) Yuanyun Tao~(1,4) (1.Department of Computer & Information Engineering,Hohai University,Changzhou 210032,China) (2.State Key Laboratory of Hydrology-water Resources And Hydraulic Engineering,Hohai University,Nanjing 210098,China) (3.Data Division of ZTE Corporation,Nanjing 210012,China) (4.East China University of Science & Technology,Shanghai 200237,China)

Based on piezoelectric ultrasound technology,the paper theoretically analyses the determination of gas concentration and presents a norm-contrast method,which is realized by high-speed chip CPLD （Complex programmable logic device）,to determine the concentration of SF6accurately with air as *** is proved that this sensor can determine the concentration of SF6with the precision of 50μg/*** sensor is in the process of producing.

关键词： ultrasound detection gas concentration CPLD

Experimental investigation of hydrate formation in water-dominated pipeline and its influential factors

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China Geology 2022年第2期5卷 310-321页

作者： Li Huang Jia-le Kang Xiao-dong Shen Jian-ye Sun Qing-guo Meng Qiang Chen Gao-wei Hu Chang-ling Liu Neng-you Wu Key Laboratory of gas Hydrate Ministry of Natural ResourcesQingdao Institute of Marine GeologyChina Geological SurveyMinistry of Natural ResourcesQingdao 266071China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and TechnologyQingdao 266071China College of Marine Science and Technology China University of GeosciencesWuhan 430074China State Key Laboratory of Oil and gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China

Blockage in water-dominated flow pipelines due to hydrate reformation has been suggested as a potential safety issue during the hydrate *** this work,flow velocity-dependent hydrate formation features are investigated in a fluid circulation system with a total length of 39 m.A 9-m section pipe is transparent consisted of two complete rectangular *** means of pressurization with gas-saturated water,the system can gradually reach the equilibrium *** result shows that the hydrates are delayed to appear as floccules or thin films covering the methane *** the circulation velocity is below 750 rpm,hydrate is finally deposited as a“hydrate bed”at upmost of inner wall,narrowing the flow channel of the ***,no plugging is observed during all the experimental *** five stages of hydrate deposition are proposed based on the experimental *** is also revealed that a higher driving pressure is needed at a lower flow *** driving force of hydrate formation from gas and water obtained by melting hydrate is higher than that from fresh water with no previous hydrate *** authors hope that this work will be beneficial for the flow assurance of the following oceanic field hydrate recovery trials.

关键词： Pipeline Water production Circulation gas hydrate Formation morphology gas concentration Flowrate NGHs exploration trial engineering Oil and gas exploration engineering Shenhu Area South China Sea

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gas control technology for coal and gas outburst mines based on new sealing materials

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Geohazard Mechanics 2024年第3期2卷 181-188页

作者： Hongwei Zhang Hongbao Zhao Dongliang Ji Shijie Jing Yuxuan Guo School of Energy and Mining Engineering China University of Mining and Technology(Beijing)Beijing100083China State Key Laboratory of Mechanical Behavior and System Safety of Trafﬁc Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China

In order to solve the problem of gas overlimit in corner corners of coal and gas prominent mines, through thecombination of air leakage mechanism in the goaf, near-ﬁeld ﬁssure expansion and rich area division, blockingmaterial development and optimization, performance measurement of blocking materials and on-site test, westarted to study the causes of gas concentration in corner corners, analysis of roof collapse and transparency incorners and performance test of blocking materials, and optimized the blocking materials by combining laboratory test and engineering test. Considering the thickness of the sealing ﬁlm, the attenuation ratio of the sealingﬁlm thickness, the gelation time, and the gelation viscosity under different ratios, we designed a multi factororthogonal experiment to optimize the optimal ratio suitable for the engineering site. Factors affecting blockingeffectiveness, such as gel water retention and gel ﬂame resistance, were also tested. The sealing scheme wasimplemented in the 2109 working face of a coal and gas outburst mine in Gansu, China. Through on-sitemonitoring of the changes in temperature, gas concentration, and air leakage at each monitoring point beforeand after the use of sealing materials, the analysis of the detection results shows that the temperature changes ateach monitoring point after the use of sealing materials do not exceed 0.2C;The change in oxygen concentrationis less than 0.27 %;The gas concentration has decreased by more than 60 %, with a decrease of 71.32 % in the gasconcentration in the upper corner. The air leakage has decreased by more than 53 %, and the proportion ofdecrease in air leakage at the upper corner is as high as 56.83 %. This air leakage control technology hasremarkable blocking effect, meets the requirements of corner near-ﬁeld ﬁssure blocking material, and is easy toprepare, inexpensive, non-toxic, tasteless and green, providing a successful experience for the treatment of similarcoal and gas outburst min

关键词： Coal and gas outburst Air leakage in goaf Near-ﬁeldﬁssure gas concentration Air leakage