The flow velocity of gases in gobs directly influences the kinetics and intensity of gaseous components release during heating and cooling of coal.The assessment of fire hazard is performed on the basis of concentrati...The flow velocity of gases in gobs directly influences the kinetics and intensity of gaseous components release during heating and cooling of coal.The assessment of fire hazard is performed on the basis of concentrations of particular gases in a mine air.These concentrations differ in coal heating and cooling phase which was proven in the study.This paper presented the results of the experimental study on temperature distribution in a simulated coal bed in heating(50–250°C)and cooling(250–35°C)phases as well as its correlation to variations in concentration of gases released in these phases and flow rates of gases flowing through the coal bed.The research was performed on twenty-two samples of bituminous coals acquired from various coal beds of Polish coal mines.Considerable differences were observed between heating and cooling phases in terms of the concentrations of gases taken into account in calculations of self-combustion index.In the heating phase temperature increase resulted in the decrease of concentrations ratios of ethane,ethylene,propane,propylene and acetylene,while in the cooling phase these ratios increased systemically.The effect of air(in heating phase)and nitrogen(in cooling phase)flow rate on the self-ignition index CO/CO2 was also determined.展开更多
This paper reviews the fire problem in critical transportation infrastructures such as bridges and tunnels.The magnitude of the fire problem is illustrated,and the recent increase in fire problems in bridges and tunne...This paper reviews the fire problem in critical transportation infrastructures such as bridges and tunnels.The magnitude of the fire problem is illustrated,and the recent increase in fire problems in bridges and tunnels is highlighted.Recent research undertaken to address fire problems in transportation structures is reviewed,as well as critical factors governing the performance of those structures.Furthermore,key strategies recommended for mitigating fire hazards in bridges and tunnels are presented,and their applicability to practical situations is demonstrated through a practical case study.Furthermore,research needs and emerging trends for enhancing the“state-of-the-art”in this area are discussed.展开更多
The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is pres...The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.展开更多
This paper focuses on how to build the model of precision fire hazard divisions in the level of forest resources sub-compartment.Based on 3D GIS technology and characteristics of forest fires in collective forest of s...This paper focuses on how to build the model of precision fire hazard divisions in the level of forest resources sub-compartment.Based on 3D GIS technology and characteristics of forest fires in collective forest of southern China,this study utilized Lin’an City,Zhejiang Province as the experimental area.Forest fire factors were divided into 11 indexes from the three categories(social and economic factors,forestry characteristics,and meteorological characteristics) and weighted for analysis.Next,three eigenvectors(one for each category) were created to build a nonlinear mathematical model called precision fire hazard divisions for forests.Then,the model was used to optimize and test forest fire hazard divisions with the least squares.Results showed that experimental and theoretical values of error were less than 0.1. Thus,in the experimental area this model and the fire occurrence history matched.展开更多
基金This work was supported by the Ministry of Science and Higher Education,Poland(No.14303018).
文摘The flow velocity of gases in gobs directly influences the kinetics and intensity of gaseous components release during heating and cooling of coal.The assessment of fire hazard is performed on the basis of concentrations of particular gases in a mine air.These concentrations differ in coal heating and cooling phase which was proven in the study.This paper presented the results of the experimental study on temperature distribution in a simulated coal bed in heating(50–250°C)and cooling(250–35°C)phases as well as its correlation to variations in concentration of gases released in these phases and flow rates of gases flowing through the coal bed.The research was performed on twenty-two samples of bituminous coals acquired from various coal beds of Polish coal mines.Considerable differences were observed between heating and cooling phases in terms of the concentrations of gases taken into account in calculations of self-combustion index.In the heating phase temperature increase resulted in the decrease of concentrations ratios of ethane,ethylene,propane,propylene and acetylene,while in the cooling phase these ratios increased systemically.The effect of air(in heating phase)and nitrogen(in cooling phase)flow rate on the self-ignition index CO/CO2 was also determined.
基金This study was supported by the National Science Foundation(No.CMMI-1068621).
文摘This paper reviews the fire problem in critical transportation infrastructures such as bridges and tunnels.The magnitude of the fire problem is illustrated,and the recent increase in fire problems in bridges and tunnels is highlighted.Recent research undertaken to address fire problems in transportation structures is reviewed,as well as critical factors governing the performance of those structures.Furthermore,key strategies recommended for mitigating fire hazards in bridges and tunnels are presented,and their applicability to practical situations is demonstrated through a practical case study.Furthermore,research needs and emerging trends for enhancing the“state-of-the-art”in this area are discussed.
基金National Outstanding Youth Science Foundation (59825105).
文摘The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.
文摘This paper focuses on how to build the model of precision fire hazard divisions in the level of forest resources sub-compartment.Based on 3D GIS technology and characteristics of forest fires in collective forest of southern China,this study utilized Lin’an City,Zhejiang Province as the experimental area.Forest fire factors were divided into 11 indexes from the three categories(social and economic factors,forestry characteristics,and meteorological characteristics) and weighted for analysis.Next,three eigenvectors(one for each category) were created to build a nonlinear mathematical model called precision fire hazard divisions for forests.Then,the model was used to optimize and test forest fire hazard divisions with the least squares.Results showed that experimental and theoretical values of error were less than 0.1. Thus,in the experimental area this model and the fire occurrence history matched.
