Gas Station safety is non-linear systems that refer to many factors and multilayer. There are much flammable and explosive compressed natural gas in gas station, and it is considered as a kind of major hazard source. ...
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Gas Station safety is non-linear systems that refer to many factors and multilayer. There are much flammable and explosive compressed natural gas in gas station, and it is considered as a kind of major hazard source. Therefore, the safety assessment of gas station has their special important and realistic significance. Based on the types of accident and risk factors, a new index system of safety assessment was set up. The weight of the evaluation index would be analyzed by analytic hierarchy process, and then the matrix of evaluating results could be calculated through fuzzy comprehensive evaluation. At last, the grade of safety for gas station could be obtained. This Safety Assessment Model can be applied for every gas station.
Gas Station safety is non-linear systems that refer to many factors and multilayer. There are much flammable and explosive compressed natural gas in gas station, and it is considered as a kind of major hazard source. ...
详细信息
Gas Station safety is non-linear systems that refer to many factors and multilayer. There are much flammable and explosive compressed natural gas in gas station, and it is considered as a kind of major hazard source. Therefore, the safety assessment of gas station has their special important and realistic significance. Based on the types of accident and risk factors, a new index system of safety assessment was set up. The weight of the evaluation index would be analyzed by analytic hierarchy process, and then the matrix of evaluating results could be calculated through fuzzy comprehensive evaluation. At last, the grade of safety for gas station could be obtained. This Safety Assessment Model can be applied for every gas station.
One of the primary reasons leading to bulging and cracking in a coke drum is the severe temperature gradient due to cyclic temperature variation. Based on the twodimensional heat conduction theory, an analytical solut...
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One of the primary reasons leading to bulging and cracking in a coke drum is the severe temperature gradient due to cyclic temperature variation. Based on the twodimensional heat conduction theory, an analytical solution of the transient temperature field in the coke drum is obtained, which is different from the known FEM results. The length of the coke drum is considered finite. The dynamic boundary conditions caused by fluid uninterrupted rising in oiling and watering stages are simulated with the iteration method. Numerical results show that the present theoretical model can accurately describe basic features of the transient temperature field in the coke drum. Effects of the geometry of the coke drum and the rising velocity of quench water on the axial temperature gradient are also discussed.
To address the problem of subdividing inflexible rectangular grid models and their poor definition of velocity interfaces, we propose a complex structure triangular net for a minimum traveltime ray tracing global algo...
To address the problem of subdividing inflexible rectangular grid models and their poor definition of velocity interfaces, we propose a complex structure triangular net for a minimum traveltime ray tracing global algorithm. Our procedure is: (1) Subdivide a triangle grid based on the Delaunay triangular subdivision criterion and the relationships of the points, lines, and the surfaces in the subdividing area. (2) Define the topology relationships and related concepts of triangular unit ray tracing. (3) The source point and wave arrival points at any time compose the propagating plane wave and the minimum traveltime and secondary source positions are calculated during the plane wave propagation. We adopt the hyperbolic approximation global algorithm for secondary source retrieving. (4) By minimum traveltime ray tracing, collect the path from receiver to source points with the neighborhood point’s traveltime and the direction of the secondary source. Numerical simulation examples are given to test the algorithm. The results show that the triangular net ray tracing method demonstrates model subdivision flexibility, precise velocity discontinuity interfaces, and accurate computations.
The energy changes in the processes of coal and gas outbursts were studied using the principle of energy conservation. The stress conditions, potential energy of elastic deformation were analyzed when digging distance...
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The energy changes in the processes of coal and gas outbursts were studied using the principle of energy conservation. The stress conditions, potential energy of elastic deformation were analyzed when digging distance was L. The released work from the accumulated internal energy of coal gas was specially studied. Also the energy used to throw the fragments of the coal, fracturing energy and kinetic energy of the gas were investigated, and the energy condition for coal and gas outburst was obtained. Took the 2nd mining area in Huachu Coal Mine of Guizhou Province as an example, studied the energy conditions of outburst. The results show that gas internal energy which is the main energy source for the outburst is bigger than potential energy of elastic deformation. An outburst with less critical gas content is more likely to happen in the following conditions: The higher stress in coal seam is, The smaller Protodyakonov coefficient is. Under the stress level in certain circumstances, outburst will happen with little critical gas content after the long digging distance. The influence of coal seam thickness for the critical gas content in outburst is not obvious.
Geological conditions in front of the tunnel is complex and changeable, in the kasrst zone, the geological disaster, such as water inrush, cave and collapse often occur in the tunnel construction, which make a serious...
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Geological conditions in front of the tunnel is complex and changeable, in the kasrst zone, the geological disaster, such as water inrush, cave and collapse often occur in the tunnel construction, which make a serious impact on the safety of the tunnel construction, progress, economic benefits. In order to guarantee the safety, geological prediction must be carried out in tunnel Construction. This paper mainly introduces principle, data processing of TGP206 tunnel geological prediction system and its several application in prediction for Zhongxing tunnel. Through analyzing the reflected signals in the karst area, it can accurately predict the rock parameters as well as the location of the cave in front of the tunnel. It is a guiding significance for tunnel geological prediction in similar geological conditions to prove the correctness and feasibility of theory and techniques of the system.
Introduce the principles of Support Vector Machines, and indicate the broken zone thickness can be forecasted by four factors: rock strength, joint coefficient, buried depth and span length. The results show that Supp...
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Introduce the principles of Support Vector Machines, and indicate the broken zone thickness can be forecasted by four factors: rock strength, joint coefficient, buried depth and span length. The results show that Support Vector Machine (SVM) is a reliable method to predict broken zone thickness, and the predictive values agree well with the verify data.
According to rock character of a certain soft rock tunnel of Chongqing, the model material is made from epoxy resin, polyamide, silicom rubber, firming agent of silicon rubber, quartz grit, powdery barite and gasoline...
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According to rock character of a certain soft rock tunnel of Chongqing, the model material is made from epoxy resin, polyamide, silicom rubber, firming agent of silicon rubber, quartz grit, powdery barite and gasoline. The physical model test of the unreinforced tunnel and bolt-reinforced tunnel are made in the true triaxial model test machine. By using strain measure technology, the strains of key parts of the surrounding rock and the bolt are measured;according to these data, the variability of the stress of surrounding rock and the variability of the axial force of the bolt are analyzed. The numerical simulation are made with the same boundary condition as the model test;according to these data, the plastic zone, stress field and the deformation of the surrounding rock are studied;the variation of the axial force of the bolt is studied. We compare the variation of stress of the surrounding rock and the variation of the axial force of the bolt of the model test with the numerical simulation and draw the conclusion that the two processes coincide with each other.
Based on equal cross area simplification of SMW method single pile section, SMW method section steel-cemented soil interface stress analysis model was built. By analyzing theory of cemented soil pile-section steel int...
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Based on equal cross area simplification of SMW method single pile section, SMW method section steel-cemented soil interface stress analysis model was built. By analyzing theory of cemented soil pile-section steel interface shear stress, distribution law of interface shear stress was deduced. Change rules of different axial load and cemented soil elastic parameters on interface shear stress were also analyzed contrastively. The larger axial load got, the greater peak value of surface shear stress was; The greater cemented soil modulus got, the smaller distribution range of surface shear stress was and the closer to ground surface peak position of surface shear stress got.
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