Papers by Keyword: Explosion

Abstract: The risk of natural gas long-distance pipeline and main factors of accidents are analyzed in this paper. According the consequences from above, quantitative risk assessment of long-distance pipelines under specific accident scenarios are completed with the help of numerical simulation model on long-distance pipeline leakage and dispersion. What’s more, on the basis of the assessment results, the necessary conditions for long-distance pipeline safe operation are presented. Finally, conclusions and safe operations under necessary conditions given in this paper are helpful for regular operation of pipeline, accident prevention, emergency response and reasonable supervision.

Abstract: Based on the features of fire and explosion accidents in petrochemical wharf storage tank area, the DOW method and fuzzy comprehensive evaluation method were applied to evaluate risk of fire and explosion. First of all, DOW method was employed to evaluate the hazard of fire and explosion of petrochemical wharf storage tank area preliminarily and risk indexes of various tanks were obtained. Then, 5 first-level and 24 second-level indexes were identified by the fuzzy mathematics, in which the entropy weight method was introduced to determine weight vector of arrangement analysis, and applied to an actual risk evaluation for a petrochemical wharf storage tank area to determine fuzzy sets. On the basis of the weighted average method, the risk level is medium. Arranges the second-level indexes, and the main factors affecting the accident were concluded,including the violation rate of labor discipline, characteristics of hazardous materials, fire facilities, safety checks, operation of the security emergency response system and so on.

Abstract: A rigorous scheme must be formulated in advance before a viaduct is to be exploded, in this case, numerical simulation can provide effective guarantee to the formulation of the scheme. Focusing on the explosion engineering of a large-scale city viaduct, the process of its explosion and collapse were simulated by the LS-DYNA software. The vibration responses of soil surface caused by the explosion and collapse were analyzed, and also the numerical results were compared with the measurement data. The numerical results agreed well with the measurement data, which showed that the simulation method proposed in the paper could simulate the explosion process well and the results could be also an guidline for the similar projections in future.

Abstract: In steelmaking and casting, there are used, stored and handled chemicals which are risk factors either in the normal operation of the technical plants, or in predictable and unpredictable failure conditions. In the steelmaking and casting plants, the substances and liquids considered risk factors are: methane, oxygen, liquid steel and water used for the cooling system. This paper deals with the risk assessment within the premises of electric steelworks, in predictable failure situations, based on the sheets of assessment and reduction of the risk associated with explosive atmospheres of methane and oxygen, in the presence of high temperatures existing at the electric steelworks.

Abstract: This paper simulates the alternation of the maximum explosion overpressure on the different condition of the concentration based on the fluent software. The results show the maximum explosion overpressure increases in the earlier stage and then decreases in the later stage because of the different flammable gas concentration: the maximum explosion overpressure enhanced in 6% gas concentration and drops in 12% gas concentration; it augments in 6% gas concentration and drops in 12% gas concentration with the joining of the hydrogen; the explosion pressure peaked just at the 9% concentration of the flammable gas.

Abstract: With the increase of terrorist attacks it is necessary to explore the option of increasing the strength of structures against the blast wave resulted from explosion of an improvised explosive device. In our research we have focused on recyclable materials that could provide such protection and their comparison with other known materials. We present a FEM analysis of a wall strengthened with different type of materials. In conclusion we show the economical and ecological comparison of used materials.

Abstract: The segment sensitivity for various pressure sensors is obtained by implementing the static and dynamic calibrations for three types of pressure sensors, i.e., CY-YD-202, CY-YD-205 and CY-YD-203T, and the average absolute value of relative errors for sensors is obtained by measuring the dynamic high-frequency signal, which provides the basis for correct selection of pressure sensor during the test.

Abstract: Unsafe acts and unsafe conditions are the main causes for all accidents in firework Industries. The accidents occurr in the fireworks industries are more severe than the accidents occurr in any other industries, because fire and explosives are the common causes of the accidents in fireworks industries. The aim of the study is to analyse the accidents in fireworks industries and recommend to build safety culture.

Abstract: Numerical simulations play a significant role in explosion in a mass of soil due to an underground explosive. Common methods available in hydrocode for fluid-solid coupling process are contact algorithm, Lagrange algorithm, and Arbitrary Lagrange-Euler (ALE) algorithm. A numerical simulation of explosion process with concentrated charge in a mass of soil was carried out by using three methods in this paper. The dynamic response of soil medium, the formation and development law of explosion cavity and the explosion wave propagation law in soil were simulated. Merits and drawbacks of three different methods are analyzed in the aspect of modeling, simulation results and computing cost.

Abstract: In this paper, the fuel-air dispersion and explosion experimental system was designed and experimental simulation on fuel-air mixture spreading and exploding in long-narrow underground fuel depot was carried out. The special phenomena of fuel-air mixture dispersion and explosion process, the characteristic feature of the pressure curve and mechanism were analyzed. The explosion process can be divided into three stages: flame accelerating section, oscillating reaction section and wave dissipating section. And under the same initial conditions, if the ignition time advanced, there is a significant intermittent and large fluctuations phenomenon.