The Experts below are selected from a list of 171 Experts worldwide ranked by ideXlab platform
Fan Bo - One of the best experts on this subject based on the ideXlab platform.
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stability analysis of tapered Floating Roof steel storage Tanks under measured differential settlement
Journal of Engineering Design, 2008Co-Authors: Fan BoAbstract:Large steel storage Tanks constructed in soft foundations are easy to generate various types of settlement deformation, among which the differential settlement beneath the tank wall is the most serious. This paper analyzes the stability behavior of large tapered Floating-Roof steel storage Tanks according to measured settlements. Geometrically nonlinear finite element analysis is carried out on the tapered Floating-Roof Tanks under the global differential settlement and local differential settlement. By analyzing the settlement-displacement response, it is found that the tank has different types of buckling mode and buckling procedure. Comparison between structural behaviors of tapered Tanks and uniform Tanks is also conducted. Finally, some suggestion on stability design of tapered Tanks is given.
Ulrich Krause - One of the best experts on this subject based on the ideXlab platform.
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emissions of volatile hydrocarbons from Floating Roof Tanks and their local dispersion considerations for normal operation and in case of damage
Journal of Loss Prevention in The Process Industries, 2020Co-Authors: Ronald Zinke, Florian Kohler, Ulrich Krause, Andrea Klippel, Bernd LeitlAbstract:Abstract This work investigates the release and dispersion of volatile organic hydrocarbons, which may escape from external Floating Roof Tanks (EFRT) during normal operation or in case of damage. The dispersion will be described using CFD simulations in close range of the EFRT where hazardous areas are assigned. The aim of this work is to investigate which events can lead to emissions in dangerous quantities and to estimate the corresponding likelihood with regard to explosion protection. An emission in hazardous amount is present if the lower explosion limit has been exceeded and if the extent of this emission is not too low. It is discussed in particular whether the used zoning of potentially explosive areas is conservative or over-conservative.
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quantitative risk assessment of emissions from external Floating Roof Tanks during normal operation and in case of damages using bayesian networks
Reliability Engineering & System Safety, 2020Co-Authors: Ronald Zinke, Julia Melnychuk, Florian Kohler, Ulrich KrauseAbstract:Abstract In this paper, events resulting in an increased or critical emission of volatile organic compounds from external Floating Roof Tanks containing crude and mineral oils with high vapor pressure, e.g. gasoline or naphtha, are investigated. Here normal operations and deviations from normal operations such as tank revision procedures and damages to pipes, seals or deck fittings are included. To record emission-relevant events or damages, a comprehensive literature survey, a Germany-wide survey of companies which use external Floating Roof Tanks and an expert survey were carried out. In addition, the probability of the occurrence of emissions-relevant events was determined and used for risk assessment based on Bayesian networks. This is a well-known method of quantitative risk analysis illustrating and describing causal dependencies. The aim of this work is to show which chains of events can lead to increased or critical emissions of volatile organic compounds. Furthermore, the available data in the literature will be extended by the damage and event rates determined in this work.
Gao Zhang - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Influence of Floating-Deck Height on Oil-Vapor Migration and Emission of Internal Floating-Roof Tank Based on Numerical Simulation and Wind-Tunnel Experiment
Processes, 2020Co-Authors: Gao Zhang, Jie Fang, Weiqiu Huang, Fengyu Huang, Hong Ji, Lipei FuAbstract:Internal Floating-Roof Tanks (IFRTs) are widely used to store light oil and chemical products. However, if the annular-rim gap around the Floating deck becomes wider due to abrasion and aging of the sealing arrangement, the static breathing loss from the rim gap will be correspondingly aggravated. To investigate the oil-vapor migration and emissions from an IFRT, the effects of varying both the Floating-deck height and wind speed on the oil-vapor diffusion were analyzed by performing numerical simulations and wind-tunnel experiments. The results demonstrate that the gas space volume and the wind speed of an IFRT greatly influence the vapor-loss rate of the IFRT. The larger the gas space volume, the weaker the airflow exchange between the inside and outside of the tank, thereby facilitating oil-vapor accumulation in the gas space of the tank. Furthermore, the loss rate of the IFRT is positively correlated with wind speed. Meanwhile, negative pressures and the vortexes formed on the leeward side of the tank. In addition, the higher concentration areas were mainly on the three vents on the downwind side of the IFRT. The results can provide important theoretical support for the design, management, and improvement of IFRTs.
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investigation of the superposition effect of oil vapor leakage and diffusion from external Floating Roof Tanks using cfd numerical simulations and wind tunnel experiments
Processes, 2020Co-Authors: Jie Fang, Weiqiu Huang, Fengyu Huang, Lipei Fu, Gao ZhangAbstract:Based on computational fluid dynamics (CFD) and Realizable k-e turbulence model, we established a numerical simulation method for wind and vapor-concentration fields of various external Floating-Roof Tanks (EFRTs) (single, two, and four) and verified its feasibility using wind-tunnel experiments. Subsequently, we analysed superposition effects of wind speed and concentration fields for different types of EFRTs. The results show that high concentrations of vapor are found near the rim gap of the Floating deck and above the Floating deck surface. At different ambient wind speeds, interference between Tanks is different. When the ambient wind speed is greater than 2 m/s, vapor concentration in leeward area of the rear tank is greater than that between two Tanks, which makes it easy to reach explosion limit. It is suggested that more monitoring should be conducted near the bottom area of the rear tank and upper area on the left of the Floating deck. Superposition in a downwind direction from the EFRTs becomes more obvious with an increase in the number of EFRTs; vapor superposition occurs behind two leeward Tanks after leakage from four large EFRTs. Considering safety, environmental protection, and personnel health, appropriate measures should be taken at these positions for timely monitoring, and control.
Bo Yu - One of the best experts on this subject based on the ideXlab platform.
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temperature drop and gelatinization characteristics of waxy crude oil in 1000 m3 single and double plate Floating Roof oil Tanks during storage
International Journal of Heat and Mass Transfer, 2019Co-Authors: Min Wang, Xinyu Zhang, Qianqian Shao, Jingfa Li, Bo YuAbstract:Abstract Single and double-plate Floating Roof oil Tanks are two types of widely used Floating Roof oil Tanks in petrochemical industry. However, the differences in flow and hear transfer characteristics of waxy crude oil inside these two Tanks have been studied insufficiently. Finite volume method is employed in this research to study the temperature drop and gelatinization processes of waxy crude oil as well as the differences in single and double-plate Floating Roof Tanks. Based on a comprehensive consideration of the atmosphere, soil, Floating Roof oil tank as well as the tank structure and the variations of the waxy crude oil state and rheological behavior, general physical and mathematical models are established. In the model, wax precipitation and gelatinization processes of waxy crude oil are described by the enthalpy-porous media method. Non-Newtonian behavior is described by the Power law equation. Turbulent natural convection is described by the LES method. SIMPLE algorithm is employed to couple pressure and velocity. Taking 1000 m3 single and double-plate Floating Roof oil Tanks as examples, the evolution of oil temperature and flow behavior is studied and the variations of the gel oil thickness and heat flux are analyzed. Moreover, the differences between these two Tanks are also discussed. Results show that due to the structure difference of the tank Roof, the temperature drop rates are 0.018 °C/h and 0.007 °C/h respectively in single and double-plate Floating Roof Tanks in the case of this research. Secondly, for the growth of gel oil on tank bottom, in double-plate Floating Roof tank, gel oil thickness keeps growing and fluctuating, while in single-plate tank, the original gelled oil layer disappears firstly and then increases gradually. Thirdly, although for both Tanks, tank Roof is the main part of heat dissipation towards the atmosphere, the maximum heat fluxes are respectively over 2.0 kW and 0.4 kW for single and double-plate Floating Roof Tanks, and the total average heat fluxes respectively are 1.49 kW and 0.59 kW.
Lipei Fu - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Influence of Floating-Deck Height on Oil-Vapor Migration and Emission of Internal Floating-Roof Tank Based on Numerical Simulation and Wind-Tunnel Experiment
Processes, 2020Co-Authors: Gao Zhang, Jie Fang, Weiqiu Huang, Fengyu Huang, Hong Ji, Lipei FuAbstract:Internal Floating-Roof Tanks (IFRTs) are widely used to store light oil and chemical products. However, if the annular-rim gap around the Floating deck becomes wider due to abrasion and aging of the sealing arrangement, the static breathing loss from the rim gap will be correspondingly aggravated. To investigate the oil-vapor migration and emissions from an IFRT, the effects of varying both the Floating-deck height and wind speed on the oil-vapor diffusion were analyzed by performing numerical simulations and wind-tunnel experiments. The results demonstrate that the gas space volume and the wind speed of an IFRT greatly influence the vapor-loss rate of the IFRT. The larger the gas space volume, the weaker the airflow exchange between the inside and outside of the tank, thereby facilitating oil-vapor accumulation in the gas space of the tank. Furthermore, the loss rate of the IFRT is positively correlated with wind speed. Meanwhile, negative pressures and the vortexes formed on the leeward side of the tank. In addition, the higher concentration areas were mainly on the three vents on the downwind side of the IFRT. The results can provide important theoretical support for the design, management, and improvement of IFRTs.
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investigation of the superposition effect of oil vapor leakage and diffusion from external Floating Roof Tanks using cfd numerical simulations and wind tunnel experiments
Processes, 2020Co-Authors: Jie Fang, Weiqiu Huang, Fengyu Huang, Lipei Fu, Gao ZhangAbstract:Based on computational fluid dynamics (CFD) and Realizable k-e turbulence model, we established a numerical simulation method for wind and vapor-concentration fields of various external Floating-Roof Tanks (EFRTs) (single, two, and four) and verified its feasibility using wind-tunnel experiments. Subsequently, we analysed superposition effects of wind speed and concentration fields for different types of EFRTs. The results show that high concentrations of vapor are found near the rim gap of the Floating deck and above the Floating deck surface. At different ambient wind speeds, interference between Tanks is different. When the ambient wind speed is greater than 2 m/s, vapor concentration in leeward area of the rear tank is greater than that between two Tanks, which makes it easy to reach explosion limit. It is suggested that more monitoring should be conducted near the bottom area of the rear tank and upper area on the left of the Floating deck. Superposition in a downwind direction from the EFRTs becomes more obvious with an increase in the number of EFRTs; vapor superposition occurs behind two leeward Tanks after leakage from four large EFRTs. Considering safety, environmental protection, and personnel health, appropriate measures should be taken at these positions for timely monitoring, and control.