Boil-Off Gas Formation inside Large Scale Liquefied Natural Gas (LNG) Tank Based on Specific Parameters

2012 ◽  
Vol 229-231 ◽  
pp. 690-694 ◽  
Author(s):  
Mohamad Shukri Zakaria ◽  
Kahar Osman ◽  
Md. Nor Musa
Keyword(s):  
Natural Gas ◽  
Large Scale ◽  
Seawater Temperature ◽  
Three Dimensional ◽  
Ambient Air ◽  
Calculation Model ◽  
Liquefied Natural Gas ◽  
Three Dimensional Model ◽  
Ambient Seawater ◽  
Lng Tank

Liquefied Natural Gas (LNG) fleets are coasting with various condition and behavior. These variable leads to different type of LNG fleets build every year with unavoidable generated Boil-off Gas (BOG). Estimation of BOG generated inside LNG tank play significant role in determines the ship specification and management method of BOG including venting, propulsion or requalification. Hence, in the present study, the right choices of boundary condition and parameter have been implementing in order to have good estimation amount of BOG evaporates for specific LNG tank. Three dimensional model of cargo with capacity 160000 m3 LNG carrier are simulate using ANSYS Fluent with specific ambient air temperature of 5oC and ambient seawater temperature of 0oC have been chosen as a calculation case, gain the total heat transfer rate and Boil-off Rate (BOR). The result shows that the calculation model and simulation are feasible with typical LNG fleet specification and International Marine Organization (IMO) standard.

Large-scale liquefied natural gas ships

2020 ◽  
Vol 7 (3) ◽  
pp. 461-465
Author(s):  
Danping Lou ◽  
Yan Li
Keyword(s):  
Natural Gas ◽  
Large Scale ◽  
Liquefied Natural Gas

Computational Simulation of Boil-Off Gas Formation inside Liquefied Natural Gas Tank Using Evaporation Model in ANSYS Fluent

2013 ◽  
Vol 393 ◽  
pp. 839-844 ◽  
Author(s):  
Mohamad Shukri Zakaria ◽  
Kahar Osman ◽  
Mohd Noor Asril Saadun ◽  
Muhammad Zaidan Abdul Manaf ◽  
Mohd Hafidzal Mohd Hanafi
Keyword(s):  
Natural Gas ◽  
Gulf Coast ◽  
Current Model ◽  
Computational Simulation ◽  
The United States ◽  
Liquefied Natural Gas ◽  
Ansys Fluent ◽  
Evaporation Model ◽  
Gas Formation ◽  
Lng Tank

Research on the waste energy and emission has been quite intensive recently. The formation, venting and flared the Boil-off gas (BOG) considered as one of the contribution to the Greenhouse Gas (GHG) emission nowadays. The current model or method appearing in the literature is unable to analyze the real behavior of the vapor inside Liquefied Natural Gas (LNG) tank and unable to accurately estimate the amount of boil-off gas formation. In this paper, evaporation model is used to estimate LNG Boil-Off rate (BOR) inside LNG tank. Using User Define Function (UDF) hooked to the software ANSYS Fluent. The application enable drag law and alternative heat transfer coefficient to be included. Three dimensional membrane type LNG cargos are simulated with selected boundary condition located in the United States Gulf Coast based on average weather conditions. The result shows that the value of BOR agrees well with the previous study done with another model and with International Marine organization (IMO) standard which is less than 0.15% weight per day. The results also enable us to visualize the LNG evaporation behaviors inside LNG tanks.

scholarly journals Coronal ejections from convective spherical shell dynamos

2011 ◽  
Vol 7 (S286) ◽  
pp. 154-158 ◽  
Author(s):  
J. Warnecke ◽  
P. J. Käpylä ◽  
M. J. Mantere ◽  
A. Brandenburg
Keyword(s):  
Magnetic Field ◽  
Spherical Shell ◽  
Large Scale ◽  
Convection Zone ◽  
Three Dimensional ◽  
Simplified Model ◽  
Spherical Coordinates ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Large Scale Magnetic Field

AbstractWe present a three-dimensional model of rotating convection combined with a simplified model of a corona in spherical coordinates. The motions in the convection zone generate a large-scale magnetic field which is sporadically ejected into the outer layers above. Our model corona is approximately isothermal, but it includes density stratification due to gravity.

Modeling of Solids and Gas Mixing Effects in Large-Scale CFB Combustors

2003 ◽  
Author(s):  
Karsten Luecke ◽  
Ernst-Ulrich Hartge ◽  
Joachim Werther
Keyword(s):  
Combustion Chamber ◽  
Residence Time ◽  
Large Scale ◽  
Control Volume ◽  
Combustion Process ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Cross Sectional ◽  
Fuel Feed ◽  
Cross Section Area

In a CFB combustor the reacting solids are locally fed into the combustion chamber. These reactants have to be dispersed across the reactor’s cross-sectional area. Since the rate of mixing is limited this leads to a mal-distribution of the reactants and to locally varying reaction conditions. In order to describe the influence of mixing a three-dimensional model of the combustion chamber is suggested here. The model is divided into three sub-topics. First, the flow structure in terms of local gas and solids velocities and solids volume concentrations is described. Second, mixing of the solids and the gas phase has to be quantified by defining dispersion coefficients, and finally the combustion process itself, i.e. the reaction kinetics, has to be modeled. Employing the information of the three sub-models mass balances for the reactants at each finite control volume inside the CFB combustion chamber can be formulated. The model was validated against data from measurements in the large-scale combustor of Chalmers University of Technology in Go¨teborg/Sweden. Concentration gradients concerning the char phase are only moderate. However, the spatial distribution of the oxygen shows strong non-uniformities, especially under conditions of staged combustion. In further predictive calculations, the influence of the fuel supply arrangement on the emissions of industrial sized CFB boilers was studied. Furthermore, the influence of the fuel composition on the feeding technique has been examined. High volatile fuels tend to form plumes of unburned hydrocarbons near the fuel feed point, and might therefore need more feed points per square meter cross-section area. Since the average gas residence time in the primary cyclone of a CFB plant is about 30–40% of the total gas residence time, a considerable burn-off of not completely oxidized gas species may occur here. An effectively used cyclone may remedy to a certain extent the negative impacts of incomplete mixing in the combustion chamber.

scholarly journals Biomechanical grounding of the transalveolar osteosynthesis of еdentulous мandible fractures

2021 ◽  
Vol 26 (1) ◽  
pp. 209-217
Author(s):  
N.H. Idashkina ◽  
O.O. Hudarian ◽  
D.V. Chernov ◽  
I.A. Samoilenko
Keyword(s):  
Simulation Modeling ◽  
Three Dimensional ◽  
Calculation Model ◽  
Mandibular Fractures ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Design Load ◽  
Load Combination ◽  
3D Computer Simulation

The purpose of the work is improvement of the effectiveness of the mandibular fractures treatment in patients with partial or complete adentia by developing and experimentally testing transalveolar osteosynthesis technique. An experimental study was carried out by 3D computer simulation modeling by the final element analysis to assess the efficiency of mandibular fractures fixation at partial or complete adentia using the Ш-shaped plate, which we developed for the transalveolar osteosynthesis method. Calculations of the immobilized fractures for static (own weight) and dynamic (functional) loads were performed according to the author's method, taking into account pronounced resorptive processes in the bone from the beginning of the reparative reaction to assess the rigidity of fragments fixation during the entire period of the fractures healing. Under the conditions of the same three-dimensional model of the mandible, calculations were performed when the fracture was fixed with ordinary linear titanium osseous plates. It is proved that at functional load the new plate provides a compression effect in the fractures region, as evidenced by the negative displacements in the final elements of the mental region according to the results of design load combination 2- 3. The maximum efforts in the screws of the calculation model with a conventional bone plate were 136.955 N, which is almost ten times more than on the model with a Ш-shaped titanium retainer (12.656 N).

scholarly journals CFD ANALYSIS OF ECONOMIZER IN A TENGENTIAL FIRED BOILER

2013 ◽  
pp. 143-147
Author(s):  
KRUNAL P. MUDAFALE ◽  
HEMANT S. FARKADE
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Large Scale ◽  
Thermal Power ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Gas Temperature ◽  
Three Dimensional Model ◽  
The Individual ◽  
Side Flow

This paper presents a simulation of the economizer zone, which allows for the condition of the shell-side flow and tube-side and tube-wall, thermal fields, and of the shell-tube heat-exchange. Selection of the economizer zone from the thermal power plant only because, it is found trends of failure that the economizer is the zone where the leakages are found more. The maximum number of cause of failure in economizer unit is due to flue gas erosion. The past failure details revels that erosion is more in U-bend areas of Economizer Unit because of increase in flue gas velocity near these bends. But it is observed that the velocity of flue gases surprisingly increases near the lower bends as compared to upper ones. The model is solved using conventional CFD techniques by STAR- CCM+ software. In which the individual tubes are treated as sub-grid features. A geometrical model is used to describe the multiplicity of heat-exchanging structures and the interconnections among them. The Computational Fluid Dynamics (CFD) approach is utilised for the creation of a three-dimensional model of the economizer coil. With equilibrium assumption applied for description of the system chemistry. The flue gas temperature, pressure and velocity field of fluid flow within an economizer tube using the actual boundary conditions have been analyzed using CFD tool. Such as the ability to quickly analyse a variety of design options without modifying the object and the availability of significantly more data to interpret the results. This study is a classic example of numerical investigation into the problem of turbulent reacting flows in large scale furnaces employed in thermal power plants for the remediation of ash deposition problems. And the experimental setup is from Chandrapur Super Thermal Power Station, Chandrapur having the unit no IV of 210 MW energy generations.

ASSESSING THE POTENTIAL OF KEY EXPORTERS IN THE GLOBAL LIQUEFIED NATURAL GAS MARKET

2020 ◽  
Vol 1 (3) ◽  
pp. 39-48
Author(s):  
A. A. SHCHEGOL’KOVA ◽  
Keyword(s):  
Natural Gas ◽  
Economic Analysis ◽  
Large Scale ◽  
Global Market ◽  
Liquefied Natural Gas ◽  
Transport Infrastructure ◽  
Graphical Methods ◽  
Analysis Calculation ◽  
Key Drivers ◽  
Gas Market

The article provides an analysis of the global market for liquefied natural gas (LNG), which revealed the key drivers of changing market dynamics. The development and prospects of large-scale gas projects of the main LNG exporting countries are shown. The potential of key LNG exporters, prospects for the development of the global LNG market has been assessed. Research and analysis of trends in the global LNG market were carried out using statistical methods of economic analysis: calculation of averages, indices; creation of ranks of dynamics; Summaries, groupings of economic indicators; Graphical methods of research were also used. The article assesses the prospects of Russian producers in the global LNG market from the perspective of diversification and modernization of gas transport infrastructure.

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