scholarly journals THE IMPACT OF LIQUEFIED NATURAL GAS COMPOSITION AND TECHNOLOGICAL CHARACTERISTICS OF THE STARTING STORAGE OF THE EQUIPMENT AT THE TIME OF OCCURRENCE OF THE PHENOMENON OF ROLLOVER

Author(s):  
R. A. Khuramshina ◽  
A. I. Yamalov

Objectives. Ways to prevent the onset of rollover in the liquefied natural gas storage.Method. The article deals with modern methods of mathematical modeling and software when solving problems in a nonlinear formulation. A regulatory analysis of existing methods of LNG transportation has been carried out.Result. Using the mathematical program ANSYS, the rollover process in the liquefied natural gas storage was modeled. In the ANSYS software package, 3d modeling of the process of heat and mass transfer of the stratified liquid in the liquefied natural gas storage was performed. When simulating a rollover phenomenon, the time to its occurrence was 30 minutes, which differs from the experimental value by 1.7%. Based on the results of the calculations, it can be determined that the time to the onset of rollover depends on the concentration of the component layers, on the filling and geometry of the reservoir. These factors lead to an increase in evaporation of liquefied natural gas of 0.04%.Conclusion. The method of numerical experiment allows to determine the distribution of pressure, temperature, density, concentration in the object under study, without resorting to real experiments. The use of the ANSYS software package of computational fluid dynamics in the process of heat and mass transfer of the stratified liquid in the liquefied natural gas storage is necessary when calculating the increased accuracy.

Author(s):  
Mohamed Haddar ◽  
Moez Hammami ◽  
Mounir Baccar

In this paper, a study of cooling system for a liquefied natural gas storage tank is conducted. Our objective is to remedy the heat ingress to the liquefied natural gas from the environment using baffles toward limiting temperature elevation in the tank, and then the Boil-off Gas (BOG) formation. A specific code based on the finite volume method is developed to supply a fine knowledge of the hydrodynamic and thermal liquefied natural gas characteristics in the cylindrical tank heated from bottom and lateral surfaces. The effect of the number, position and dimension of baffles, on the flow structure and thermal behavior, has been analyzed. According to our simulation results, the baffles should be placed at the top of tank nearby the lateral wall as the liquefied natural gas dimensionless average temperature can be reduced by 36%. The installation of four rectangular baffles, equally spaced around the perimeter of the tank, gives better homogenization of the temperature field and decreases the average temperature by about 44% in order to limit BOG formation. Finally, two correlations of the Nusselt number are established for the flat rectangular baffle plates and the lateral surface of the cylindrical liquefied natural gas storage tank as a function of the Rayleigh number, as well as the baffle number. Scaling of these correlations with the Rayleigh number gives exponents of 0.25 and 0.18 for lateral surface and baffle, respectively, which are in good agreement with literature.


2014 ◽  
Vol 6 ◽  
pp. 845-853 ◽  
Author(s):  
Mohamad Shukri Zakaria ◽  
Kahar Osman ◽  
Ahmad Anas Yusof ◽  
Mohamad Hafidzal Mohd Hanafi ◽  
Mohd Noor Asril Saadun ◽  
...  

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