Numerical Simulation of Gas Leakage and Diffusion Based on FLUENT

2013 ◽  
Vol 726-731 ◽  
pp. 888-891
Author(s):  
Lin Zhi Fu ◽  
Yu Feng Li ◽  
Gang Li
Keyword(s):  
Numerical Simulation ◽  
Simple Algorithm ◽  
Coke Oven ◽  
Speed Increase ◽  
Coal Gas ◽  
Gas Leakage ◽  
Plant Area ◽  
Distribution Laws ◽  
And Diffusion ◽  
Gas Medium

A two-dimensional unsteady flow model was established by Realizable k-ε turbulence model and SIMPLE algorithm, which was applied to conduct numerical simulation of sudden leakage and diffusion of coal gas in the plant area. Then, time-dependent distribution laws of coal gas under different influencing factors were analyzed. The results showed that as the leaking mouth diameter, internal pressure and wind speed increase, the concentration was roughly the same near the mouth; coal gas that was 3m away from the mouth diffuses more quickly and the area covered within explosion limit of coal gas expanded to some extent. For different gas medium, converter gas spread more widely than coke oven gas. The former accumulated on the ground, the latter accumulated above the ground.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

The Application of Numerical Simulation to Liquid Pipeline Leakage at LNG Terminal in China

2020 ◽  
Author(s):  
Zhichao Guo ◽  
Zhaoci Li
Keyword(s):  
Numerical Simulation ◽  
Liquid Phase ◽  
Natural Gas ◽  
Diffusion Process ◽  
Gas Phase ◽  
Stokes Equations ◽  
Response Strategy ◽  
Movement Trajectory ◽  
Two Phase ◽  
And Diffusion

Abstract In 2018, China’s natural gas import reached 90.39 million tons, and the liquefied natural gas (LNG) import was 53.78 million tons, accounting for 59.5% of total natural gas imports. With the construction of LNG terminals, more studies on the leakage of LNG storage and transportation facilities have emerged to prevent catastrophic consequences such as explosions and frostbite. However, most of previous researches focused on gas pipeline leakage after LNG gasification, and few of those have been done on LNG liquid pipeline leakage. In this paper, Fluent software is used to numerically simulate the process of LNG liquid pipeline leakage. After the occurrence of LNG leakage, it will suffer the process of endothermic, evaporation, and diffusion, which is considered as a two-phase diffusion process. The Euler-Lagrangian method is introduced to simulate the diffusion process of gas phase and liquid phase separately. In the simulation, the liquid phase is regarded as discrete droplets for discrete processing. The movement trajectory, heat transfer process and evaporation process of each droplet are tracked respectively. Different from the liquid phase, the gas phase is regarded as a continuous phase and the Navier-Stokes equations are adopted for calculation. Thereafter, coupling calculations of two phase are performed to determine the concentration field and temperature field of the LNG liquid pipeline leakage. As a supplement to this research, the influence of wind speed on LNG leakage and diffusion process is analysed in detail. Finally, the numerical simulation method is applied to a coastal LNG terminal in northern China to determine the distribution of natural gas concentration and temperature, as well as delimit the combustion range. The results can provide scientific reference for the delimitation of risky zones and the formulation of emergency response strategy.

Experimental research of flow rate and diffusion behavior of nature gas leakage underwater

2020 ◽  
Vol 65 ◽  
pp. 104119
Author(s):  
Yixiang Zhang ◽  
Jianlu Zhu ◽  
Youmei Peng ◽  
Jun Pan ◽  
Yuxing Li
Keyword(s):  
Experimental Research ◽  
Flow Rate ◽  
Diffusion Behavior ◽  
Gas Leakage ◽  
Nature Gas ◽  
And Diffusion

Numerical Simulation Study on Air-Flow Migration Law about Vortex Air Curtain of Plane Wall Fan Drum

2012 ◽  
Vol 241-244 ◽  
pp. 1285-1292
Author(s):  
Gang Zhou ◽  
Sen Cao ◽  
De Ming Wang ◽  
Wei Min Cheng ◽  
Wen Nie
Keyword(s):  
Numerical Simulation ◽  
Control System ◽  
Simple Algorithm ◽  
Plane Wall ◽  
Dust Control ◽  
High Concentration ◽  
Air Curtain ◽  
Working Face ◽  
Simulation Results ◽  
Migration Law

Vortex air curtain of plane wall fan drum can control the diffusion of air stripping dust effectively. In order to solve the high-concentration dust problem in fully mechanized excavation face, formation mechanism of vortex air curtain was analyzed. According to fluid mechanical control equations of gas phase flow, mathematical model was established to solve air migration law of vortex air curtain in fully mechanized excavation face. By using Simple algorithm based on collocated grid and fluent software, numerical simulation of air spatial migration law of closed-end dust control in fully mechanized excavation face was carried out. The simulation results show that vortex air curtain dust control system can form dust control fan drum along driving head to the front of the roadheader driver. According to the simulation results and actual conditions of working face field, vortex air curtain suction dust control system consisted of plane wall fan drum and exhausted dust purification device in fully mechanized excavation face was designed, and after it was applied in fully mechanized excavation face, the dust concentration decreased effectively in the working face field.

scholarly journals A study on a numerical simulation of the leakage and diffusion of hydrogen in a fuel cell ship

2018 ◽  
Vol 97 ◽  
pp. 177-185 ◽  
Author(s):  
Feng Li ◽  
Yupeng Yuan ◽  
Xinping Yan ◽  
Reza Malekian ◽  
Zhixiong Li
Keyword(s):  
Numerical Simulation ◽  
Fuel Cell ◽  
And Diffusion ◽  
Diffusion Of Hydrogen

Numerical Simulation of the Flow Field in Cavitations Nozzle for Impinging Streams Reactor

2010 ◽  
Vol 139-141 ◽  
pp. 1048-1051 ◽  
Author(s):  
Qin Li ◽  
Hui Lin Wang ◽  
Fu Bao Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Surrounding Medium ◽  
Analytical Calculation ◽  
Simple Algorithm ◽  
Shear Effect ◽  
Outlet Pressure ◽  
Pressure Distributions ◽  
Strong Shear ◽  
Simulation Results

The pressure distributions in cavitations nozzle of three different structures were studied by Hydromechanics theory, the models and mashes were completed by using Gambit software, for the conditions of the inlet pressure to 20MPa and the outlet pressure to 0.1MPa, the flow field within cavitations nozzles is simulated based on the standard k-ε model and the SIMPLE algorithm with Fluent. The result of numerical simulation is consistent with that of analytical calculation. Simulation results show that the flow has a strong shear effect with the surrounding medium in the diffuser, resulting in significant negative pressure, which is conducive to the formation of cavitations bubbles. The angle nozzle is best selected for impinging streams cavitations reactor on this basis in the paper.

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