Lattice Boltzmann Simulation Of Two Dimensional Carbon Rod Combustion

Combustion of carbon or coal widely exist in nature and engineering. As the coal is the main primary energy source in our country, the studies of carbon combustion, which is the main composition of coal,has very important practical significance.In this paper,the lattice Boltzmann method(LB) and MPI parallel program are used to simulate the combustion of a single carbon rod as well as a groups of carbon rods in various conditions, this paper mainly studies the influence of various factors on the combustion rate and the disturbance of flow field with groups of carbon rods,as well as the influence of the disturbance on combustion.In this paper, in dealing with the gas-solid two-phase combustion, the boundary chemical reaction is related to the diffusion equation, thus the chemical reactions is performed in the form of diffusion.First of all, the combustion of a single carbon rod is simulated in this paper, and effects of the temperature of coming flow, Reynolds number(velocity of flow), oxygen concentration and environment of combustion(air and oxygen) on burning rate are analyzed.Results show that with the increase of the coming flow temperature, the burning rate of the carbon rod decreases, this is mainly due to the decrease of oxygen concentration near the carbon rod;And the carbon burning rate increases with the increase of Reynolds number;The effects of oxygen concentration on burning rate is significant too, figures display that the burning rate has a linear relation with the oxygen concentration; According to the results of combustion in N2 and CO2 environment respectively, when the concentration of oxygen in gas mixture is high(> 0.08), the carbon burning rate in N2 environment is higher than that in CO2 environment, and when the oxygen concentration is less than this value, the contrary is the case.In this paper, combustion of different number of carbon rods are also simulated, and the effect of flow field disturbance on each component of combustion as well as the effect of carbon rod number on burning rate are discussed.By simulating the combustion of different number of carbon rod, we find that the disturbance of flow field is much more intense, along with the increase of number of carbon rod and at the same time each component of the mixture gas in disturbed areas has also changed intensely;And the average burning rate of the carbon rod decreases with the increase of the number of that, and when the number of carbon rod is 9 or higher the average carbon burning rate tends to be stable.