| In this paper,the data analysis of the results of the total oxygen diffusion combustion experiment is carried out,and the distribution characteristics of the diffusion vortex motion and the structure in the furnace are found.The combustion process is numerically simulated and analyzed.The first attempt to apply the typical vortex structure identification method to the diffusion combustion process The eddy current law was analyzed and it was found that using the omega method to identify the eddy current in the furnace is more accurate than other methods.The research results provide a certain reference value for the development and application of total oxygen dispersion combustion technology.In this paper,the velocity field and concentration field comparison analysis of nozzles with parallel arrangement,mirror arrangement and opposite arrangement are carried out by numerical simulation.It is found that the vortex motion conditions of the three nozzles arranged in the furnace are basically the same in the general trend,but the mirror nozzle arrangement is Speed field,the concentration field is better.Then using the Q criterion,the criterion,the omega method vortex structure identification method for comparative analysis,it is found that the omega vortex structure identification method is more accurate in identifying the eddy current motion law in the diffusion combustion process,and is less subject to human interference.Using the vortex distribution characteristics of the omega vortex structure identification method in the furnace,it is found that most of the triangular vortex,diamond vortex and other irregular vortex structures are formed at a position 0 to 1 m from the inlet end of the furnace,and the structure is small.The 1m to 2m position of the inlet end is the rear part of the furnace,and the vortex formed in this area is mainly the structure of the furnace vortex structure of the circular vortex structure with large structure.It is indicated that under this kind of working condition,it is accurate to use the omega method to identify the vortex motion in the furnace.Through the analysis of the law of the oscillating motion of the full-oxygen diffusion combustion of the mirror nozzle arrangement,it is found that under the conditions of oxygen and propane speeds of 196.58m/s and 39.32m/s,the optimal mixing region is 1/4 of the initial position of the furnace.At 1/2(x = 0.5m-1m),the eddy current motion exhibits an irregular motion pattern.The eddy current movement at this position is mainly dominated by a triangle-like shape,and its size is mostly concentrated between 1 mm and 5 mm.At a distance of 1m-2m from the initial position of the furnace,the eddy current movement in the furnace is relatively gentle,and the vortex structure is relatively regular,showing a circular structure.The vortex structure is large in size,and the size is mostly concentrated at 5 cm,and the strength is weak.The vortex structure formed at the end of the furnace is found to have an "8" shape.The protruding portion corresponds to the nozzle jet portion,thereby indicating that the influence of the jet can be diffused throughout the furnace.In addition,using the different eddy structure identification criteria for the vortex structure analysis of the mirror nozzle arrangement,it can be seen that the three identification methods of eddy current motion at the end of the furnace are basically the same in the general trend.However,the "8" word recognized by the omega method can better reflect the asymmetric characteristics of the nozzle jet,and its recognition method is superior to the other two vortex structure identification methods.According to the initial jet velocity and the distribution law of the optimal mixing point formed by it,it can be found that appropriately increasing the initial velocity of the nozzle is more conducive to the realization of the per-oxygen diffusion combustion. |
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