Study On The Process And Mechanism Of Particle Vortex And Collision

Coal-fired power plants are an important source of fine particulate matter emissions.The vortex condensing device can gather small particles into large particles,thereby improving the collection efficiency of fine particles by the dust removal equipment.The collision coalescence process and coalescence mechanism of particles are the key to turbulent vortex coalescence technology.In this paper,numerical simulation method is used to study the process and mechanism of particle vortex and collision.Based on the CPFD theory,the discrete element analysis EDEM coupled with FLUENT,the dynamic characteristics of the fine particles in a certain area of the concentrator in the flow field are simulated.The results show that the spoiler blade can change the trajectory of the particles,and the particles are passing through the concentrator.After the blades are combined,a certain enrichment effect is produced;the multi-stage blades can increase the turbulence of the particle trajectory;the spoiler blades can change the relative velocity between the particles.The CPFD Barracuda software was used to simulate the gas-solid two-phase flow in the coal-fired flue gas in the turbulent coalescing unit,and the dynamic change process of the particle behavior was obtained.The results show that the spoiler blade can increase the particle concentration on both sides of the blade and some areas in the downstream flow field,and increase the probability of contact and collision between particles;small particles can follow the fluid movement well,and large particles have their own inertia,The state of motion between particles is relatively independent and not easily affected by the flow field;small particles are entrained by the vortex and move in the middle of the channel.Large particles can pass through the area where small particles are located and interact with small particles.Contact collision;on the one hand,multiple blades can cause the vortex generated by the upstream blades and the size of the near wake area to be compressed and reduced;on the other hand,the turbulent effects of multiple blades on the flow field can be superimposed on each other to increase the disturbance of the flow field;The spoiler blade can expand the relative velocity between particles,create conditions for the collision between particles,thereby promoting the collision and agglomeration of particles.