Numerical Simulation In The Swirl Coal Powder Distributor

With the development of the national economy, the energy issue has become animportant issue of our economic development. The energy shortage has affectedpeople’s life in some places. We should use energy more effectively.In addition to theexploitation of new energy, a very effective method is to maximize energy combustionutilization rate. The structural design of the distributor of pulverized coal that is animportant equipment in the pulverizing system of the power plants and the size of thepulverized coal distribution rate will cause the level of Pulverized coal combustionrate.If the deviation of the distribution of the pulverized coal distributor is too large,it can not guarantee the full combustion of pulverized coal in the boiler and may evencause the precipitation of pulverized coal in the boiler resulting in too largetemperature difference between Inter-regions that can cause the explosion of the boiler.The swirl pulverized coal distributor can avoid a pile of pulverized coal to enter theburner， but a certain angle of the blade can divide the gas-solid flow into six sharesof mixed flow and the swirl transport the multi-strand trickle to the burner. Takinginto account the reasons of complex structure, size and temperature higher,so I cannot obtain analysis by experiments.So the main content is to analysis the flowcharacteristics and speed characteristics of two-phase flow in the cyclone distributorby using CFD software for numerical simulation analysis.Three-dimensional model is drew and imported into the Gambit of processingsoftware to mesh and set the boundary conditions. The characteristics of gas phaseflow and gas-solid mixed phase flow are simulated and analyze in the Fluent. Thesingle-gas select standard model and SIMPLE algorithm, while the solid phase systemtrace particle trajectory by using discrete phase model.In this paper, the fluidproperties of the following three different conditions are analysized.：the different leafshapes (rectangles, arcs); the different number of blades (5,6,7); the different blade angle (45~o,60~o,75~o). This process compared with the experimental study is safe、short-time and less investment funds and other characteristics. The Details are asfollows:(1) I need to simulate the whole flow field of three different conditions to obtain theminimum impact and the best blade angle.(2) In order to research more clearly the velocity field and pressure field inside thedistributor. So I get X, Y, and Z different cross-section and the four differentcross-sections at Z location. So that I can simulate the fluid properties more fully.(3) The gas-solid flows into the inside, impacts the inner cylinder and leaves first andflow out after the formation of cyclone. That is to determine the blade angle to form astable swirl through simulating the velocity and pressure field the internal the tube andleaves.(4) Finally, we use the discrete model (DPM) for trajectory tracking of coalparticle.The method is one-way coupling method that is only to consider onedispersion. A particle is given the viscous drag and inertia force.