Numerical Simulation Of Penumatically Conveyed Dense Phase Gas Solid Two-phase Flow Based On FLUENT

Gas solid two-phase flows in pneumatic conveying are related to energy, environmental protection, aerospace and many other industries. Gas-solid two-phase flows are more and more widely applied in the chemical industry, metallurgy, energy, environmental protection, light industry and national defense fields, such as the coal conveying and dust measurements. The engineering applications of this discipline to ecological environment protection and energy fully utilization of resources play an important role in promoting.Study on the gas solid two-phase flow characteristics are mainly divided into theoretical and experimental studies. A set of comprehensive experiments of dynamic parameters testing of the two-phase flows, gas solid two-phase flow status monitoring and gas solid two-phase flow simulation, all of these could combine theoretical studies with experimental investigations to characterize deeply the gas-solid two-phase flows. It is more difficult to get flowing details of gas solid two-phase flow inside pipelines due to the complexity of gas solid two-phase flow dynamics characteristic and the limitations of existing experimental devices. With the development and application of computational fluid mechanics, CFD becomes the analysis, by means of computer-based simulations, of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions, flowing characteristics and visualization in gas solid two phase flow area.This paper focuses on the target of establishing a set of dense gas solid two-phase flow experimental device, the pressure loss of pipeline horizontal pipeline section and vertical pipeline section was calculated and repeatedly verified based on the dense phase static empirical formula to provide reliable reference to select driving device for the pneumatic conveying system.Taken the pulverized coal particles flow in the vertical pipe flow of pneumatic conveying as an investigated object, the flow state of pulverized coal particles in a vertical pipe was simulated using the FLUENT platform. The geometry modeling of the investigated object was firstly built using GAMBIT software for meshing and setting boundary conditions, as well as the grid testing. The geometry modeling was then input onto FLUENT platform, and setting initial conditions, selecting models, conducting simulation. The simulation model is a two-fluid model based on the theory of particle dynamics. The mutual collision of gas-solid two-phase flow, interphase interaction between solid particles and solid particles colliding with the pipe wall were considered in the model.In this paper, analysis is performed towards data obtained from this simulation and results from somebody else’s work. Under conditions of approximate identical boundaries, initial premises and calculating solvers, the radial velocity distribution of gases in different cross sections of the vertical pipe and the axis average static-pressure exhibit a consistent trend between both simulations. Meanwhile, a striking difference can be found from the radial velocity distribution of moving solids between two simulations. However, the analysis shows that results in this study are much more practical due to a resistance force existing in two phases, and this will results in a velocity difference between the gas and the solids. Concentration distributions of gas phase and solid along radial direction in this study are also different from that of the references. Some further experiments and simulations will have to be carried out to verify these details.