Numerical Simulation Of Gas-solid Separation Characteristics On Ventilate Equipment Cabin Grille Of High-speed Train

As one of the types of EMU which running on the second double-line of Lanzhou-Xinjiang, the CRH5 H type sets the ventilation grille on both sides of the skirt-board with a totally enclosed design in its equipment cabin. This kind of ventilation grille has the V-V groove while the anti-dust filter mesh is equipped behind the ventilation grilles, and it is divided into several enclosed spaces. Because the second double-line of Lanzhou-Xinjiang crosses five wind-areas which are located in desert and the environment there is seriously poor, there comes a higher requirement for the ventilation equipment. Therefore, in order to make sure that all the equipments in the cabin can work correctly, it is necessary to study the property of the separation of gas and solid of ventilation grilles.Being based on the projects-“The performance and improvement of the equipment cabin of ventilation and dust removal device of EMU of CRH5H” cooperated with Changchun Railway Vehicles Co., Ltd, this thesis adopts the techniques of Computational Fluid Dynamics(CFD) and studies the commonly used structure of the two ventilation grille filters, namely the V-V-type ventilation grille and GL-type ventilation grille. Because the airflow through the ventilation grille filter is the flow of air and solid, starting from the basic theory of fluid mechanics, this paper firstly introduces the research methods of gas-solid two-phase flow and current studies about several commonly-used ventilation grille filters at home and abroad. The flow in the grille belongs to the turbulence, so the commonly-used turbulence models are also introduced in this thesis and the low Reynolds number k-ε model is selected finally as the turbulence model in this paper. The discrete particle trajectory model based on the coordinate system of Euler-Lagrange is also chosen as the simulation of solid-phase flow in this paper. In order to ensure the correctness and accuracy of the numerical simulation, the author has been to Baili and Yandun wind-area which are the typical regions of sand to take samples and make field works about the characteristics of sand, the diameter as well as the properties of the dust deposit along the second double-line of Lanzhou-Xinjiang.Through the research of ventilation grille of V-V type, this paper obtains the filtration efficiency and pressure loss of ventilation grille of this type, the velocity field and pressure field of gas phase as well as the concentration of dust in the field. The optimal length of the V-shaped edge and longitudinal gap parameter are achieved through the parameter’s optimization of ventilation grille. At last, the more suitable type of the ventilation grille is chosen at the same time. After obtaining the performance of the ventilation grille of V-V type, this thesis makes a further study about the performance of ventilation grille of GL type, getting the result of filtration efficiency and pressure loss of ventilation grille of this type, the velocity field and pressure field of gas phase as well as the concentration of dust in the field. After comparing the ventilation grille’s performance of V-V type with the one of GL type, this thesis concludes that the latter is better. Hopefully, the research methods and conclusions in this paper can offer some beneficial reference resources to the subsequent study.