Numerical Study On Gas-solid Two-phase Flow In Dust Filter For Locomotive

The first-stage dust filter for locomotive is a device that separates dust particles and droplets from the air flow.As an air dust separation that filters large particles,it is often used on the skirt board on both sides of the locomotive as one of the key equipment to ensure the normal operation of the locomotive.The first-stage dust filters commonly used for locomotives include V-V dust filter,GL dust filter and plate-type dust filter.As a new type of dust filter,plate-type dust filter has few related researches at home and abroad.For this purpose,the computational fluid dynamics(CFD)method is used to simulate the gas-solid two-phase flow inside a plate-type dust filter.For the gas,use the Realizable k-?turbulence model that is in good agreement with the experimental results.For the particle phase,use the DPM model that can better simulate the dilute phase two-phase flow in the filter.The main research content and conclusions are as follows:First uses the realizable k-? turbulence model combined with the DPM model to steady and unsteady analyze oi the gas phase and particle phase in a two-dimensional plate-type dust filter,focus on the effects of operating parameters and structural parameters on the dust separation efficiency and pressure loss of the Plate-type dust filter.Then,in order to get the best combination of parameters,the response surface method was used to improve the structure parameters of the Plate-type dust filter.In addition,the CFD-DEM coupling method was used to simulate the three-dimensional plate-type dust filter,which can more directly observe the distribution of gas phase and particle phase in the three-dimensional space at different tines.Finally,the perfornance of' different structural types of dust filters was compared and analyzed.The results show that:(1)With the increase of particle size,the dust separation efficiency rises first and then decreases,and the pressure loss changes little;with the increase of the inlet gas velocity,the dust separation efficiency of different particle sizes are different,and the pressure loss increases with the increase of the inlet gas velocity;with the particle concentration increases,dust separation efficiency and pressure loss increase.(2)Through the research on the structural parameters of the plate spacing of the plate-type dust collector,the length of the dust hook,the width of the dust hook,the turning angle of the plate,etc.The different structural parameters of the plate-type dust filter have obvious influence on the dust separation efficiency and pressure loss.(3)The structural parameters of the plate dust filter were optimized using the RSM method,the pressure loss of the plate-type duster after optimization was greatly reduced,and the dust separation efficiency of large particle size particles was greatly improved.The simulation results of two-dimensional unsteady flow simulation and three-dimensional CFD-DEM simulations show that the inside flow field of the plate-type dust filter reaches a steady state in a very short time.For large particle size particles,the main capture point is at the first position.(4)According to comparison,it was found that the separation efficiency of GL filter and V-V filter was slightly greater than that of plate-type dust filter,but the pressure loss was greater than that of plate-type dust filter.The pressure loss of the V-V filter is much higher than that of the GL filter and plate-type filter.