Research On The Prediction Method And Structure Optimization Of Gas-Solid Two-Phase Flow Erosion Wear On The Distribution Plate With Bubble Cap

The gas-solid two-phase flow erosion wear in throttling process are researched in this paper.The failure mechanism of gas-solid two-phase flow erosion wear in throttling process clarified by analyzing the technical process,operational condition and micro-morphology of worn surface.The mechanisms of erosion wear and particle motion process in the distribution plate with bubble cap are investigated by the experiments of particle erosion.Moreover,the particle erosion wear model is modified and the mathematical model of gas-solid two-phase flow erosion wear in throttling process with harsh working is constructed.Based on the verification of mathematical model and calculation method,the erosion wear in the distribution plate with bubble cap are numerically predicted.The numerical simulation was performed by using actual running and fluid physical parameters.The numerical results are in good agreement with the actual failure morphology,then the numerical calculation is verified.The improved structure of bubble cap are proposed and validated.The main content of this paper are described as follows:(1)In this paper,the work flow and function realization of the continuous high temperature erosion wear experimental device are introduced.The erosion wear experiments of three materials(PTA-STL12,PTA-YDCL-01(* 1),PTA+PVD-Ni60+(* 1)(* 1)denoted the number of secret materials))under three different influence factors,(namely temperature,abrasive quantity and impact angle)are carried out respectively.Their macroscopic and microscopic erosion damage morphologies are analyzed and discussed,and the erosion wear mechanism of materials under different working conditions is explored.Material 1(PTA-STL12)produces metallurgical bonding between coating and substrate.Under the erosion of particles,the material was extruded and shoveled,and finally flaked off.Material 2(PTA+PVD-Ni60+(*1))is coated with Ni60 and TiN powder.The hardness and wear resistance of the coatings are improved due to the existence of a large number of reinforcing phase particles TiN on the surface of the coatings.Under the erosion of the particles,the material is squeezed,shredded,and eventually chipped off.Material 3(PTA-YDCL-01(*1))is made by Ni60 A powder by plasma spray welding and surfacing to 316 L stainless steel.Under the erosion of the particles,the material is squeezed,shredded,and eventually chipped off.(2)The amount of abrasive,temperature and impact angle have a significant effect on the erosion wear of the three materials.The amount of abrasive and temperature are roughly linearly positively correlated with bulk worn loss of material 1(PTA-STL12)and material 3(PTA-YDCL-01(*1)).However,as the coating is thinned and the shape of the pit changes,the material etch pit will expand to the periphery.Due to material 1(PTA-STL12)and material 3(PTA-YDCL-01(*1))show the characteristics of plastic material,the surface plastic deformation of the specimens is obvious under the low angle of impact,the radius of erosion pit and the depth of the center of the pit are steeply increased,and the material falls off in block shape,and the overall wear amount is relatively large.The bulk worn loss of material 2(PTA+PVD-Ni60+(*1))is positively correlated with the amount of abrasive.The material wear rate is the smallest at 90° angle of attack.The depth of the center of the pit increases sharply at 60°,the surface deformation is obvious,and the overall wear amount is large.(3)Construction of mathematical model for calculating the gas-solid two-phase flow erosion wear in throttling process.Based on the methodology of SST k-? model,particle motion model,recovery coefficients model and particle erosion model,the mathematical model of gas-solid two-phase flow erosion wear is constructed.The critical parameters in the particle erosion model are modified by using the experimental data of erosion wear.The accuracy of numerical calculation is verified by comparing with the actual experimental results.(4)The failure mechanism of gas-solid two-phase flow erosion wear in the distribution plate with bubble cap clarified by analyzing the technical process,operational condition and micro-morphology of worn surface.The numerical simulation was performed by using actual running and fluid physical parameters.The numerical results are in good agreement with the actual failure morphology,then the numerical calculation is verified.The improved structure of bubble cap are proposed and validated.The structure optimization scheme of the distribution plate with bubble cap is as follows:(1)the flow passage is changed into an expanded structure and arc transition is adopted at the outlet of the runner;(2)the fixing method of blister cover is changed from side rib plate fixing to top bolt fixing;(3)appropriately increasing the number of openings N and the inner diameter of the lifting pipe can not only disturb the flow field well,but also promote good contact and mixing of the adsorbent and the material,while maintaining the wear level is reduced,the wear range is not diffused,and the overall service life of the distribution plate is improved.