基于DPM模型的变径管冲蚀磨损分析与结构改进

Erosion Wear Analysis and Structural Improvement of Reducing Pipe Based on DPM Model

针对变径管冲蚀失效的问题,基于DPM模型、Realizeble k-ε模型和颗粒磨损方程对变径管进行数值模拟计算,分析流速、颗粒直径、质量流量、过渡倾角、改进后过渡圆角对变径管的冲蚀磨损规律和改进后变径管的性能。结果表明:过渡段与小径管相贯处冲蚀磨损最为严重;随流速、质量流量的增大和颗粒直径的减小,最大冲蚀速率逐渐增大,其中受流速的影响最大。过渡倾角由5°增加至35°,最大冲蚀速率在9.32×10^(-5) kg/(m^(2)·s)上下波动;由35°增加至85°,最大冲蚀速率整体上升、后大幅度下降;80°~85°时,最大冲蚀速率较小且受各因素的影响很小,尤其等于85°时,其最大冲蚀速率降低了23.5倍。结构改进后过渡圆角7.5~15 mm变径管的最大冲蚀速率小于改进前变径管,且冲蚀分布比较均匀;随过渡倾角的增大,结构改进后过渡圆角2.5~15 mm变径管与改进前变径管相比,管内最大压力相差逐渐减小,且改进后管内最大压力及应力均低于改进前变径管,管内压力最大降低了2.25倍。该结果可为实际作业中变径管的选用及结构设计与优化提供参考。

In order to address the problem of erosion failure of the reducer,numerical simulation of the reducer was carried out based on the DPM model,realizeble k-ε model and particle wear equation to analyse the flow velocity,particle diameter,mass flow rate,transition inclination,the improved transition angle of the reducer's erosion and wear law and the performance of the improved reducer.The results show that the erosion wear is most serious at the intersection of the transition section and the small pipe.The maximum erosion rate increases gradually with the increase of flow velocity,mass flow rate and the decrease of particle diameter.The transition Angle increases from 5° to 35°,and the maximum erosion rate fluctuates from 9.32×10~(-5) kg/(m~2·s).The maximum erosion rate increases from 35° to 85°,and then decreases significantly.When 80° ~ 85°,the maximum erosion rate is small and the influence of various factors is small,especially when 85°,the maximum erosion rate is reduced by 23.5 times.The maximum erosion rate of the transition fillet 7.5~15 mm is less than that of the transition fillet before the improvement,and the erosion distribution is more uniform.With the increase of the transition Angle,the difference of the maximum pressure in the modified 2.5~15 mm transition reducer is gradually reduced,and the maximum pressure and stress in the modified pipe are lower than those in the modified pipe,and the maximum pressure in the pipe is reduced by 2.25 times.The results can provide reference for the selection,structural design and optimization of the reducer in practice.