液压支架缸体内壁面再制造粉流场影响规律分析

目的 开展液压支架缸体内壁面再制造粉流场规律分析，以提高液压支架缸体内壁面的修复效率，降低其修复成本。方法 采用激光沉积技术修复液压支架缸体内壁面时，侧向送粉粉流集聚性是影响液压支架缸体内壁面修复效率的重要因素。建立修复液压支架缸体内壁面的长悬伸激光沉积模型，基于DEM-CFD双向气固两相流耦合模型，在送粉喷嘴位姿不变的条件下，分析送粉工艺参数（即载气流速度、保护气速度、送粉速率）对液压缸内孔流域粉流集聚性的影响规律。结果 随着载气流速度的增大，粉流与激光交汇处单位体积粉流浓度呈现先增大后减小的趋势，粉流分布直径呈现先减小后增大的趋势。随着保护气速度的增大，粉流与激光交汇处单位体积粉流浓度呈现先增大后减小的趋势，粉流分布直径呈现先减小后增大的趋势。随着送粉速率的增大，粉流与激光交汇处单位体积粉流浓度变大，粉流分布直径呈现先减小后增大的趋势。结论 当载气流速度为4 m/s、保护气速度为3 m/s、送粉速率为5 g/min时，粉流集聚效果好，粉体利用率高，有助于提高液压支架缸体内壁面的修复效率。

Analysis of the Influence Law of the Remanufactured Powder Flow Field on the Inner Wall of Hydraulic Support

This paper aims to analyze the flow field of remanufactured powder on the inner wall of hydraulic support cylinder, which is helpful to improve the repair efficiency and reduce the repair cost. When laser deposition technology was used to repair the inner wall of the hydraulic support cylinder, the powder flow concentration of lateral powder feeding was an important factor in improving the surface repair efficiency of the hydraulic support cylinder. The model of the long-distance powder feeding nozzle used to repair the inner wall of the hydraulic support cylinder body was established. Based on the DEM-CFD gas-solid two-phase flow coupling model, the influence of the powder feeding process parameters (carrier gas velocity, shielding gas velocity, powder feeding rate) on the agglomeration of powder flow was analyzed separately under the condition of the constant pose of the powder feeding nozzle. The research showed that as the speed of the carrier gas increased, the density of the powder flow per unit volume at the intersection of the powder flow and the laser showed a trend of first increasing and then decreasing. The distribution diameter of powder flow showed a trend of first decreasing and then increasing. As the speed of the shielding gas increased, the density of the powder flow per unit volume at the intersection of the powder flow and the laser showed a trend of first increasing and then decreasing. The distribution diameter of powder flow showed a trend of first decreasing and then increasing. As the powder feeding rate increased, the concentration of the powder flow per unit volume at the intersection of the powder flow and the laser became larger. The distribution diameter of powder flow showed a trend of first decreasing and then increasing. From the regression model of powder flow concentration per unit volume, it can be seen that when the carrier air velocity is 4 m/s, the shielding gas velocity is 3 m/s, and the powder feeding rate is 5 g/min, and the powder flow accumulation effect is good. At this time, the utilization rate of powder is high, which helps to improve the repair efficiency of the inner wall of the hydraulic support cylinder.