基于CFD数值模拟的排污阀冲蚀磨损影响规律

Influence law of erosion wear of blowdown valve based on CFD numerical simulation

针对排污阀因长期排污工作导致的冲蚀失效问题,采用CFD仿真模拟的方法开展关于流体流速、颗粒粒径、含砂体积比与阀门开度等因素对阀套式排污阀冲蚀磨损性能影响的评价分析.结果表明:阀芯、阀座密封接触壁面间的冲蚀破坏是造成整个排污阀失效的主要原因.在流速1~9 m/s、颗粒粒径0.1~0.5 mm、含砂体积比2%~10%、阀门开度15%~90%时,冲蚀磨损率与流体流速呈指数型正相关,冲蚀磨损区域随流速增加明显扩大.砂浓度增多加大了颗粒碰撞阀腔壁面的频率,其冲蚀率近似呈线性增长.颗粒粒径变化对排污阀平均冲蚀磨损率影响较小,小颗粒冲蚀行为下产生的冲蚀破坏相比大颗粒更为均匀一些.排污阀开度在15%~30%过程中,阀冲蚀磨损程度变化剧烈,从60%开度开始,阀的受损情况趋于平稳.同时,在阀门开度增大的过程中,阀芯最大冲蚀磨损区域从圆周壁面逐步移动到阀芯下端面.研究结果对排污阀的整体耐冲蚀性能评价具有指导意义.

Aimed at the erosion failure of the sewage valve due to long-term sewage work.The CFD simulation method was used to evaluate the erosion wear performance of the sleeve-type blowdown valve by factors such as fluid flow rate,particle size,sand-containing volume ratio,and valve opening.The results show that the erosion damage between the valve core and the seat sealing contact wall surface is the main reason for the failure of the entire drain valve.When the flow rate is 1-9 m/s,the particle size is 0.1-0.5 mm,the sand-containing volume ratio is 2%-10%,and the valve opening range is 15%-90%,the erosion wear rate is positively correlated with the fluid flow rate.The erosion wear area significantly increases with flow velocity increasing.Increased sand concentration increases the frequency of particles hitting the valve cavity wall surface,and the erosion rate increases approximately linearly.The change of particle size has little effect on the average erosion wear rate of the sewage valve.The erosion damage caused by the erosion behavior of small particles is more uniform than that of large particles.During the opening of the blowdown valve in the range of 15%to 30%,the degree of erosion wear of the valve changes drastically.From 60%of the opening,the damage of the valve tends to be stable.At the same time,in the process of increasing the valve opening,the maximum erosion wear area of the valve core gradually moves from the circumferential wall surface to the lower end surface of the valve core.This study provides some guidances for the overall erosion resistance evaluation of blowdown valves.