大导流面柱塞型节流阀冲蚀规律研究

Study on Erosion Law of Large Diversion Surface Plunger Type Throttle Valve

为了探究柱塞型节流阀在节流过程中因受到高速颗粒冲击和流体冲蚀而导致节流阀失效的问题,以PCG,2-9/16×15M型节流阀为研究对象,采用欧拉-拉格朗日法和离散模型,研究了不同开度、质量流量、流体速度及颗粒直径对阀座和阀芯的冲蚀规律。研究结果表明:随着开度的减小,节流阀主要冲蚀区域从阀体内腔节流处转为导流面节流处;在不同开度下,随着流速的增加,最大冲蚀率统一呈现上升趋势,并随着开度的增加,上升趋势更加明显;随着颗粒直径的增加,最大冲蚀率呈现上升趋势;随着质量流量的增加,最大冲蚀率不稳定,大体呈现上升趋势;节流阀通常在小开度下工作,小开度的不同工况下,节流阀最大冲蚀位置都处在节流阀阀芯上,将节流口处改为阶梯形结构,通过仿真结果对比,可有效降低节流阀最大冲蚀率。研究结果可为节流阀的进一步优化设计提供参考。

In order to explore the failure of the plunger type throttle valve due to high-speed particle impact and fluid erosion in the throttling process,taking the PCG,2-9/16×15 M throttle valve as the research object,the Euler-Lagrange method and discrete model were used to study the erosion law of different openings,mass flows,fluid velocities and particle diameters on the valve seat and valve core.The study results show that as the opening decreases,the main erosion area of the throttle valve changes from the bottleneck of cavity to the bottleneck of diversion surface;at different openings,as the flow rate increases,the maximum erosion rate shows an upward trend,and the upward trend is more obvious with the increase of opening;when the particle diameter increases,the maximum erosion rate increases;as the mass flow increases,the maximum erosion rate is unstable,but generally shows an upward trend;the throttle valve usually works at small opening;under different working conditions of small opening,the maximum erosion position of the throttle valve is on the valve core;when the choke is changed to a trapezoid-structure,the simulation result comparison shows that it can effectively reduce the maximum erosion rate of the throttle valve.The study results provide references for the further optimum design of the throttle valve.