单座调节阀流场分析及阀芯不平衡力特性研究

Analysis of flow field of single-seat regulating valve and research on characteristics of unbalanced force of spool

为了研究阀芯结构对单座调节阀性能特征的影响,以某蒸汽调节工况用的DN80单座调节阀作为研究对象,建立阀芯头部为凸面和平面的2种结构。在流体流向为低进高出的情况下,通过稳态流场仿真研究了阀芯头部结构对阀门的流量系数的影响,通过瞬态流场仿真研究了实际工况下阀门的流场瞬态特性和阀芯不平衡力特性。结果表明,阀芯头部是凸面还是平面对阀门的流量系数(C_(v))和流量特性曲线无影响;2种阀芯结构对阀门内部的流体流动特征影响不大;阀芯受到的压力脉动曲线趋势和压力脉动频谱的趋势与其头部是凸面还是平面无关,但头部为凸面的阀芯压力脉动峰值频率比平面阀芯的压力脉动峰值频率高2~4 Hz;在保证阀芯从阀门全关到全开设计行程的曲面坐标相同时,阀芯头部为凸面还是平面对调节阀的影响不大。研究结果可为用户选择何种阀芯结构提供参考,为阀门的振动特性分析提供支撑。

In order to study the influence of valve spool structure on the performance characteristics of single seat regulating valves,a DN80 single-seat regulating valve used in certain steam regulating condition was used as the research object,and two structures of spool head with a convex surface and flat surface were created.In case of fluid flow in from low side and flow out from high side,influence of head structure of the spool on flow coefficient of valve was studied by simulating steady-state flow field,and transient characteristics of flow field and unbalanced force characteristics of the valve spool under actual working conditions were studied by simulating transient flow field.The results show that whether head of the spool is convex surface or flat surface has no effect on C_(v) and flow characteristic curve of valve;The two spool structures have little effect on fluid flow characteristics inside valve;Trends of pressure pulsation curve and pressure pulsation spectrogram of the spool have nothing to do with whether its head is convex surface or flat surface,but peak frequency of pressure pulsation when spool is convex head is 2~4 Hz higher than that when the spool is flat head;When ensuring that coordinates of curved surface of the spool from fully closed to fully opened are the same,whether head of the spool is convex surface or flat surface has little effect on regulating valve.The research results can provide a reference for users to choose structure of the valve core,and provide support for the analysis of vibration characteristics of the valve.