定压活门稳定性定量分析

提出了一种定压活门(CPV)稳定性的定量分析方法.首先通过稳态分析,得到影响定压活门稳态性能的主要参数.通过小偏差动态分析,获得定压活门闭环极点根轨迹图.提出临界进口压力概念,得到5个主要结构参数对定压活门稳定裕度的定量影响:弹簧刚度对稳定裕度影响很小;而增大阀芯直径,提高阻尼系数,增加负载,减小定压腔容积都分别能够明显提高定压活门的稳定裕度,计算结果与实际工程经验及AMESim仿真结果基本一致.最终,得出增强定压活门稳定裕度的改进措施和设计方法:①定压活门改进问题,最有效的方法为改动出口流通面积;②定压活门设计时,首先应根据其工作进口压力要求及最小负载,确定临界进口压力,然后通过动态分析,以阀芯面积和定压腔容积作为主要的设计参数. 

Quantitative analysis on constant pressure valve stability

A quantitative methodology on constant pressure valve (CPV) stability analysis was presented. Firstly, the main parameters affecting static property of CPV were got by static analysis. The root-locus plots of CPV were achieved through small deviation dynamic analysis. By defining the concept of critical inlet pressure, the quantitative results of five main structural parameters' effect on the CPV stability margin was got: the spring stiffness has a little effect on stability margin; the increase of spool diameter, damping coefficient, load, and decrease of constant pressure chamber volume could enlarge the stability margin. The analytical result has an excellent consistence with AMESim simulation result and engineering experience. Finally, two conclusions were presented for enhancing the stability margin of CPV: (1) for improving problem of CPV, the most effective method is to change the outlet area; (2) for CPV design problem, based on the inlet pressure requirement and the minimum load, the critical inlet pressure need be determined firstly, and then the spool area and constant pressure chamber volume are taken as main design parameters by dynamic analysis.