高压降套筒式蒸汽疏水阀振动特性研究

A study on the vibration characteristics of high pressure drop sleeve trap

针对高压降套筒式蒸汽疏水阀节流内件无法针精确设计和选用,并产生强烈振动的问题,基于直接边界元法对不同降压级数、节流孔径的疏水阀模型进行流激振动数值模拟研究,得到疏水阀不同开度下监测点处的振动频谱曲线及总振级随阀门开度变化规律。分析结果表明:不同开度下蒸汽疏水阀流激振动频谱特性由阀内节流件结构决定,受开度变化影响很小;在额定流量和额定压差不变情况下,总振级随降压级数增加而降低,但振动频谱特性基本不变,随节流孔径减小,总振级显著降低,且振动主要成分向50~500 Hz频率范围集中,为阀内节流件设计时避免流激共振提供参考,考虑节流套筒开孔时加工特点,节流孔径应取4~5 mm;实际使用中,为降低振动应尽量使疏水阀在中间开度下工作。

Aiming at the problem of strong fluid vibration induced by improper design and selection of throttling element,high pressure drop multistage sleeve trap was taken as the research object.Based on the theory of direct boundary element method,flow-induced vibration of traps at different pressure-drop stages and throttle hole diameters was simulated.The vibration spectrum curves and total vibration level curves of monitoring point at different openings were obtained.The results show that flow-induced vibration spectrum characteristic is mainly affected by interval throttling elements but less affected by opening degree.Under constant rated flow and pressure,total vibration level reduces with the increase of pressure-drop stages,while the characteristics of vibration spectrum remains unchanged.With the decrease of throttle hole diameter,the total vibration level significantly reduces,and main ingredients of vibration concentrate in 50-500 Hz,which provide references for the design and selection of throttling elements.Considering the processing characteristics of the throttle sleeve,the throttle hole diameter should be 4-5 mm.In practical use,steam traps should work under the middle opening degree in order to reduce vibration.