泵停机瞬态振动的非定常数值解析与试验研究

摘要

Quantitative analysis of pump operation performance was acquired based on vibration test. The vibration test analysis showed that the res-onance of beam was the reason to cause the intensive vibration. Unsteady numerical simulation by CFD was introduced to capture the flow character-istics inside the pump on vibration condition. The spectrum analysis results of pressure,velocity and force of simulation flow showed the low-fre-quency water pulse pressure in pump and pipes was clear to be the reason of beam’s intensive vibration. With the“shut pump before valve closed”strategy that proposed in this paper was put into effect,the intensive vibration was avoided. CFD numerical simulation technique could be used to realize continuous sampling of dynamic signal on transient conditions in pump. Since it could acquire the time-frequency symptom of non-stationary signals that impossible for vibration test,CFD could be an effective method to analyze the pump vibration.%通过振动试验，量化分析了机组性能，探明异常振动为横梁共振引发。引入CFD技术展开非定常数值模拟，捕捉振动工况的泵内流动特性。数值仿真场中压力、速度和力的频谱分析表明，当阀门开度较小时，泵和管道内水压脉动的低频分量频率与横梁固有频率相近，产生共振，引发强烈振动。采用“提前停泵”的减振方案，消除了阀门关死点的机组异常振动现象。CFD数值模拟实现了瞬态工况下泵内流动态信号的连续采样，解决了测量中无法获取过渡过程非平稳信号瞬态频率的难题，可作为水泵振动分析的有效手段。