双吸离心泵隔舌区压力脉动特性及改进

针对某石化股份有限公司双吸离心泵振动超标的问题,研究了叶轮外径对双吸离心泵隔舌处压力脉动特性的影响。采用雷诺时均法和滑移网格技术,对双吸离心泵内部流场进行三维非定常数值模拟,分析了隔舌处流场和压力脉动情况。研究结果表明:隔舌处的压力脉动幅值大小与流量呈正相关;不同工况以及不同叶轮外径情况下,隔舌区的脉动频率均以叶片通过频率为主;随着叶轮外径切割量的增加,隔舌处压力脉动幅值呈现减小趋势,说明合理地切割叶轮外径能降低压力脉动幅值。

Characteristics and Improvement of Pressure Pulsation near Volute Tongue in a Double-Suction Centrifugal Pump

In order to solve the problem of excessive vibration for a double-suction centrifugal pump in a petrochemical corporation, the influence of impeller diameter on the characteristic of pressure pulsation near volute tongue was studied. Reynolds-Average Navier-Stocks method with sliding mesh technology was used to analyze the unsteady flow field and pressure pulsation in different conditions. The results of pressure pulsation before and after impeller cutting were compared to illustrate the effect. The result indicates that the amplitude of pressure pulsation is positive correlated with flow rate. The blade passing frequency dominates pressure pulsation in different conditions and different impeller diameters. With the increase of the cutting amount of impeller diameter, the amplitude of pressure pulsation shows a decreasing trend. The research shows that cutting impeller diameter is an effective way to improve the pressure pulsation.