重庆理工大学学报(自然科学) ›› 2023, Vol. 37 ›› Issue (10): 174-181.

• 机械·材料 • 上一篇    下一篇

挡板长度对半螺旋吸入室内部流动及空化影响

付 强,杨大伟,张吉来   

  1. (1.江苏大学 流体机械工程技术研究中心,江苏 镇江 212013; 2.中国核电工程有限公司,北京 100840)
  • 出版日期:2023-11-20 发布日期:2023-11-20
  • 作者简介:付强,男,博士,教授,主要从事流体机械泵及装置系统研究,Email:ujsfq@sina.com。

The effect of baffle length on the flow and cavitation inside a semi spiral suction chamber

  • Online:2023-11-20 Published:2023-11-20

摘要: 为改善半螺旋型吸入室对双吸离心泵的不利影响,探究了挡板长度对半螺旋吸入 室内部流动及空化影响。采用 3种挡板长度对比半螺旋吸入室水力性能,分析挡板对半螺旋吸 入室双吸泵性能的影响。运用计算流场软件 ANSYSCFX,采用 SST湍流模型和基于 Rayleigh Plesset方程的空化模型,对双吸离心泵内部的半螺旋吸入室进行定常三维湍流全流道数值模拟。 计算得到了半螺旋吸入室内部速度和压力变化分布图,进一步研究进入叶轮前的流态。结果表 明:在 0.8~1.2Q的流量下,挡板末端越接近叶轮中心,在保持效率变化小于 0.36%的情况下,其 扬程逐步上升,幅度在1.2%~1.6%,同时改善了不切断型半螺旋吸入室隔舌处的流态。探究空化 下不同有效的空化余量及其空化初生阶段的发展,发现挡板会导致空泡的初生阶段提前,但空化 发展较缓慢,在扬程下降3%时,对应的有临界空化余量减小0.3m。因此,增长挡板可以改善空化 性能,在维持效率的情况下提高扬程,可为半螺旋型吸入室设计提供参考。

关键词: 双吸离心泵, 半螺旋型吸入室, 挡板, 空化, 数值模拟

Abstract: To improve the adverse effect of a semi spiral suction chamber on a double suction centrifugal pump,the effect of baffle length on the flow and cavitation inside the semi spiral suction chamber is investigated.Three types of baffle length are used to compare the hydraulic performance of the semi spiral suction chamber and analyze the impact of the baffle on the performance of the semi spiral suction chamber double suction pump.With the computational flow field software ANSYS CFX,the SST turbulence model and the cavitation model based on the Rayleigh Plesset equation are used to numerically simulate the steady-state three-dimensional turbulent full channel flow in the semi helical suction chamber of a double suction centrifugal pump.The distribution of velocity and pressure changes in the semi spiral suction chamber is calculated,and further research is conducted on the flow pattern before entering the impeller.The calculation results show that at a flow rate of 0.8~1.2 Q,the closer the end of the baffle is to the center of the impeller,while an efficiency change is maintained less than 0.36%,the head gradually increases,with an amplitude of 1.2%~1.6%.At the same time,the flow pattern at the tongue of the non cutting semi spiral suction chamber is improved.After exploring the different effective cavitation margins and their development in the initial stage of cavitation under cavitation,it is found that baffles can lead to an earlier initial stage of cavitation,but the development of cavitation is relatively slow.When the head decreases by 3%,the corresponding critical cavitation margin decreases by 0.3 m.Therefore,increasing the baffle can improve cavitation performance and increase the head while maintaining efficiency,providing assistance for the design of a semi spiral suction chamber.

中图分类号: 

  • TH311