| This article has been：Browse 2382Times Download 3329Times |
|
|
|
| DOI： |
|
| Analysis of the Influence of the Length of the Hub and Shroud inCentrifugal Pump on Performance of the Pump under Unsteady Flow Condition |
|
HAO Zhibang, YANG Zhongqiang
|
|
Hebei Province Ziya River Management Office, Hengshui 053000, China； Hebei Shexian Water Conservancy Bureau Qingta Reservoir Irrigation District Management Office, Handan 056400, China
|
| Abstract: |
| This work investigated the influence of the length of the hub and shroud in centrifugal pump on pump performance under unsteady flow condition. We took a centrifugal pump at specific speed of 80 as an example. The outlet diameter of the cutting impeller was kept unchanged, and we examined the change in radial force and pressure pulsation when the diameter of the hub and shroud varied from168 mm to 180 mm. The flow field in the pump under unsteady condition was calculated. It was found that the pumping-height and the efficiency increased as the length of the hub and shroud increased, and the maximum difference between pumping-height and efficiency was 2.14 m and 3.5% respectively. For the pump we examined, the radial forces changed periodically under all conditions, and the vector diagram was pentagram-distributed. The more the hub and shroud were retained, the larger the radial force was. Due to the interaction between the impeller and the tongue, the main frequency of the pressure pulsation at the monitoring point was a leaf-frequency. As the gap between the impeller and the volute decreased, the pressure pulsation at the leaf tongue remained unchanged, while its frequency multiplication increased gradually. Pressure pulsation coefficient also gradually increased. The results provided reference for practical application of the impeller cutting. |
| Key words: centrifugal pump; cut impeller; hub; shroud; pressure fluctuation; radial force |
|
|
