Test investigation on hydraulic losses in

discharge passage of axial-flow pump

QIU Baoyun¹  HUANG Jiyan¹  YUAN Shouqi²  LIN Haijiang¹  FENG Xiaoli¹

(1. College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou 225009;

2. Research Center of Fluid Machinery  Engineering and Technology, Jiangsu  University, Zhenjiang 212013)

Abstract: Under the influence of guide blade discharge circulation, discharge bend pipe secondary flow, the flow in the 1-channel discharge passage of an axial flow pump is complicated spiral flow, the discharge in the left channel is bigger than that in the right one as for 2-channel passage, and the passage hydraulic losses are abnormal. The section current energy of the passage is measured and determined with 5-hole probes accurately. The hydraulic loss characteristics are determined and analyzed. The methods deducing the hydraulic losses are investigated. The results indicate that the passage hydraulic losses are not proportional to the flow discharge. Compared with circle pipe, the hydraulic losses of divergent discharge passage are smaller and the pump assembly efficiency is higher with 10%~30%. As for 1-channel passage , axial-flow pump outlet circulation is too big usually, the passage hydraulic losses are big too, but small circulation can slightly reduce hydraulic losses. As for 2-channel passage, discharges in 2 channels are not equal and the hydraulic losses increase. The outlet guide blade with small discharge circulation or without circulation could reduce discharge passage hydraulic losses and pump assembly efficiency increases with 6%~11%.

Key words: Axial-flow pump  Discharge passage  Hydraulic losses  5-hole probe

CLC No: TH3  TK7

国家自然科学基金(50179032)和江苏省水利动力工程重点实验室基金(KJS03086)资助项目. Received 20050523, received in revised form 20051028