Abstract:The change of head range of the running condition is relatively large in Lingcheng Pump Station. It can be found that the hydraulic model test of South-to-North Water Diversion Project on the same test-bed can meet the basic requirements of running condition when making axial-flow pump selection analysis for the pump station. But it has its irrationality: when the design head is according to high efficiency, the maximum head lacks safety margin; when the maximum head is satisfied, the design head is not within the high efficiency area. Thus, a specific design for Lingcheng hydraulic model based on CFD calculation was done. By changing the cascade dense degree and the airfoil placed angle, the method of multi-operation optimization was adopted to make the final design scheme, which can meet the running requirements of Lingcheng Pump Station. Then numerical simulation study of the final specific-designed hydraulic model was conducted. At its design condition, the head was 5.48 m and the efficiency achieved 86.3% of maximum value. Head increased with the decrease of flow rate, in the calculation of minimum flow rate as 240 L/s, it did not reach the saddle area condition, when head reached 8.46 m, and the efficiency was still in the acceptable range. In a word, the simulation results showed that the specific-designed hydraulic model had higher efficiency and satisfied the highest head requirement of Lingcheng Pump Station. Finally, the experiment results showed that the specific design of axial-flow pump based on CFD was accurate and reliable, and it can meet the special water level requirements of Lingcheng Pump Station. At the same time, specific design research is necessary for the large pump station renewal and reconstruction.
