Abstract:In order to better understand the hydraulic performance of cube-type pump system with inlet and outlet conduits, based on CFD numerical simulation and DOE orthogonal experimental design method of a model test, a three dimensional parametric model of the inlet and outlet conduits was constructed with the velocity uniformity of outlet-section for inlet passage and the hydraulic loss as objective function. The five factors and four levels orthogonal test was designed in view of the inlet flare tube, the water-guide cone, the outlet flare tube and the control size of outlet-guide piers. Aiming at the design flow point, totally 16 numerical simulation schemes of the inlet passage and outlet passage were calculated respectively by means of CFD numerical simulation to analyze the effect of different control sizes on the performance of inlet and outlet conduits. The reliability of optimization numerical results was validated through the model test finally. As shown in the numerical simulation and experimental results, the inlet conduit optimization design by means of DOE orthogonal design method, the influence of control parameters on hydraulic loss of an inlet passage and the primary and secondary effects on the uniformity of export section can be got. The largest hydraulic loss was 8.56cm, the smallest hydraulic loss was 3.91cm, the optimized hydraulic loss was 3.65cm, and the uniformity of outlet velocity was 93.07%, the optimization design made the hydraulic loss reduced by 1.31cm and the uniformity of outlet velocity increased by 1.17 percentage points compared with the initial plan. The largest hydraulic loss of outlet conduit was 46.07cm, the hydraulic loss of outlet conduit for the optimal combination scheme was 32.53cm,which was reduced by 7.96cm compared with the original plan. According to the whole characteristic curve of the pump system, it can be learned that the pump hydraulic loss of outlet conduit was minimum under the design condition, the highest efficiency was 70.04%, the highest running head was 4.0m under the design condition with head of 1.36m, the efficiency was 66.82%, and the corresponding flow rate was 34.31m3/s. The highest efficiency of the model test can be up to 71.5% under the design condition with head of 1.36m, the test efficiency was around 64%, which was in good agreement with the numerical simulation results. It illustrated that the better scheme can be designed by using the orthogonal design method, this study also provided reference for the similar optimization design of pump station.
