OPTIMIZATION DESIGN AND INNER FLOW ANALYSIS ON A MEDIUM-HIGH SPECIFIC SPEED CENTRIFUGAL PUMP

摘要

Aiming at the problems of low efficiency, easily overload and having humps of the TS100-200 centrifugal pumps, four impellers are designed with different blade curves to improve the performances of the pumps. Non-overload design method is adopted for parameters selection of impellers. The 3-D models and the 1.61 million structure grids were generated by Pro/E and ICEM respectively. After the boundary conditions of velocity inlet, outflow in the outlet and no-slip wall were specified, and the flow model was complemented with the standard k-ε model by using the commercial software CFX 12.1. The distributions of pressure, turbulence kinetic energy and streamlines in four impellers are obtained during simulation, as well as their hydraulic performances. The wrap angle Φ is a critical parameter to the blade shape. Impeller-2 with appropriate wrap angle Φ shows good hydraulic characteristics and excellent inner flow patterns, and it is produced for experiments by prototyping rapidly. The test results are in accordance with the simulating results. The head of impeller-2 is 5% higher than the design parameter at most and the efficiencies are nearly 6% higher than the efficiencies of the prototype pump at the design flow rate Q_R. The test results also show a good non-overload performances. The results prove that it is an effective and reliable method to the optimal design of centrifugal pumps with medium-high specific speed.