Optimized Design And Engineering Application Of The Long Axis Pump

The long axis of pumps are widely used in agricultural irrigation, flood control, drainage, sewage treatment, power station(coal-fired power plants, nuclear power stations, storage power and tidal power plants), cooling system and other fields. However, because of their special structure, the long axis of pumps with guide vane exist poor performance, shaft fracture and severe vibration problems generally. So how to improve the performance and the reliability of the shaft are currently important research directions.The design optimization and flow field of the marine long axis of pump with a space guide vane and the reliability analysis of shaft were studied systematically in the paper. The main contents and conclusions are as follows:1 The hydraulic design and optimization of the long axis of pump were introduced. Based on a JLY-80-27-type pump as the research object, a detailed analysis of different throat area, blade exit angle of guide vane and number of guide vane blades on the influence of the pump's performance was done by numerical calculation. For the designed marine pump, the impeller and space guide vane were put as a whole and the main performance parameters of the space guide vane were carried on reasonable design and optimization. Finally, the impeller, space guide vane and computational domain of the whole flow were generated by PRO/E.2 The internal flow field was simulated by FLUENT software. The flow distributions of the whole flow, impeller, annular space, space guide vane and its internal and external cover were analyzed. The results show that:(1)The inlet of impeller appears negative pressure, where cavitation will occur. (2)The flow in annular space is chaotic, which has a great impact on loss. (3)The velocity of flow in the face and back of the guide vane shows an increase-decrease trend from the inlet to the exit, which reaches the maximum near the middle of the guide vane. The secondary flow emerges in the back of guide vane. (4)There are different degrees of swirl in its internal and external cover of the guide vane, which shows the flow is rather chaotic and complex.3 Carbon disulfide and water were used for conveyance medium respectively and the flow field conditions under different flows of the pump were calculated. The calculated results and experimental results were compared and analyzed. The results indicate that:The overall trend of characteristic curve between calculation and test is consistent and the head and the efficiency increase obviously; The maximum error is basically less than 18% in the same flow between numerical calculation results and experimental data, which proves the effectiveness of the numerical calculation and optimization. The obtained result complies with the design requirements; The calculated head and efficiency when the medium is carbon disulfide are slightly higher than that when the medium is water under the same flow.4 Based on ANSYS software and traditional checking theory of pump shaft, the pump shaft was conducted for static and fatigue strength analysis. The pump shaft was also checked according to the danger point of principal stress value.The deformation and vibration circumstances of the pump shaft were analyzed and studied.