Study The Influence Of Internal Flow Of Impeller Geometric Parameters In Centrifugal Pump

As a major project for people live, using Yellow River water has a great significance to the sustainable economic development. The Yellow River become the most sediment concentration river in the world, because of carrying a large amount of sediment when it trough the loess plateau. It is always damaged when the pump working at the yellow river, because of the sand water. through many years of the observation for the centrifugal pump operation at yellow river, it is found that the centrifugal pump performance forced down sharply after running3000-4000 h. the surface scratches was found in impeller blade. It has severe perforation in the front of the impeller inlet, and the damage direction was from the pressure face to suction surface.The inlet impeller was found local perforation after the double suction centrifugal pump of 1200S56 type of three different blade inlet angle. For the local perforation damage phenomenon, this topic to the 1200S56 type double suction centrifugal pump as the research object,trough the numerical simulation software Fluent, cumulating the process of the centrifugal pump transport water and sand water. Analysis the radial velocity and pressure cloud picture in the impeller passage when the fluid medium through the centrifugal pump, researching the improve perforation damage for different blade inlet angle at the centrifugal pump impeller import. In order to find the more effective methods of numerical prediction the impeller passage flow pattern. Trough the above of study the following conclusions:(1) By comparing the radial velocity and pressure cloud picture under different condition when the pump transport water and sand water. it is found that water’s negative radial velocity value is large the sand water’s. and the centrifugal pump in the process of actual operation, the sand water’s destruction is much more serious than the water’s, when the pump running the same time. It shows that the sand plays an important role in the impeller entrance perforation damage in the centrifugal pump running at sand water.(2) The negative radial velocity and local low pressure in the impeller passage at the same position under the large flow condition. It is closely at the local low pressure in the impeller passage and the flow separation position’s. With the actual operation process of centrifugal pump impeller perforation damage location, analysis on breakage types of impeller, the impeller perforation damage from pressure surface to suction surface. It shows that the centrifugal pump impeller entrance of perforation caused by turbulence damage due to flow separation.(3) By comparing the different blade angle was laid in centrifugal pump impeller passage of radial velocity and pressure distribution can be found, changing the blade inlet angel can change the flow condition of the impeller flow passage. Thedetermine flow has a suitable blade inlet angle, but still there will be a negative radial velocity impeller entrance, this is because the axial vortex in impeller inlet position.(4) The diameter and concentration of sand is influence in the centrifugal pump transport sand water. With the increase of particle size of the grains of sand, the following of the single sand is badly, the concentration of sand is relatively low at the flow separation position. For the same size for different volume fraction of sand water, a single sand relative to the water change small. In the concentration of flow position relatively little change, but due to the increase of the sand concentration in a centrifugal pump impeller entrance of wear effect.