Optimization Design Research On Improvement Performance Impeller Of Low Specific Speed Centrifugal Pump Based On CFD Technique

As natinal economy is developing rapidly, electric power will be in need more and more heavily. Our power structure is mainly heat power, which will be not changed in very long time. Heat power is the biggest coal consuming user, energy has been become more and more short recently, and price of the coal has shown a continuas up-trend, therefore ,how to increase heat efficency to save coal is focused by many power plant. The effective means for increasing the efficiency of power plant is to connect the extraction feedwater system with drainage pump. But the running conditions of drainage pump is bad, because the working substance in drainage pump is generally low pressure heater drainage which is of features such as high back pressure and suction temperature. Species of the drainage pump are single and mold making difficult, and cavitation is apt to occur which makes the amount of maintenance work inereased, so only few heat power units take drainage pump as attended modle. Therefore, it is very necessary to develop more exellent drainage pump with more specics and more cavitation.In this paper, the CFD technique which grows fast recently is applied in the study of anti-cavitations performance. The 3D turbulent numerical simulation for the low specific speed centrifugal pump where clear water flow in by N-S equation \RNG k- ε turbulent model and CFD software, and the velocity and pressure distribution of three kinds of blades with different shape. Combining with experimental findings, the relation between distribution of flow field and cavitations is analyzed and foundational reference is brought up for the perfection of the theory on low specific speed centrifugal pump and optimum design. The main work is outlined as following:1. Summarizing the research result on cavitations fundamental theory and the improvement in cavitations performance of the centrifugal pump, generalizing the advancement in anti-cavitations design.2. RO/E software is used to make the impeller entity. In the process of modeling, impeller has been constructed to different shapes such as whole flow passage and single flow passage.3. Combining with FLUENT, numerical simulation of the 3D incompressible flow field for four kinds of impeller which have been designed at the same design work condition according to actual qualification in later calculation, at pre-treatment of the numerical simulation, impeller entity which is made by PRO/E software is led to...