Parametric Design And Tentative Research Of Blade In Centrifugal Pump

Centrifugal pumps have been widely applied in various sectors of the national economy. About 20% of national generating capacity is consumed by the pump each year in China.The centrifugal pump accounts for about 95% total value of pump.At present, the national pay more attention on the energy conservation and low-carbon economy. Therefore,that demand all the fluid machinery researchers study on the principles and methods of energy-saving for centrifugal pump to increase efficiency.Impeller hydraulic efficiency is a key factor affecting the efficiency of the centrifugal pump.And conformal changes which is the most commonly used method in the design of the centrifugal pump impeller has a large random.One is the determination of wrap angle.The other is the size of the entrance angle of the impeller-type line on different axial plane.That is,how to Select the variation of angle that located from impeller inlet to the outlet in the flow line of grid expansion plan. Therefore,this article research on the following two point:First,wrap angle has been studied.A new method of determining the wrap angle of blade was proposed when the entrance angle and exit angle of blade have been defined. The article designed a centrifugal pump which have been used in a company. The parameters are as follows:Q=200 m3/h,H=20m,n=1450r/min,required no more than 260mm diameter of impeller centrifugal pump.The wrap angle was determined for 70°,80°,90°by the method.The impeller's hydraulic model was got Separately by hydraulic design.The following conclusions ware found by simulation of FLUENT 6.1.22.Warp angle of 90°of the impeller efficiency is 2% higher than that when the Warp angle is 70°.So the methods used in design the pump is feasibilitySecond,the influence which the entrance angle changes in different axial plane's variation to centrifugal pump was researched.The impeller-type lines have been designed using four kinds of different Variation.The wrap angle of 90°has been selected as the optimal angle.The impeller of centrifugal pump has been designed in the methods above.Through simulation can draw the following conclusions:In the front part of the blade, the change of placement angle is relatively large.and the change of that is relatively small in the back part of leaves.And the centrifugal pump designed following the above method compared with the other three centrifugal pumps that have been designed by the other three methods,the head was reduced by about 1.84m,but the efficiency was improved about 2%.