Channel Type Guide Vane Of Multi-stage Centrifugal Pump And Study On Structural Modification

Centrifuges play an important role in industrial production,but they are generally lower and follow the calls of countries to reduce emissions,improve the performance of fluid machinery is one of the important research goal,many researchers interstage guide vane is of great importance in multistage centrifugal pump flow components,to improve its performance is an important research content of this article,In this paper,the head of a multistage centrifugal pump as the research object,using numerical simulation method to optimize a flow guide vane type,without changing the original impeller parameters,flow guide vane type multiple arguments for a wide range of selection,the influence of different guide vane parameters on the performance of centrifugal pump was determined to obtain higher channel guide vane efficiency.In order to explore the reasons for the difference between the working efficiency of the multistage centrifugal pump in the factory and the numerical simulation results,the real flow of the fluid in the centrifugal pump was simulated,the suction chamber was designed and modeled according to the drawing parameters of the suction chamber given by the factory,and the influence of different inlet ways of the centrifugal pump on the performance of the centrifugal pump was analyzed.At present,there are more studies on the clearance of centrifugal pump,such as blade tip clearance and mouth ring clearance,but less analysis on the clearance caused by centrifugal pump casting.A simple water model from the impeller outlet to the two sides of the mouth ring seals was established,and the effect of the operating clearance between the impeller and the guide vane on the performance of the centrifugal pump was analyzed.The main research contents and conclusions are as follows:Firstly,parametric modeling of the head parts of the multi-stage centrifugal pump and the annular suction cavity between the centrifugal pump inlet flange and the impeller inlet is carried out,and numerical simulation analysis is carried out.The results show that the flow in the suction chamber is not uniform,and the flow in other parts is more uniform,which accords with the situation of energy conversion.Secondly,the inlet angle,outlet angle and blade thickness of the channel guide vane were optimized successively without changing the impeller parameters,the optimized model is compared with the original model.The study shows that the change of inlet angle of the guide vane will affect the static pressure distribution and velocity vector distribution at the dynamic and static interface,the internal flow field is more evenly distributed at the inlet angle of 80 degrees;The change of the channel guide vane outlet angle has little influence on the performance of the unipolar centrifugal pump,and different velocity distributions are generated on both sides of the guide vane outlet blade because of the working principle of the guide vane.The intense collision at the blade outlet will affect the flow state of the fluid at the inlet of the next impeller.18 degrees is selected as the outlet angle parameter of the channel guide vane;The blade thickness affects the inlet pressure distribution of the guide vane,and the uniform decrease of the blade thickness will weaken the backflow effect of the guide vane.However,as the flow area between impellers increases,the crowding between blades is reduced.Uniform thickening will increase the backflow capacity of guide vane.In the final optimization model,blade thickness is uniformly thinned by 50%,efficiency is increased by5%,and head is increased by 2.79 m.Finally,by analyzing the influence of radial inlet and axial inlet on the performance of centrifugal pump,the research shows that the radial inlet of centrifugal pump with suction chamber is less efficient than axial inlet of centrifugal pump,but the head is partly improved,and the loss is mainly due to the unstable flow in the annular suction chamber,which produces vortexes in the annular area.The existence of impeller leakage clearance is disadvantageous to the efficiency and head of centrifugal pump,and the clearance between blade tip and mouth ring leads to the flow disorder in the main channel.Appropriate clearance can improve the flow state in the flow channel.