Papers by Keyword: Impeller

Abstract: The primary energy losses of electric submersible pump (ESP) are waterpower loss and volumetric loss. Owing to the limit of current casting technique of the ESP impeller, some fractions of casting residua will be settled in the flow passage of impeller and cause local jam-up in the flow passage, which will increase additional waterpower loss and reduce the pump efficiency. Because of the complicated structure of ESP impeller, conventional nondestructive testing (NDT) is difficult to inspect the defects fast and efficiently. Fluid energy analysis method based on the boundary layer theory and the flow resistance theory analyzes the fluid kinetic energy loss caused by obstacles in the flow passage of impeller and the change of flow rate caused by the change of flow resistance. Based on the similarity principle of fluid movement, abnormal change of waterpower construction in flow passage of impeller can be reflected by measuring and analyzing the impact pressure change generated by flow rate of each flow passage using air as flow medium. The theoretic analysis and experimental results show that this method can identify the defective impeller quickly, efficiently and correctly and will be of some revelatory action on measuring the waterpower structure change of complicated impeller machinery with small size.

Abstract: Chemical composition and metallographic organization were analyzed for the failure characteristics and main reasons of the imported slurry pump impeller used by Chehe Dressing Plant China Tin Group. A series of larger long strip form carbides found on the metallographic organization, which improving cut apart trend on matrix seriously, was the main reason of the impeller failure. Proper amount of vanadium, titanium and rare earth complex modifier can refine carbides and improve their morphology. The best mortar proportion was identified in the laboratory analysis conditions through the wear experiments.

Abstract: The fit clearance between the impeller and the impeller shell directly affect the characteristics of the turbocharger. Assembly dimension chain is the basis of the design and analysis of workpiece size.Reducing the fit clearance of the impeller and the impeller shell can improve the booster effect. The impeller of the small inertia is beneficial to increase the rotation speed of the impeller and the impeller rotation stability requirements.The turbocharger of installation small inertia impeller is characterized by small size. Followed by its supercharged performance

Abstract: The three-dimensional flow field simulation of a centrifugal pump was presented by using commercial CFD code. In order to study the most suitable turbulence model, the three known turbulence models of Standard k-ε, RNG k-ε, Realizable k-ε were applied to simulate the flow field of the MJ125-100 centrifugal pump and predict the performance of the pump. The simulation results of head and efficiency were compared with available experimental data, and the comparison showed that the result of the numerical simulation by RNG k-ε model had the best agreement. Additionally, the effect of number of blades on the efficiency of pump was studied. The number of blades was changed from 4 to 7. The results showed that the impeller with 7 blades had the highest efficiency.

Abstract: A numerical analysis on the steady-state front leakage flow of an eccentric impeller is done based on a bulk-flow model. A set of nonlinear partial differential governing equations is derived on a control volume from the flow. The SIMPLE algorithm is used to develop the computational procedure for solving the equations. A MATLAB computer program in accordance with the computational procedure is written to conduct the numerical calculations. Numerical results are represented with the diagrams of pressure and velocity distribution of the flow. The influences of the impeller eccentricity on the flow are examined in a limited range of engineering practice. Conclusions are reached that the impeller eccentricity has substantial effects on the pressure and velocity distributions of the front leakage flow.

Abstract: The flow inside the impeller and diffuser of a turbocharger compressor was analyzed numerically in this paper. The results indicate that the internal flow is disturbed and efficiency is low. There exists a big vortex in the diffuser which dissipates a large amount of energy. Based on the commercial design software, different design parameters were optimized by trial-and-error. Numerical flow analysis results of the final design show that the efficiency is increased by 6.26% and internal flow is improved greatly. It can be concluded that the meridian radius of the impeller flow path has great effect on the compressor performance.

Abstract: In order to research the effects of leading edge shapes on the strength of centrifugal compressor compeller, the shrouded impellers of a large centrifugal compressor were introduced for finite element analysis. In the present study, the geometric models of 3 shrouded impellers were established in Solidworks 2007, and then numerical simulations were carried out using ANSYS. Through visualization of the computational result of the impellers with a square leading edge, a semi-circular leading edge and a elliptical leading edge, it was clarified by comparison that different leading edge shapes had significant influences on the compressor strength. According to the charts of the Von Mises stress versus leading edge shapes, it was indicated that approximately a 27% drop and a 32% drop in maximum Von Mises stress value occurred in the shrouded impellers of a semi-circular leading edge and a elliptical leading edge compared to a square leading edge respectively. That is, the semi-circular leading edge or elliptical leading edge employed in a centrifugal compressor would dramatically improve structural strength. This paper aims to provide the reference significance the structural optimization and reliability improvement of a large flow centrifugal compressor.

Abstract: Nuclear main pumps are one of the most important devices in nuclear plants. Hence hydraulic performances of the nuclear main pump are important. Compared with the traditional speed coefficient method, a revised speed coefficient method is employed to design a nuclear main pump, which is based on the extension chart of the traditional speed coefficient chart. Meanwhile numerical simulations are carried out to examine performances of the designed pump. Results show that performances of the designed pump meet specifications. Clearance leakage causes decrease in head and efficiency of the pump (about 4%). This work provides useful information for the study of nuclear main pumps.

Abstract: For the large centrifugal fan impeller, its working condition generally is bad, and its geometry generally is complex. So its displacements and stresses distribution are also complex. In this paper, we can obtain the fan impeller’s displacements and stresses distribution accurately through numerical simulation in G4-73 type centrifugal fan impeller using the finite element method software ANSYS. The calculation result shows that the maximum total displacement of the impeller is m, it occurs on the position of the half of the blade near the outlet of the impeller; and the maximum equivalent stress of the impeller is 193 MPa, it occurs on the contacted position of the blade and the shroud near inlet of the impeller. Furthermore, check the impeller strength, the result shows that the strength of the impeller can meet the requirement.

Abstract: The impeller of submersible mixer in some sewage treatment plant, whose parts are imported from other countries, is heavily abased. To solve this problem and realize domestic manufacture, based on reverse engineering theory, utilizing 3 coordinates measuring machine and applications of Surface and Pro/E, 3D solid model of impeller are gained. The gained impeller model accords with the physical one with high accuracy. The flow formulation is founded as console formulation first, and with the body-fitted coordinate system and standard turbulent model, the numerical simulation of the internal 3-D incompressible turbulent flow agitated flow field of submersible mixer is carried out by numerical simulation software Fluent. The results showed that: the mixer impeller produced vortex jet flow, the constant velocity lines advanced as ellipse, the velocity along the centerline are larger than others, and utilized volume flow to transport the liquid.