Design Of Centrifugal Pumps Research Articles

Economic efficiency due to increasing the turnaround period of operation of oil producing wells

The turnaround period of well operation is influenced by an extremely large number of factors covering the geological, physical, technical and technolog ical conditions of their operation. The higher the indicator of the turnaround period of well operation, the more efficiently the stack of wells works according to planned indicators, as well as low, first of all, operating costs for well maintenance, which accordingly affects the economic efficiency of well operation.
 In recent years, a number of oil companies have been paying close attention to the problem of increasing of the turnaround period of well operation. Measures being developed are aimed at:
 reducing the aggressiveness of the extracted products;
 improvement of the installation design of an electric centrifugal pump;
 improving the design of downhole pumping equipment.

Investigation of the influence of blade configuration on the hemodynamic performance and blood damage of the centrifugal blood pump.

The design and optimization of centrifugal blood pumps are crucial for improved extracorporeal membrane oxygenation system performance. Secondary flow passages are common in centrifugal blood pumps, allowing for a high volume of unstable flow. Traditional design theory offers minimal guidance on the design and optimization of centrifugal blood pumps, so it's critical to understand how design parameter variables affect hydraulic performance and hemocompatibility. Computational fluid dynamics (CFD) was employed to investigate the effects of blade number, blade wrap angle, blade thickness, and splitters on pressure head, hemolysis, and platelet activation state. Eulerian and Lagrangian features were used to analyze the flow fields and hemocompatibility metrics such as scalar shear stress, velocity distribution, and their correlation. The equalization of frictional and flow losses allow impellers with more blades and smaller wrap angles to have higher pressure heads, whereas the trade-off between the volume of high scalar shear stress and exposure time allows impellers with fewer blades and larger blade wrap angles to have a lower HI; there are configurations that increase the possibility of platelet activation for both number of blades and wrap angles. The hydraulic performance and hemocompatibility of centrifugal blood pumps are not affected by blade thickness. Compared to the main blades, splitters can improve the blood compatibility of a centrifugal blood pump with a small reduction in pressure head, but there is a trade-off between the length and location of the splitter that suppresses flow losses while reducing the velocity gradient. According to correlation analysis, pressure head, HI, and the volume of high shear stress were all substantially connected, and exposure time had a significant impact on HI. The platelet activation state was influenced by the average scalar shear stress and the volume of low velocity. The findings reveal the impact of design variables on the performance of centrifugal blood pumps with secondary flow passages, as well as the relationship between hemocompatibility, hydraulic performance, and flow characteristics, and are useful for the design and optimization of this type of blood pump, as well as the prediction of clinical complications.

Liquid-vapor two-phase flow in centrifugal pump: Cavitation, mass transfer, and impeller structure optimization

Computational fluid dynamics (CFD) has been widely used to model the internal flow field of centrifugal pumps to analyze cavitation phenomena. However, accurate determination of cavitation in pumps remains a challenge. In this study, liquid-vapor two-phase flow in centrifugal pump at different conditions and impeller structural parameters were studied numerically and experimentally. Cavitation multiphase unsteady model was proposed to simulate the flow field in the centrifugal pump by CFD method, and an experimental platform was set up to obtain cavitation performance results. The simulation data were validated with experiment and good consistency was achieved. This study investigated the mass transfer and cavitation behavior of centrifugal pumps under various conditions and customizes a simulation process to obtain the optimal combination of impeller blade number, blade wrap angle, and blade installation angle, which was expected to provide helpful insights into the structural optimization design of centrifugal pumps with good cavitation resistance.

Optimization design and unsteady flow analysis of stall characteristics in a vertical centrifugal pump

Abstract In this paper, an optimization design of the vertical centrifugal pump with vaned diffuser was accomplished, and analyzed the internal flow pattern of the model before and after optimization under stall conditions to explore the relationship between design parameters and the stall characteristics. The reasons for the improvement of efficiency and hump characteristics curve after optimization were revealed combined with streamline distributions, entropy production theory and pressure fluctuation. The results show that the error between the external characteristic result calculated by Computational Fluid Dynamics (CFD) and the experimental value is less than 5%, which proves the reliability of the numerical simulation method adopted in this paper. The hydraulic efficiency under multiple operating conditions and stall characteristics of the optimized model have been significantly improved. After optimization, the entropy production rate in the vaned diffuser is greatly reduced, and the improvement of the internal flow pattern in the vaned diffuser is the main reason for slowing down the hump characteristic curve. The hydraulic performance and the stall characteristics of the vertical centrifugal pump can be significantly improved by properly increasing the radial distance of the vaneless region. The matching relationship between the vaned diffuser and the impeller is one of the important factors that affect the stall characteristics. The large-scale vortices in the vaned diffuser is the main reason for the low-frequency pressure fluctuation signal when operating in the hump region. The low-frequency signal in the vaned diffuser of the optimized model is obviously weakened.

Numerical calculation and analysis of axial force of multistage centrifugal submersible pump

Abstract The study of axial force has been a hot spot in fluid mechanics research, and the magnitude of axial force directly affects the stability, safety, and efficiency of submersible pumps. This paper takes 200QJ50 multistage centrifugal submersible pump with spatial guide vane as the research object, simulates and numerically calculates the internal flow field of multistage submersible pump based on Standard k-ε turbulence model, a SIMPLE algorithm, and high-resolution format through CFX software, analyzes the distribution law of static pressure and velocity field of the multistage submersible pump under 0.7Qd , 0.8Qd , 0.9Qd , 1.0Qd and 1.1Qd working conditions and compared the theoretical and simulated values of the corresponding axial force for each working condition. The results show that with the increase of the flow rate, the axial force of the multistage submersible pump shows a downward trend; the axial force generated by the first stage impeller has a larger proportion, and reaches the maximum value in the design condition; the traditional axial force calculation formula can more accurately predict the axial force under the design condition, and the error is 6%. The results of this study can provide references for the design and optimization of multistage centrifugal submersible pumps.

An energy consumption improvement method for centrifugal pump based on bionic optimization of blade trailing edge

The centrifugal pump is one of the most widely used types of power machinery in the water resource utilization and chemical industries. Its energy consumption cost accounts for a large proportion of its total economic cost. In this paper, an energy consumption improvement method for centrifugal pump is proposed by referring to the bionic structure to reduce the energy loss of the centrifugal pump. Four types of impellers with different types of sinusoidal tubercle trailing edges (STTE) are designed. Experiment and numerical simulation are combined to explore the beneficial effects of STTEs. Experimental research shows that this structural change will not affect the performance of the pump. On this basis, the entropy generation rate analysis method was introduced, and the numerical calculation results were analyzed to explore the internal influence of the STTE on the energy loss characteristics of the centrifugal pump. Results show that the use of STTEs can adjust the proportion of energy loss of each component in a centrifugal pump and effectively reduce the overall energy loss. Quantitative research indicated that the STTE3 has the optimal effect of reducing energy consumption. The use of STTE3 can reduce the total energy consumption by more than 5% at all flow rate conditions and reach a peak of 16.95% under 1.2 times nominal flow rate conditions. Thus, the bionic structure optimization method to improve the internal energy loss characteristics of centrifugal pumps will be beneficial and can provide a certain degree of reference for the hydraulic design of centrifugal pumps.

A comparative study of Gaussian process regression with other three machine learning approaches in the performance prediction of centrifugal pump

Accurate prediction of performance indices using impeller parameters is of great importance for the initial and optimal design of centrifugal pump. In this study, a kernel-based non-parametric machine learning method named with Gaussian process regression (GPR) was proposed, with the purpose of predicting the performance of centrifugal pump with less effort based on available impeller parameters. Nine impeller parameters were defined as model inputs, and the pump performance indices, that is, the head and efficiency, were determined as model outputs. The applicability of three widely used nonlinear kernel functions of GPR including squared exponential (SE), rational quadratic (RQ) and Matern5/2 was investigated, and it was found by comparing with the experimental data that the SE kernel function is more suitable to capture the relationship between impeller parameters and performance indices because of the highest R square and the lowest values of max absolute relative error (MARE), mean absolute proportional error (MAPE), and root mean square error (RMSE). In addition, the results predicted by GPR with SE kernel function were compared with the results given by other three machine learning models. The comparison shows that the GPR with SE kernel function is more accurate and robust than other models in centrifugal pump performance prediction, and its prediction errors and uncertainties are both acceptable in terms of engineering applications. The GPR method is less costly in the performance prediction of centrifugal pump with sufficient accuracy, which can be further used to effectively assist the design and manufacture of centrifugal pump and to speed up the optimization design process of impeller coupled with stochastic optimization methods.

The Usage of Numerical Methods (HAD/CFD) in The Design of Centrifugal Pumps

Santrifüj pompalar mühendislik alanında yaygın olarak kullanılan ürünlerdir. Kullanım alanlarına göre çok farklı parametre içermektedir. Tasarım aşamasında ise farklı debiler, basma yükseklikleri için bir çok dizayn parametresi oluşturulması gerekmektedir. Teknolojinin gelişmesi ile birlikte bilgisayar destekli programların tasarım sürecinde kullanımı yaygınlaşmıştır. Bu sayede hem zamandan tasarruf sağlanmakta hem de maliyet azaltılmaktadır. Hesaplamalı Akışkanlar Dinamiği (HAD) veya yabancı dilden alıştığımız şekliyle CFD analizleri pompa tasarımında oldukça yaygın olarak kullanılmaktadır. Ürün tasarımı yapıldıktan ve katı model oluşturulduktan sonra analiz programları kullanılarak pompa içindeki sayısal analizler yapılabilir. Burada deneysel metotlara göre en önemli olan avantaj ise parametrelerin sınırsız sayıda değiştirilebilir olmasıdır. İstenilen değerler elde edilinceye kadar süreç devam ettirilebilir. Bilgisayar yardımıyla elde edilen bilgiler ışığında üretim ve kullanım süreçlerine geçilebilir. Bu çalışmada örnek bir santrifüj pompa ele alınarak sayısal analiz adımları sırasıyla açıklanmıştır. Program içinde kullanılan yöntem ve kabuller genel literatür bilgisine göre ele alınmıştır. Uygulanacak yöntemler sınırsız olup istenildiği takdirde farklı yollar ile çözüm ağları genişletilebilir.

Surrogate-Based Optimization of a Centrifugal Pump with Volute Casing for an Automotive Engine Cooling System

This paper investigates the capability of a surrogate-based optimization technique for the advanced design of centrifugal pumps. The centrifugal pump considered in this work is designed for the automotive cooling system and consists of an impeller, a vaneless diffuser and a volute. A fully three-dimensional geometry parametrization based on Bézier surfaces is presented. The optimization procedure includes the following software packages: Scilab for the geometric parametrization, Ansys-CFX for the CFD simulations and DAKOTA for the optimization management. The initial geometry is defined by a 0D code that provides a preliminary design of the pump, given the operating conditions, i.e., the volumetric flow rate, the head and the rotating speed. In this work an operative point typical of high performance gasoline cars is considered.

In vitro hemocompatibility investigation for the development of low-flow centrifugal blood pumps with less platelet clogging.

Low-flow blood pumps rated under 1 L/min are emerging for new medical applications, such as hemofiltration in acute use. In those pumps, platelet adhesion and aggregation have to be carefully considered because of clogging risk in the filter part. To find an acceptable hemocompatibility that can be applied to low-flow centrifugal blood pump design, the platelet aggregation index, clogging on a micromesh filter, and the hemolysis index were investigated using a low-flow blood pump designed for hemofiltration use. We conducted circulation testing in vitro using fresh porcine blood and two centrifugal pumps with different impeller inlet shapes. The Negative Log Platelet Aggregation Threshold Index (NL-PATI), which reflects the ability of residual platelets to aggregate, and flow rate were measured during reflux for 60 min, and the Normalized Index of Hemolysis (NIH (g/20 min)) was calculated. In addition, blood cell clogging after reflux was observed on the micromesh filter by SEM, and the adhesion rate was calculated. Our results showed that the platelet clogging on the micromesh filter occurred when the average NL-PATI was greater than 0.28 and the average NIH (g/20 min) was greater than 0.01. In contrast, platelet clogging on the micromesh was suppressed when NL-PATI was less than 0.17 and the NIH (g/20 min) was less than 0.003. These values might be used as acceptable hemocompatibility of low-flow centrifugal blood pumps with suppressed platelet clogging for hemofiltration pumps.

Many-Objective Hybrid Optimization Method for Impeller Profile Design of Low Specific Speed Centrifugal Pump in District Energy Systems

Low specific speed centrifugal pumps (LSSCP) are widely utilized in district energy systems to promote the integration of renewable energy. However, the performance of LSSCP becomes inefficient due to harsh operating conditions resulting in substantial increase in energy consumption. Many-objective optimization is significant in improving the performance of LSSCP and promoting the sustainability of district energy systems. Among the existing optimization methods, global optimization methods are limited by high computational cost when solving many-objective optimization problems, and gradient-based optimization methods face difficulties in locating the global optimum. In the present study, a hybrid optimization method was developed for solving many-objective optimization problems of LSSCP. The LSSCP optimization result of the hybrid algorithm was compared with that of the non-dominated sorting genetic algorithm (NSGA), so as to demonstrate the capacity of the proposed method. In the designed flow condition without cavitation, the hydraulic efficiency obtained by the hybrid optimization algorithm was found to be 9.5%, 5.4%, and 4.7% higher than those of the original, NSGA-II, and NSGA-III optimized results, respectively. The shaft power was 10.3%, 8.7% and 5.1% less than said three optimized results. The maximum turbulent kinetic energy in the flow passage obtained from the hybrid optimization was only 2.2 J/kg, which was 67% and 46% less than that of the NSGA-II and NSGA-III optimized results, respectively. In the designed flow condition with cavitation, the net positive suction head critical optimized by the hybrid model was 0.857 m, which was substantially reduced compared with the original and NSGA- II optimized results.

스크류원심펌프 임펠러 자오면형상 설계파라미터 최적화

Screw centrifugal pump is a non-clog type pump, which is widely used for drainage and sewage control systems. The screw centrifugal pump combines the advantages of the screw pump and centrifugal pump. Screw centrifugal pump shows the relatively high efficiency and the good solids handing capability. Based on a screw centrifugal pump design method, the parameters of impeller meridional plane shape are investigated for the improvement of pump performance. The design parameters of impeller meridional plane shape, such as impeller inlet and outlet diameters, outlet width, total axial length, blade inlet and outlet angles, and inclination angles, were investigated to examine their effects on the pump performance. Numerical analysis was conducted to determine the essential design variables for the screw centrifugal pump. Furthermore, flow passage shape optimization was conducted to enhance the performance of the screw centrifugal pump.

Pressure Fluctuation Reduction of a Centrifugal Pump by Blade Trailing Edge Modification

The pressure fluctuation inside centrifugal pumps is one of the main causes of hydro-induced vibration, especially at the blade-passing frequency and its harmonics. This paper investigates the feature of blade-passing frequency excitation in a low-specific-speed centrifugal pump in the perspective of local Euler head distribution based on CFD analysis. Meanwhile, the relation between local Euler head distribution and pressure fluctuation amplitude is observed and used to explain the mechanism of intensive pressure fluctuation. The impeller blade with ordinary trailing edge profile, which is the prototype impeller in this study, usually induces wake shedding near the impeller outlet, making the energy distribution less uniform. Because of this, the method of reducing pressure fluctuation by means of improving Euler head distribution uniformity by modifying the impeller blade trailing edge profile is proposed. The impeller blade trailing edges are trimmed in different scales, which are marked as model A, B, and C. As a result of trailing edge trimming, the impeller outlet angles at the pressure side of the prototype of model A, B, and C are 21, 18, 15, and 12 degrees, respectively. The differences in Euler head distribution and pressure fluctuation between the model impellers at nominal flow rate are investigated and analyzed. Experimental verification is also conducted to validate the CFD results. The results show that the blade trailing edge profiling on the pressure side can help reduce pressure fluctuation. The uniformity of Euler head circumferential distribution, which is directly related to the intensity of pressure fluctuation, is improved because the impeller blade outlet angle on the pressure side decreases and thus the velocity components are adjusted when the blade trailing edge profile is modified. The results of the investigation demonstrate that blade trailing edge profiling can be used in the vibration reduction of low specific impellers and in the engineering design of centrifugal pumps.

Design and Analysis of the Multi Blade Angle Centrifugal Pump Impeller by Using CFX Tool

This project investigates the study of complex internal flows in centrifugal pump impellers with the aid of Computational Fluid Dynamics software thus facilitating the design of pumps. Here three different types of Pump impellers had been taken, the pump specifications considered for investigation are discharge and speed. A design of centrifugal pump is carried out and analyzed to get the best performance point. The design and performance analysis of centrifugal pump are chosen because it is the most useful mechanical rotodynamic machine in fluid works which widely used in domestic, irrigation, industry, large plants and river water pumping system. These specifications have been varied toper form a comparative study of these pump impellers. The impeller was modeled and the blade to blade plane of the impellers was taken for the detailed study purpose because the flow occurs through this passage only. The blade-to-blade plane is modeled and the flow analysis is carried out using FLUENT software. Thus the valid results regarding the velocity distribution and pressure distributions were predicted for different blade angles.

Calibration of CFD grid for simulating the impeller clearance flow and axial hydraulic force of centrifugal pump

The axial hydraulic force of centrifugal pump is an important parameter affecting pump performance. The force mainly includes the force inside impeller and in clearance. Due to the special structural characteristics of the clearance, the influence of grid discretization method on the calculation of axial force in the clearance is not fully understood. Therefore, based on the Reynolds-averaged method with shear stress transport turbulence model, an orthogonal experiment was designed to compare the correlation coefficient of velocity and pressure distribution between shear stress transport model and large eddy simulation models. A more suitable grid discretization strategy was found by artificial neural network for grid calibration. When the strategy is applied to the entire centrifugal pump, the prediction of axial force has high accuracy. The range analysis shows that the grid node number in the wall-wall direction has the greatest impact on velocity distribution. When the mesh parameters are in a certain range, it can compromise between the simulation accuracy and computational resource. The Reynolds-averaged model based simulation is proved accurate in capturing the complex velocity and pressure field inside clearance. The entire pump model is also used for the verification after the calibration of grid. The typical axial force law can be found under different flow rate conditions. This study provides a significant guidance in determining the grid scheme for accurate prediction of centrifugal pump’s axial force. It makes the computational fluid dynamics simulation feasible in the initial design of centrifugal pump which specifically considers the axial force problem.

Liquid/solid flow field in a centrifugal pump with different impeller blade types by PIV

In this study, a non-stirred Particle Image Velocimetry (PIV) testing device is developed to measure the flow field in a solid–liquid two-phase centrifugal pump. The pump casing and impeller are made of an organic glass material. Two types of impellers are designed considering different structure parameters. The performance curves of the pump are obtained for the different impellers at a rotating speed of 900 rpm with particle concentrations of 0%, 3%, 5%, and 10%. The flow fields for water and a solid–liquid two-phase mixture for the two impellers are measured utilizing the PIV system in a centrifugal rotating frame at the designed condition. The distribution of the particles, together with its influence on the performance of the different impellers, is analyzed. From a comparison of the relative velocity vector fields, the following can be concluded. First, the pump with a double arc-shaped profile demonstrated a more uniform and stable flow field distribution and higher performance than that with a single arc profile. Secondly, the solid particles were distributed mainly at the outlet of the impeller and volute wall, whereas the concentration distribution of the larger particles tended to match the pressure surface. This research can provide theoretical guidance for the design and optimization of two-phase flow centrifugal pumps.

Effect of Rotation Speed and Flow Rate on Slip Factor in a Centrifugal Pump

This work analyzes the causes of the slip phenomenon in the impeller on the basis of the internal flow mechanism. Detailed optical measurements of the flow inside the rotation passages of a five-bladed centrifugal pump impeller are obtained through particle image velocimetry (PIV). On the basis of experimental data, the deviation coefficient of slip velocity is proposed and then revised according to the slip factor calculation formula of Stechkin. Results show that, at the same rotation speed, the slip factor increases with the flow rate and reaches the maximum value at 1.0 QBEP flow rate. At different rotation speeds, the slip factor increases with the rotation speed and shows a relatively large variation range. Moreover, a revised slip factor formula is proposed. The modified model is suitable for the correction of slip factor at part-load flow rates and serves as a guide for the hydraulic performance design and prediction of centrifugal pumps.

Design and analysis of a radial centrifugal pump for cryogenic helium based application

A centrifugal pump is a rotordynamic machine that has wide spread application in industry. After analytical design, it is important to check the machine performance by some numerical method to be assured of machine performance before manufacturing. In the present study, a centrifugal pump conforming to a specific process requirement for cryogenic helium fluid has been developed in detail. This involves analytical design derivation of the stator and rotor part, computer aided design (CAD) modelling, meshing and detailed computational dynamic analysis (CFD) analysis. In line with analytical prediction, it is seen from simulation results that the designed machine meets the given requirements with an achieved hydraulic efficiency of 88%.

Study on the induced noise of gas–liquid two-phase flow in a centrifugal pump

With a wide application of multiphase flow pumps, it is obvious that the flow-induced noise in the transportation of gas–liquid two-phase media is turning more and more into the focus. To study the influence of different inlet gas volume fractions (IGVFs) on the flow-induced noise in a pump, this study focused on the internal flow characteristics and the noise radiation characteristics of acoustic vibration coupling under gas–liquid two-phase flows. The results showed that the introduction of gas does not affect the main frequencies in the pump. The radiated noise mainly stems from the inner-wall pressure fluctuation of the pump. However, with the increase of IGVF, the liquid phase is squeezed by the gas phase, the flow stability in the pump becomes worse and causing the pump performance degradation. The flow induced noise in the pump increases correspondingly. The research results are of great significance to noise reduction studies and the design of quieter centrifugal pumps.

PIV test of the flow field of a centrifugal pump with four types of impeller blades

Abstract Flow fields for various impellers were measured using water and a two-phase liquid–solid mixture with a particle image velocimetry system in a centrifugal rotating frame in controlled conditions. After measuring absolute velocity vectors in impeller passages, the vectors were decomposed based on the triangle speed principle and the distribution of relative velocity vectors within the impeller was obtained. Then, the distribution of particles and their influence on the performance of different impellers were analyzed. The following conclusions were made from the comparison of relative velocity vector field: first, the wear on the outlet of blades can be mitigated effectively by reducing the outlet angle of impeller blades; second, the pump with a double-arc-shaped profile had a more uniform and stable flow field distribution and higher performance than that with a single-arc profile; and finally, the “jet–wake” structure can be improved significantly by using impellers with long and short blades, resulting in a remarkable reduction in energy loss and improvement in pump efficiency. We also found that solid particles were mainly distributed at the outlet of the impeller and volute wall, while the concentration distribution of large particles tended to match the pressure surface. This research can provide some theoretical guidance for the design and optimization of two-phase flow centrifugal pumps.