Pump Casing Research Articles

A Digital Twin Framework for Nuclear Power Equipment Maintenance: Design, Prototyping, and Preliminary Validation

Throughout the lifecycle of Nuclear Power Equipment (NPE), maintaining high-safety maintenance services is essential for optimal operation. Traditional time-based maintenance strategies are limited in NPE contexts due to stringent safety requirements and high costs of complex systems. Specifically, maintenance processes lack transparency, state monitoring relies heavily on manual inspections, and decisions depend passively on individual expertise. Digital Twin (DT) effectively breaks down "information silos," leverages data value, and enables proactive maintenance decision-making for NPE. However, DT application in the nuclear industry is still exploratory, with limited systematic and practical research, especially for critical equipment maintenance. This paper introduces a DT-based intelligent maintenance decision system featuring three key technologies: DT modeling, state monitoring with dynamic early warning, and systematic intelligent decision-making and verification. A DT-based prototype using a cooling water pump case study preliminarily validates the state monitoring model's accuracy. Results indicate that the proposed framework and methods are feasible and hold significant application potential.

Pulsation Analysis of Hose Pumps with Different Roller Counts Based on Two-Way FSI

Xinjiang, as a major agricultural region, offers extensive application potential for hose pumps, given their excellent performance as fertilization devices. Analyzing the pulsation characteristics of hose pumps during operation is valuable for reducing noise and extending pump service life. To investigate the pulsation characteristics and unsteady flow of hose pumps with different roller numbers, this study adopts a bidirectional fluid-structure interaction (FSI) method and utilizes ANSYS 19.0 commercial finite element software to analyze the outlet and inlet pressure pulsations, outlet flow velocity pulsations, and the distribution of the flow field at the intermediate plane for both two-roller and three-roller pumps transporting high and low Reynolds number fluids under the same working conditions. It was observed that the three-roller pump exhibited higher outlet pressure compared with the inlet and that the pulsation intensity was lower in the three-roller pump than in the two-roller pump under the same conditions, with an analysis provided on the reasons for this phenomenon. This study offers theoretical support for the selection and further optimization of hose pump designs. To further reduce the negative effects of pulsations, it is recommended to increase the number of rollers in the design while also considering shape optimization of the pump casing or using feedback control systems to adjust and reduce pulsation intensity.

Optimized impeller hydraulic performance of submersible drainage pumps: An experimental study

Optimizing the hydraulic efficiency of submersible drainage pumps (SDPs) is crucial for energy conservation and performance enhancement, especially in emergency applications. Therefore, this study aims to develop an energy-efficient SDP by designing an optimized impeller model using a numerical scheme and introducing a flow balance block (FBB) as an alternative to modifying the pump casing, thereby reducing internal space and improving performance. Experimental validation of the optimized impeller and FBB was conducted by comparing their performance with the original pump model. The results demonstrated that the optimized impeller increased efficiency by 3.35% at a flow rate of 0.195 m3/min, with an overall average efficiency improvement of 2.33%. Additionally, when the optimized impeller and FBB were combined, the pump's efficiency was further enhanced by 5%, and the flow rate increased by approximately 10%. The study also proposed that the tap bolt method is more effective for installing the FBB than the silicone attaching method. This research provides a comprehensive experimental approach to improving SDP efficiency and offers valuable insights for future pump optimization.

Design and analysis of pump casing and impeller using reverse engineering technique

Abstract Advances in three-dimensional (3D) laser measurement technology have resulted in progress in the field of Reverse Engineering. This study introduces a Reverse Engineering technique utilized to restore the initial design of a Pump Casing and its Impeller. This study provides a detailed understanding of the creation of the casing and its impeller 3D model by using the scanned model and its detailed steps, and a 3D deviation report is plotted in order to get a complete deviation idea between the scan data and the design extracted. The Casing and Impeller both have a range of upper and lower is +/− 0.75 mm for the deviation measurement. The Casing is that all points are within its limit, and it’s 100% for most points within its limit and the impeller is 90.9% for most points is in its limit.

Estimate of the radial unsteady forces acting on a cavitating inducers from casing pressure measurements

Abstract This paper presents a methodology to estimate the radial forces acting on a cavitating inducers from the pressure signals measured at the machine casing by a set of sensors installed at different axial and azimuthal locations. The results of these methodologies are validated on the experimental data obtained on a water loop dedicated to the study of the performance and the unsteady phenomena in a cavitating inducer. The pressure and efforts are traced by unsteady pressure sensors on the pump casing and by a 6 components balance measuring efforts on the inducer shaft. For the validation, tests at two different rotating velocities were conducted during which a continuous pressure drop was imposed to the inducer, starting from a non cavitating operating point at given rotating speed and flow rate, down to a 20% pressure drop.

Gossen’s first law in the modeling for demand side management: a thorough heat pump case study with deep learning based partial time series data generation

Gossen’s First Law describes the law of diminishing marginal utility. This paper aims to further verify the proposed hypothesis that Gossen’s First Law also holds in the modeling for Demand Side Management (DSM) with a thorough heat pump case study. The proposed hypothesis states that in general the complexity-utility relationship in the field of DSM modeling could be represented by a diminishing marginal utility curve. On the other hand, in data based modeling, when utilizing a large dataset for validation, the data integrity is critical to the reliability of the results. However, the absence of partial time series data may occur during the measurement due to missing sensors or IT related issues. In this work, an extensive real-world open dataset of a ground source heat pump is utilized for the case study. In the raw data, one key variable namely the flow rate is missing. Thus, three different algorithms based on machine learning and deep learning architectures namely Random Forest (RF), Long Short-Term Memory (LSTM) and Transformer are applied to predict the flow rate by utilizing an open loop forecasting. The raw data are first pre-processed with a time interval of one hour and then used for training, validation and forecast. Furthermore, a modified persistence model as the baseline is also defined. The predicted flow rate using LSTM yields the lowest error of 7.47%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document} nMAE and 10.56%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document} nRMSE respectively. The forecast results are then utilized in the following step of modeling of a heat pump use case. With the introduced quantification method for complexity and a modified version for utility, we further verify the proposed hypothesis with a longer time horizon of 7 days.

Development of the Rodsim numerical simulator for the study of a sucker rod pump, comparing the Gibbs (1963) and Lea (1990) models

It is of great importance to be fully cognizant of the sucker rod pump system in order to make reliable production forecasts and to evaluate potential strategies for optimizing production processes. A frequently employed methodology in such circumstances is numerical simulation. A numerical sucker road pump simulator can provide valuable insights into production performance by generating dynamometric charts that represent the efficiency of this activity. Since the rod column behaves like a thin rod, it is possible to represent the mathematical model by a one-dimensional wave equation that describes the forces acting on this rod column. Lea (1990), proposing an improvement of the work of Gibbs (1963), considers the effects of the viscosity of the fluid produced in a vertical well without heat exchange, the piston diameter, the production column and the rods to obtain the damping factor, thus being more complete and producing a more accurate result in the dynamometric charts. Both models are implemented and discussed herein. The equations are discretized and solved in the Matlab® environment. The code includes a graphical user interface that generates the internal Rodsim application. The application is used to solve a typical case of a sucker rod pump and to obtain the surface and downhole dynamometric plots for certain scenarios.

Condition monitoring and failure analysis of a liquefied natural gas plant cryogenic heavies removal column reflux pump

Critical rotating equipment machines like pumps, gas compressors, heavy duty gas turbine and diesel engines are subject to wear and aging. The materials and components they are made from degrade over time, and if no action is taken they will eventually fail. Fortunately most types of failure can be prevented by maintenance. To plan maintenance effectively, the plant operator must have accurate information, which components need repairing or replacing, and when. Maintenance planning management plays a big role in preserving equipment reliability and availability of a liquefied natural gas (LNG) plant. This paper investigates failures on cryogenic heavies removal column reflux pump on LNG plant. Root cause analysis (RCA), was conducted to determine, the pump failure pattern. Failure of the thrust equalizing mechanism (TEM) caused excessive downward thrust in the rotor, as demonstrated by the gap seen between the alignment of the wear ring and casing on the seized impeller. Debris (aluminium, stainless steel, and iron) from the pump, obstructed the flow to the ball bearing and caused lack of lubrication and cooling for the bearing which consequently increased the bearing temperature, created localized heat vaporization and the bearings catastrophically failed. The pump casing was found with damage from the impeller thrusting against it during its failure with deposits from the wear ring embedded in the contacted area. This placed the bearing into axial strain and caused the failure. Condition monitoring graphs of the pump performance prior to failure were critically analysed and presented in this paper.

The multi-stage adding strategy on Kriging and applied to cavitation optimization of centrifugal impeller

In order to realize the intelligent optimization design of cavitation performance of fuel centrifugal pump, a multi-stage active learning adding strategy based on Kriging is proposed. The focus is to establish the three-stage adding strategy by using MSE, EI and CV, and clarify the switching criteria for each stage. Based on the test functions such as one-dimensional function and multi-dimensional function, it is compared with the single-stage adding strategy to verify the effectiveness of the proposed strategy. Furthermore, for a certain type of fuel centrifugal pump, the optimization application of the proposed strategy in its cavitation characteristics is completed. The result of the test function calculation shows that the proposed strategy takes slightly longer to achieve the same accuracy than MSE, which is better than EI and CV. However, compared with MSE, the local accuracy of the global optimal solution is higher. The result of centrifugal pump case shows that the pressure loss at the inlet of the optimized pump decreases, the local flow such as return flow and vortex at the inlet is weakened, the pressure gradient and the vortex flow in the volute weakens. Moreover, the cavitation coefficient of the optimized pump is increased by 30.83%, the NPSH allowance is reduced by 9.14%, the cavitation ratio is reduced by 7.17%, and the gas content in the pump is reduced by 17.27%. Thus, the proposed method improves the cavitation performance of the centrifugal pump effectively.

Integrated CFD-FEM approach for external gear pump vibroacoustic field prediction

In this work, a three-dimensional fluid-structural and vibro-acoustics coupled model of a gear pump is presented. Gear pumps represent the majority of the positive displacement machines used for flow generation in fluid power systems. Typically, the dynamics of gear pumps are dependent on the characteristics of the fluid dynamics inside the pump, which translates into vibrations to the housing. These vibrations then propagate to the surrounding medium and emit sound. The purpose of this study is to propose a three-dimensional fully integrated computational model to simulate the complete gear pump behaviour from the fluid dynamics to the structural vibrations, up to the vibroacoustic response. In this hybrid configuration, a transient CFD (Computational Fluid Dynamics) model is first developed to simulate the 3D flow field with a deforming and re-meshing approach to take into account the variation of the volume between the gears. Second, the internal pressure field calculated at each time step is then used as a loading into a structural FEM (Finite Element Method) model of the gear pump to compute the actual stresses and deformations of the housing. Third, the results of the structural response are used as excitation in a vibroacoustic sub-model to simulate the radiated noise using a high-order FEM technique. The comparison between the numerical and experimental flow curves validates the CFD model. The sound power calculations from the vibroacoustic model show good comparison with the sound intensity measurements around the pump casing, confirming the validity of the proposed coupled model. The described CFD-FEM approach proves to be a powerful gear pump design tool: it provides a reliable estimate of gear pump working parameters such as fluid power and vibroacoustic characteristics, starting from the CAD (Computer-Aided Design) geometry of the components. Furthermore, being one of the first multi-domain simulation models of a gear pump, this work can be useful to researchers as a starting point to correlate the noise emitted with the internal flow in full 3D conditions.

Integrated design and hydraulic model optimization of model horizontal main pump based on CFD fluid dynamics analysis

There are few studies and reports related to horizontal main pumps for nuclear power plants. The installation of vertical main pumps for small reactors requires the design of special elbows on the pressure vessel. Horizontal main pump, as a new main pump structure, can reduce the diameter of the main pressure vessel and simplify the structure of the pressure vessel. Compared with the vertical main pump, the horizontal main pump needs to control its axial dimension to improve its stiffness, which makes it impossible to set a long straight pipe section at the inlet, which has an impact on the pump performance. On the other hand, the compression of the axial dimension of the pump casing makes the overflow area of the press-out chamber small, resulting in large hydraulic losses. In this paper, in order to improve the efficiency of the pump and reduce the influence of non-uniform incoming flow, the optimization design is carried out with the SST k-ω model, and it is shown that: 1. the suction port of the curved impeller is easier for the fluid to enter into the impeller in the axial direction; and 2. the axially symmetric worm gear produces more vortex flow losses.

Particle distribution and two-phase flow characteristics of twin-screw pump during solid-liquid transfer

The twin-screw pump is a kind of positive displacement machinery with smooth pressure and flow pulsation and strong self-priming ability, which is widely used in the fields of oilfield production, marine engineering, and other fields. However, in the process of conveying liquid-phase media, it is difficult to avoid the inclusion of solid impurities and grit, resulting in wear of the pump casing and rotor, and the pump’s pressurization capacity is reduced or even shut down. At present, the solid-liquid two-phase flow characteristics within the twin-screw pump have not been clarified, which hinders the study of particle wear in the pump. In this paper, a solid-liquid two-phase flow study is carried out on a twin-screw pump through numerical simulation and experimental testing. The distribution of particles with different diameters in the rotor domain with the liquid-phase transport process is explored by simulating the two-phase flow under different differential pressures and particle concentrations. The results show that the particles in the rotor domain are mainly distributed in the region away from the male and female rotor engagement, and the number of particles near the engagement is small but the velocity is higher under the influence of the clearance jets; the elevation of the differential pressure and the particle concentration increase the risk of the particles to collide with the rotor more frequently and at higher velocity; at different particle concentrations, new localized vortices are caused by particle conveying which compared to pure liquid transport, but there are also cases where the original vortices are suppressed. The results will provide a theoretical basis for further research on particle wear characteristics in twin-screw pumps.

Centrifugal Pump Cavitation Fault Diagnosis Based on Feature-Level Multi-Source Information Fusion

In nuclear power systems, centrifugal pumps often need to operate under extreme conditions. However, accurately determining the cavitation status of centrifugal pumps under such extreme conditions is challenging. To improve the recognition accuracy of the three statuses of non-cavitation, incipient cavitation, and severe cavitation while improving the anti-interference capability of the monitoring system, this study extracted cavitation features from centrifugal pumps’ motor current and vibration signals under three different operational conditions. It fused the features using feature-level multi-source information fusion (MSIF) based on the backpropagation neural network (BPNN) or support vector machine (SVM) to construct a cavitation status recognition model and analyzed the results to compare with those of recognition without information fusion. The results show that, compared with one signal source, MSIF can significantly improve the recognition accuracy of cavitation statuses. Combined current and pump casing axial monitoring based on the BPNN is the optimal scheme, with an overall recognition accuracy of 97.3% for all operational conditions, compared to 73.9% for the single current signal and 89.3% for the single casing axial vibration signal. These research results can guide the monitoring of cavitation statuses in practical engineering, as well as timely intervention at incipient cavitations to reduce structural damage to centrifugal pumps and prolong service life.

Visualization investigation of the motion of rags in a double blades pump

Accumulation of fibrous materials often leads to pump clogging in wastewater systems. Visualizing these clogging phenomena helps identify ways to reduce the risk. In this study, we analyze a double blades pump made of acrylic glass using a fast digital camera to record the motion of rags inside. Recordings at three rotational speeds investigate the impact of rag materials, sizes, and quantities on their passage through the pump. Results show that smaller rags pass through the pump more quickly. At the same rotational speed and with the same material, the maximum passage time increases by over 100% compared to the shortest passage time. Additionally, rags flow more rapidly at high impeller speeds. At low speeds, rags tend to linger inside the impeller or stick to the pump casing’s tongue. The passage time at high speed is about 10% less than at lower speeds. Furthermore, under the same mass concentration, larger rags with fewer quantities are more prone to clogging than smaller rags with greater quantities. The proportion of larger rags with fewer quantities smoothly leaving the pump is about 10% less than that of smaller rags with greater quantities.

A Comprehensive Study on Phase Sensitive Amplification and Stimulated Brillouin Scattering in Nonlinear Fibers with Longitudinally Varying Dispersion

Fiber optic parametric and phase sensitive amplifiers (PSA) are interesting for modern day communication technologies due to their low noise and high gain amplification properties with a potential for all optical signal processing and wide band operation. PSAs are typically employed in either a single pump or dual pump configuration. In this article we explore the utilities of both configurations, however considering a fiber with a longitudinally varying dispersion profile. For the single pump case, PSA operation at large pump-signal detunings, that arise due to the longitudinal dispersion variation, were studied numerically, and recipes of using the system as a wide band wavelength selective filter were laid out. For the dual-pump case, emphasis was laid on achieving a larger signal gain, by reducing stimulated Brillouin scattering (SBS) that prevents large pump power transport through the nonlinear fiber. First, the effects of dispersion variation on the gain of a dual pump PSA were studied analytically and numerically in order to optimize the dispersion variation profile, neglecting SBS processes. Then we independently studied the SBS dynamics of the system numerically. A sinusoidally dispersion oscillating fiber (DOF) was found to be an optimal candidate with respect to its PSA and SBS performances. To establish this claim, we also experimentally compared the performance of an available DOF over a standard highly nonlinear fiber (HNLF) that has a constant dispersion profile and established its utility for designing a high gain PSA system, thanks to the SBS mitigation due to the longitudinal dispersion variation of the fiber.

Prioritizing Patient Safety: Analysis of the Procurement Process of Infusion Pumps in Spain.

To understand whether patient safety and human factors are considered in healthcare technology procurement, we analyzed the case of infusion pumps as their use critically affects patient safety. We reviewed infusion pump procurements in the Spanish Public Sector Procurement Database. Sixty-three batches in 29 tenders for supplying 12.224 volumetric and syringe infusion pumps and consumables for an overall budget of EUR 30.4 M were identified and reviewed. Concepts related to "ease of use" were identified in the selection requirements of 35 (55.6%) batches, as part of the criteria for the selection of pumps in 23 (36.5%) batches, related to "intuitiveness" in the selection requirements of 35 (55.6%) batches, and in the criteria in 10 (15.9%) batches. No method to evaluate the ease of use, intuitiveness, or usability was mentioned. A review of the procurement teams responsible for the evaluation of the tenders showed no reported human factors or patient safety expertise. We conclude that infusion pump procurement considers usability as a relevant criterion for selection. However, no human factor experts nor specific methods for evaluation of the technology in this field are usually defined. Potential room for refining the selection of healthcare technology to improve patient safety is detected.

Anomaly Detection of Axial Piston Pump Based on the DTW-RCK-IF Composite Method Using Pressure Signals

Axial piston pumps are critical components of hydraulic systems due to their compact design and high volumetric efficiency, making them widely used. However, they are prone to failure in harsh environments characterized by high pressure and heavy loads over extended periods. Therefore, detecting abnormal behavior in axial piston pumps is of significant importance. Traditional detection methods often rely on vibration signals from the pump casings; however, these signals are susceptible to external environmental interference. In contrast, pressure signals exhibit greater stability. In this study, we propose a novel anomaly detection method for axial piston pumps, referred to as DTW-RCK-IF, which combines dynamic time warping (DTW) for data segmentation, a random convolutional kernel (RCK) for feature extraction, and isolation forest (IF) for anomaly detection using pressure signals. The model is trained using normal operating data to enable the effective detection of abnormal states. First, the DTW algorithm is employed to segment the raw data, ensuring a high degree of similarity between the segmented data. Next, the random convolutional kernel approach is used in a convolutional neural network for feature extraction, resulting in features that are representative of normal operating conditions. Finally, the isolation forest algorithm calculates the anomaly scores for anomaly detection. Experimental simulations on axial piston pumps demonstrate that, compared with vibration signals, the DTW-RCK-IF approach using pressure signals yields superior results in detecting abnormal data, with an average F1 score of 98.79% and a good fault warning effect. Validation using the publicly available CWRU-bearing and XJTU-SY-bearing full-life datasets further confirms the effectiveness of this method, with average F1 scores of 99.35% and 99.73%, respectively, highlighting its broad applicability and potential for widespread use.

A Numerical Simulation and Multi-objective Optimization for the Plastic Injection Molding of a Centrifugal Pump Casing

Plastic pumps are used to efficiently move liquids within aquaculture systems and seafood processing facilities. Commonly, the centrifugal pump casing is fabricated by plastic injection molding technology. In the plastic injection molding process, the control parameters are essential to the success of plastic molding product fabrication. This study aims to optimize process parameters for the quality of centrifugal pump casing during plastic injection molding using a combination of response surface methodology (RSM) and the NSGA-II method. Firstly, the L27 orthogonal array design of the experiment method is used, which has four input variables, including plastic temperature, mold temperature, cooling time, and injection time (filling time and packing time). The output responses of the injection molding process to be evaluated are the warpage and shrinkage deformation of the molded product. After obtaining data, the RSM model is applied to describe the relationship between the input and output variables. Finally, multi-objective optimization uses the NSGA-II method for the best product quality. The results show that the optimized parameters for injection molding of the centrifugal pump casing are a plastic temperature of 200°C, mold temperature of 65°C, cooling time of 25s, and injection time of 10s with warpage of 0.868 mm, and shrinkage of 10.104mm.

Parametric Optimization of a New Gear Pump Casing Based on Weight Using a Finite Element Method

Reducing the weight of the structures and choosing the materials used in mechanical engineering is an important and pressing economic and environmental problem. The design of a gear pump is developed from the point of view of the geometry of the gears, as well as the casing. This paper tested a gear pump casing using the environment of the ABAQUS 2020 system in the field of statistical strength analysis using the finite element method. The tests were carried out on the pump body and the front and rear covers, which were made of three types of materials (cast iron, aluminum, and polycarbonate), at a pressure of 28 MPa. After loading, the maximum stresses in the aluminum casing (177 MPa), the cast iron casing (157 MPa), and the polycarbonate (200 MPa) were determined. The largest stress concentrators are the grooves at the bottom of the pump casing. Rounding the internal chamber of the casing with a radius of 4 mm made it possible to reduce stress in this zone by 10 MPa. The parametric optimization of the front and back covers of the gear pump made it possible to reduce the total weight of the aluminum structure by 14%, the cast iron by 12%, and the polycarbonate by 16%. The 3D models show areas of minimal stress where the size and weight of the structure could be reduced in the future using a comprehensive approach involving parametric and topological analysis.

Experimental evaluation on OSNR and DMG performance of cascade FM-EDFA systems by equivalent input spectrum method

An all-fiber few-mode erbium-doped fiber amplifier (FM-EDFA) is constructed by the integration of few-mode isolator wavelength division multiplexers (FM-IWDMs), which act as the multiplexing or demultiplexing function between signal and pump light. The gain performance of the FM-EDFAs under forward, bidirectional and backward pumping cases is investigated by experiment. For LP01, LP11e and LP11o-mode signals, the minimum differential mode gain (DMG) of 0.14 dB can be achieved by forward LP11e and LP11o-mode pumping. We propose the equivalent input spectrum method to experimentally simulate the cascade FM-EDFA systems. For the three-mode amplification, the optical signal-to-noise ratio (OSNR) and overall DMG after 8-stage transmission are respectively 13.89 dB and 1.59 dB, which may theoretically support 1000 km-long transmission of 100 Gb/s DP-QPSK signal. A cascade amplification system composed of six-mode EDFA with the DMG of 1.35 dB is also considered to verify the feasibility of the equivalent input spectrum method.