Performance Improvement Of Pump Research Articles

Bubble breakage and aggregation characteristics in a vortex pump under bubble inflow

The behaviors of bubbles in a vortex pump play a crucial role in its performance when handling gas–liquid flows. However, not much research has been done on the distribution of the gas–liquid phases and the characteristics of bubble breakage and aggregation in vortex pumps. This lack of understanding hinders the improvement of pump performance in gas–liquid flow transport. This study aims to investigate the bubble characteristics in a vortex pump using the population balance model, focusing on the variation of bubble size and the influence of the inlet gas volume fraction (IGVF) on bubble breakage and aggregation. The results show that as the IGVF increases, the gas volume fraction in the impeller becomes larger than that in the bladeless chamber. The majority of bubbles in the impeller are concentrated near the hub, while they also remain in the circulating-flow zone of the bladeless chamber. Under low IGVF conditions, the average diameter of bubbles decreases from the pump inlet to the outlet. The bladeless chamber has a larger average bubble diameter and a higher percentage of large bubbles compared to other parts of the pump. Moreover, the bubble number density at the pump outlet increases with the IGVF, indicating the production of more bubbles, while the increase in IGVF also results in an increase in the percentage of large bubbles. The study also discusses the mechanism of bubble breakage and aggregation in vortex pumps. It suggests that the effective breakage frequency and effective aggregation frequency are responsible for bubble breakage and aggregation in the vortex pump. The gas volume fraction and turbulent dissipation rate are identified as important parameters affecting the effective breakage and aggregation frequency. These findings provide new insights into understanding the characteristics of bubble breakage and aggregation in vortex pumps.

Mixed-flow pump performance improvement based on circulation method

Mixed-flow pumps have been extensively employed in daily life, improving their energy characteristics contribute to the reduction of energy consumption worldwide. In this study, to overcome the decrease of optimization upper limit caused by using a single type of parameter as the design parameter, a typical mixed-flow pump was chosen for study, and its impeller was parameterized by five geometric and eight hydrodynamic parameters. With head and efficiency as the constraint and optimization objective respectively, 27 schemes were constructed by the Taguchi method. The influence of design factors to the objective and constraint was analyzed based on range and regression analysis. The optimization mechanism was elucidated using the entropy production method. The result reveals that the geometric and hydrodynamic parameters have a significantly impact on the mixed-flow pump’s energy characteristics. The optimized model head is 12.43m, which meets the constraints, while the efficiency increases by 3.2%–88.51%. Therefore, considering both geometric and hydrodynamic parameters in the mixed-flow pump optimization is workable and necessary. This paper can provide practical instructions on the optimal design of different turbomachines.

Comparative design and performance of surface water irrigation pumps for smallholder farmers in South and Southeast Asia

An experimental study on the performance of various Thai irrigation pump impellers and a newly design conical hollow-shaped impeller was investigated. They were tested experimentally. The design pump based on a similar theory was developed. The objectives of this experiment were to provide data for comparison of Thai irrigation pump impellers, to evaluate, and to improve the current design of Thai irrigation pumps in a cost-effective and energy-efficient manner. The efficiency and design variables of Thai irrigation pump impellers were presented as a function of dimensionless specific speed in the range, 2.1 < Ns < 4.1. The geometric and design variables as functions of the specific speed and the specific diameter or Cordier diagram presented in this paper could be used as a practical design guide for Thai irrigation pump impellers. This is a preliminary design phase of Thai irrigation pump impellers and the result from this study is intended to make a modest contribution. However, they are facing new challenges that require pump performance improvement and innovative design.

Dynamic performance evaluation of LNG vaporization system integrated with solar-assisted heat pump

The heat transfer deterioration caused by frosting is the critical factor affecting the liquefied natural gas (LNG) vaporization efficiency of the ambient air vaporizer (AAV). In this paper, an LNG vaporization system using a solar-assisted heat pump (DX-SAHPNV) was proposed for AAV defrosting and LNG auxiliary heating, and a low-temperature LNG bypass flowing through the collector/evaporator was adopted for heat pump performance improvement and LNG preheating. Moreover, a dynamic model of the DX-SAHPNV system was established. Based on the meteorological data in Beijing, the system performance throughout the year and on typical days was analyzed, as well as the main meteorological factors effecting the system performance. Results showed the annual COP and the heat collection efficiency of collector/evporator with LNG bypass were 10.77% and 12.84% higher than that without LNG bypass, respectively. Comparing with the conventional AAV, the two-phase length of AAV in the DX-SAHPNV system was reduced by 12.7% and 20.2% on the typical winter and summer day, while the outlet LNG temperature was improved by 5.33 K and 11.56 K. The proposed system may provide a new perspective for the AAV defrosting and LNG vaporization optimization.

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.

Pump performance improvement using DMAIC method for industrial application

In recent years, regenerative model pumps have become more interested in various commercial processes. Havells India Limited Produces regenerative water pumps which is mostly used in domestic application. Duration of assembly of regenerative water pump we found from the quality supervisors and production monthly data, a self-priming mono block regenerative pump (M1 model) have jamming issue. Due to this jamming of pump rejection is 20% of monthly production which is a major problem. For solving this problem, two techniques are used. The result of the project was to reduce the overall refusal rate in the production line from 20% to 2%, which enabled the production line to meet demand-using DMAIC. This analysis presents the current product improvement based on the DMAIC approach as a preferential method for defect identification and process improvement using various statistical tools such as the Cause and Effect Diagram.

Performance improvement of the sanitary centrifugal pump through an integrated approach based on response surface methodology, multi-objective optimization and CFD

Performance improvement of the pumps leads to the reduction in power consumption of industrial pumping systems. This paper presents an effective approach for the enhancement of the performance of a sanitary centrifugal pump by adopting computational fluid dynamics and response surface methodology with a multi-objective optimization algorithm. An experimental apparatus with a closed loop is set up in laboratory to measure the pump performance and then to valid it with the numerical results. In this study, three input design parameters, namely blade outlet angle, blade wrap angle and blade outlet width, are investigated for the simultaneous optimization of pump head and efficiency. Twenty-five samples of impeller are generated with the help of the Latin hypercube sampling method. All impellers in the design space are numerically simulated. The multi-objective optimization algorithm is used to get the Pareto optimal solution between head and efficiency. Looking at the results, 9.154% and 10.15% improvement in head and efficiency are observed at the design point as compared to initial pump. Further, the effect of the three design variables on head and efficiency is also studied. The results indicate that the blade outlet width and blade wrap angle are most significant parameters that affect the efficiency of the pump.

Modelling of a Large Vertical Ground Heat Exchanger Integrated with a Heat Pump for Building Energy Simulation in China

Vertical ground coupled heat pump (GCHP) systems used in buildings in China can help to increase the share of renewable energy and improve the energy efficiency. A building energy simulation (BES) tool including a vertical GCHP model is beneficial for analysing the system performance under dynamic building loads. This paper presents a large-scale vertical ground heat exchanger model integrated to a heat pump model in the BES tool COMFIE, in a Matlab-Delphi co-environment. This model was applied to a residential building block with a 26 × 26 borehole field in Wuhan, China. The heat pump performance improvement was investigated for different design parameters. For half-hourly simulation of 1 year, the specific calculation time of the proposed GCHP model is 4 seconds out of 8 minutes for the whole building. The proposed model can be used as a design aid to optimise the system performance.

Comprehensive Improvement of Mixed-Flow Pump Impeller Based on Multi-Objective Optimization

The spanwise distribution of impeller exit circulation (SDIEC) has a significant effect on the impeller performance, therefore, there is a need for its consideration in the optimization design of mixed-flow pumps. In this study, a combination optimization system, including a 3D inverse design method (IDM), computational fluid dynamics (CFD), Latin hypercube sampling (LHS) method, response surface model (RSM), and non-dominated sorting genetic algorithm (NSGA-Ⅱ) was used to improve the performance of the mixed-flow pump after considering the effect of SDIEC on the performance of the impeller. The CFD results confirm the accuracy and credibility of the optimization results because of the good agreement the CFD results established with the experimental measurements. Compared with the original impeller, the pump efficiency of the preferred impeller at 0.8Qdes, 1.0Qdes, and 1.2Qdes improved by 0.63%, 3.39%, and 3.77% respectively. The low-pressure region on the blade surface reduced by 96.92% while the pump head difference was less than 1.84% at the design point. In addition, a comparison of the flow field of the preferred impeller and the original impeller revealed the effect of SDIEC on mixed-flow pump performance improvement and flow mechanism.

Direct Shape Optimization and Parametric Analysis of a Vertical Inline Pump via Multi-Objective Particle Swarm Optimization

The vertical inline pump is a single-suction single-stage centrifugal pump with a curved inlet pipe before the impeller, which usually causes a significant increase of hydraulic losses in the inline pump. Considering the matching relationship between the inlet pipe and impeller, a multi-objective direct optimization based on the MOPSO of the inlet pipe and impeller was carried out to broaden the efficient operating area of the vertical inline pump. Bezier curves were adopted to control the profiles of the inlet pipe and impeller and 39 coordinates of the control points and the blade number were selected as the optimization variables. The efficiencies of the inline pump at the part-load and nominal conditions were chosen as the objective functions, which were obtained by the automatic simulation program. A dramatic improvement in pump performance was found after optimization. In the set of Pareto solutions, the maximum increases of efficiency at part-load and nominal conditions were 8.06% and 7.33% respectively. It also reported that the inlet pipe with longer horizontal length and lower bend curvature could reduce the hydraulic losses of the inlet pipe and increase the pump performance.

An iterative code to investigate heat pump performance improvement by exhaust gases heat recovery

ABSTRACTThe race between the development of technologies and energy demand has drawn the guidelines of energy strategies for the next two decades. Indeed, the governmental organizations as well as the private sectors are spending huge effort to come up with new adequate strategies that allow to decrease energy consumption. Having said that, heat pump becomes an essential system in our daily life not only in residential building but also in hospital, industrial and touristic building. Nonetheless, (HP)s have very high energy consumption rate. Thus, and to be in line with the new trends in energy strategies, it is convenient to find new methods to enhance the performance of heat pump in order to reduce energy consumption. In this frame, the present paper suggests an approach to enhance the performance the heat pumps using the heat recovery from generators. For this purpose, an in-house code is developed allowing to simulate two new proposed systems (condenser upstream exhaust gases heat recovery system (CU-EGHRS) and condenser downstream exhaust gases heat recovery system (CD-EGHRS). It has been shown that the increase in the performance of the heat pump depends on the capacity of the generator. Also, the CD-EGHRS is shown to be the best. For instance, in the case of a 15 kVA generator, the enhancement could reach 42% for the CD-EGHRS. This enhancement increases to 5640% in the case of a 180 kVA generator.

Combined effects of viscosity and surface roughness on electric submersible pump performance

An electric submersible pump that lifts crude oil from well bore is a type of multi-stage centrifugal pump. The unexpected wellbore conditions like change in pumping fluid viscosity and sand production severely affect pump performance and eventually lead to breakdown. The present study proposes a numerical approach to understand the effects of fluid viscosity and surface roughness of the flow passages in an electric submersible pump at design and off-design conditions. A three-dimensional numerical analysis was carried out by solving Reynolds-averaged Navier–Stokes equations with shear stress transport turbulence model to characterize performance of the pump. The pumping fluids, i.e., water and crude oils of different viscosities were analyzed for different surface roughness ( Ks) values. The model predictions were compared with a theoretical one-dimensional model for the effect of viscosity and surface roughness. It was found that the disc-friction and the skin-friction losses are sensitive hydraulic losses of which the disc-friction loss increases with increase in viscosity, whereas skin-friction loss decreases with increase in surface roughness at high viscosity. The combined effect of viscosity and roughness showed a complicated behavior and eventually an improvement in pump performance at a higher surface roughness compared to a smoother and lowers surface roughness.

PERFORMANCE IMPROVEMENT OF MIXED FLOW PUMP IMPELLER THROUGH CFD ANALYSIS

Centrifugal pumps are the largest used hydraulic machine. However, the performance of centrifugal pump is generally not very good. Making them more efficient is a major challenge. The performance of the centrifugal pump greatly depends on its geometrical parameters and the vane profile. Computation fluid dynamics (CFD) has been found to be very good tool for numerical analysis of flow through complex system including centrifugal pumps. The present study deals with the performance analysis of a mixed flow type centrifugal pump designed centrifugal pump to deliver 0.25 m 3 /s water at a head of 20 m running at 1450 rpm using ANSYS CFX 14.0 software. Modeling of the pump unit has been done using PTC Cre-o 2.0 software. The performance of the pump was first determined using the initially obtained vane angles. The inlet vane angle and outlet vane angle are then varied to analyses the improvement in pump performance .The results shows that for an initial inlet angle 20.08 and outlet angle 16.28 , the efficiency of the pump is 83 %.however, for an optimized angles at inlet and outlet as 20.16 and 16.62 respectively, the efficiency of pump raised to 88 % thus showing an improvement in the performance of mixed flow pump.

Novel Therapeutic Targets in Heart Failure: The Phospholipase Cβ1b–Shank3 Interface

Inotropic agents are often used to improve the contractile performance of the failing myocardium, but this is often at a cost of increased myocardial ischemia and arrhythmia. Myocyte contractility depends on the release of Ca2+from the sarcoplasmic reticulum, and this Ca2+is subject to regulation by the phosphorylation status of phospholamban (PLN). Many currently used inotropic agents function by increasing the phosphorylation of PLN, but these also heighten the risk of ischemia. Another approach is to reduce the dephosphorylation of PLN, which can be achieved by inhibiting pathways upstream or downstream of the protein kinase Cα. Phospholipase Cβ1b is responsible for activating protein kinase Cα, and its activity is substantially heightened in failing myocardium. We propose phospholipase Cβ1b, a cardiac-specific enzyme, as a promising target for the development of a new class of inotropic agents. By reversing changes that accompany the transition to heart failure, it may be possible to provide well-tolerated improvement in pump performance.

Performance Improvement of Pumps Fed by the Variable Speed Drives

Abstract Speed inaccuracy decreases the pump efficiency, reliability, and energy saving. This research is devoted to the determination of the ways of accurate speed control of the pump drives operated under changeable loads. The impact of speed inaccuracy on the pump performance is studied. Based on the analysis of methods for the static accuracy improvement, the drawbacks of the traditional approaches have been shown with reference to the pumping applications. A new methodology of the slip compensation has been proposed for implementation to improve the scalar drive performance. It notably decreases the speed inaccuracy of the open-ended pumping applications. The enhanced quality of the drive control at different loading conditions has been shown on a laboratory test bench. Also, for the multi-pump systems this approach results in an additional benefit from the viewpoint of the operation around the best operation point providing a safe pump control both to exclude the pump damage and to improve the process quality.

The effect of step height on the performance of three-dimensional ac electro-osmotic microfluidic pumps

Recent numerical and experimental studies have investigated the increase in efficiency of microfluidic ac electro-osmotic pumps by introducing nonplanar geometries with raised steps on the electrodes. In this study, we analyze the effect of the step height on ac electro-osmotic pump performance. AC electro-osmotic pumps with three-dimensional electroplated steps are fabricated on glass substrates and pumping velocities of low ionic strength electrolyte solutions are measured systematically using a custom microfluidic device. Numerical simulations predict an improvement in pump performance with increasing step height, at a given frequency and voltage, up to an optimal step height, which qualitatively matches the trend observed in experiment. For a broad range of step heights near the optimum, the observed flow is much faster than with existing planar pumps (at the same voltage and minimum feature size) and in the theoretically predicted direction of the “fluid conveyor belt” mechanism. For small step heights, the experiments also exhibit significant flow reversal at the optimal frequency, which cannot be explained by the theory, although the simulations predict weak flow reversal at higher frequencies due to incomplete charging. These results provide insight to an important parameter for the design of nonplanar electro-osmotic pumps and clues to improve the fundamental theory of ACEO.

Loss Analysis of Very Low Specific Speed Centrifugal Pump

In the range of very low specific speed ns, improvement of efficiency is the most important subject in order to apply turbo machine to such a low specific speed range. The purpose of the present study is focused on the performance improvement of pump in the range of ns?80 [m, m3/min, min-1], and CFD simulation is performed to determine the reason why efficiency is very low. The result shows that a rapid increase of leakage rate and disk friction rate with a decrease of ns is the main reason of low efficiency. Also, the result shows that if the leakage loss is reduced by use of Labyrinth seal at ns=25, the disk friction rapidly increases in spite of the leakage reduction and pump overall efficiency becomes only 5% higher.

극저비속도 원심펌프의 펌프성능 및 흡입성능 향상

There are high expectations of improving the performance of a centrifugal pump in the range of very low specific speed which has been developed recently for the use instead of a conventional positive displacement pump. However, even though elaborated studies has been done for the pump intensively, the pump performance has not increased so much. Also, it is difficult to find detailed information from published literatures for suction performance of the very low specific speed centrifugal pump. Therefore, this study is aimed to improve the pump performance more and to make clear suction performance of the very low specific speed centrifugal pump. Recircular flow stopper is installed on the pump casing wall at the region of impeller outlet to improve the pump performance and J-Groove is also installed at the inlet of the pump casing for the purpose of suppressing occurrence of cavitation as well as improving pump performance. The result suggests that the simultaneous improvement of pump performance and suction performance of the very low specific speed centrifugal pump is possible by adopting optimum configuration of the recirculation flow stopper and J-Groove.

An integrated off-on line approach for increasing stability and effectiveness of automated controlled systems based on pump dependability—case study: Offshore industry

Automated controlled systems are vulnerable to faults. Faults can be amplified by the closed loop control systems and they can develop into malfunction of the loop. A control loop failure will easily cause production stop or malfunction at a petrochemical plant. A way to achieve a stable and effective automated system is to enhance equipment dependability. This paper presents a standard methodology for the analysis and improvement of pump performance to enhance total operational effectiveness and stability in offshore industry based on dependability. Furthermore, it is shown how a reliability–safety analysis can be conducted through equipment dependability indicators to facilitate the mitigation of hazard frequency in a plant. The main idea is to employ principle component analysis (PCA) and importance analysis (IA) to provide insight on the pumps performance. The pumps of offshore industries are considered according to OREDA classification. The approach identifies the critical pump and their fault through which the major hazards could initiate in the process. At first PCA is used for assessing the performance of the pumps and ranking them. IA is then performed for the worst pump which could have most impact on the overall system effectiveness to classify their components based on the component criticality measures (CCM). The analysis of the classified components can ferret out the leading causes and common-cause events to pave a way toward improving pump performance through design optimization and online fault detection which ultimately enhance overall operational effectiveness.

원형케이싱이 극저비속도 원심펌프의 성능에 미치는 영향

Recently, according to the trend of small size in scale and high speed in rotation of turbomachinery, very low specific speed centrifugal pump is taking a growing interest because the pump is characterized by high head and low flow rate with convenience of manufacturing and maintenance compared with conventional positive displacement pump. However, the efficiency of the very low specific speed centrifugal pump drops rapidly with the decrease of specific speed. The purpose of this study is not only to examine the influence of casing type on the performance of centrifugal pump in the range of very low specific speed but also to determine the proper casing type for the improvement of pump performance. The results show that circular casing is suitable for the centrifugal pump in the range of very low specific speed and the influence of impeller configuration on the pump performance is very small. Radial thrust in the circular and volute casings is considerably small in the range of very low specific speed.