Hydraulic Pump Research Articles

Impeller design and performance characteristics of a side channel pump

Flow non-uniformity inherent at the impeller passages is realized to have pronounced effects in hydraulic pumps, which leads to severe operational challenges. Cutting the blade tip has emerged as a research hotspot, which is deemed to be a feasible and viable approach to mitigate flow-induced problems. Therefore, this paper reveals more insight into the inner flow phenomena in a side channel pump under different impeller geometry. First, five models of impeller blades are designed with different tip cutting angles ranging from 10° to 50°. Based on the experimental data and the reliable shear stress transport k-ω model, the turbulent flow nature of the pump was established by numerical simulations. The performance curves revealed that impeller model 2 attained the highest efficiency of 37.13% at the best efficiency point, although registering 26.9% and 32.9% at part-load and over-load conditions, respectively. At over-load conditions, the efficiency of model 2 improved by 3.46%, 3.13%, 2.21%, and 8.72% compared to models 1, 3, 4, and 5, respectively. The pressure distribution at the impeller passage was higher compared to the side channel of all the impeller models. Noticeably, each type of vortex structure occupies nearly all the impeller passages of the impeller models justifying the complicated flow in the side channel pump. Impeller models 1, 2, and 3 produced better flow exchanges with the higher mass flow in and out, hence stimulating improved energy conversion. The conclusion can provide a physical foundation for designers in selecting a reasonable tip angle for specific tasks from engineering perspectives.

PLC Modification of Lubrication System for Mining Dump Trucks

The automatic lubrication system of the mining dump truck is provided with pressure by a hydraulic gear pump. The pressure sensor provides real-time working pressure feedback for the lubrication system, serving as a basis for the electromagnetic pressure relief valve control system. The lubrication condition of the articulated bearings in the mining dump truck has a significant impact on the truck's utilization rate. Proper lubrication is directly related to extending equipment lifespan and reducing equipment maintenance costs. By researching and analyzing the principles of the automatic lubrication control system for mining dump trucks, and considering the characteristics, types, and maintenance difficulties of lubrication system failures, we propose a PLC modification to the original control system. This modification aims to enhance system operational stability and reduce maintenance costs.

MODEL FOR CALCULATING THE STATIC CHARACTERISTICS OF HYDRAULIC SYSTEMS OF HYDRO TECHNICAL BUILDINGS

Hydraulic mechanisms that actuate flat gates, widely used in hydraulic structures, are studied as hydraulic actuators of the system. Their static mathematical models are developed using an integrated methodology with a hydraulic pump, inlet and suction pipes, and internal and external resistance factors. Unlike existing mathematical models, the model developed in this paper allows a detailed description of the characteristics of hydraulic drives due to the fact that pressure losses in the throttle, regulator, and power amplifier, as well as local resistances in hydraulic pipelines, are taken into account.

Газоприводная скважинная насосная установка для добычи нефти из наклонных и горизонтальных скважин

The design of a gas-driven downhole pumping unit for oil production from directional and horizontal wells has been developed. The unit has no rod string, the slide and pneumatic jack are located in the tubing string. Using these units with a compressed associated gas as a working fluid will allow, unlike the hydraulic pumps, avoiding complex surface equipment for preparing the working fluid, maintenance of which is rather labour-consuming, and increasing the reliable operation of slides and downhole pumping units as a whole. In the course of experimental study of the parameters of the proposed installation it was shown on a laboratory bench showed that the fluid feed increases in direct proportion to the rate from 0.6 to 3.6 m/min. There has been obtained an empirical dependence to determine the flow of a borehole pump depending on its geometric parameters, plunger stroke length, stroke speed and gas content in the produced oil. According to the estimated parameters of the developed gas-driven unit, the supply can reach 386 m3/day, which is comparable to the supply of hydraulic units in use.

Construction of spherical non-circular wheels formed by symmetrical arcs of loxodrome

Bevel gears are used to transmit torque between intersecting axes. They demonstrate high reliability and durability of work, as well as a constant gear ratio. The disadvantage of such a transmission is the mutual sliding of the surfaces of the teeth of the gears, which leads to the emergence of friction forces and wear of their working surfaces. In this regard, there is a task to design such bevel gears that would have no slip. Non-circular wheels are understood as a pair of closed curves that rotate around fixed centers and at the same time roll over each other without sliding. They can serve as centroids for the design of cylindrical gears between parallel axes. If the axes of rotation of the wheels intersect, then the gears are called conical. An analog of gears between parallel axes, in which centroids are flat closed curves, for gears with intersecting axes are spherical closed curves. For a bevel gear with a constant gear ratio, such spherical curves are circles on the surface of the sphere, and with a variable gear ratio, spatial spherical curves. This paper considers the construction of closed spherical curves that roll around each other without sliding when they rotate around the axes intersecting in the center of the spheres. These curves are formed from symmetrical arcs of the loxodrome, a curve that crosses all the meridians of the ball at a constant angle. This angle should be 45°, which ensures the intersection of the loxodrome at right angles. Analytical dependences have been derived underlying the calculations of profiles of spherical non-circular wheels and their visualization by means of computer graphics. The results could be used to design non-circular wheels for textile machines, hydraulic machine pumps, pump dispensers, etc.

THE OPTIMIZATION OF PUMP TYPE HYDRAULIC PUMPING UNIT BY REDESIGNING WELL SB-02 AT PT SMD TAMPI FIELD

Production is an activity to transport hydrocarbon fluids from the subsurface (reservoir) to the surface. To increase the productivity of a Hydraulic Pump Unit, it is necessary to pay attention to pump production capacity, stroke length, pumping speed. A decrease in pump production can be caused by a variety of factors. This study aims to evaluate the possibility of increasing production in the study well by redesigning the Hydraulic Pump Unit in order to achieve optimum volumetric efficiency in the SB-02 Well in the Lampi Field. In this study, the data processing method by evaluating the installed pump and calculating the evaluation of the installed pump then calculating the volumetric efficiency of the pump if the production of SB-02 Well has not reached the specified target, it is necessary to optimize it. Based on dynagraph analysis, it is known that there is damage in the pump, namely in the fluid pound, so that the pump can be optimized by changing the pump parameters. HPU pump optimization is making an IPR Curve using the Darcy Method, because the water cut is only 1%. The optimization method was doing to change the pump parameters, namely pump stroke speed (SPM) and pump stroke length (SL). To get the optimal combination of pump parameters is done by nodal analysis (Pump Intake Curve). The redesign of the HPU pump optimization method is to change the pump stroke speed from 10 SPM to 9 SPM, Fixed Stroke Length which is 80 inches. After optimization was carried out on the SB-02 Well, the result obtained was an increase in the volumetric efficiency of the installed pump. The volumetric efficiency of the previously installed pump was 58.25% to 75.45%, the increase in production flow rate (Qt) from SB-02 Well was 32.90 bfpd, with the previous flow rate of 217.10 bfpd rising to 250 bfpd.

Comparative Analysis of the Overall Efficiency of a Hydraulic Pump Unit with and without a Separate Pre-Charging System

The overall efficiency and energy consumption problem in hydraulic power pack units with and without an additional pre-charging system was analyzed in this paper. A theoretical mathematical model was developed for calculating energy losses in both pump unit structures. To verify the theoretical relationships, a laboratory test stand was built, upon which the results of calculating the overall efficiency were compared with the results of the laboratory tests. Universal diagrams of the overall efficiency dependence as a function of pressure load and geometric adjustment of the main pump’s working volume were created for the case of a particular hydraulic pump unit without and with a pre-charging system. Based on this, discussions were carried out on whether and the way in which the additionally pre-charging system affects the parameters of the overall efficiency characteristics of the researched pump unit. Additionally, the dependence of the optimal pressure load and the maximum overall efficiency of the pump unit on the geometric adjustment of the main pump’s working volume was analyzed. It was shown that the pre-charging system affects the increase in the optimal pressure load at which the most favorable operating conditions, in terms of energy consumption, are obtained for the researched hydraulic pump unit.

Determining the pressure increase in the hydraulic cylinders of powered roof support based on actual measurements

Powered roof support in a longwall operation is designed to maintain a safe working area and allow the immediate roof to fail and collapse behind the support. The powered supports are loaded using large hydraulic pumps with non-return and preset-yielding valves. In addition to providing support to the immediate roof in the longwall production area, it also moves the armoured face conveyor and shearer forward as coal mining progresses. The research aimed to analyse the changes in the pressure values in the powered roof support section's hydraulic cylinders in relation to the occurrence of rock mass movements in the roof. The pressure measurements are based on the sensors in the sub-piston space of the powered roof support hydraulic prop located in the steel wall. The results allow a correlation to be developed between the roof movement and the loads generated in the hydraulic cylinders.

Possessing Nature. Mexican Pavilion at the 56. Venice Biennale

The piece Possessing Nature was presented by Tania Candiani and Luis Felipe Ortega at the 2015 Venice Biennale, its content and context were transcendental for the historical memory of the Mexican participation that restarted in 2007. The conceptual piece is a metal structure where water flows, and in its shape and angles recalls the topographical path the Mexican pavilion has had in various exhibition places in Venice. The water flows with the help of a hydraulic pump and the piece is complemented by the projection of photographs that refer to the water relationship between Mexico City and the city of Venice, both cities being built in lake environments. Thus, this article examines the fifth pavilion of Mexico at the Venice Biennale by addressing the historical context of the national pavilion in the 21st century and the symbolic content of the piece, since in its analysis the cultural policies that have led to the Mexican pavilion at each Biennale, together with the reflection and evidence that the artists made around water as an element dominated and even avoided by modernity, all related to the proposal of the artistic director of the 56th Venice Biennale, the Nigerian-American Okwui Enwezor and which he called All the World’s Future.

Research on high efficiency and high dynamic optimal matching of the electro-hydraulic servo pump control system based on NSGA-II

An electro-hydraulic servo pump control system (hereinafter referred to as EHSPCS) is a volume servo control unit that is highly integrated with servo motors, fixed-displacement pumps, hydraulic cylinders and functional valve groups. Because of its unique volume direct-drive control mode, the dynamic performance of the system is limited, and the thermal power loss is large, which seriously restricts the improvement of the working quality of the system. To improve the dynamic performance of the system and reduce the thermal power loss to the maximum extent, a multi-objective optimization design method for the EHSPCS is proposed by comprehensively considering the dynamic and efficient energy-saving characteristics of the system. The evaluation model of the dynamic period of the hydraulic cylinder and the thermal power loss of the servo motor are given. Parameters such as the electromagnetic torque of the servo motor, displacement of the hydraulic pump, and working area of the hydraulic cylinder are intelligently optimized by a non-dominated sorting genetic algorithm with elite strategy (NSGA-II). The Pareto front of multi-objective optimization and the corresponding Pareto solution set are obtained; thus, the optimal matching of the system characteristics is realized. Finally, the relevant theory of the multi-objective optimization algorithm is applied to optimize the performance parameters of the hydraulic servo motor, and the prototype is tested in engineering. The experimental results show that the dynamic period of the hydraulic servo motor is accelerated after optimization, and the thermal power loss is significantly reduced. The dynamic and efficient energy-saving characteristics of the system are improved, which further verifies the feasibility of the proposed theory.

Remaining useful life prediction of lubrication oil by integrating multi-source knowledge and multi-indicator data

Insufficient data restrains the accuracy of the remaining useful life (RUL) prediction for lubricating oil. For this problem, multi-indicator modeling can be an effective solution. However, the unknown coupling effects of the indicators still impose difficulties. To address this issue, a coupling model integrating both knowledge and data is proposed. Originally, multi-source knowledge is embedded to guide both the state characterization and the threshold setting for improving the accuracy of the multi-indicator oil RUL prediction. In particular, the multi-indicator evidences and the knowledge-based rules, are adopted to handle overlapping information and inconsistent decision-making by considering interactions between indicators. A three-layer hierarchical model integrating evidence and rules is firstly established to connect the indicator, attribute, and oil state. Furthermore, the rule-base containing multi-failure modes is constructed to extract the random thresholds from the training samples. Finally, an exponential Wiener stochastic process embedding the oil degradation mechanism is used to describe data fluctuation. After the training stage, the probability density function of RUL is estimated. Finally, the proposed method is validated with four sets of test data from a real-world hydraulic pump bench test.

A feasibility and dynamic performance analysis of hydromechanical hybrid power transmission technology for wind turbines

Abstract. A multi-body dynamical model of a wind turbine power generation system (WTPGS) based on hydromechanical hybrid power transmission (HMHPT) technology is developed and simulated to overcome the individual drawbacks of the gear train and hydrostatic power transmission (HPT) system. The HMHPT is a hybrid concept of a single-stage planetary gear train (SSPGT) and a typical HPT. The input shaft of the SSPGT is coupled with the turbine rotor, whereas the output shaft of the SSPGT is coupled with the shaft of a hydraulic pump. The hydraulic pump supplies flow to the hydro-motor, and its shaft is coupled with the generator. An existing turbine blade model of 750 kW based wind turbine is used for further development and analysis of the HMHPT. The simulation responses indicate that the power generation and the control potential both have been improved using the HMHPT in a wind turbine. Moreover, the influence on the motor power generation due to variations of pump and motor leakages is addressed. Additionally, it is found that if the order of the SSPGT and the HPT are swapped in the proposed HMHPT, then the settling time, maximum overshoot, and rise time of the system responses are increased. As a result, the controllability of the system is decreased.

Dynamic thermal analysis of a coupled solar water heaters-thermal storage tank for solar powered district heating networks

The integration of solar thermal and energy storage systems into district heating networks (DHNs) has been considered as one of the most advantageous solutions to reduce the use of fossil fuels and carbon emissions. In this context, this work deals with the numerical investigation of a coupled solar water heaters-thermal storage unit for urban heating networks. The studied system contains flat plate solar collectors (FPCs) for hot water production, a shell-and-tube thermal storage unit with phase change material (PCM) for latent storage or water for sensible storage, hydraulic pumps and a mass flow rate regulation system. The functioning of the coupled system is simulated using a detailed dynamic model based on transient energy and mass balances. The reliability of the developed model is verified through comparing numerical results with measurement data from the literature and a good agreement is obtained with a maximum relative error of about 4.5 %. The validated model is used to investigate the system thermal performance under the weather conditions of the city of Pau, France, and the effects of multiple parameters such as the FPC area, the DHN target thermal power, and the storage medium type (latent or sensible) during both charging and discharging processes are presented and analyzed. Results show that the use of FPCs is beneficial for DHNs during summer as they allow the production of thermal energy for both the DHN use and the storage process. It was also shown that increasing the DHN target thermal power from 30 kW to 50 kW leads to a reduction in the thermal storage process duration by up to 40 %. For both charging and discharging operations, the use of PCM (latent storage) as a storage medium is more suitable than water (sensible storage) as it leads to an increase in the storage density and extends the duration of hot water production with constant thermal power by about 65 %.

Numerical investigation of the effects of model and operator uncertainties on component-based transfer path analysis methods with substructuring applied to aircraft-like components

Hydraulic pumps are considered to have a major contribution to the structure borne noise generated inside aircrafts. Methods such as Component-Based Transfer Path Analysis (CB-TPA) are promising tools for aircraft manufacturers to build internal processes for the specification, design and validation of the impact of vibrating systems on new aircrafts. However, the experimental applicability of these methods remains limited due to some experimental difficulties. CB-TPA' formulation is based on dynamical quantities, which require the determination of terms related to rotational degrees of freedom. Virtual Point (VP) or Equivalent Multi-Point Connection (EMPC) methods are commonly employed for this purpose, but both result in more cumbersome experimental set-ups and increased measurement uncertainties. The implementation of these methods is difficult in the case of a flat and thin receiving structure as commonly encountered in aircraft applications, since in-plane translational excitations have to be applied and the access to the vibrating system/structure interface points is limited. In this work, a decoupling procedure is used to overcome these issues. A numerical model is used to investigate the influence of model and operator uncertainties on the CB-TPA' predictions, when the dynamical quantities are provided by VP and EMPC methods including the decoupling procedure.

Fluid End Blocks: Numerical Analysis of Autofrettage and Reautofrettage Based Upon a True Material Model

AbstractFluid end blocks (FEBs) are the most important components of hydraulic fracturing pumps. A potential important application of the hydraulic autofrettage process (HAP) is to strengthen the fatigue-prone FEBs. This creates a favorable compressive residual stress field near to the critical surface locations within the component and serves to increase its pressure-bearing capacity and/or improve lifetime. This requires a fundamental understanding and modeling of the complex mechanics of the HAP in order to accurately predict such residual stresses. The key outstanding modeling issue is the complex material behavior, dominated by the Bauschinger effect and associated with reversed yielding. This effect differs throughout the FEB. It has been modeled for plane axisymmetric cylinders but has not previously been incorporated into FEB analyses. In this paper, a newly developed finite element analysis (FEA)-based user programable function (UPF), featuring true material constitutive behavior, i.e., replicating an existing Bauschinger-effect characterization (BEC), is adopted to accurately simulate the HAP and quantitatively investigate the stress–strain evolution and residual stress fields throughout the FEB. This simulation is then compared with FEA modeling by a traditional bilinear kinematic hardening material model to indicate the importance of the accuracy of the material constitutive model in determining appropriate residual stresses and strains. An autofrettage pressure of 500 MPa generally achieves net compressive hoop stresses at each of four critical crossbore location. Finally, a prospective re-autofrettage sequence is described; approximate modeling suggests an improvement that might permit operation at higher working pressure.

Failure analysis of auxiliary support bearing/shaft tribopair in seawater hydraulic axial piston pump

The auxiliary support structure is used to prevent the cylinder block from tilting in seawater hydraulic axial piston pump (SHAPP). The failure modes of auxiliary support bearing and shaft under different material combinations were compared. Experimental results show that improper design of radius fitting clearance in auxiliary support bearing/shaft tribopair will seriously affect the normal operation of SHAPP and even lead to its damage. Based on the inertia force, nonlinear water film force and dynamic load balance of the rotating cylinder block, the mathematical model of the nonlinear shaft centerline orbit of the auxiliary support bearing was established. The nonlinear shaft centerline orbit of auxiliary support bearing in the cylinder block bore during SHAPP operation is analyzed accurately. Simultaneously, the water film pressure field under different radius fitting clearance is simulated and the range of the optimal value is determined. The running-in experiment of SHAPP is carried out under the optimum clearance of the auxiliary support bearing/shaft tribopair. The results show that the SHAPP can run normally and the performance is obviously improved without the wear on the friction pair surfaces. Therefore, the proposed method has provided the guidance reference for the design of auxiliary support bearing in SHAPP.

Tribological behavior of tribo-pairs in water hydraulic radial piston pumps

Friction and wear tests were performed on five Cu-based materials and three polyether ether ketone (PEEK)-based composites sliding against 17-4PH and 42CrMo4 coated with tungsten carbide-reinforced Ni-based coating. Two types of pin-on-disk specimens were used to represent the slipper/eccentric drive and piston/sleeve gap seal tribo-pairs in water hydraulic radial piston pumps. The experimental results showed that the QSn8-0.3 slipper material exhibited the highest steady-state friction coefficients for sliding against both 17-4PH (0.156) and coated-42CrMo4 (0.894). Glass fiber-reinforced PEEK exhibited the highest steady-state friction coefficients for sliding against the two specimens (0.540 and 0.420). The ZCuPb15Sn8/17-4PH showed the highest wear rate for the representative slipper/eccentric drive tribo-pair (26.86 × 10−6 mm/Nm); glass fiber-reinforced PEEK/17-4PH showed the highest wear rate for the representative piston/sleeve gap seal tribo-pair (46.91 × 10−6mm/Nm). The wear mechanisms of the two types of tribo-pairs were characterized through scanning electron microscopy, profilometry, and energy-dispersive spectroscopy analyses. Furthermore, the effects of hardness, pv values, coating, and reinforcement on the tribological behavior of the two types of tribo-pairs were analyzed.

Internal Leakage Detection in Hydraulic Pump Using Model-Agnostic Feature Ranking and Ensemble Classifiers

Abstract Hydraulic pumps are key drivers of fluid power-based machines and demand high reliability during operation. Internal leakage is a key performance deteriorating fault that reduces pump’s efficiency and limits its predictability and reliability. Thus, this article presents a methodology for detecting internal leakage in hydraulic pumps using an unbalanced dataset of its drive motor’s electrical power signals. Refined composite multiscale dispersion and fuzzy entropies along with three statistical indicators are extracted and followed by second-order polynomial-based features. These features are normalized and visualized using partial dependence plot (PDP) and individual conditional expectation (ICE). Subsequently, ten machine learning classifiers are trained using four features, and their statistical hypothesis test is performed using a 5 × 2 paired t-test cross-validation for p < 0.05. Subsequently, top four performing classifiers are optimized using grid and random search hyperparameter optimization techniques. Due to slight difference in their accuracies, an ensemble of three best-performing algorithms is trained using the majority voting classifiers (MaVCs) for three splitting ratios (80:20, 70:30, and 60:40). It is demonstrated that MaVC achieves the highest leakage detection accuracy of 90.91%.

A new test method for simulating wear failure of hydraulic pump slipper pair under high-speed and high-pressure conditions

In practical engineering, it is very difficult to obtain data on the slipper wear of hydraulic pumps, especially under high-speed, high-pressure conditions, which limits the development of fault diagnosis technology for hydraulic pumps. At present, a test method that can accurately simulate the operating state of the slipper pair under high-speed and high-pressure conditions does not exist. The reliable load-bearing design of the slipper pair is difficult to carry out effectivetest verification, which limits the development of high-speed and high-pressure piston pumps. Therefore, an experimental design method was proposed to directly simulate the high-speed, high-pressure friction state of the slipper pair based on the change law of reprinting residual pressing force.

Experimental sample for diagnosis of hydraulic drive pumps of agricultural equipment by pressure pulsation coefficient

It is well known that often hydraulic pumps are resource-limiting components of the units in whose design they are included, and the condition of the hydraulic pump determines the performance and efficiency of the entire unit. The purpose of the work was to develop a prototype of a diagnostic tool that provides monitoring of the technical condition of hydraulic pumps during operation. An analysis of the tools produced by the Federal Scientific Agro-Engineering Center VIM for diagnosing the technical condition of hydraulic pumps of agricultural machinery was carried out. The material of research was a prototype of a tool for diagnosing the technical condition of hydraulic units, which was based on the method of amplitude-phase characteristics for rapid assessment of the technical condition of pumps during operation. On the base of our research we came to conclusions that for further development of the technology and subsequent implementation of the presented prototype in the process of diagnosing hydraulic pumps by pulsation coefficient it is necessary to increase the controllability of hydraulic systems of agricultural machinery by installing diagnostic points for connecting pressure sensors. Also together with manufacturers of hydraulic units, develop criteria for nominal, permissible, limit states, characterized by both the supply coefficient KQ and the pulsation coefficient ɛ.