Plunger Pump Research Articles

Tribological properties of a novel iron‐based self‐lubricating composite

AbstractIn this work, the tribological properties of a novel iron‐based self‐lubricating composite as the tribopairs of a plunger pump were systematically studied on an end‐face tribometer, and the tribological mechanism was also revealed. The results show that the wear mechanism of the composite can be ascribed to adhesive wear when the sliding speed is lower than 1.5 m/s. As the sliding speed increases from 1.5 to 2.0 m/s, the wear type transforms to oxidative wear due to the increase of tribo‐oxidation. In addition, the failure criteria of the tribopair composite materials are summarised. When the average coefficient of friction is greater than 0.04, or the wear rate is greater than 9.66 μm3/(N m), the tribopair fails. This offers a valuable reference for industrial application of the tribopairs made from the iron‐based self‐lubricating composite.

Vibrational Analysis and Optimization of a Water Injection Pipeline in a High-pressure Plunger Pump

Vibrational Analysis and Optimization of a Water Injection Pipeline in a High-pressure Plunger Pump

Lubrication and leakage characteristic research of aviation plunger pump considering plunger deflection

Aiming at the crucial issues of serious friction, wear and large leakage in the key friction pair on the aviation plunger pump, the influence factors of pressure and shear flow are introduced to correct the Reynolds governing equation of the clearance flow, the oil film thickness equation considering the deflection of the plunger was established, and the lubrication and leakage characteristics of the plunger/cylinder pair are analyzed using finite element method, and the following conclusions are obtained: the inclination angle of the plunger has a significant influence on the lubrication characteristics of the plunger pair, the maximum oil film pressure of the tilted plunger is significantly greater than that of the non-tilted plunger, a transition from elastohydrodynamic lubrication to mixed lubrication occurs in the plunger/cylinder pair at an inclination angle of 0.00015°. When the inclination angle is 0.00025°, the maximum oil film pressure is about 14 times than that without inclination, and the minimum oil film thickness when the plunger is deflected is significantly smaller than that without inclination. As the pressure difference gradually increases, the leakage ratio of a single plunger/cylinder pair mostly shows an approximate linear increase trend. When the contact length is 17 mm, the leakage amount is the largest and the slope of the varied curve is the steepest, when the unilateral clearance increases above 3 µm, the leakage ratio increases significantly. The research can provide references for the plunger/cylinder pair precise theoretical design and the instability of the core rotating components of aviation plunger pumps.

Research on fuel injection characteristics of common rail system based on high pressure pipeline integration and matching

AbstractThe modular prediction model of high pressure common rail system was established to study the influence of high‐pressure pipeline integration matching on the fuel injection characteristics of common rail system. The influence of common rail volume on pressure building and pressure fluctuation in common rail tubes was analyzed. The influence of common rail volume on the matching of fuel injection frequency (number of fuel injectors) and fuel supply frequency (number of plunger pumps) was studied by using the control variable method, and the basic optimal solution of the system was obtained. The influence of the common rail structure on the fuel flow characteristics of the system was also studied. The matching relationship between high pressure tubing and common rail system is studied by introducing dimensionless numbers such as length‐diameter ratio of pipeline. The results demonstrate that the increase of the storage space of the accumulator can effectively reduce the fluctuation in the system, so that the injection volume increases slowly and then decreases rapidly, with a slope of −5.70 × 10−3 mm3. The increase of the diameter of the common rail makes the fuel flow characteristics become good first and then bad, and the increase of the length of the common rail can soothe the pressure fluctuations. The increase of the diameter of the link tube (LT) makes the fuel injection volume of the injector increase first and then decrease. The optimal VR solution for the LT is 0.0249 and the optimal ratio of the length to diameter of a pipeline solution is 55.10. The structure of the distribution tube and its matching to the common rail have little effect on the fuel flow characteristics. When the diameter and length of the injection tube are too large, the influence on the injection pressure of the injector is negatively correlated.

Comprehensive wheel cylinder pressure estimation based on systematic hydraulic control unit model

Wheel cylinder pressure (WCP) is a crucial state for vehicles, directly influencing safety, comfort, and fuel economy. Serving as the foundation for sensor-less control and sensor redundancy, WCP estimation is a promising work for brake-by-wire systems (BBW). Nevertheless, WCP estimation is a challenging problem due to the nonlinear characteristics and intricate coupling within the hydraulic control unit (HCU). To enhance the performance of BBW, this paper proposes a comprehensive WCP estimation scheme based on the systematic HCU model. Component models including direct current (DC) motor pump and normally open valve (NOV) are established first. Considering the pulsation of the plunger pump, a modified nonlinear observer (MNO) is used to observe the angular speed of the DC motor. Inspired by the critical state, the linear pressure-drop relationship of NOV is analyzed and the NOV is simplified as a relief valve model expressed by algebraic equations. Dividing the HCU into the pump front part, pump rear part, and cylinder part, the systematic HCU model is then established, based on which, the comprehensive cause-based WCP estimation scheme is proposed. Next, simulations utilizing Amesim validate the angular speed estimator, while bench experiments prove the NOV model. Finally, vehicle tests under active and passive pressure regulating conditions are conducted. The results indicate the proposed scheme exhibits satisfactory performance while preserving computational efficiency.

Analysis of temperature characteristics of the plunger pair of the ceramic plunger pump for hemodialysis

Through the design of the ceramic plunger pump for hemodialysis, the mathematical model of the water film of the plunger pair of the ceramic plunger pump was built. The distribution characteristics of the speed and pressure of the water film of the plunger pair were analyzed, and the temperature distribution characteristics of the water film surface were obtained. The effects of inlet pressure, inlet temperature, rotational speed, and chamber temperature on the water film temperature of the plunger pair were studied. Experiments and analysis show that the closer the temperature of the plunger pair is to the inlet of purified water, the smaller the temperature change. The farther the ceramic plunger rod is from the inlet of purified water, the greater the temperature change, and the main influencing points are concentrated inside the plunger pair. Therefore, maintaining a certain amount of purified water temperature, pressure, and flow rate for lubrication is crucial for the service life of ceramic piston pumps.

基于虚拟现实技术的柱塞泵实践教学系统开发

基于虚拟现实技术的柱塞泵实践教学系统开发

Justification of structural technological solutions for the restoration of plunger pairs

The article explores the relationship of structural technological solutions to recover plunger pairs. The results studied are presented in graphical form. Equipment and devices were selected and developed for the conditions of repair factories and auto repair shops. The mini-technology of restoring high-pressure fuel pump plunger pairs was demonstrated. Fixtures were designed to allow manual sizing of plungers and bushings. For the mechanical finishing of plungers, a construction of a flat-finishing machine with high precision has been developed. Designs of devices for checking piston pairs of diesel cars have been developed. It was found that the hydrostatic properties of the restored plunger pairs meet the requirements imposed on them. A six-stage description of plunger pair restoration technologies and equipment is provided.

Analysis of the Manufacturability of the Design of the Crankshaft of the Plunger Pump NTP-175, Produced at PJSC “Izhneftemash”

Currently, mining and processing of minerals plays an important role in the economy of the country. In conditions of creating artificial economic problems for the supply of high-quality equipment, there is a high demand for inexpensive plunger pumps with suitable output characteristics and a sufficiently high resource. High-pressure pumps, which create high productivity, are urgently needed in mining, chemical, processing and other industries. Domestic enterprises have long been producing this type of product in the required quantity in mass production. But even a well-established and mastered structure in production must be constantly improved to improve operational performance. In all areas of application of high-performance pumps, an increase in specific characteristics is required, and of course, everyone expects an increase in the life of this equipment. An important factor in the choice of such equipment by the operating organization is the price. Production costs consist not only of initial capital investments for the purchase of pumping equipment, but also the cost of operation and repairs. In the mining industry, transportation costs associated with long distances to remote mining sites and repair or operating bases account for most of the increase in production costs. In this case, the less obvious specific characteristics of power and performance in relation to weight and dimensions provide huge advantages when transporting such equipment to the place of operation. Thus, the improvement of such a product as a pumping unit should follow all the laws of the development of technical systems with an increase in specific characteristics, and finally, a reduction in cost, which can be obtained only by improving the manufacturability of this design in the conditions of existing production. Only by improving the design can an increase in technology and an increase in specific characteristics be achieved simultaneously. This study describes the stages of design testing for the manufacturability of one of the key elements of a plunger pump mass-produced at the PJSC “Izhneftemash”.

OPTIMIZATION OF OPERATION MODES OF THE PLUNGER PUMP OF THE FORMATION PRESSURE MAINTENANCE SYSTEM

The efficiency of pumping equipment in the context of continuous growth in electricity prices is a priority for any oil and gas production department (OGPD). The pumping stations of the reservoir pressure maintenance system are the main consumers of electricity in the OGPD. The efficiency of pumping units, as a rule, is reduced primarily to the value of their efficiency, and the criterion for the efficiency of the injection system is usually the consumption of electrical energy per unit volume of pumped liquid. At the same time, they often focus only on maintaining high pump efficiency, which optimizes pump operation, but does not take into account the impact of collectors on electricity costs.Typically, the PPD pump station will inject service water into several directions. The purpose of the studies is to find optimal modes of pumping by pumps of a pump station in several directions, which ensure minimum electric power consumption for injection. The presented article presents the calculation of the cost of pumping by one plunger (volume) pump into two directions during laminar movement of liquid in the pipeline. Injection volumes for each area are specified. Three options are considered: separate injection in each direction (1), parallel injection in both directions simultaneously until the ordered volume is injected in one of the directions, after which this direction is blocked and injection in the other direction (2), and parallel injection in both directions simultaneously with «pressed» one direction, so that the injection of the ordered volumes is completed simultaneously (3).The performed calculations showed that the useful operation of the pump performed during simultaneous pumping of some volumes of liquid (modes 2 and 3) in two different directions of the same system is the same and significantly less compared to the operation of the pump performed to fill one of these directions during separate pumping (mode 1). The maximum effect is achieved with equal injection volumes in each direction and the same reservoirs. In this case, the useful operation of the pump for simultaneous injection (mode 2 and 3) is half as much as for separate injection (mode 1).

Attempts to Electrochemically Synthesize Palladium Superhydrides By High Pressure Method – Combination of Electrolytic Hydrogen Charging and Electroplating of Protective Coatings –

IntroductionIncited by the possibility of room-temperature superconductors in superhydrides, numerous them have been synthesized using a diamond anvil cell under high pressures up to several hundred GPa. Although palladium has widely researched for a long time as a prototype hydrogen-absorbing metal, the palladium superhydrides has not yet been obtained under such high pressures. A recent theorical calculation has predicted that the palladium superhydrides (e.g., PdH10) may be synthesized by combing electrolysis and high pressure1), but it is not certain whether it can be achieved. In this study, we attempted to synthesize the palladium superhydrides by using electrolytic hydrogen charging under high pressures, and subsequently applied protective coatings to suppress the hydrogen desorption from the palladium hydrides at ambient pressure.ExperimentalFigure shows a schematic illustration of the high-pressure apparatus. The high-pressure apparatus can apply the pressure of up to 400 MPa to the electrolyte in the electrolytic cell by pumping water into a sealed high-pressure vessel using a plunger pump and pressure multipliers. A cold-rolled palladium foil of 30 ~ 40 μm in thickness was used as a cathode, and a zinc plate was utilized as a soluble anode. Hydrogen was electrochemically loaded into the palladium foil at 0 V vs. Zn in an electrolyte consisting of 0.1 mol dm-3 sulfuric acid and 4.6 mmol dm-3 zinc sulfate under various pressures for 6 hours. Subsequently, the palladium foil was coated with the zinc film at constant current density 25 mA cm-2 for 120 seconds under the high pressure. The specimen was removed from the electrolytic cell in the high-pressure vessel at ambient pressure, and the hydrogen concentration of the palladium hydride PdH x was determined by thermal desorption spectroscopy. Structural analysis was conducted using X-ray diffraction and scanning electron microscopy.Results and discussionA number of bubbles were observed on the palladium foil surface during the electrolytic charging at ambient pressure. On the other hand, no bubbles were observed at 300 MPa. The zinc film with approximately 1.4 μm thick was coated on the PdH x surface after the electrolytic hydrogen charging. The hydrogen concentration of the PdH x was approximately x = 0.7 immediately after synthesis, which decreased to x = 0.2 without the zinc coating. On the other hand, the hydrogen concentration of the PdH x was maintained at least 1 week with the zinc coating. This result indicates that the zinc film acts as a barrier to hydrogen desorption from PdH x , and suggests that if the palladium superhydrides could be synthesized by electrolytic hydrogen charging under high pressure, it could be taken out to ambient pressure while maintaining its concentration.Reference1) W. Guan, R. J. Hemley, and V. Viswanathan, PNAS, 118, e2110470118 (2021) Figure 1

IMPROVEMENT OF THE OPERATION OF SUBMERSIBLE CONTAINERS OF DOWNHOLE UNITS FOR OIL PRODUCTION

The stable growth of oil production in the Russian Federation observed in recent years is characterized by commissioning of new fields and off-balance hydrocarbon reserves. In these conditions, occurrence of complications during operation of wells by mechanized method significantly increases the costs of enterprises and reduces the cost-effectiveness of oil production. The article presents statistical data on failures of submersible pumping units caused by complicated operating conditions. It is shown that one of the most widespread complicating factors is high corrosive activity of the well fluid and development of scaling that lead to failures of submersible pump units, reducing their operation time below the warranty period. It is indicated that out of the currently existing methods of preventing scale deposition and reducing the intensity of corrosion of downhole equipment in oil production the most technologically and economically feasible is the chemical method, which is realized through the use of inhibitors. Nowadays producers of oil and gas equipment produce in batch borehole containers for solid and encapsulated inhibitors. The main disadvantage of these submersible containers is uneven dosing of reagents into the wells. Experimental downhole submersible containers for liquid reagents are characterized by unstable and unreliable operation, complexity and high cost. The presence of significant disadvantages of experimental and commercially available submersible containers has necessitated the development of the most versatile, reliable and efficient products. The authors propose a design of a mechanized downhole submersible container equipped with a plunger pump and performing a uniform feeding of an inhibitor into a well.

Energy-Saving Testing System for a Coal Mine Emulsion Pump Using the Pressure Differential Flow Characteristics of Digital Relief Valves

Most energy-saving testing methods for plunger pumps use hydraulic motors. The loading test of coal mine emulsion pumps generally uses an overflow valve as the loading unit, which is characterized by high energy consumption. The coal mine emulsion pump uses emulsion as the transmission medium, and the viscosity and lubricity of the emulsion are much lower than those of hydraulic oil, which creates great difficulties in the development of high water-based hydraulic products. The nominal flow rate of the emulsion motor is much smaller than that of the emulsion pump, and there is no mature and reliable water-based flow control valve. Based on the above reasons, traditional energy-saving testing methods cannot be utilized for the testing process of emulsion pumps. The loading test of emulsion pumps generally uses an overflow valve as the loading unit, and during the testing process, all electrical energy is converted into internal energy, resulting in very high energy consumption. This article proposes an energy-saving testing system for emulsion pumps based on multiple emulsion motors in parallel. In order to solve the flow regulation problem of each parallel branch, a flow-intelligent control algorithm is proposed that utilizes the pressure difference flow characteristics of digital relief valves combined with artificial neural network predictive control. Firstly, the feasibility of the proposed system and method is theoretically verified through the analysis of the mathematical model of the digital relief valve. Secondly, further verification is carried out by establishing simulation and testing platforms. The simulation results show that the energy recovery efficiency of the system exceeds 53%. The experimental results show that the proposed testing system has a pressure control error of less than 1%, a flow control error of about 5%, and a maximum overshoot of about 9 L/min relative to the steady-state flow rate. The control accuracy and system stability are high.

Hydraulic-Pump Fault-Diagnosis Method Based on Mean Spectrogram Bar Graph of Voiceprint and ResNet-50 Model Transfer

The vibration signal of a pump is often used for analysis in the study of hydraulic-pump fault diagnosis methods. In this study, for the analysis, sound signals were used, which can be used to acquire data in a non-contact manner to expand the use scenarios of hydraulic-pump fault-diagnosis methods. First, the original data are denoised using complete ensemble empirical mode decomposition with adaptive noise and the minimum redundancy maximum relevance algorithm. Second, the noise-reduced data are plotted as mean spectrogram bar graphs, and the datasets are divided. Third, the training set graphs are input into the ResNet-50 network to train the base model for fault diagnosis. Fourth, all the layers of the base model are frozen, except for the fully connected and softmax layers, and the support set graphs are used to train the base model through transfer learning. Finally, a fault diagnosis model is obtained. The model is tested using data from two test pumps, resulting in accuracies of 86.1% and 90.8% and providing evidence for the effectiveness of the proposed method for diagnosing faults in hydraulic plunger pumps.

Exploring the effects of water content on friction behavior and mechanism of DLC films in oil production environment based on molecular dynamics simulation and first-principles calculations

To provide atomic-level insights for improving the service life of the Sucker Rod Production System (SRPS) in the harsh oil extraction environment, we attempted to investigate the friction and wear behavior of the FeFe model (conventional steel plunger pump barrel) and the DLC-Fe model (DLC-coated plunger pump barrel) in the oil extraction environment through molecular dynamics (MD) simulations and first-principles calculations. The results show that the interaction force between the conventional steel plunger and the light oil chain increases significantly as the crude oil moisture content increases. The shear strain of friction layer is intensified, severely limiting its wear resistance in the harsh oil extraction environment. Interestingly, due to the weaker interaction with the light oil chain, the plunger-pump barrel system coated with DLC films exhibited excellent frictional performance. Further studies showed that the passivation of C-suspension bonds on the films surface in the crude oil effectively improved the shear resistance of the DLC friction layer with the increase of water molecules. The related results provide a theoretical support for the practical engineering application of DLC film on the surface of oil well pump plunger.

Study of an Indirect Injection Diesel Engine Using Pure Coconut Oil, Pure Tamanu Oil and B-20 as Fuel for Smart Microgrid Applications. Part I: Laboratory Testing

Smart Microgrid (SMG) is a hybrid system based on renewable energy which can use biofuel, taking advantage of local resources, as one of its energy sources. This study was conducted to determine the effect of using pure tamanu oil and pure coconut oil on engine performance, emissions, as well as their effects on particular components before and after endurance testing. The experiments were done using a diesel engine at speeds of 2200 rpm. In this study, engine performance and emission tests were done before and after the accelerated endurance tests, with loads of 800 W to 4000 W. The dimensions of the fuel injector nozzle needle and plunger pump were also measured. The fuel performance and emissions results showed slight differences between, before, and after endurance testing. The emissions tests also showed that the two biofuels, especially tamanu, are cleaner than B-20 and have better dimensional measurement results, compared to B-20. Therefore, these biofuels are feasible for replacing B-20, as shown in laboratory testing

Fault detection of a reciprocating plunger pump with fault-free data based on an unsupervised feature encoder and minimum covariance determinant

It is well known that complex mechanical equipment has many differnt the failure modes, and monitoring data for fault conditions are scarce. Therefore, research on fault detection for reciprocating plunger pumps with fault-free data is significant for theory and application. Due to the lack of prior knowledge of faults, it is always a great challenge for researchers to extract fault features from signals. In this paper, an innovative fault detection method for a reciprocating plunger pump is proposed based on an unsupervised feature encoder (UFE) and minimum covariance determination (MCD). Firstly, a criterion based on mutual information maximization for local and global features is proposed for unsupervised feature extraction. In addition, an unsupervised training strategy based on negative sampling is proposed to train the encoder, so that the model can converge quickly and improve the stability of model training. A fault detection algorithm for a reciprocating plunger pump is proposed based on a UFE and MCD. Finally, the effectiveness and superiority of the proposed method are verified with the measured data for a reciprocating plunger pump. The results show that the proposed method can accurately detect the faults in the reciprocating plunger pump with a detection accuracy of more than 98%. Compared with other methods, the proposed fault detection algorithm has better applicability and accuracy for fault detection with fault-free data.

A Computational Fluid Dynamics Study for Simulation of the Unsteady State Two-Phase Flow in Vertical Separators and Plunger Pumps Simultaneously

A Computational Fluid Dynamics Study for Simulation of the Unsteady State Two-Phase Flow in Vertical Separators and Plunger Pumps Simultaneously

Analysis of the Thermal–Mechanical–Hydraulic Coordination Mechanism of a Constrained Piston Hydraulic Engine

By effectively integrating traditional engines with reciprocating plunger pumps, the constrained piston hydraulic engine can simultaneously output hydraulic energy and rotational mechanical energy, which effectively solves the problems of the complex structure, long power transmission chain, and low energy conversion efficiency of traditional power sources. Based on a certain single-cylinder diesel engine, a single-cylinder axial constrained piston hydraulic engine was designed, and its thermal–mechanical–liquid coordination mechanism was studied and analyzed in-depth. A mathematical model of the thermal–mechanical–liquid coupling working process of the single-cylinder axial hydraulic engine was established, and the conversion mechanism and output of the three types of energy, thermal, mechanical, and liquid, were simulated and analyzed. The results show that under the premise of improving the overall efficiency, the constrained piston hydraulic engine can effectively output mechanical–hydraulic dual-element power, and its combustion characteristics and output power performance indicators meet the expected design requirements. The maximum amplitude difference of the output hydraulic oil flow rate reaches 248 L/min, and the flow rate fluctuates greatly, so it is necessary to adopt methods to suppress the flow rate pulsation to ensure the reliability of the output flow rate.

A Method for Mathematical Modeling of Hydrodynamic Friction of Plunger Pairs with Consideration of Microgeometry

The fuel injection system heavily relies on the high-pressure fuel pump, which plays a critical role in its overall performance. The fuel pump plunger is subjected to high levels of stress and experiences irregular lubrication during dynamic loads, causing premature wear. In the industrial sector, laser surface micro-texturing has been utilized to reduce friction and enhance anti-wear properties, and its positive impact has been supported by both theoretical and experimental evidence. This article presents a method for determining the hydromechanical characteristics of plunger pairs under conditions of hydrodynamic friction. The microgeometry of friction surfaces was taken into account through the cavitation effect of the lubricating fluid, described by the modified Reynolds equation. Software was developed according to the proposed method. The developed software can be used to analyze the contacting surfaces of plunger pairs and evaluate their tribotechnical characteristics based on the microgeometry parameters of the friction surfaces. The article also discusses the impact of the microgeometry parameters on the quality criteria of the hydromechanical characteristics of the plunger pairs. Computational examples are given for the analysis of contacting surfaces of plunger pairs separated by a lubrication layer. The technical characteristics are evaluated depending on the parameters of the microgeometry of the roughness of the friction surfaces. The influence of the microgeometry parameters on the quality criteria of the hydromechanical characteristics of the plunger pairs is presented.