Plunger Pump Research Articles

Узел трения-скольжения головки шатуна плунжерного насоса высокого давления с применением самосмазывающегося подшипника из порошкового антифрикционного материала

Узел трения-скольжения головки шатуна плунжерного насоса высокого давления с применением самосмазывающегося подшипника из порошкового антифрикционного материала

Experimental Study on Fracture Failure of BRW 250 Pump Liquid Valve Mechanical Spring Surface

In this paper, the singularity analysis method based on the continuous wave for the vibration signal of the plunger pump liquid valve under different conditions was studied, and the LMS based weighted least square method with good robustness and validity was proposed to calculate the LPZ index, which was the judgment criterion for fault of liquid valve mechanical spring. Fault diagnostic test results showed that the method could overcome the singularity of the binary discrete wave in the detection and quantitative accuracy problem, realize the accurate positioning of the singular point in the signal, identify the liquid valve disc in the spring break state to the liquid valve seat or lift limit the impact of the moment, and determine the fault of the liquid valve mechanical spring effectively.

Exergy and performance analysis of a CI engine fuelled with HCNG gaseous fuel enriched biodiesel

Soybean oil based fatty acid methyl ester (FAME) is produced and blended with diesel fuel at 25% volumetric ratio. Besides, pure hydrogen (H2) and compressed natural gas (CNG) mixture named HCNG fuel is used with 20 litres per minute (L/min) volumetric flow rates. The amount of liquid fuel injected into the cylinders is reduced by 30% via fuel pump plunger pin without structural changes on the diesel engine. Instead of the reduced liquid fuel, 20% hydrogen with 80% CNG gaseous fuel mixture (by volumes) are supplied by using mixing chamber before intake manifold of the test engine. Brake power, brake torque and brake specific fuel consumption and also thermal efficiencies are presented under performance outputs subsection. Results were compared and discussed. Additionally, exergy analysis of control volume has been performed. Using HCNG fuel enriched biodiesel effects on performance and energy efficiency are examined. Therefore comparison between diesel operation and alternative fuel usage is evaluated.

Analysis of Operating Conditions of Sliding Friction Units of Driving System of High-Pressure Oil and Gas Well Service Plunger Pumps

The characteristic parameters for evaluating the efficiency of working surfaces of sliding friction units and calculating their operating conditions are the speed of movement of the mated surfaces relative to each other and the loads on them. To determine them by analytical methods, kinematic and force studies of the crank mechanism of the driving system were carried out with reference to a chosen typical representative of this group of pumps. The proposed method can be used to obtain initial approximate data that are adequate for further structural analysis and designing of these friction units.

A Study of the Mechanism of Separation in a Multi-Cup Downhole Gas-Oil Separator

A mathematical model (numerical simulation) of gas-oil flow in a multi-cup downhole gas-oil separator is proposed. The model takes into account the Gibbs wave equation to obtain the pump plunger velocity and the population balance model (PBM) for describing bubble aggregation and breakage. The gas-oil flow field distribution and the bubble behavior in the multi-cup gas-oil separator were simulated using computational fluid dynamics (CFD). The numerical simulation results showed that the main role of gas-oil flow distribution in the process of oil separation from the separator cup wall is the viscous effect. Small bubbles in the center tube aggregate into large bubbles, and interaction of the bubbles along the flow and the fluid running down the cup wall forms a clockwise spiral, which accelerates separation of the gas and oil phases in the separator cup. During the upstroke, the oil volume being sucked out by the center tube through the small hole is larger than the oil volume in the separator cup, which causes entry of air into the center tube and failure of the separator cup.

The Research of Reliability Test Platform for Plunger Pump in Profiling Buoy

The Research of Reliability Test Platform for Plunger Pump in Profiling Buoy

Study on the diaphragm fracture in a diaphragm compressor for a hydrogen refueling station

When a diaphragm compressor applied in the hydrogen refueling stations, the diaphragm fracture occurred frequently in the edge and middle region of the outer circular groove of the perforated plate. The unstable operation of the plunger pump caused the oil shortage in the oil cylinder, so the diaphragm would cling to the perforated plate while the piston reached the bottom dead center. Thus, the diaphragm in the groove region would endure the radial stress caused by the large deflection deformation and the additional stress caused by the perforated plate's groove. In this paper, a theoretical calculation method combined with the thin-plate large deflection theory and the thin-plate small deflection theory was proposed to analyze the two kinds of the radial stresses. The experimental and numerical methods also were conducted for mutual verification. Furthermore, the influencing factors of the diaphragm radial stress were investigated, including the radius of the groove fillet, the groove width and the diaphragm thickness. The results indicated that the radial stress caused by the large deflection deformation is similar to that caused by the small deflection deformation. The maximum radial stress of the diaphragm increased slowly with the increase in the radius of the groove fillet. But with increasing the diaphragm thickness or decreasing the groove width, both the deflection and the radial stress of the diaphragm had an obviously decrease.

The Tribological Behaviors of Different Mass Ratio Al2O3-TiO2 Coatings in Water Lubrication Sliding against Si3N4

ABSTRACTThe tribopairs of water hydraulic plunger pumps are usually operated under severe conditions, due to the poor lubrication of water and silt suspended in natural water. It is essential to identify the desired engineering materials and material combinations for designing water pumps. As the candidate materials of tribopairs, the tribological characteristics of different Al2O3-TiO2 coatings combined with Si3N4 ceramics under silt-laden water and tap water lubrication were investigated. The Al2O3-TiO2 coatings with different weight percentages of TiO2 in a wide range from 3 to 100% were tested. The tribological characteristics of the various couple pairs were researched using a ring-on-ring test rig. The microstructures of the contact surfaces were analyzed with a scanning electron microscope before and after the test to study the wear mechanism. The experimental results indicate that the friction coefficient of the Al2O3-TiO2/Si3N4 tribopairs increases with an increase in the percentage of TiO2 content in the Al2O3-TiO2 coating. However, the TiO2 content does not present a clear relationship with the wear rate. Considering the friction and wear properties, Al2O3-13%TiO2 is the preferred coating to use in water hydraulic pumps when sliding against Si3N4.

Effect of using Hydroxy – CNG fuel mixtures in a non-modified diesel engine by substitution of diesel fuel

In this experimental study, Hydroxy (HHO; Oxy-hydrogen) – CNG (Compressed Natural Gas) fuel mixtures were used as an additional fuels in a non-modified diesel engine via intake manifold by substitution of diesel fuel. Three cases of experiment performed in a 3.6 L, four cylinders, four stroke diesel engine; first case is non-substitute liquid fuel, neat diesel operation; second case is HHO (5.1 lpm) addition to air mixture and operated under substituted diesel engine and third case is 25HHO-CNG mixture (25% Hydroxy-75% CNG-(5.1–15.3 lpm)) inducted the intake manifold and running with substituted diesel engine. During the tests stepping motor and driver used on fuel pump plunger to substitute diesel fuel as similar to pilot diesel injection. The effects of HHO and HHOCNG fuels relative to neat diesel operations were investigated in between 1200 and 2600 rpm engine speeds and expressed on both engine performance values like; brake torque, brake power, brake specific fuel consumption and brake thermal efficiency; and exhaust emissions; NOx, CO2, CO and exhaust gas temperature (EGT). Results showed that the addition of HHO-CNG mixture is most effective in improving the engine performance and providing more environmentally friendly attitude on exhaust emissions compared to neat diesel operations.

Incremental supervised locally linear embedding for machinery fault diagnosis

Locally linear embedding (LLE) is a promising algorithm for machinery fault diagnosis, but LLE operates in a batch mode and lacks discriminant information, which lead to be negative for fault diagnosis. In this paper, incremental supervised LLE (I-SLLE) is investigated for submersible plunger pump fault diagnosis. In the I-SLLE algorithm, block matrix decomposition technology is introduced to deal with out-of-sample data, while a part of old low-dimensional coordinates is also updated, upon which an iterative method is presented to update all the data for refining the accuracy. Furthermore, in order to improve the classification capability of LLE, discriminant information is assembled in the cost function of LLE. Based on I-SLLE, a new machinery fault diagnosis method is proposed. At first, I-SLLE is utilized to extract the feature of an original dataset, and then support vector machine (SVM) is employed to classify the test data in the feature space. Experiments on synthetic datasets as well as real world datasets are performed, demonstrating the efficiency and the accuracy of the proposed algorithm.

LLE for submersible plunger pump fault diagnosis via joint wavelet and SVD approach

Locally linear embedding (LLE) is a classical non-linear dimension reduction algorithm. LLE can deal with a nonlinear dataset and extract the significant feature from the dataset. However, LLE may fail, when signal is non-stationary or contains strong noise. In this paper, wavelet transformation, singular value decomposition (SVD), and LLE are assembled to extract the feature of a dataset based on which a new fault diagnosis method is developed for submersible plunger pump fault recognition. First, each sample is preprocessed by wavelet transformation and SVD, upon which a new feature space is constructed; then, LLE is utilized to reduce the dimensions of the feature space; finally, support vector machines (SVM) is invoked to recognize the device status. The experiments performed on submersible plunger pump dataset and bearing dataset demonstrate that the proposed method is effective and can achieve a high diagnosis accuracy.

Development and Application of the Downhole Drilling String Shock-Absorption and Hydraulic Supercharging Device

It is a hot topic for deep/ultradeep wells to improve rock-breaking efficiency and drilling speed by available downhole energy. Based on different downhole energies and working conditions, specialized plunger pump is proposed to convert longitudinal vibration of drilling string into rock-breaking energy. Technical design is developed to generate high-pressure water jet. And then a simulation model is built to verify feasibility of the technical design. Through simulation, the influence law of key factors is obtained. On this basis, this device is tested in several wells. The result indicates this device can increase drilling speed as much as 136%. Meanwhile the harmful vibration can be absorbed. The energy from drilling string vibration is of high frequency and increases as well depth and formation anisotropy increase. By reducing adverse vibration, this device is able to increase the drilling speed and the service life also meets the demand of field application. The longest working time lasts for more than 130 hours. The performance of this device demonstrates great application prospect in deep/ultradeep resources exploration. To provide more equipment support for deep/ultradeep wells, more effort should be put into fundamental study on downhole drill string vibration and related equipment.

水压作用对裂隙岩体断裂行为影响研究

为研究在地应力场与水压耦合作用下裂隙岩石破坏特性，利用MTS815岩石力学测试系统，并结合柱塞泵水压加载装置，对含有预制裂隙的混凝土试样加载预应力后，进行有无水压作用单轴循环加卸载压缩破坏对比试验。试验结果表明：有水压作用的试件在加载初期便出现初始裂隙，而无水压时试件往往在塑性区或接近塑性区时出现初始裂隙，两者的破坏模式也不相同，在有水压作用时，试件是由于水压引起的表面裂纹扩展而导致破坏，而无水压时则是因为试件内部损伤微裂隙扩展引起的失稳破坏；然而两种条件下的试件强度相差不大，但其破坏过程中产生的耗散能却高于后者。 In order to study the failure characteristics of rocks under coupling effect of ground stress field and seepage field, MTS815 rock mechanics test system combined with plunger pump hydraulic loading device are used to load water pressures on concrete samples containing precast crack. After that, uniaxial cyclic loading and unloading compression failure contrast experiments are conducted with the seepage field and without the seepage field. The results show that: specimens with the seepage field present initial crack at the initial stage of loading, but species without seepage field present initial crack always in plastic zone or close to plastic zone. The failure mode under both conditions is not the same. The failure is caused by surface crack expand under the water pressure effects, and without water pressure it is caused by the internal damage and micro cracks extend. The strength under the two kinds of conditions is equivalent, while the dissipated energy in the process of failure is higher than those without seepage field.

Vibration Modes and the Dynamic Behaviour of a Hydraulic Plunger Pump

Mechanical vibrations and flow fluctuation give rise to complex interactive vibration mechanisms in hydraulic pumps. The working conditions for a hydraulic pump are therefore required to be improved in the design stage or as early as possible. Considering the structural features, parameters, and operating environment of a hydraulic plunger pump, the vibration modes for two-degree-of-freedom system were established by using vibration theory and hydraulic technology. Afterwards, the analytical form of the natural frequency and the numerical solution of the steady-state response were deduced for a hydraulic plunger pump. Then, a method for the vibration analysis of a hydraulic pump was proposed. Finally, the dynamic responses of a hydraulic plunger pump are obtained through numerical simulation.

Surface Integrity Evaluation of Brass CW614N after Impact of Acoustically Excited Pulsating Water Jet

Presented article is focused on surface integrity evaluation of brass CW614N form the sight of surface topography, structural changes in surface layers and strengthening character in subsurface layers after impact of acoustically excited pulsating water jet (PWJ). Surface topography was evaluated using optical profilometry. Structural changes in subsurface layer were observed based on mass material removal Δm [mg/s] and maximal depth of penetrance of PWJ hmax [mm]. Nano indentation measurement according to Berkovich were used to examination of strengthening character in subsurface layer. Disintegration of experimental samples was performed under constant technological conditions: hydraulic power of plunger pump Ph = 19kW; round nozzle diameter d = 1.6mm; feed speed rate v = 0.75mm/s; pressure of plunger pump p = 38MPa, stand-off distance of nozzle from target material z = 45mm; ultrasound frequency f = 20.29kHz and as variable factor was set power of ultrasound P on values 340, 360 and 380W. In terms of surface topography experimental investigation proved that PWJ under selected conditions is not suitable for precision machining. Evaluation of the surface characteristics indicates that the chemical composition has a significant effect on material weight loss Δm [mg/s] and a maximum depth of penetration of PWJ hmax [mm]. Evaluation of characteristics of subsurface layer was observed strengthened area with lower elasticity.

Improvement of Surface Roughness with Micro-Axial Vibration of Spindle by Pressure Pulsation of Grinding Fluid Supplied through inside of Wheel

In grinding, the moving trajectories of abrasive grains are almost straight to the motion of the rotation and feed of the grinding wheel, so that grinding marks are formed continuously. As a result, surface roughness is dependent on grain size and organization of the grinding wheel. If the trajectory of the abrasive grain is wavy, the peak lines of the grinding marks will be partially removed by following the abrasive grain. This improves surface roughness. The objective of this study is to develop a mechanism to give axial vibration to the grinding wheel by the pulsation of the plunger pump, and thus to improve the surface roughness of the machined surface.

Optimum IMFs Selection Based Envelope Analysis of Bearing Fault Diagnosis in Plunger Pump

As the plunger pump always works in a complicated environment and the hydraulic cycle has an intrinsic fluid-structure interaction character, the fault information is submerged in the noise and the disturbance impact signals. For the fault diagnosis of the bearings in plunger pump, an optimum intrinsic mode functions (IMFs) selection based envelope analysis was proposed. Firstly, the Wigner-Ville distribution was calculated for the acquired vibration signals, and the resonance frequency brought on by fault was obtained. Secondly, the empirical mode decomposition (EMD) was employed for the vibration signal, and the optimum IMFs and the filter bandwidth were selected according to the Wigner-Ville distribution. Finally, the envelope analysis was utilized for the selected IMFs filtered by the band pass filter, and the fault type was recognized by compared with the bearing character frequencies. For the two modes, inner race fault and compound fault in the inner race and roller of rolling element bearing in plunger pump, the experiments show that a promising result is achieved.

How Giraffes Drink

Giraffes face unique challenges for drinking due to their long necks. In this article we use evidence from videos, size estimates, and elementary fluid mechanics to make a strong case for a plunger pump mechanism moving water up from their lips to their shoulders.

Mathematical Modeling of Fuel System with Respect to Reliability

authors have considered here helps to transfer the fuel from the fuel tank to the engine and regulate its flow into the cylinder depending on speed and local requirement. Here, a multi-component fuel system in diesel engine, comprised two subsystems 1 and 2 in series has been considered. In this system the fuel is injected into the cylinder using an injection pump and injectors. The block diagram depicts the fuel system in an N-cylinder diesel engine. The diesel fuel from the tank is pump to the fuel injection device. This device consists of small plunger pumps operating to push the fuel through the injectors (nozzles) into the cylinders one can operated one pump from the fuel injection pumps at the appropriate time i.e., towards the end of the compression stroke the fuel is pushed through the small hole in the injector and is atomized as it enters into the cylinder.

Improvement of Surface Roughness with Micro-Axial Vibration of Spindle by Pressure Pulsation of Grinding Fluid Supplied through inside of Wheel

In grinding, the moving trajectories of abrasive grains are almost straight to the motion of the rotation and feed of the grinding wheel, so that grinding marks are formed continuously. As a result, surface roughness is dependent on grain size and organization of the grinding wheel. If the trajectory of the abrasive grain is wavy, the peak lines of the grinding marks will be partially removed by following the abrasive grain. This improves surface roughness. The objective of this study is to develop a mechanism to give axial vibration to the grinding wheel by the pulsation of the plunger pump, and thus to improve the surface roughness of the machined surface.