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The plunger valve has an important role in a large compressor system as its operating characteristics directly affect the aerodynamic boundary condition of the compressor equipment. In this study, dynamic modeling and analysis method of the plunger valve are proposed for an accurate control of the system. By considering the interaction between the dynamic flow in the valve and actuator action, a lumped parameter model for the fluid–structure interaction force and multibody dynamic model of the actuator are developed based on intrinsic correlation parameters. A combination analysis to simultaneously predict valve flow and actuator dynamic characteristics is proposed. The predicted results are in a good agreement with experimental data, which validates the proposed model and analysis method. The analysis results show that the coupling effect between the valve flow and actuator is significant and has an important role in valve control, particularly when the valve opening is smaller. Compared to the experimental data and computational fluid dynamics results, the presented methods are accurate for valve control and effective for prediction of flow rate.

In this study, a plunger and injection nozzle were designed to improve the injector used in multi-point injection NGV engines. The purpose of this study is to analyze the pressure and velocity characteristics of the injector plunger and show mass flow rate trends for the gas injected from the nozzle. Using the ANSYS program, a new injector was modeled according to applicable design variables, and the gas flow into the plunger was visualized. In addition, methane fuel was used in the simulation, and the inlet and outlet of the injector were applied with 8 bars pressure and opening conditions. As a result, in the model with a 1.2 mm inner diameter plunger valve, the mass flow rate of gas injected from the injection nozzle was stable from 0.075 mm to 0.2 mm, and it was possible to reduce the velocity variation and pressure generated inside the plunger.

When designing motorcycle engine, engine cylinder head abnormal noise is common, and difficult to eliminate due to thermal expansion and contraction of the aluminum alloy cylinder head. In this study, on the basis of dynamic change with the performance of 157FMI engine in hot and cold, the reasons for engine cylinder head abnormal noise are analysed, and valve plunger with variable length is applied to minimize the valve clearance, and to make the valve clearance of engine in cold and hot zero, and thus the noise problem of cylinder head with 157FMI engine in hot is completely eliminated.

In order to study the effect of fuel leakage of an ultra-high pressure common rail injector control valve coupling on fuel injection performance, a simulation model was established by AMESim and the accuracy was verified by fuel injection test data. The leakage law of couples with different clearances was analyzed by using numerical simulation method and then the influence of control valve coupling on fuel injection performance was analyzed. The results demonstrate that the increase of the matching clearance of the slide valve coupling makes the start time of needle valve advanced and delay its end time. The injection rate and injection duration increase with the increase of the matching clearance of slide valve coupling. The increase of the matching clearance of the control plunger coupling keeps the start time of the needle valve unchanged at first, and then delay slightly, while the end time remains unchanged at first, and then show the trend of advance. The injection rate and injection duration decrease with the increase of the matching clearance of plunger coupling.

In order to develop a new electro-hydraulic vibration device with higher efficiency, a digital pump-controlled electro-hydraulic vibration cylinder was proposed based on the closed-loop hydraulic system, and its mathematical model was derived. The virtual prototype model of closed-loop plunger pump-controlled electro-hydraulic vibration cylinder was established and numerically solved and simulated. The numerical calculation results and simulation results were basically consistent. The motion characteristics, closed-loop flow characteristics, vibration waveform characteristics and oil replenishment system characteristics of virtual prototype under mechanical–electrical -hydraulic coupling were studied. The results showed that increasing the inclined angle of swashplate will obviously increase the flow pulsation of the system. Changing the transmission shaft speed (or vibration period) and the inclined angle of swashplate can accurately adjust the vibration frequency and vibration amplitude. Too large or too small flow rate of oil replenishment system will cause vertical offset of vibration waveform, but it has little influence on waveform amplitude, and oil replenishment pressure has little influence on vibration waveform. The electro-hydraulic vibration cylinder based on closed-loop hydraulic system has higher fluid power transmission efficiency. The virtual prototype model can comprehensively predict the performance of the system, verify the feasibility of the scheme, and reduce the cost of experiment and research for further development of physical prototype.

Internal curve motors (ICMs) are used in construction and port machinery owing to their low speed and strong torque. The internal leakage of an ICM has a direct impact on its working performance; however, research on the internal leakage of ICMs is unclear. A method, based on the Computational Fluid Dynamics (CFD) transient simulation of an ICM, for obtaining the transient pressure in the plunger chamber and combining the mathematical model of internal leakage is calculated, and the internal leakage is proposed. We one-factor analyzed the internal leakage of the ICM and the effect of the valve pair and plunger pair leakage, and conducted multifactor analysis on the effect of the interaction between those two factors on the internal leakage of the ICM. The results show that the internal leakage mechanisms affecting the ICM were, in descending order of impact, the inlet pressure, oil temperature, and rotational speed, and a significant interaction existed between the inlet pressure and oil temperature, whereas the influence of rotational speed was not significant.

With the rapid development of material science and manufacturing capabilities, hydraulic technology is increasingly high-pressure, lightweight and miniaturizing. Micro plunger pump is widely used in the field of deep-sea hydraulic equipment and advanced intelligent hydraulic equipment, owing to its high-power density, high output pressure and many other advantages. Its broad application aims to examine the inlet and outlet distribution valve spring parameters change on the micro high-pressure plunger pump volumetric efficiency, by changing the inlet and outlet distribution valve. This paper is based on the simulation of AMESim engineering software to derive multiple sets of data. It compared and analysed the specific effect of different spring stiffness and opening pressure on the volumetric efficiency of the micro high-pressure plunger pump which was then verified through experiment. Results of this study have certain reference significance for the design of the spring of the inlet and outlet distribution valve of the micro high-pressure plunger pump, which facilitates the optimization and improvement of the dynamic performance of the micro high-pressure plunger pump.

The technology for stepper drive that can achieve accurate motion in the hydraulic field has always been urgently needed in the industry. This paper proposes a hydraulic stepper drive based on five high speed on/off valves and two miniature plunger cylinders. The stepper drive discretizes the continuous flow medium into fixed small steps through the miniature plunger cylinder and realizes the state control of the drive through the logic action of the high speed on/off valve. This paper improves the current stepper drive and establishes a mathematical model to analyze the error of the drive and calculate the position of the actuator. In addition, through simulation research, the performance parameters such as the single-step step characteristic and pressure characteristic of the stepper drive are studied. The results show that, compared with the technology of current stepper drive, this stepper drive can effectively remove the “post step” phenomenon, greatly improve the stepper accuracy of the stepper drive, and have a more excellent performance.

In intermittent gas lift (IGL), not all the liquid initially in the tubing is usually produced at the surface in one cycle. This is due to a concept known as fallback, which occurs when some amount of the initial liquid column drops back to join the next slug. We conducted a review of earlier works on IGL and the behavior of the fallback factor. The dependence on the fallback factor on the operational conditions such as slug velocity, valve opening pressure, valve closing pressure, casing–tubing pressure ratio, diameter of tubing, and amount of gas injected during IGL are discussed in this paper. The effect on the shape and stability of the nose of the Taylor bubble on the lifting efficiency of the bubble is also explained. In trying to reduce the fallback factor per cycle, there have been recommendations to combine gas lift with plunger lift. We also present the results of this combination and the effects on the fallback factor in gas-assisted plunger lift (GAPL). More light is shed on the behavior of the velocity of the liquid slug and how it affects the fallback factor during IGL. The behavior of the fallback factor with an increase or decrease in plunger velocity during GAPL is also presented in this paper. This review is categorized into experimental and numerical studies on fallback factor to evaluate their impact on production efficiency in IGL and GAPL. Additionally, different formulas for fallback proposed by different literature are compiled.

An anti-lock braking system (ABS) is an anti-skid braking system commonly used as a safety feature in vehicles. The hydraulic control unit for the ABS of a vehicle includes a plunger pump between the wheel and master cylinder. This paper presents numerical investigations of the effect of valve shapes on the performance improvement provided by a plunger pump, focusing on two different valve shapes, ball-type and hat-type. Transient laminar flow analyses of plunger pumps with ball and hat-type inlet valves are performed under motor speeds from 1000 to 5000 rpm using the fluid-structure interaction (FSI) and user-defined function (UDF) techniques. An experimental verification of the simulation results for the plunger pump with a ball-type valve was conducted using the standard pump test of the Mando Corporation, South Korea. A comparison of the simulation and experimental results suggests that these are in good agreement. The simulation results indicate that the hat-type valve outperforms the ball-type valve due to a shorter delay in the closing time at the end of the suction cycle. These findings suggest that valve shape has a considerable impact on the performance improvement provided by a plunger pump, providing crucial insights into the future design of high-efficiency pumps.