Study on erosion performance evaluation and law of high-pressure liquid-solid two-phase flow throttle valve

Study on the high-pressure hydrogen gas flow characteristics of the needle valve with different spool shapes

Evaluation and compensation of steady gas flow force on the high-pressure electro-pneumatic servo valve direct-driven by voice coil motor

Editorial: Software survey section

Numerical simulation of condensation flows of humid air in the high-pressure pneumatic pressure-reducing valve

In high-pressure gas field exploitation, wellhead fluids contain not only gas phases but also liquid water and solid particles; thus, the valve seat and core of high-pressure throttle valves are extremely susceptible to failure caused by complex fluid erosion, which seriously threatens gas field production and human safety. The historical development of erosion theory is surveyed initially, followed by a summary of current erosion theories, highlighting the limitations of single-theory formulations in modeling complex erosion processes. The erosion research framework for solid-laden fluids is subsequently described, comprising governing equations, turbulence models, calculation methods, particle behavior models, and erosion models. Besides, structural factors, flow conditions, solid particle properties, substrate properties, and interaction between erosion wear and corrosion influencing throttle valve erosion wear are summarized, clarifying the mechanisms and recent investigation findings of various factors. Following that, two research methods for erosion wear-experimental and numerical simulation methods, are introduced comprehensively. Finally, trends of future research on erosion wear in high-pressure throttle valves are predicted.

Characterization of high-pressure cavitating flow through a thick orifice plate in a pipe of constant cross section

The relief valve is an important control and overload protection component of the emulsion pumping station. Its performance will affect the overall performance of the emulsion pumping station and the stable and intelligent control of the working surface. However, the research on high pressure and large flow relief valve for mine emulsion pumping station is still inadequate. In order to meet the requirements of emulsion pump station for large flow sensitivity, stability, reliability, and remote intelligent control of overflow valve, this paper uses the digital control method to establish the mathematical model of the relief valve and uses the software such as AMESim to its dynamic characteristics. The simulation results show that the structural parameters such as spool quality, damping hole, and spring stiffness have an effect on the working characteristics of the relief valve. It also provides reference for the intelligent control research of the large flow relief valve for the emulsion pumping station.

Dynamic characteristics measurement of a novel high-pressure large-flow water hydraulic proportional flow valve driven by high-speed switching valves

The objective of the present study is to investigate the steam flow behavior through the high-pressure turbine bypass valve. Efforts have mainly been directed at investigating the process of steam flow and property variations aforementioned bypass valve as well as to obtain correlations between the flow rate and the valve opening ratio. Modeling of the high-pressure turbulent steam flow was performed on a three-dimensional non-staggered (co-located) grid system by employing the finite volume method and by solving the three-dimensional, turbulent, compressible Navier-Stokes, and energy equations. Through this research, numerous data have been acquired and analyzed. These efforts enable us to obtain a correlation data set for the flow rate coefficient as a function of valve opening. One of the significant accomplishments is to use the model presented here for further improve a design of a turbine bypass flow valve.

To realize the requirement of large-range linear adjustment of the mass flow rate for the large flow pneumatic system, a high-pressure air flow control valve is designed. On the premise of not affecting its flow capacity, the flow channel of the control valve is designed based on the principle of contraction-expansion nozzle, and the shape of the valve spool is designed. The numerical simulation is carried out by Fluent, and the shape and size of the internal flow channel of the control valve are optimized by response surface analysis so that under the condition of high pressure, high downstream and upstream pressure ratio, equal area of valve body inlet and valve seat throat, the flow velocity of 75 % opening valve port of flow control valve reaches sonic, and the flow state reaches the choking flow state, thus realizing the large-scale linear regulation of the flow control valve. The flow channel optimization design and simulation results in this paper can provide a reference for the optimization design of the same type of high-pressure air flow control valve.

The objective of the present study is to investigate the steam flow behavior through the high-pressure turbine bypass valve. Efforts have mainly been directed at investigating the process of steam flow and property variations aforementioned bypass valve as well as to obtain correlations between the flow rate and the valve opening ratio. Modeling of the high-pressure turbulent steam flow was performed on a three-dimensional non-staggered (co-located) grid system by employing the finite volume method and by solving the three-dimensional, turbulent, compressible Navier-Stokes, and energy equations. Through this research, numerous data have been acquired and analyzed. These efforts enable us to obtain a correlation data set for the flow rate coefficient as a function of valve opening. One of the significant accomplishments is to use the model presented here for further improve a design of a turbine bypass flow valve.

Design and Development of a Packed-bed Continuous Pneumatic Conveyor

Robust anti-disturbance control of a high-pressure electro-pneumatic servo valve directly driven by voice coil motor

Water has the disadvantages of low viscosity, poor lubrication, and easy leakage, which leads to many problems in water hydraulic flow control valves, such as low working pressure and large flow fluctuations. To address these issues, this paper proposes a novel digital flow control valve. The valve uses a linear stepper motor as the driving device. Compared to proportional electromagnets, the thrust and stroke of the linear stepper motor are larger, making the valve more suitable for high-pressure working conditions. Simultaneously, the valve innovatively incorporates a set of pilot valve spool strings at the front end of the pilot valve damping hole. Through controlling the two pilot valves to regulate the pressure difference before and after the damping hole, the flow passing through the pilot valve is maintained stable, thereby making the pressure of the upper chamber of the master valve spool more stable. In comparison to a single pilot valve structure, this design ensures a more stable main valve core position and reduces flow fluctuation. A mathematical and simulation model of the valve has been established, confirming the performance advantages of the new structure. The impact of structural parameters (such as valve core diameter, spring stiffness, and diameter of damping hole) on the stability of flow regulation has been investigated. A genetic algorithm has been employed to optimize the key parameters that influence valve flow stability, resulting in the identification of optimal parameters. The simulation results indicate that the optimized parameters lead to a reduction of approximately 45% in the maximum overshoot oscillation amplitude of the valve flow regulation. A prototype of the new flow control valve was developed, and a test system was established for conducting tests. The test results also confirmed the performance advantages of the valve and the accuracy of the optimal design.

The high-temperature fastening bolt of the high-pressure main steam valve of the steam turbine of 330MW unit in a thermal power plant breaks during operation. In this paper, the causes of bolt fracture are analyzed by means of macro morphology observation, fracture SEM detection, microstructure detection, mechanical property detection and chemical composition detection. The results show that during the long-term high-temperature service, the matrix structure of the fastening bolt of the high-pressure main throttle valve is aging and carbide particles are gradually precipitated. With the increase of operation time, the carbide particles continue to aggregate and grow up and distribute along the grain boundary, and a large number of creep holes and creep cracks are formed on the grain boundary. A large number of coarse carbides and creep cracks lead to the decline of mechanical properties of bolts, especially the deterioration of impact toughness and tensile strength; The accumulation of creep cracks becomes the crack source. Under the impact load formed during the action of high-pressure main throttle valve, the stress concentration part of the bottom of the first thread of the bolt external thread cracks, and the cracks continue to expand, resulting in the brittle fracture of the bolt.