Research and Analysis of the Hysteresis Characteristics of a Large Flow Directional Valve

Abstract

The 1000 L/min large flow hydraulic system for the hydraulic support used in a coal mine is currently a topic of great interest. The large flow directional valve is a key component for hydraulic systems, so the design of the 1000 L/min large flow directional valve is essential. The designed single-channel valve shows serious hysteresis characteristics in a 1000 L/min large flow condition, but it does not happen in a 16 L/ min small flow condition. Based on this phenomenon, the computational fluid dynamics (CFD) technology was used to simulate the flow in the valve. It was discovered that the single-channel caused unbalanced pressure in the annular region and on the surface of the valve spool, so the valve spool is subjected to great radial unbalanced force. Then a double-channel valve was designed to improve the pressure distribution. The simulated radial unbalanced force on the double-channel valve is 67.2% lower than that of the single-channel valve. The experimental results showed that the hysteresis characteristics also disappeared under the 1000 L/min large flow condition. Therefore, the conclusion can be drawn that the hysteresis characteristics of the single-channel valve is due to the radial unbalanced force caused by the unsymmetrical flow field. The results show that the maximum radial unbalanced force the valve spool can withstand is 170 N. Furthermore, symmetrical flow passages have to be taken into account in large flow conditions. This paper provides valuable references for the design of large flow valves.

Design, failure analysis, and optimization of a high-flow water valve: A case study

“…In a previous study, 25 a symmetrical dual-channel structure was proposed for a 1000-L/min valve by the author to reduce the additional imbalanced force on the valve spool. The imbalanced force decreased by 67.2% at 1000 L/min.…”

Pressure Loss Reduction in an Innovative Directional Poppet Control Valve

“…Based on geometrical complexity of flow channels, relatively high Reynolds number value and a general assumption that the flow is considered over the entire cross section of the channels, the Standard k − ε model was used in the research. This model was also used in similar research on the flow through control valves [8,14,23,27].…”

“…Zhou used a two-dimensional approach on an axisymmetric fluid model, pointing out that it is widely utilized in the research related to hydraulic applications due to its relatively low computational requirements and convenience to apply. Similarly, Sapra et al [11] used the CFD method to obtain flow characteristics of a large cone element, Ferreira et al studied a ball valve behaviour [12], Brunone and Morelli [13] tested automatic control valves (ACV), while Liao et al [14] carried out analysis of a large flow directional valve hysteresis. Recent studies include In addition to the CFD method, analyzes of hydraulic spool valve characteristics were also performed using different methods as particle image velocimetry [15] and various simulation environments such as Matlab-Simulink [16][17][18][19], SimScape [20] and AMESim [21,22].…”

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“…Compared with oil hydraulic systems, water hydraulic systems could be a good solution for the environmental and safety problems [1]. Water hydraulic systems are widely used in steel and glass production, ocean exploration, food and medicine processing, and coal mining [2] to [4]. The water hydraulic control valve is one of the most important components of hydraulic systems, and its dynamic performance has an important impact on the performance of hydraulic systems [5].…”