Simulation Study On The Flow And Fluid-solid Coupling Characteristics Of The High Pressure Differential Labyrinth Valve

Control valve is one general-purpose equipment, which is applied to industrial automation control field, such as aerospace, petroleum electric power, national defense construction, pipeline transportation and so on. Its major function is to regulate and control pressure, flow rate and temperature of fluid.etc. via altering the valve stroke. In recent years, the control valve has to face some higher requirement as high temperature, high pressure drop, low noise and anti-cavitation.etc. during the rapid development of large-scale, automation, informatization of modern industry. Moreover, the requirement of high pressure drop valve is no longer confined to safety and reliability, but high energy saving, accuracy and sensitivity. The Labyrinth valve is more and more used in power station, petroleum and chemical industry as one multi-stage pressure reduction valve on account of high pressure reduction, low noise,reasonable safety and service life. However, the research to labyrinth valve started obvious late in domestic, most of manufacturers is relying on introducing or copying foreign products. The lack of experience on theoretical researching and hydraulic testing is not to only cause that the performance, accuracy and safety of this valve will not meet the requirement of service line, but also to restrict its sustainable research, development and optimization. Hence, in this article, flow characters and fluid-solid coupling features of the fluid inside the labyrinth valve will be analyzed and researched from the view of hydraulic power and fluid-solid coupling, with the following contents:① Description of the rapid development of industrial control field and the new requirement of control valve, which introduces the history, current situation and development of control valve, emphasizes on the origin, development and structural features of control valve, the domestic and foreign research status of fluid, structure and fluid-solid coupling field. It lays the foundation for understanding and mastering the theory and research direction of labyrinth valve.② This article introduces floating control equation, turbulence model, control principle and attentions of discrete and solving in computational domain for the usage of finite element method realizing simulated analysis of structure, flowing and fluid-solid coupling. Meanwhile, it also introduces the strength check principle, the type and calculation mode of fluid-solid coupling, which is the strong theoretical support for research.③ The modeling of three-dimensional geometry for labyrinth valve. The similarity of geometric and actual model has the significant influence on simulation based on the geometric model. In order to simulate more realistically and optimize more easily, the parameterized valve geometric model will be built via three-dimensional software. And remove in reverse to create fluid domain geometric model.④ As the high safety requirement of valve in service line and high pressure and complex stress conditions, it computes the stress, strain and shift of any point via finite element method to achieve scientific and safe strength check, which supplies reference to optimize valve and improve safety.⑤ The research of fluid flow characteristics inside High pressure drop labyrinth valve. It includes the two aspects: a. Flow characteristics through the flow path. Combining the computing fluid dynamics and experiment is to discuss the impaction on flow characteristics, especially flow resistance from the pressure reduction level, curve type, width of axial and radial direction and depth of flow path.etc., and analyze the internal reason. b. Flow characteristics in the valve body. Regard the water under ambient temperature as the fluid with confirmation of the type and structure of flow path, combining the computing fluid dynamics and experiment is to discuss the impaction on flow coefficient and characteristics from the value and distribution of the velocity, pressure and temperature, and quantity and distribution of labyrinth flow path under the different pressure drop.⑥ The research of liquid-solid coupling. The labyrinth valve is always used in the service line under high pressure and high pressure drop, and its flow path is smaller, so the high pressure will impact on the structure parameters if the flow coefficient and accuracy is higher, and then the impaction on flow coefficient and accuracy must be considered. This article takes into account the dual-coupling of liquid and solid, and combines the fluid mechanics and solid mechanics to research the coupling features, and supplies the realistic testing data for high-precise regulation, which can be to the benefit of precise structure analysis and improve the safety performance of labyrinth valve.