Valve Flow Field Simulation And Dynamic Analysis

With the rapid development of coal mining efficiency face, the hydraulic support also gradually toward big mining height, the diameter of the cylinder direction. Safety valve as a key component in the hydraulic support control system to maintain safety and effectively operation of the entire Hydraulic support system. So for design of safe, durable and big flow safety valve has been the focus of today’s scientific research, In this paper, the FAD125/50safety valve for the study object conducted a comprehensive study.This paper introduced the safety valve internal structure, working principle and the safety valve spool by the steady-state flow force and the total force carried out a theoretical analysis and simulation. While taking advantage of the dynamic characteristic simulation software AMEsim established the safety valve of the simulation model and control system in the whole hydraulic support in the process of overflow, and carry out a detailed analysis of the dynamic characteristics of the safety valve in the actual work process, Introduces the structure of the different dimensions of the safety valve the influence of dynamic performance, draw a conclusion that increase the number of overflow port is in favor of the safety valve rapidly overflow. Using CAXA software established the safety valve2d simulation model, and by using fluid dynamics analysis software FLUENT front processor GAMBIT for grid division, simulate the safety valve internal flow channel in the process of overflow. Comparative analysis of the safety valve in the opening degree different, import and export the same pressure and opening degree of the same, import and export of pressure different the velocity distribution and pressure distribution in internal flow.The simulation results show that there is the maximum speed when the liquid flows through the orifice, The opening degree and the differential pressure also have the most direct impact on the overflow rate. The greater the differential pressure and the degree of opening, the bigger the maximum speed of the place. Pressure drop is mainly distributed in the orifice, there is an obvious area of low pressure near the orifice, and the opening degree is smaller, the greater the low pressure, the greater the pressure difference, the greater the low pressure. Due to the mouth of the static pressure value in orifice below the water saturation steam pressure, so here is very easy to produce cavitation phenomenon. Because the flow cross-section of the change, the liquid flow speed also change, in the place such as the corner flow easily to have whirlpool, and the smaller the pressure difference the smaller the whirlpool area, On the contrary the bigger will be. Along with the increase of the inlet pressure, the flow speed becomes faster, the minimum pressure near orifice becomes smaller, and thus prone to the phenomenon of cavitation, whirlpool. As inlet pressure increases, the flow speed becomes faster, smaller the minimum pressure near orifice becomes small, and thus prone to the phenomenon of cavitation, whirlpool. Therefore, to increase the outlet pressure or to reduce the inlet pressure are is helpful to increase the minimum pressure, and then reduce the probability of cavitation, whirlpool phenomenon.In this paper, the hydraulic support safety valve for research, the structure of the relief valve to improve and perfect the use of performance, providing a valuable theoretical and practical basis, to ensure the stability of hydraulic support, fully the whole mechanized working face production has a certain practical significance.