Numerical simulation on internal flow performances of multi-stage pressure drop valve

To study the internal flow process of the multi-stage pressure drop valve and the influencing factors and influence laws of the pressure drop of pressure-drop-stage, based on the numerical calculation method of the Mixture two-phase flow model and the Schnerr-Sauer cavitation model, the calculation model of the flow field of a multi-stage inside the valve was established. The flow characteristics inside the pressure drop valve are obtained through numerical simulation calculation, and the impact of various pressure differences and various opening degrees of the valve on the pressure drop of each pressure-drop-stage is analyzed and discussed. Numerical calculation results show that there are a large number of vortices in the valve due to the vigorous mixing and shear of multiple fluids when the fluid flows through the throttle element of the valve. The pressure drop of each pressure-drop-stage is different, and the degree of cavitation of the third stage sleeve is the largest, cavitation is more likely to occur at the valve seat. The pressure drop of the working fluid along each pressure-drop-stage exhibits the same changing trend at the same opening degree of the valve under various pressure differences. The pressure drop of the third pressure-drop-stage rises when the opening degree of the valve is reduced. The average pressure drop of the 3rd pressure-drop-stage reaches 8 MPa at the opening degree of 25% . The velocity of working fluid in the small hole of the pressure-drop-stage also increases under the condition of the same mass flow rate. This paper provides the theoretical basis and reference value for the designs of the pressure reducing valve. © 2022 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.