CFD dynamic mesh-based simulation and performance investigation of combined guided float valve tray

Abstract

This paper simulated the combined guided float valve tray based on the computational fluid dynamics (CFD) dynamic mesh technique. The motion equation of the float valve under force was compiled into the user-defined function (UDF) to calculate and finally obtained the float valve opening height under distinct working conditions. Based on this, adjustments were applied to the float valve opening height of the geometric model and were validated. The clear liquid heights obtained were closer to calculated values than when the float valve fully opened under identical working conditions. The errors between the simulated values and two correlative calculated values reduced from 10.68% and 19.01% to 7.35% and 15.55%, indicating the simulation results are reliable. Furthermore, this paper quantified the liquid phase reverse flow and used the reverse flow area fraction to measure the liquid back-mixing degree. The simulation results of six tray structures were compared, and it was verified that specific deflection angles of trapezoidal float valves could effectively reduce the back-mixing degree. Notably, 10° is the optimum float valve deflection angle of the tray, which can reduce the average reverse flow area fraction from 40.4% to 33.1%, with a reduced rate of 18%.