三偏心蝶阀的流场和阻力特性研究

摘要

In order to obtain correct flow resistance coefficients of a triple eccentric butterfly valve with 680mm diameter, flow resistance test was developed for different valve disk positions and inlet air velocities .Then a set of numerical model was set up based on test results to get flow details inside the tested valve .SST model was selected as the turbulence model .This numerical model was applied to predict the flow field and flow resistance coefficients of the tested valve for disk positions 90°, 70°and 50° (where 90°was the fully opened position ).Test results show that flow coefficient of 50°disk position is the same as nine times as that of 90°position.They also show that the tested valve has a flow coefficient for 90°which is six times bigger than that of the symmetric valve for 90°.Numerical results show that there is more vortex around the disk than that of the symmetric valve for 90°, so the shape of the tested valve disk can be optimized to reduce the flow coefficient .And there is torque acting on disk pro-duced by the air flow with the disk positions from big degrees to fully closed .It is helpful to close the disk .%通过流阻试验获得了直径为680 mm的三偏心蝶阀在不同开度和速度下的流阻系数。以试验结果为基础验证湍流模型，选择SST模型作为湍流模型，建立获得三偏心蝶阀详细流场的数值模型。利用该数值模型对试验蝶阀在90°、70°、50°开度下的流场和流阻系数进行预测，90°代表全开。试验结果表明，50°开度的流阻系数值约为90°开度流阻系数值的9倍；三偏心蝶阀全开时的流阻系数值约为中线蝶阀全开时流阻系数值的6倍。数值分析表明，全开状态下，三偏心蝶阀阀板处存在的漩涡比中线蝶阀多，可对三偏心蝶阀阀板形状进行优化，以减小流阻系数；随着开度减小，流体的流动产生与阀板关闭方向一致的力矩，帮助阀板关闭。