不同开度下三偏心蝶阀流场特性分析

Flow Field Characteristics of Three Eccentric Butterfly Valve at Different Opening Degrees

基于三偏心蝶阀结构特性的特点,并对其不同开度及下流场特点进行了研究。采用流阻模拟实验方式,分析DN750 mm三偏心蝶阀在不同开度和流速条件下的内部流场和流阻系数分布情况,并建立三偏心蝶阀结构为标准湍流模型。对DN750三偏心蝶阀在90°、70°、50°、30°开度下的内部流体和流阻系数进行试验测试,获得了不同开度下流阻系数和流场效果。试验结果表明,在0~30°区间流动稳定性和流阻系数较大,当开度大于50°时并随着开度变大,阀门流阻系数随着开度变化较为均匀,和中线蝶阀相对比有着显著差异,三偏心蝶阀全开条件下的流阻系数比中线蝶阀全开条件下流阻系数的5倍多。数值结果表明,在全开状况下,三偏心蝶阀靠近蝶板附近区域湍流和分流迹象较中线蝶阀的高,因此可对三偏心蝶阀蝶板形状加以优化,可以降低流阻系数,增加流速系数,从而提高了阀门的流通流量。

Based on the structural characteristics of three eccentric butterfly valve,the characteristics of different opening and flow field were studied.The flow resistance simulation experiment was used to analyze the internal flow field and flow resistance coefficient distribution of DN750 mm triple eccentric butterfly valve under different opening and flow velocity conditions,and the structure of triple eccentric butterfly valve was established as the standard turbulence model.The internal fluid and flow resistance coefficient of DN750 triple eccentric butterfly valve were tested at 90°,70°,50°and 30°,and the flow resistance coefficient and flow field effect of different opening degrees were obtained.The test results show that the flow within the range of 0 to 30°the stability and the flow resistance coefficient is larger,when opening than 50°and the opening,the valve flow resistance coefficient with the change of the opening is relatively uniform,and significant difference compared with center line butterfly valve,the flow resistance coefficient of triple eccentric butterfly valve fully open under the condition of low resistance coefficient of the center line butterfly valve fully open to more than 5 times.The numerical results show that in the fully open condition,the signs of turbulence and shunt near the three-eccentric butterfly valve are higher than those near the midline butterfly valve.Therefore,the shape of the three-eccentric butterfly valve butterfly plate can be optimized to reduce the flow resistance coefficient and increase the flow velocity coefficient,thus improving the flow rate of the valve.