【摘要】 为了研究双蜗壳离心泵在启动过程中蜗壳内部液体瞬态流动特性和隔板处的压力脉动特性,以一台比转速为90的双蜗壳离心泵作为研究对象,建立了一套循环管路系统,选用RNG k-ε湍流模型,应用ANSYS CFX软件对双蜗壳离心泵及循环管路系统进行了三维非定常数值计算,分析了启动过程中蜗壳内部流场演化规律和外特性变化趋势,并对隔板不同位置处压力脉动的变化情况进行了比较.结果表明:在启动初期,蜗壳内部流速变化较为剧烈,隔舌和隔板初始位置出现高速区域,蜗壳入口处存在明显的速度梯度,随着转速增大,高速区域逐渐减小,内部流动趋于稳定;在启动过程中,隔板初始位置和末端位置的压力脉动幅值相对较大,且隔板外侧的压力脉动相对于隔板内侧更为稳定.更多还原

【Abstract】 To investigate the transient flow characteristics of the liquid inside volute and the pressure pulsation characteristics at the splitter during startup process of double-volute centrifugal pump, a double-volute centrifugal pump with specific speed of 90 was used as research object, and a set of circulating pipeline system was established. According to RNG k-ε turbulence model, ANSYS CFX software was used to simulate the three-dimensional unsteady state of double-volute centrifugal pump and circulating pipeline system. The evolution law of flow field and the variation tendency of hydraulic characteristics during startup process were analyzed, and the changes of pressure pulsation at different splitter positions were compared. The results show that at the beginning of startup, the flow velocity inside volute changes sharply, and the high-speed regions appear at the tongue and the initial position of splitter. There is an obvious velocity gradient at the entrance of volute. With the increasing of rotate speed, the high-speed regions are gradually decreased, and the internal flow tends to be stable. During the startup process, the pressure pulsation amplitudes at the initial position and the end position of splitter are relatively large, and the pressure pulsation on the outer side of splitter is more stable than that on the inner side of splitter.更多还原