超低比转速高速离心泵复合式叶轮的正交设计

Orthogonal design of complex impeller of centrifugal pump with super-low-specific-speed

针对影响超低比转速高速离心泵复合式叶轮短叶片设计的叶片数、叶片径向进口的相对位置、叶片周向偏置度及偏转角等4个主要因素,设计了16种不同短叶片型式的复合式叶轮.通过对正交设计方案结果的极差分析,得出各因素水平对扬程和效率影响的主次顺序分别为短叶片数、偏转角、周向偏置度、径向进口的相对位置和短叶片数、径向进口的相对位置、周向偏置度、偏转角,从而得到超低比转速高速离心泵复合式叶轮短叶片的最佳设计方案.利用CFD软件,分别对采用常规叶轮和正交设计的复合式叶轮两种方案进行了数值模拟和性能预测.结果表明,采用正交设计的复合式叶轮内部压力场和速度场分布合理,Q-H曲线更加平坦,Q-η曲线最高效率点向大流量偏移,在相同设计方案下,复合式叶轮离心泵在大流量工况条件下工作性能良好.

Based on the four main factors influencing the design of short-blade of complex impeller which contains the number of short-blade, the radial inlet position, the bias angle in peripheral direction and the deflection angle, 16 different types of complex impellers with different combinational form of short-blades have been designed. By range analysis of the orthogonal designing scheme, the sequence affecting pump head and efficiency of the four main factors were obtained, the number of short-blade, the deflection an- gle, the bias angle in peripheral direction, the radial inlet position and the number of short-blade, the ra- dial inlet position, the bias angle in peripheral direction, and the deflection angle, meanwhile the best design scheme of short-blade was given. Performance tests were conducted by the CFD software. The test results show that the distribution of pressure field and velocity field of the compound impeller designed by orthogonal design are reasonable, the Q - H curve is more flat and the Q - ~ curve shifts to the larger flow rate. In the same design conditions, the centrifugal pump with complex impeller works with good performance at larger flow rate.