中比转速离心泵无过载优化设计

Parameter Optimization of Medium Specific Speed Non-overload Centrifugal Pump

对D450-60-10型中比转速离心泵进行无过载优化设计,原始方案采用模型换算法设计模型泵进行试验并换算得到原型泵性能,同时利用Fluent模拟得到模型泵和原型泵性能,对泵性能分析后提出基于叶片出口角、叶轮出口直径和叶轮出口宽度等结构参数的3种原型泵优化方案。结果表明:当叶片出口角β2=10°时,与β2=15°相比,功率曲线的拐点更接近额定工况点,且最大功率下降了6.78%,但会牺牲部分扬程;3种优化方案下离心泵都达到了无过载的要求,功率备用系数K均小于1.2;最佳方案(叶轮出口直径D2=0.49m,叶轮出口宽度b2=0.03m,叶片出口角β2=10°)的功率备用系数最低,为1.09,与原始方案相比,扬程和效率分别提高了6.94%、1.95%,为中比转速离心泵无过载设计提供了参考。

To meet the demand of a medium specific speed centrifugal pump for the non-overload characteristic,a series of optimizations were done on a pump D450- 60- 10. In the original scheme the theory of resemble conversion was applied for designing a model pump,and the corresponding test was carried out,after which the performance curve of the prototype pump was got,meanwhile,the Fluent simulations of the prototype pump and the model pump were done. Analyzing the performance of the pump,three optimized schemes were carried out based on the parameters such as the impeller outlet angle,the impeller outlet diameter and the impeller outlet width. The results indicate that when the impeller outlet angle is 10° the extreme point of shaft power curve appeases nearer the designed working condition than that when the outlet angle was 15°,and the maximal axle power decreases6. 78% while the head decreased too. All of the pumps among three optimized schemes reach the goal of non-overload,and the coefficient K,the ratio of the maximal axle power to the power in designed working condition,is less than 1. 2. In the best optimized scheme the impeller outlet angle is 10°,the impeller outlet diameter is 0. 49 m,the impeller outlet width is 0. 03 m,and the K in this scheme is the minimum among three schemes,meanwhile the head and the efficiency increase by 6. 94% and 1. 95% than that in the original design scheme. The investigation can provide certain scientific basis for the performance optimization of medium specific speed non-overload centrifugal pumps.