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针对双吸中开泵吸入室结构的自由性和复杂性加大了设计难度、改变了叶轮的进口流动环量及均匀度并影响泵的汽蚀性能,采用理论方法研究了叶轮进口环量对汽蚀性能的影响,并对一单级双吸中开式离心泵的吸入室进行了优化改型,用数值模拟和试验方法验证了改进型半螺旋吸入室对叶轮汽蚀特性的改善效果。结果表明,进口稍微带正环量能改善叶轮的汽蚀性能,但正环量加大到一定程度后汽蚀又会逐渐恶化;吸入室对叶轮汽蚀的影响因素包括叶轮进口环量和进口流场的均匀度,改进型的半螺旋吸入室提供了叶轮进口的正环量,并提高了叶轮进口流场的均匀度、大幅降低了泵的必需汽蚀余量。
In view of the freedom and complexity of pump suction chamber structure in double suction, the design difficulty is increased, the flow ring volume and uniformity of the inlet flow of the impeller are changed, and the cavitation performance of the pump is affected. Cavitation performance. The suction chamber of a single-stage double-suction open centrifugal pump was optimized and modified. The numerical simulation and experimental results verify the improved effect of the improved half-spiral suction chamber on the cavitation characteristics of the impeller. The results show that the slightly positive inlet capacity of the impeller can improve the cavitation performance of the impeller, but the cavitation will deteriorate gradually when the amount of the positive ring is increased to some extent. The influencing factors of impeller cavitation in the inlet chamber include impeller inlet ring volume and inlet The uniformity of the flow field, the improved semi-helical suction chamber provides the amount of positive loop impeller inlet, and improve the uniformity of the flow field of the impeller inlet, significantly reducing the necessary NPSH surplus.