不同结构形式对串并联离心泵振动特性的影响

为了研究串并联离心泵不同结构形式对泵外特性及其振动特性的影响,选取叶轮匹配螺旋型压水室和叶轮匹配导叶匹配环形压水室2种结构形式,并参考优秀水力模型采用速度系数法对2种结构形式的串并联离心泵的叶轮进行水力设计,按照标准专门搭建了外特性与振动试验台,对串并联离心泵2种结构形式下的外特性及不同监测点的机脚加速度的1/3倍频程进行数据采集、测试与分析.研究结果表明:叶轮匹配螺旋型压水室的原始结构形式的效率比叶轮匹配导叶匹配环形压水室的新型结构形式的效率要高;串并联离心泵采用叶轮匹配导叶匹配环形压水室的结构形式对于泵组的减振降噪具有良好的作用,新型结构比原始结构在全频段各个监测点振动噪声减小3~4 dB;各个监测点的振动在各个频段的变化无规律可循,监测点的振动噪声也有所变化,监测考核时应布置多个监测点进行综合评价.

Effects of pump hydraulic structure on vibration characteristics of series-parallel centrifugal pump

In order to study the changes in performance and vibration characteristics for different structures in a series-parallel centrifugal pump, the original volute of a series-parallel centrifugal pump is replaced with a new structure-radial diffuser plus annular ring. The hydraulic design of the two structures is conducted by making use of existing hydraulic models and velocity constants method. An experimental stand is built according to relevant standards, then the performance and vibration characteristics of the pumps with two structures are measured on the stand, respectively. The vibration is monitored in the pump feet and analyzed in 1/3 octave band of vibration acceleration. The results show that the original volute configuration can achieve a higher pump efficiency but is subject to a high vibration level than the new structure. In particular, the noise level of the pump with the new structure is 3dB-4dB lower than the pump with the original volute structure. Unfortunately, the vibration characteristics at various monitoring points don′t show any regular patterns at each octave, and the noise changes from one monitoring point to another. As a result, when monitored parameters are assessed, all monitoring points should be taken into consideration in a comprehensive manner.