针对船用离心风机存在多工况运行特点,为研究工况变化对船用离心风机振动的影响,以某型离心风机为研究对象,搭建满足其工况变化及振动测试要求的试验台架.首先对离心风机主要激励特性的产生机理及对应的特征频率进行分析,然后从试验角度分析工况变化对离心风机振动影响的规律.从分析结果可以看出,风机振动实测值总体变化趋势与经验公式计算值趋势基本一致,验证了转速-振动、流量-振动关系经验公式;流量变化对离心风机振动、噪声影响比较明显,对叶频的影响最为突出;离心风机存在一个振动最佳运行工况,在此工况下风机振动、噪声均为最佳状态.在风机设计过程中,应当考虑将设计工况选择在此振动最佳工况附近,对船用风机设计有一定的参考价值.%Abastract : Influence of change of working conditions on the vibration characteristics of marine centrifugal fans is studied. With a centrifugal fan of a certain type as the object, a test bench which satisfies its working condition change and vibration measurement requirements is established. Firstly, the mechanism of the main excitation generation of the centrifugal fan and its characteristic frequency are analyzed. Then, the law of influence of the working condition change on the vibration characteristics is studied experimentally. It can be seen from the results of the analysis that the general variation tendencies of the measured fan's vibration values and the calculated values according to the empirical formulas are basically consistent. Thus, the relation formulas between the rotating speed and vibration characteristics and between the flow rate and the vibration characteristics are verified. It is noticeable that vibration and noise of the centrifugal fan are significantly affected by the flow-rate changing;especially its influence on the blade frequency is very large. The centrifugal fan has a best operation condition in which the fan's vibration and noise are the best. In the design process of the fan, the design working condition should be chosen near the best working condition. This work has some reference value for the design of marine fans.
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