动力涡轮多跨轴系振动特性研究

Research on Vibration Properties of Multi-span Power Turbine System

为了分析动力涡轮一拖二机组振动超标问题,计入地基刚度对轴系振动的影响,建立了多跨转子耦合系统动力学有限元模型。首先就耦联系统进行了模态分析,分析结果表明地基刚度不足是水力测功机振动超标的主要原因;基于此分析结果,在原始基座内添加钢砂、增加辅助筋板加强地基支撑刚度,后经不平衡响应分析轴系仍然存在不稳定问题;最后提出通过改变重型联轴器跨度和增加辅助支撑两种方案来优化轴系结构,从而达到轴系稳定性的提高;该结果为国内首例30MW级燃气轮机一拖二机组的成功运行提供理论支持和技术保障。

In order to analyze the vibration problem of the gas turbine 1 operating 2 unit system,the dynamic modal with pedestal property was built.And its vibration response was calculated and analyzed,the results showed that lack of foundation stiffness was the main reason for the vibration of hydraulic dynamometer.The stiffness of foundation support was strengthen by adding grit and reinforcing ribs but the shaft system was still unstable after unbalance response analysis.Finally,it was proposed to optimize the shafting structure by changing the span of heavy coupling and increasing the number of bearing,so as to improve the stability of the shaft system.The results provide theoretical and technical support for the first successful running of 30 MW gas turbine 1 operating 2 unit system in China.