超超临界660 MW燃煤发电机组管式烟气换热器流致振动分析

Analysis on fluid-induced vibration of tubular gas-gas heat exchanger for ultra-supercritical 660 MW coal-fired generating unit

流致振动会导致换热器结构破坏和失效。以某超超临界660 MW燃煤发电机组管式烟气换热器振动为例,采用ANSYS有限元分析方法对多跨度U型翅片管和管式烟气换热器整体结构进行模态分析,计算换热管束的固有频率,并分析旋涡脱落、湍流抖振和声学共振等因素对管式烟气换热器振动的影响。结果表明,旋涡脱落或湍流抖振诱发的声共振是管式烟气换热器振动的根本原因。基于此,提出相应的消除振动(消振)的方法,并在实际工程中取得有效的消振效果。

The flow-induced vibration will cause structure damage and failure for heat exchanger. By taking the tubular gas-gas heat exchanger vibration in an ultra-supercritical 660 MW coal-fired generator unit as an example,the vibration modes of multi-span U-fin tube and tubular gas-gas heat exchanger were analyzed by ANSYS finite element analysis method, and the natural frequency of the heat exchange tube bundle was calculated. The effects of vortex shedding, turbulent buffeting and acoustic resonance on the vibration of tubular gas-gas heat exchanger were analyzed. The results indicate that, the acoustic resonance induced by vortex shedding or turbulent buffeting is the root cause of the tubular gas-gas heat exchanger vibration. On this basis, the corresponding vibration control method is put forward, and the effective vibration elimination effect is achieved in practical engineering.