The vibration of dip tube in multi-burner gasifier changes the stress at the connection, causing flange seal failures and high temperature gas erosions with heavy economic losses and industrial accidents. This work aims to reveal the dip tube vibration mechanism, with special focus on obtaining the effect of operational parameters on the fatigue damage and long-term stable operation of gasifiers. A three-dimensional numerical simulation of the water-scrubbing cooling chamber was conducted to obtain the excitation source in the flow field. Then a FSI (fluid-structure interaction) transient dynamics simulation was carried out to investigate the vibration characteristics. Two major flow forms were found: a vertical annular flow near the dip tube outlet in the water-scrubbing cooling chamber; and a gas-liquid coupled flow caused by the syngas entrained the liquid. These two unstable multiphase flow forms exerted an energy excitation on the dip tube, resulting in a self-excited flutter. The dip tube vibration was similar to the first mode of a cantilever beam. The peak frequency was less affected by the initial liquid level and the syngas stream inlet velocity, which was close to its own first natural frequency. Note that, the alternating load generated by vibration may cause fatigue damage, which needs to be specifically considered in the design and manufacturing process of opposed multi-burner gasifier.

多燃烧器气化炉中汲取管的振动会改变连接处的应力，从而导致法兰密封失效和高温气体侵蚀，并带来巨大的经济损失和工业事故。这项工作旨在揭示浸入管的振动机理，特别着重于获得运行参数对气化炉疲劳损伤和长期稳定运行的影响。对水洗冷却室进行了三维数值模拟，得到了流场中的激发源。然后进行了FSI（流固耦合）瞬态动力学仿真，以研究振动特性。发现了两种主要的流动形式：水洗冷却室中汲取管出口附近的垂直环形流动；以及 合成气夹带液体引起的气液耦合流动。这两种不稳定的多相流形式在汲取管上施加了能量激励，导致了自激颤动。汲取管的振动类似于悬臂梁的第一种模式。峰值频率受初始液位和合成气流入口速度的影响较小，接近其自身的第一个自然频率。请注意，振动产生的交变载荷可能会导致疲劳损伤，这在对置多燃烧器气化炉的设计和制造过程中需要特别考虑。峰值频率受初始液位和合成气流入口速度的影响较小，接近其自身的第一个自然频率。请注意，振动产生的交变载荷可能会导致疲劳损伤，这在对置多燃烧器气化炉的设计和制造过程中需要特别考虑。峰值频率受初始液位和合成气流入口速度的影响较小，接近其自身的第一个自然频率。请注意，振动产生的交变载荷可能会导致疲劳损伤，这在对置多燃烧器气化炉的设计和制造过程中需要特别考虑。