Study on Countermeasures for High Level Sound Generated in Boilerand Heat Exchanger

当气体通过燃气加热器和锅炉等热交换器管组的管道时，会产生卡门涡，由于涡流和管道内声场的干扰，会产生被称为“自持音”的非常高水平的噪声。一般来说，挡板是用来抑制自持音的。然而，由于插入条件模糊，很难有效地使用它们。然后，在管道两侧安装橡胶板作为柔性墙，以抑制自维持的音调。因为我们认为当发生自持音时，垂直于气流方向的管道的共振模式可能会被橡胶板的振动所抑制。对安装的橡胶板的抑制效果进行了试验研究。结果表明，在一定条件下出现抑制效应。本研究的目的是澄清“橡胶片的自我维持色调的有效性”。

Karman vortex occurs when the gas passes through the duct with tube bank of the heat exchangers, such as a gas heater and a boiler, and the very high level noise called “Self-Sustained Tones” occurs due to the interference of the vortex and the sound field in the duct. In general, baffle plates are used to suppress the self-sustained tone. However, it is difficult to use them effectively, because insert condition is vague. Then, rubber boards as flexible walls are installed in both sides of the duct to suppress the Self-Sustained Tones. Because we thought that the resonance mode of the duct perpendicular direction to the flow may be suppressed by rubber boards vibrating, when Self-Sustained Tones occurred. The experiment was carried out to examine the suppression effect of the rubber boards installed. As a result, the suppression effect appeared at a certain condition. The purpose of this study is to clarify” Effectiveness of the rubber sheet for Self-Sustained Tones”