Study on a Countermeasure of Self-Sustained Tone by a Baffle Plate in Boiler Tube Banks

摘要

In heat exchangers such as boilers and gas heaters, tube banks are set in a duct such that water passes through inside the tubes and warm gas outside the tubes. Due to the external flow, the resonance phenomenon called the self-sustained tone occurs at a certain velocity. The self-sustained tone might cause noise problems in the surroundings, cause losses due to plant shutdown, etc. The insertion of baffle plates in the duct is one of a few countermeasures of the self-sustained tone. However, the mechanism of suppression of the self-sustained tone is not understood. Therefore, the use of the baffle plate in the tube bank has unclear points for instance baffle plate length and the insertion conditions. Thus, the purpose of this study is to clarify a new mechanism of suppression of the self-sustained tone by baffle plate insertion and the best insertion conditions for baffle plates in tube banks.