Abstract: For the marine power plant with the side exhaust system cooled by water spraying, the opening of the water spray cooling device will cause significant change of the temperature in the system. The properties of the flue gas in the exhaust system will therefore change, which accordingly affects the acoustic performance of the side exhaust silencer system. This paper firstly calculates the hydrodynamics of the side exhaust system before and after the water spraying through Fluent, and then the temperature distribution of the side exhaust silencer system at the different water spray flow by changing the cooling water flow. The CFD results are then used as the input to calculate the transmission loss of the exhaust system in order to obtain the acoustic performance of the side exhaust system before and after water spraying. It concludes that the water spry cooling can improve the acoustical behavior of the whole system at the low frequency range. The results can provide reference for the design of the side exhaust system in the future.

Key words: side exhaust system, water spray cooling, silencer, transmission loss

摘要： 对于船舶动力装置喷水冷却式舷侧排气系统,喷水降温装置的开启会使系统内温度发生剧烈变化,因此排气系统内烟气属性会发生改变,进而影响舷侧排气消声系统的性能。文章首先通过Fluent获得喷淋冷却前后舷侧排气系统的流体动力学计算结果,改变冷却水流量后又得到消声系统在不同喷水流量下的温度场;再将CFD计算结果作为求解排气系统传递损失的计算输入,得到了冷却水喷淋前后舷侧排气系统的声学性能,从而获得喷水降温冷却可以提高整个系统在低频段的消声性能的结论。该结果可为今后舷侧排气系统紧凑化设计提供参考。

关键词: 舷侧排气系统, 喷水降温, 消声器, 传递损失