Research on the Influence of Metaconnection Methods on Low-Frequency Acoustic Noise Reduction Performance in Nuclear Power Plant Main Control Rooms

During the operation of nuclear power plants， vibration from equipment and pipelines readily induces building structure vibration and noise radiation， particularly in the low-frequency range， which poses significant impacts on personnel health and equipment safety. Therefore， developing a novel vibration and noise reduction method that meets both safety requirements and spatial constraints is of great importance. Leveraging the advantages of acoustic metamaterials in low-frequency wave manipulation， a composite metastructure capable of simultaneously suppressing both airborne and structure-borne sound was proposed. Using a combined approach of numerical simulation and scale-model testing， the effects of two installation methods—rigid connection and elastic connection—on noise reduction performance were systematically investigated， and key structural parameters were optimized. Simulation results indicated that rubber pads with a Shore hardness of 40 were more suitable for low-frequency noise control in the main control room， which guided the subsequent experimental design. Test results demonstrated that the metastructure provided effective noise reduction in the 150-315 Hz low-frequency band， with a reduction of 8.5 dB for the elastic connection and 5.9 dB for the rigid connection， indicating the superior performance of the elastic connection. Acoustic metamaterial structures show significant promise for low-frequency noise control in nuclear power plants， where the elastic connection method can more effectively enhance noise reduction.