The sound transmission through tube arrays in power boilers based on phononic crystals theory

The heat exchanger structure in power plants can be treated as two-dimensional phononic crystals. The aim of this paper is to show the sound transmission characteristics through the heat exchanger. The plane wave expansion method is presented to compute the band gaps of the tube arrays which are composed of square or rectangular lattices of solid cylinders in the air matrix. By using the Matlab and Comsol software, and setting the pitch and diameter parameters of the tube arrays and the temperature of circumstance, the sound band-gap diagram and the impact of the sound transmission are got to understand the acoustic signal processing in power station boilers. In simulation, two-dimensional pressure acoustics Application Mode (acpr) is chosen, and finite difference method is used to divide the grid. For the sound vertically incident upon the tube arrays, we can get that the experimental results can be matched with the numerical results quite well. The results obtained through experiments and calculations can tell us that the band gaps are associated with the structure and the temperature. The study can provide new idea and method on theory and application of sound propagation in power station boilers. (C) 2016 Elsevier Ltd. All rights reserved.