Acoustic-Aerodynamic Processes in the Macroporous Modules Used in the Silencers of Noise from Steam Dumps at Thermal Power Plants

Steam dumps from thermal power plants (TPPs) into the atmosphere are among the most powerful man-induced noise sources. The protection, by means of silencers, against the noise produced by high-pressure steam dumps includes, in the general case, implementation of low-noise throttling and installation of sound-absorbing components. The comparative efficiency of the silencer throttling and sound-absorbing components depends on the location and intensity of physical noise sources, which are determined by the steam dumping pipeline’s operating and geometrical parameters. The use of macroporous modules in steam dump silencers is of significant interest owing to their relative simplicity and good performance. Such modules can be used as continuously operating throttling devices; in addition, they have certain sound-absorption properties. The aerodynamic and acoustic properties of macroporous modules used as part of the silencers of noise produced by the TPP steam dumps are analyzed. The main sources causing noise from the TPP steam dumps are considered, and analytical relations for comparing their intensities are formulated. Proceeding from the performed assessments, methods for protection from the noise produced by steam dumps are suggested, which involve the use of silencers equipped with macroporous modules. In discussing matters concerned with the aerodynamics relating to continuous throttling of gaseous medium in macroporous channels of various shapes, it is shown that correct profiling of channels in coordination with the characteristic pore sizes is important for practical applications. Assessments of sound absorption in a macroporous medium are carried out. Recommendations on shaping the macroporous modules of silencers are given, and methods for calculating their efficiency in solving problems of protection from noise caused by dumping high-pressure steam into the atmosphere are presented.