Features of Noise Emission from Various Types of Cooling Towers

The article discusses the issues of noise impact of various types of cooling towers on the surrounding area. An analysis of the noise characteristics of counterflow natural draft cooling towers and dry fans cooling towers of steam turbine and steam-gas thermal power plants of various capacities is presented. The noise from natural draft counterflow cooling towers is due to the noise of falling water. The noise from dry fans cooling towers is due to the noise of the fans. In the Automated workplace Acoustics program, mathematical models of thermal power plants with counter-flow natural draft cooling towers and dry fans cooling towers were built and an acoustic calculation was performed. As a result of the calculations, the sound pressure levels were found at the border of the sanitary protection zone for octave bands from 31.5 up to 8000 Hz. The change in the excess of sanitary standards for the noise factor impact during the operation of the considered cooling towers, depending on the power of the station, is shown. It was found that for fans cooling towers the greatest excess of the maximum permissible sound pressure levels is observed at the low and middle part of the spectrum, and for counterflow cooling towers with natural circulation - in the high-frequency spectrum. The values of the required level reduction for different types of cooling towers have been determined. The required noise characteristics of dry cooling tower fans have been established, which provide the required noise level at the border of the sanitary protection zone. The article suggests possible measures to reduce the noise of “dry” fans of cooling towers when it is impossible to install “silent” fans.