Reduce The Noise Level In Power Plants Using Simulation

The team in the Acoustics department at Siemens Power and Gas deals with noise, vibration and occupational safety. Among other things, its job is to ensure the lowest possible noise level. The aim of the experts: to modify the sound sources of a system before construction until they only emit a minimum of noise. The knowledge gained through simulation of noise reduction measures has made several power plants quieter since the department was founded in 1987.

Room acoustic simulation shows virtual sound

The work of Holger Ennes and his team in Erlangen initially happens on the screen. In addition to the noise level in power plants, the experts also reduce those in power transmission stations. A three-dimensional model shows the area on which the power transmission station is to be built. The station is modeled and examined virtually. The sound appears in the room acoustic simulation of the converter halls as a colored, cloud-like structure that illustrates the extent to which the noise develops within a hall.

The team first looks at the sound distribution within the ward hall taking various parameters into account. For further acoustic simulation, it is important to know where the station is and how it is constructed. In a first step, the noise level in the hall is determined using the room acoustics software and data from comparative measurements.

Noise protection in offshore wind turbines

When the acoustic team has calculated how high the noise level within the power transmission station will be, it simulates the sound propagation outside the station: "Here a tree, there a shrub, a path, a house, a street and a bridge - every detail of the surroundings can be found in the virtual simulation again,”explains Ennes. "We also take into account variables such as geometric spread, wind characteristics, air absorption, soil absorption, temperature and obstacles."

The team then compares the calculated sound propagation data with the statutory sound limit values ​​and the customer's requirements. If the calculated value is above this or if the background noise can be further minimized than originally requested by the customer, Ennes and his team make suggestions as to which changes to the design of the system would result in noise reduction. Sometimes there are thicker or thinner outer walls, sometimes "enclosures" for outdoor components, for example sound hoods for transformers or pumps, or soundproof walls.

The team is not only concerned with sound insulation in power plants on land. "We also take care of sound insulation at offshore stations in the North Sea," explains Ennes. When an offshore wind farm is built, steel piles are driven into the seabed for the foundation. “Noise is generated at these ramming points, which is transmitted four times faster by the medium water than by the medium air. This noise must not exceed a limit.”Otherwise, marine mammals could be damaged by the very high sound level. Here, too, various noise-reducing measures are used in accordance with the legal regulations. (kj)