In a power plant with gas turbines (combustion turbines), air intake system is a very powerful noise source potentially causing sound nuisance for personnel of the operator operating in the vicinity as well as for the neighborhood (including long distance, a fortiori in case of air intake openings with big size due to the low speed imposed in filters that must treat an important air flow). It is often necessary to use in such cases a soundproofing equipment of high technology to ensure compliance of the installation on the one hand with respect to the legislation on noise at work and on the other hand with respect to the regulation in terms of environmental protection. In fact silencers for gas turbines air intake systems must often have outsized acoustic performance (the overall sound power level to consider is often greater than 145 dBA and noise emissions are with a very wide frequency spectrum) in a context where very high gas flow rates (which are sometimes counted in hundreds of kg/s) must be considered: great care must be taken when sizing to limit the total pressure loss directly impacting the productivity of the plant.
ITS has participated in the design of an air intake system silencer for a gas turbine / combustion turbine with a power above 47 MW for simple cycle operation and above 135 MW for combined cycle operation (2 x 1) in the context of a project of development of an new air intake system concept.
Of course, this soundproofing equipment must have a sound transmission loss particularly important, overall sound power level to be accounted being 153 dB(A). But in addition, with a flow rate being above 130 kg/s, the fluid flow speed into the silencer was high, requiring a specific design of the silencer in particular with respect to issues related to aerodynamic and to self-noise.
Therefore, the simulation of the insertion loss (with or without flow noise) as well as of the total pressure loss of the silencer (whose splitters will be equipped of extremities with a special aerodynamic shaping) in the foreseen operation conditions was performed by the means of the software SILDIS (cf. acoustics simulation software)
It was the same for the sound power emitted by the air intake openings, accounting the other componenets of the air intake system.
Specific absorbent materials wich properties must satisfy both the ambitious goals of acoustic performance and also to requirements related to high mechanical solicitations were incorporated into the design as required.
In addition, the course of this project shows - once again - the possibilities for design and optimization of soundproofing equipment of the software SILDIS, whose computing power and reliability, as well as whose versatility made of it a choice tool for the selection of products and construction systems for many projects of sound insulation.