Soundproofing is an integral component of the quality of an industrial installation and its compliance with applicable regulations, which - among other things - regulate noise emissions, often distinguishing the daytime period and the nighttime period, when it comes to preserving the environment.
To prevent noise nuisance with respect to the neighborhood, acceptable values for emergence are set, in particular for Establishments Classified for Environmental Protection. (ECEP). This is the difference between the A-weighted equivalent continuous pressure levels of ambient noise (establshment in operation) and residual noise (in the absence of the noise generated by the facility but measured over the operating period of the facility).
In a number of contexts, noise levels not to be exceeded are specified by reference documents (e.g. prefectural decree or its equivalent in countries other than France, contract signed with the contracting authority in the case of a construction), namely with respect to the limitation of exposure to noise of workers: thresholds trigger, in Europe, action in terms of industrial soundproofing, on the basis of a directive transposed into French law.
In particular, in a gas-fired power plant, the noise limitation of turbomachines, including combustion turbines, is a major concern, requiring specific soundproofing means.
It is necessary to limit the transmission of the sounds emitted by the body of these mechanical organs (casings), which is generally achieved by means of a structure which surrounds the turbomachine (indifferently called canopy, enclosure, soundproof building sometimes gigantic, a fortiori if it is a question of sheltering in the same hall several gas turbines of big capacity).
Therefore, it is essential to choose soundproofing constructive systems that have a significant sound transmission loss (these are often multilayered acoustic structures whose performance, not only in terms of airborne noise insulation but also in terms of sound absorption, must be evaluated because it is necessary to limit the amplification of sound levels inside the engine room).
For soundproofing, such a construction, in addition to its noise insulation functionality (not only for the personnel working on the site but also for the neighbors), must also allow (by means of complex ventilation systems, themselves noisy, so themselves needed to be also soundproofed and sometimes having to integrate air filtration equipment) the evacuation of the heating power emitted by the turbomachine (convection, thermal radiation) with respect to a temperature rise limit (often controlled with a system of sensors) acceptable inside the enclosure thus created.
Its design and implementation must take into account specific site data: climatic conditions, seismic risks, local regulations and building codes imposed by the Client or by an administrative authority (sometimes subject to a broad consensus as for its use e.g. Eurocodes, code UBC, but not always, in particular as regards norms applicable to electrical apparatus or construction regulations); taking into account additional features (fire safety, access management, disassembly) is often necessary.
ITS will participate in a soundproofing project relating to 4 gas turbines and related equipment (in relation to gas combustion processes for energy production in Central Europe).This will be the extension of a combined cycle gas plant i.e. with Heat Recovery Steam Generators (HRSG), for what ITS can also, in other contexts, market (for the sake of nois emissions limitation) soundproofing devices such as noise barrier walls and stack silencers.
This project, also providing for the installation of 2 steam turbines, is regarded as one of the most important of the last five years in Europe.