ITS contributed to noisy industrial equipment soundproofing, in the context of the construction, in North Africa, of a gas-fired power plant with a power of 1.2 GigaWatt comprising 4 large-capacity combustion turbines.
This included limiting the noise impact of these turbines and related generators, both for the personnel of the energy production site and for the neighborhood.
In such cases, high acoustic performance is required when the sound power level of some noise sources approaches 140 dB(A) ref. 1 pW (this is not far from the noise level near an airplane engine taking off) and that a sound pressure level as low as 80 dB(A) ref. 20 µPa at 1 meter is targeted to meet the sound limitation requirements both in the near acoustic field and in the far acoustic field, taking into account the spatial sound decay and the atmospheric sound attenuation - depending on the context - up to the limit of industrial property and/or up to the zones where emergence i.e. the difference between the equivalent continuous A-weighted pressure levels of the ambient noise (power plant in operation) and the residual noise (in the absence of the noise generated by the power plant, but measured over the period of operation of the plant) is regulated.
Techniques and means for noisy industrial equipment soundproofing
In the context of the project that is the subject of this article, the techniques and means for noisy industrial equipment soundproofing were as follows:
- for combustion turbines: an action "at source" allowing the reduction of the sound power level (which is an intrinsic characteristic i.e. independent of the environment) consisting in the construction of industrial buildings with reinforced acoustic insulation (1 for each turbine) with an efficient ventilation system to evacuate the thermal power dissipated by the enclosed hardware and avoid an undesirable rise in temperature both for maintenance personnel and for some sensitive electronic components; the installation of silencers was necessary to limit the propagation of noise through the openings (air intakes and outlets equipped with fans which are also noisy, and must therefore also be soundproofed)
- for generators: protection of specified locations by means of acoustic screens (noise barrier walls), which allow (when the generators already have an enclosure) an additional reduction in the sound pressure level under the condition that there are not too many reflective surfaces at the start or end of the path of the sound waves and that the dimensions of the screen (both horizontal and vertical) are sufficient with regard to the wavelength corresponding to each frequency of interest
The technical scope to be considered for such noisy industrial equipment soundproofing works includes in particular:
- structural calculations: for very large metal constructions, exposed to bad weather and seismic risks and which must allow the dismantling of some sub-assemblies (with large wall areas: walls and roofs) during maintenance work or repair of turbines and auxiliary equipment
- acoustic engineering: determination of the sound reduction index of modular soundproofing panels, of the insertion loss of silencers
- aeraulic engineering: with regard to air renewal and temperature rise limitation
- the electrical study: in relation to the installation of fans and sensors
As part of this project for noisy industrial equipment soundproofing, a metal frame (steel) and:
- for fixed or easily removable parts, by elements: industrial soundproofing panels with an absorbing face (modular)
- for acces for employees and some hardware: (rotating) acoustic doorsets with, for translucent parts (with glazing guaranteeing residual safety in the event of accidental breakage): acoustic window sets
In addition, ventilation silencers were installed:
- for the air inlets and outlets of buildings with reinforced acoustic insulation intended for the soundproofing of gas turbines
- for the air intakes in the lower part of the acoustic screens (noise barrier walls) intended for the soundproofing of generators (the design and construction of which differ from that of buildings with reinforced acoustic insulation intended for the soundproofing of gas turbines due to the absence of a roof), a principle of ventilation by natural convection being used
This realisation was for ITS and its commercial partners an additional opportunity to be involved in a noisy industrial equipment soundproofing project, which is both the heart of their current activity and the field in which they have references in relation to the biggest internationnal clients.
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Structures for soundproofing noisy industrial equipment in a power plant similar to those covered by this article |
In addition to industrial buildings with reinforced sound insulation and acoustic screens (noise barrier walls), ITS markets, for noisy industrial equipment soundproofing (visible in the photo opposite but not delivered as part of the project subject of this article) soundproofed air intake systems for combustion turbines / gas turbines, exhaust silencers for combustion turbines / gas turbines, and also Vent silencers for pressurized gas | |