ITS has participated in the construction of an exhaust silencer for an industrial genset, in order to reduce noise emissions (related to the evacuation of flue gases) from a heat engine used for energy production.
The soundproofing device has been inserted into the exhaust line, making it possible to reduce the noise upstream of the chimney of the thermal power station, so as to avoid any noise nuisance for the neighborhood which, otherwise, could have been caused by a excessive sound power level at the outlet.
Such an establshment, classified for environmental the protection (ECEP), is subject to a strict regulation for the prevention of neighborhood noise, based on emergence i.e. on the difference between the A-weighted equivalent continuous pressure levels of ambient noise (establishment in operation) and residual noise (in the absence of noise generated by the establishment, but measured over the operating period of the establshment): 3 dB (A) is the permissible emergence for the period 22h - 7h, as well as Sundays and public holidays, for Zones with Regulated Emergence (ZRE) when the ambient noise level (including the noise of the establshment) is greater than 45 dB (A).
A careful dimensioning must therefore be carried out in the case of an exhaust silencer for an industrial genset, because its acoustic performance must not generate a total pressure loss that is too high, affecting the efficiency of the facilityCareful sizing must therefore be carried out in the case of an exhaust silencer for an industrial generator set, because its acoustic performance must not generate an excessively high total pressure loss, affecting the efficiency of the energy production facility. For such a noise limitation device, the following therefore requires special attention:
- the reactive part (in general: constituting the upstream stage), based on changes in the section of tubes (perforated or not), e.g. connecting chambers - often: multiple -, which are often accompanied by a significant point pressure drop, especially at usually high gas passage speeds
- the dissipative part, for which the effects of the friction of the transported fluid (taking into account its viscosity) on the rough surfaces of a sound-absorbing lining protected by a perforated sheet are not necessarily negligible (especially if it is not not a straight-through silencer, but a sound attenuator with a sound-absorbing central pod, or with concentric or transverse splitters) and, of course, all the more so as the considered length is important
The ITS human resource has the appropriate simulation resources, for some: developed in-house [1], for others: being commercial software, based on finite elements [2].
In addition to a good design, which is absolutely necessary, careful selection of materials and meticulous construction (the assemblies are made by welding) are also required to obtain a quality exhaust silencer: durability is a criterion of choice for an exhaust silencer for an industrial genset.
Finally, meeting deadlines (often restrictive for the supplier because the exhaust silencers for an industrial generator set are supplied just in time) is a key factor for Customer satisfaction.
[1] cf. Computer Aided Design (CAD): SILDIS® calculation software for acoustics and aeraulics in the construction sector (in Excel format)