In a power plant with combustion turbines (gas turbines), some airborne noise is emitted by the various subsets making up each turbomachinery (in addition to noise emissions associated with the mouths for air intake and exhaust not included in the current project, although regularly studied and subject of simulation and design work by ITS as part of other projects in the field of energy production):

  • the turbine compartment i.e. compressors, combustion chamber, turbine
  • the auxiliary compartment
  • the load compartment
  • the portion of the envelope of the intake duct enclosed
  • the portion of the envelope of the exhaust duct enclosed
  • related equipments: e.g. gas module, generator

This noise is so powerful that it is potentially causing noise pollution for personnel of the operator operating in the vicinity as for the neighborhood (including long distance). It is often necessary to use in such cases a soundproofing equipment of high technology to ensure compliance of the installation of 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.

ITS will participate in the diminution of noise emitted by two combustion turbines with high power output (almost 400 MW) for a power generation unit in the Indian sub-continent.

This equipment will have a sound reduction particularly important (the overall sound power level to be considered is greater than 135 dBA for one of the sub sets and noise emissions are with a very wide frequency spectrum), requiring a specific design of the partitions and of the ventilation system which is one of the major features of the soundproofing equipment.

The optimization of the cost and of the duration of intervention for assembly and disassembly operations are key factors of success of the efficient soundproofing concept considered for the diminution of the noise emitted by those combustion turbines.

The simulation of the sound attenuation of partitions, of the insertion loss (with and without flow noise) and of the total pressure loss of ventilation silencers as well as the simulation of the impact after soundproofing on the one hand in terms of sound power level and on the other hand in terms of sound pressure level at specified positions will be performed

Specific materials and construction systems to meet ambitious and varied targets in terms of technical performance will be integrated into the design as required for the diminution of the noise emitted by those combustion turbines.

Related features such as weather resistance, disassembly of the whole and of subsets, securities, lighting, electrical works ... will be integrated according to the needs.

The reduction of the noise emitted by these two combustion turbines will be achieved by the construction of soundproof buildings, consisting of a metal frame, modular industrial sound insulation panels, removable to make maintenance operations possible, acoustic door units to allow access for personnel assigned to monitoring and maintenance and ventilation systems for the inlet of fresh air and for the outlet of hoter air, the temperature rise being a function of the thermal power thermal to be evacuated and of air change rate.

The whole set will be prefabricated in the workshop, packed in sea containers that will be transported by truck, by boat and then by truck to the site of the power plant in question.

The assembly will be carried out by local teams, using the documentation carefully prepared by the commercial partner of ITS in charge of factory manufacturing, to make possible such assembly work even by a workforce for which the achievement of such tasks do not constitute rotonier or even habitual work.

If necessary, a supervisor attached to the entity in charge of factory manufacturing can be sent on site to facilitate the familiarization of local fitters (if none has experience) for a construction technology which has been proven for decades in similar contexts of soundproofing of power generation equipment.

As always required in this case, the prior  design and engineering works will have taken into account the specificities of the project, in particular site data (snow, wind, seismic risks) and technical and administrative local charges (e.g. a particular construction code).

The respect of the deadlines (especially in a context involving a transport by boat that would not accommodate a possible delay), limiting the duration of the development and all the other phases of the soundproofing project, will constitute of course a key factor for the success of this operation, for which the technical and financial issues will be important (the application of penalties in case of delay is a common practice in the oil and gas sector when it comes to preventing  operating losses due to the non-operational nature of facilities).