Emission reduction - noise
Noise is an increasing form of environmental pollution. During the past ten years the significance of noise has increased heavily, both from the society’s and especially from the industry’s viewpoint. People do not accept noisy surroundings or noisy machines anymore.
The requirements set by legislation for noise vary depending on the projected location and operational mode of the plant. E.g. residential or industrial area, country of location, baseload or peaking plant and finally hours of operation affect this. Primary design target is to meet local legislation and regulations on environmental noise. In absence of local norms, international criteria on environmental noise such as World Bank Environmental, Health and Safety (EHS) guidelines can be applied.
Power plant environmental noise
The acoustical design of a power plant is being integrated to the Wärtsilä plant delivery process to an increasing degree, starting already in the sales phase.
Wärtsilä’s responsibility for environmental noise depends on the scope of the delivery, reaching its maximum in EPC or “turnkey” projects. Typically Wärtsilä guarantees the noise immission of a power plant at a specified distance from the site or at specified receptor positions. Or the sound power level (noise emission) of plant equipment can be specified.
Power plant acoustic integrated in the design process
Power plant noise impact is estimated during the environmental impact assessment process. Starting point is the evaluation of background noise on the area surrounding the power plant during the sales phase of a delivery project.
The potential disturbance to facilities in the plant proximity such as residences, schools and hospitals is assessed by environmental noise modelling. The technical feasibility and machinery-acoustical functioning of the design is estimated by utilising different acoustical modelling methods. All the modelling work is based on reliable experimental source data definition and validation work.
The purpose of power plant acoustical modelling and simulation is to optimize the methods used to reduce the plant noise impact. The process is iterative by nature.
Suitable solutions for different environments
A concept plant with inbuilt silent features is an option for urban generation. The solution can also be a Wärtsilä standard power plant, modified by utilising different acoustical technologies to achieve the required low noise emission.
A plant to be located on industrial areas can usually be designed to less stringent acoustical standards. The background noise level is often relatively high and the standard power plant is then a cost-effective solution, without significant impact on the ambient noise level or soundscape.
A technically feasible and acoustically good solution is achieved by addressing the following aspects:
- Optimising the plant layout: selection and location of noise-critical components.
- Attenuation of the charge air intake and exhaust outlet
- Cooling and ventilation systems: effective cooling and ventilation by usign optimal fans, minimisation of fan-generated noise, control of ventilation intake and outlet noise
- Power plant building design: optimal wall structures
It is apparent that the plant noise emission is as much due to auxiliary components as the actual generating set. One important aspect of power plant acoustics is the design of better and silent auxiliary components in co-operation with suppliers.