Noise Reduction

Minh Thanh J.S.C. has years of experience in generator room noise reduction. The principle of noise reduction is to, with ventilation conditions being guaranteed, or without reducing the output power, adopt highly efficient sound-absorbing materials and noise-reducing muffler for treatment on the intake and exhaust systems, so as to reach the national standard. Provisions on noise at various occasions are proposed by the Ministry of Environmental Protection of the PRC as follows:

 

Class Day Night Applicable areas of each standard
0 50 40 Class 0 is applicable for sanitarium areas, premium villas, luxury hotel areas and other places where quietness is specially required. This kind of areas located in suburbs and villages are strictly executed according to 5dB standard as stipulated by Class 0.
1 55 45 Class 1 is applicable for areas based on residential and cultural and educational institutions. The standard can also be referred to for rural living environments.
2 60 50 Class 2 is applicable for mixed areas of residence, commerce and industry.
3 65 55 Class 3 is applicable for industrial areas.
4 70 55 Class 4 is applicable for highways and both sides of highways in the city as well as inland waterways running across the urban area. The standard is also applicable for limits of background noise (i.e., level of noise when no train is passing by) at both sides of railway trunks and distributors.

 

The basic method of noise reduction is to apply noise reduction technology on the sound source: such as muffler, sound insulation, sound absorption and vibration isolation etc. The following is our governance program room noise sources provided on the basis of a comprehensive analysis of noise sources

 

  1. Reducing exhaust noise. Exhaust is the main noise source of the genset, which is characterized by high temperature and speed. The second muffling and the special complex impedance muffler are able to reduce the noise by 40-60db (a)
  2. Intake and exhaust. To solve the heat problem within the generator room, the air intake and the air exit are best to be designed on the same line. Resistive noise reduction grid pieces are set in the intake and outlet ducts, where the sound waves are cut and its direct transmission is hindered
  3. Sound insulation. After venting and exhaust noise treatment, the rest sound source primarily comes from machine and combustion. The method is to, except for the necessary interior observation window connected to the observation room, remove all other windows and tightly block all holes. Sound insulation of brick wall is required to be 40db (a) or above, and fire-resistant soundproof doors and windows shall be used for the generator room
  4. Sound absorption. The 5 walls except for the floor of the generator room shall be processed with sound absorption treatment. Based on the spectral characteristics of Genset, the resonant structure of micro-perforated plate is used, glass fiber cotton is paved inside the walls and fixed by light steel keels which are also installed with perforated noise-reducing plate for diffusion and sound absorption
  5. Indoor air convection. Good sound insulation will disable the air convection in the generator room when the closed water-cooled Genset has shut down and the room temperature will not come down in time. In this case, low axial fans can be used with impedance piece device to prevent acoustic wave leakage
  6. Vibration isolation. Before the Genset is installed, the foundation and isolation ditch shall be set up, with damping pads installed on the foundation for vibration isolation so as to avoid vibration transmission.

 

Sufficient space within the generator room is generally required for noise reduction. The noise reduction effects will be greatly affected if the user is unable to provide a generator room with sufficient area and height. In order to realize noise control without compromising the normal operation of the Genset, it is necessary to leave certain space in the generator room for setup of the outlet duct, sound-absorbing walls, ceiling, and the operating space for staff