Xiamen Aosif Engineering Ltd 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,
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 the floor of the generator room shall be processed with sound absorption treatment. Based on the spectral characteristics of genset, 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 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.