How to Do Noise Reduction in Generator Room

by Generator D. Diesel Generator

In normal operation, the noise of diesel generator set is mainly exhaust noise. The noise of diesel generators will cause certain pollution to the environment, which will easily affect people's work efficiency and interfere with their normal life. Low noise generators/silent generators must be used in densely populated areas or in places with stringent environmental noise requirements. Therefore, it is necessary to reduce noise in the diesel generator room.

1. Ventilation and noise reduction in machine room

In practical work, we must consider both the effective noise reduction and the air flow required for the operation of the generator set. Two air inlet shaft are built with bricks outside the machine room. A low-noise axial flow fan is installed under the air inlet wall to supply air to the machine room. A large air volume combined muffler is installed in the air duct to absorb airflow noise and mechanical noise. An air inlet is opened on the wall outside the air inlet duct and a protective screen is installed at the air inlet to prevent foreign matter from entering the air duct.

2. Machine room exhaust system silencing

Exhaust air must be silenced through the muffler air duct provided outside the machine room to minimize noise. The outside of the muffler air duct is a brick wall structure, and the inside is a sound absorbing panel. Air outlet is arranged directly in front of the genset, and the front end of the unit radiator is provided with a vibration-damping flexible joint and a wind-conducting expansion sound-absorbing air duct, which is connected to the exhaust hot air silencing channel. Special aluminum alloy shutters and protective wire mesh are installed at the outlet of the exhaust duct to prevent foreign matter from entering the air duct.

3. Genset exhaust silencer

A sound reducing enclosure can be added to the exhaust gas system of the generating set, and at the same time, the exhaust silencing pipes are all wrapped with fireproof rock wool material, which can not only reduce the heat dissipation of the unit into the machine room, but also reduce the working vibration of the unit, so as to achieve the purpose of noise attenuation.

4. The machine room sound absorption

Since the generator room is brick concrete structure, it has strong noise reflection. In order to achieve the sound absorption effect, the wall and the top surface of the machine room are reasonably equipped with high-efficiency sound absorbing materials, and the sound absorbing layer structure is an aluminum alloy perforated gusset plate + centrifugal sound absorbing cotton + light steel keel + support hanger. The original average sound absorption coefficient in the equipment room is α1≈0.10. After the sound-absorbing material is installed, the average sound absorption coefficient in the machine room is α2≈0.75～0.85, and the sound absorption can reach 9～12dB(A), and the reverberation time can be reduced to 2~3s. The loudness in the equipment room is also greatly reduced, which greatly improves the working conditions and the sound insulation performance of the generator room.

5. Sound insulation system

In order to ensure good sound insulation performance of the machine room, a fireproof soundproof door is installed in the connection between the machine room, and the sealing material of the door is a rubber seal strip. Other holes that cause sound leakage are blocked with brick walls.