The existence of diesel generators facilitates our lives and provides us with backup power in the event of an accident, but diesel generators provide us with convenience at the same time, they also bring us noise, which directly affects our health, work and life.
The noise of diesel engine set is a complex sound source composed of many kinds of sound sources. The main noise sources are generated by diesel engines, including exhaust noise, mechanical noise and combustion noise, cooling fan and exhaust noise, air intake noise, generator noise, and noise generated by the transmission of foundation vibration.
1. Exhaust noise. Exhaust noise is a kind of high temperature, high speed pulsating air flow noise, is a kind of energy in engine noise, its noise can reach more than 10, is an important part of the total engine noise.
2, mechanical noise and combustion noise. Mechanical noise and combustion noise is difficult to strictly distinguish, usually due to the pressure fluctuation caused by combustion in the cylinder through the cylinder head, piston, coupling, crankshaft, body radiation noise is called combustion noise. The noise caused by the impact of piston on cylinder liner and the mechanical impact vibration of moving parts is called mechanical noise. Generally, the combustion noise of direct injection diesel engine is higher than the mechanical noise, and the mechanical noise of non-direct injection diesel engine is higher than the combustion noise. However, combustion noise is higher than mechanical noise at low speed.
3, cooling fan and exhaust noise. Fan noise is composed of eddy current noise, rotating noise and mechanical noise. Exhaust noise, airflow noise, fan noise, and mechanical noise will spread out through the exhaust channel, thereby causing noise pollution to the environment.
4. Air inlet noise. The role of the air inlet channel is to ensure the normal operation of the engine and to create good heat dissipation conditions for the unit itself. The air intake channel of the unit must be able to allow the air to enter the room smoothly, but at the same time, the mechanical noise and airflow noise of the unit will also radiate to the outside through this air intake channel.
5. Transmission noise of foundation vibration. The intense mechanical vibration of the diesel engine can be transmitted over long distances through the ground and then radiated through the ground.
In the case that the noise source can not be reduced, the diesel generator set can be taken according to the need for sound insulation, sound absorption and sound reduction of the comprehensive treatment.
1. Ventilation and noise reduction in the equipment room. In actual work, when we consider the scheme, we should not only effectively reduce noise, but also meet the air flow required by the operation of the generator set.
(1) Air inlet noise reduction system in the machine room. In order to meet the amount of cooling air and combustion air required during the operation of the unit, the machine room is ventilated by mechanical air intake. Two air inlet channels are built with bricks outside the equipment room, and a low noise axial fan is installed under the air inlet channel wall to supply air to the equipment room. A large air volume combined plate muffler is installed in the air inlet duct to absorb airflow noise and mechanical noise. An air inlet is opened on the outer wall of the air inlet, and special aluminum alloy shutters and protective mesh are installed at the air inlet to prevent foreign matter from entering the air inlet.
(2) Exhaust air muffler system in the machine room. Brick two exhaust ducts outside the machine room. A large volume combined sheet muffler is installed in each exhaust duct to absorb exhaust flow noise and mechanical noise. The exhaust outlet is arranged in front of the unit, and the front end of the radiator of the unit is provided with a vibration reduction flexible connector and an air deflector expansion muffler air pipe, which are connected to the hot air muffler channel. Special aluminum alloy shutters and protective mesh are installed at the outlet of the exhaust duct to prevent foreign matter from entering the air duct.
(3) Unit exhaust muffler
The exhaust muffler randomly configured in the generator set has a very small amount of noise, and an efficient micro-perforated plate exhaust muffler designed for high, medium and low frequency noise is re-installed on the exhaust pipe of the generator set. It is characterized by large noise reduction, low resistance, and high temperature resistance of material and structure. The exhaust pipe and the flue gas outlet of the unit are connected with metal bellows to reduce the vibration and noise caused by the steel connection.
2. Sound absorption in the equipment room.
Because the generator room is a brick concrete structure, the sound reflection is strong. In order to achieve the sound absorption effect, the walls and top surfaces of the equipment room are reasonably equipped with efficient sound absorption materials. The sound absorption layer structure is aluminum alloy perforated fastener plate + centrifugal sound absorption cotton + light steel keel + support hanger. The loudness in the machine room is also greatly reduced, greatly improving the working conditions, and improving the sound insulation performance of the machine room.
3. Sound insulation system.
To ensure sound insulation in the equipment room, install a fire insulation door at the communication between the equipment room and the outside. The sealing material for door cracks is rubber sealing strips. Other leaky holes should be blocked with brick walls.
Post time: Jun-21-2023