Noise types of diesel units (for reference only: YANAN diesel generator response: 4000-080-999)
1. Exhaust noise:
The exhaust air noise is loud. temperature, noise of high speed pulsing air flow. This is the most energetic part and the most component of engine noise. It is much higher than the intake noise and the mechanical noise emitted by the body, and constitutes the largest component of the total engine noise. Its fundamental frequency is the engine firing frequency. The main components of exhaust noise are: low-frequency pulsation noise caused by periodic exhaust smoke, resonance noise of the air column in the exhaust pipe, Helmholtz resonance noise of the cylinder, high-speed airflow through valve clearances and twisting pipes. noise, eddy noise and regeneration noise generated by the evacuation systemn fumes under the excitation of pressure waves in the pipe, etc., increase significantly as the air flow speed increases.
2. Mechanical noise:
Mechanical noise is mainly caused by the vibration or mutual impact of the moving parts of the engine caused by the periodic changes of gas pressure and inertia force of movement during Among The most serious ones are: crank rod mechanism noise, valve mechanism noise, transmission gear noise, and mechanical vibration and noise caused by unbalanced inertia force . The strong mechanical vibration of the diesel generator set can be transmitted to various places outdoors through the foundation over long distances, and then form noise by ground radiation. This type of structural noise travels far and has low attenuation, making it difficult to isolate onceshape.
3. Combustion Noise:
Yanan Generator Tip: Combustion Noise is the structural vibration and noise generated by diesel during the combustion process. The sound pressure level of the combustion noise in the cylinder is very high. However, most parts of the motor structure have high rigidity, and their natural frequencies are mainly in the mid to high frequency range. frequency of propagation of sound waves, in the low frequency band. Very high cylinder pressure peaks cannot be transmitted smoothly, while cylinder pressure levels in the mid to high frequency range are relatively easy to transmit.
4. Cooling Fan and Exhaust Noise:
Cummins generator set fan noise is composed of eddy current noise and rotation noise. The rotation noise ist generated by the engine blades. the fan cuts off the air flow. Caused by periodic disturbances; A swirling sound is generated when the airflow separates over the rotating blade section. The vortex flow caused by the viscosity of the gas emits unstable flow noise. Exhaust noise, airflow noise, fan noise and mechanical noise are all radiated through the exhaust channels.
5. Intake Air Noise:
Yanan Generator Tips: The diesel generator set should have sufficient fresh air supply during normal operation. On the one hand, it ensures the normal operation of. the engine. On the one hand, good heat dissipation conditions must be created for the unit, otherwise the unit cannot guarantee its performance. The air inlet system of the unit basically consists of the air inlet channel and the air inlet system of the engine itself. The air inlet channel of theUnit must be able to allow fresh air to enter the engine room smoothly. Mechanical noise and airflow noise from the unit can also be radiated to the machine room through this outside air inlet channel.
6. Generator noise:
Generator noise includes electromagnetic noise caused by the pulsation of the magnetic field between the stator and rotor, as well as mechanical noise generated by rotating bearings