Analysis on Noise Control of Diesel Generator Set

With the continuous development and progress of society, the demand for electricity in various industries in China is constantly increasing, and the performance requirements for power supply facilities and systems are also increasing. In the field of generators, diesel generators have made significant progress, but inevitably generate a large amount of noise pollution during their operation, which has a certain impact on the surrounding environment and people's health. This article analyzes the noise sources of diesel generator sets and proposes effective control measures, which have reference value for noise reduction work of diesel generator sets.

Keywords: diesel generator; Noise; Noise reduction; control measures

The noise of diesel generators is usually caused by the following factors: aerodynamic noise caused by intake and exhaust, combustion noise of diesel generator sets, and mechanical noise caused by vibration of mechanical components during operation. The noise composition of diesel generator sets is relatively complex, usually formed by a combination of multiple types of noise sources. Through the propagation and radiation of noise, the main sources of diesel engine noise are generally aerodynamic noise and surface radiation propagation noise. Based on the cause of diesel generator noise. The surface radiation noise of diesel units can also be divided into the noise generated by diesel combustion and the noise generated by mechanical component operation.

1、 Analysis of Noise Sources of Diesel Generator Sets

（1） Aerodynamic noise

During the operation of the diesel generator set, the disturbance of the air causes a sound source to be generated between the air and the diesel generator set, resulting in noise. This noise directly radiates externally, including; The noise of the exhaust system, the noise of the intake system, and the rotational noise of the diesel engine cooling fan.

(1) Exhaust system noise. The most direct source of noise for diesel generator sets is the noise generated by the exhaust system, which is relatively high in intensity. Compared to normal engine noise, its noise value is about 10-15dB (A) higher. During the operation of the generator set, high-temperature and high-pressure exhaust gases need to be continuously discharged. According to the operating status of the generator set, the exhaust system has two stages during exhaust, They are free exhaust of the generator set and forced exhaust of the generator set. When the exhaust gas from the generator set is discharged from the exhaust valve, it will flow from the exhaust pipe to the muffler. Finally, it is discharged into the air through the tail exhaust pipe, and during the entire exhaust process, a large amount of exhaust noise is generated, which is also the main source of noise for diesel generator sets. Analyzing the noise generated during the exhaust process, it was found that the components of the noise sources are relatively complex, including the noise generated by the frequency fluctuations of the exhaust system's exhaust per unit time, the noise caused by the resonance of exhaust gas in the exhaust pipeline, and the blowing noise caused by the airflow ejected from the exhaust pipe mouth. The main reasons that can have an impact on the noise of the exhaust system of the generator set include the internal pressure of the engine cylinder, the diameter of the exhaust system pipeline, the rated exhaust volume of the generator set, as well as the operating speed and workload of the generator set. Increasing the working load of the generator set or increasing the engine speed will increase the gas flow, leading to an increase in exhaust noise.

(2) Intake system noise. The noise generated by the intake system, as one of the main noise sources of diesel generator sets, is the main cause of its formation