Analysis of the noise of diesel generators have what classification

Diesel generators to customers constitute the problem is the noise of these loud curbing noise, these noises in addition to the noise of the generator itself, but also the following classifications:.

　　A, mechanical noise: in the process of operation, the engine's moving parts by the pressure of the gas, and the movement of the inertial force of the cycle of change constitutes a boom known as mechanical noise, serious

　　(1) the noise of the piston crank connecting rod organization

　　(2) the noise of the gas distribution organization

　　(3) the noise of transmission gear

　　(4) unbalanced inertia force constitutes the mechanical boom and noise.

　　Second, exhaust noise: exhaust noise is a high temperature, high-speed pulsating airflow generated by the noise, in is the diesel generator noise is zui. Primarily divided into.

　　(1) periodic smoke exhaust caused by low-frequency pulsation noise

　　(2) The noise generated by the resonance of the gas column in the exhaust pipe

　　(3) The noise generated by the resonance of the cylinder Helmholtz

　　(4) High-speed airflow through the valve gap and the noise generated by the curved pipe

　　(5) Vortex noise and smoke exhaust system in the duct inside the pressure wave inspired by the regeneration noise, etc.

　　Third, the cooling fan and exhaust noise: diesel generator fan noise is composed of eddy current noise and rotating noise, airflow in the rotating blade cross-section of the noise generated by the separation of eddy current noise, electric fan blades cut the air flow generated by the periodic disturbance of the noise caused by rotating noise.

　　Fourth, into the wind noise: diesel generator normal operation requires an adequate supply of fresh air. One is to ensure the normal operation of diesel generators, the second is to create outstanding heat dissipation conditions for diesel generators. Diesel generator air inlet channel to allow fresh air into the room, together with the diesel generator mechanical noise and airflow noise, but also through this air inlet channel radiation to the outside of the engine room.

　　Fifth, combustion noise: diesel fuel in the process of combustion generated by the structure of the boom and noise is combustion noise. Combustion noise in the cylinder inside the sound pressure level is very high, however, in the structure of the diesel generator most of the parts of the steel is relatively high, their self-vibration frequency is mostly in the high frequency region, the frequency response to the acoustic communication does not match, in the low frequency band very high cylinder pressure level peak can not be smoothly transmitted out, and the high frequency band cylinder pressure level is relatively simple and easy to transmit out.