Noise Source Identification And Control Of Small Gasoline Generator

For the reason of their in-use environment, the noise pollution of the generator sets and other non-road equipment have more serious negative effect on people. Therefore, in order to minimize the hazards to human, their radiation noise level has been restricted strictly by developed countries. The small gasoline-powered generator sets was one of the most salable product in Chinese electromechanical products exported and which brings about enormous foreign exchange earnings for China. However, the noise of the small gasoline generator sets is difficult to control, which has seriously affected the export of the generator sets. In this paper, taking homegrown 5kW gasoline generator sets as the research object, carrying out the research work of the noise source identification and control.First, the main noise source of the generator sets was identified based on the sound intensity measurement method, and the sound power contribution ratio of the sound source for the whole machine was calculated, and the order of the noise sources needed to be control was ascertain to be exhaust noise, intake noise and fan noise. Based on above study, in order to reduce the exhaust noise, improved design and numerical value simulation was applied on the muffler assembled to the generator sets; the acoustics Finite Element model of the muffler was founded; the Transmission loss of muffler was analyzed by using software SYSNOISE. Then compared the Transmission loss of these mufflers with the different configuration; selected the optimum design configuration. The test result showed that the Insertion Loss was improved about 3dB(A) and the Power Loss was reduced about 1.3%. Aiming at the induction noise and the cooling fan noise, Airflow of air cleaner and fan were analyzed based on CFD method, and the gas pulsation and acoustics characteristic of air cleaner and cooling fan were further researched. By comparing the numerical value simulation result of air cleaner and fan with the different configuration, the design configuration was optimize and the induction noise and the fan noise was reduce. The results showed that the sound power of whole machine's noise could be reduced about 1.6dB (A) by using the improved air filter with optimal structure, and could also be reduced about 1.6dB (A) by using the improved cooling fans with optimal structure.According to the improvement, the noise of 5kw small gasoline generator was controlled and reached the expected aim, the sound power of the whole noise was decreased from 101dB (A) to 97 dB (A). The results showed that the method of the noise source identification and control aiming at small gasoline generator sets was correct; the main noise source control program was effective. Research methods and the improved design provided reference for the noise control of other types gasoline generator set.