Jun 20, 2016 - AgricEngInt: CIGR Journal Open access at http://www.cigrjournal.org. Vol. 18, No. ..... generator equipped with modified enclosure at full load in.
September, 2016
AgricEngInt: CIGR Journal Open access at http://www.cigrjournal.org
Vol. 18, No. 3
159
Noise reduction of a portable gas generator set using an acoustic enclosure Zahra Ghorbani1, Seyed Reza Hassan-Beygi1*, Barat Ghobadian2 (1. Department of Agro-technology, College of Abouraihan, University of Tehran, Tehran, Iran; 2. Department of Mechanics of Biosystem Engineering, Tarbiat Modarres University, Tehran, Iran) Abstract: The present experimental study has been conducted to evaluate the effect of different developed acoustic enclosures on the noise emission of a small generator set fuelled by natural gas. The sound signals of generator without enclosure and covered by developed enclosures were measured in front of the generator exhaust at five electric loading conditions (0%, 25%, 50%, 75% and 100% load). The sound signal was measured according to SAE J1074 test procedure. The recorded digital sound signals were converted to frequency domain using Fast Fourier Transform (FFT) algorithm. The results revealed that the simple enclosure (SE) and modified enclosures were effective to attenuate the generator noise at frequencies greater than 800 Hz and 250 Hz, respectively. The acoustic performance in attenuating the generator noise for the semi-covered modified enclosure (SME) and fully covered modified enclosure (FME) was better than for the SE enclosure. The acoustic performance of all enclosures was reduced with increasing the generator load especially at full load condition. The results of analysis of variance (ANOVA) showed that the generator loading condition, the enclosure setup mode and their interaction had a significant effect (P
