Vol. 10, No 1, 2013 pp. 13 - 26
UDC 534.61:613.644:64.06
SOUND INTENSITY MEASUREMENT AS A DIAGNOSTIC TOOL FOR THE NOISE REDUCTION OF DOMESTIC REFRIGERATORS
Nikola Holeček1, Momir Praščević2
1Gorenje, d.d., Environmental protection College, Velenje, Slovenia
E-mail: nikola.holecek@gorenje.si
2University of Niš, Faculty of Occupational Safety of Niš, Serbia
Abstract. In addition to highly complex functional features and low energy consumption, the silent operation of a domestic appliance is an essential design component of a modern integrated refrigerator and freezer. This is because noise emission is an extremely important differentiating factor when choosing a new appliance; therefore, manufacturers of exceptionally silent appliances usually advertise their low noise emission using terms such as "super silent operation". This article presents a procedure to obtain the desired noise level for such an appliance. All measurements were conducted in an acoustics laboratory, under free-sound-field conditions. The level of noise in the different development phases was represented by the total sound-power level, the frequency spectrum and the use of sound imaging analysis. The critical sources of internal noise were determined based on experimental results and based on this the necessary design modifications to reduce the sound-power level from 57.6 dB (A) to an acceptable 44.5 dB (A) were made.
Key Words: noise source, sound intensity measurements, noise source location, noise reduction, domestic appliance
MERENJE INTENZITETA ZVUKA KAO DIJAGNOSTIČKI ALAT ZA REDUKCIJU BUKE KUĆNIH FRIŽIDERA
Pored vrlo složenih funkcionalnih karakteristika i niske potrošnje energije, tihi rad je bitna komponenta modernog integralnog frižidera. To je zbog toga što je emisija buke izuzetno važan faktor za kupca pri izboru novog aparata. Proizvođači tihih frižidera obično reklamiraju njihovu nisku emisiju buke koristeći pojmove "super tihi rad". Ovaj rad predstavlja postupak za postizanje željenog nivoa buke za jedan takav aparat. Sva merenja izvedena su u laboratoriju za akustiku, u uslovima slobodnog zvučnog polja. Nivo buke u različitim fazama razvoja je izražen ukupnom zvučnom snagom, frekvencijskim spektrom i pomoću vizualiziranih slika zvučnog intenziteta. Na osnovu tih eksperimentalnih rezultata određeni su kritični izvori buke, što je omogućilo neophodne izmene konstrukcije frižidera za smanjenje ukupnog nivoa zvučne snage od 57 dB(A) na prihvatljivih 44,5 dB (A).
Ključne reči: izvor buke, merenje zvučnog intenziteta, lokacija izvora buke, smanjenje buke, aparati za domaćintstvo