Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
EXPANSION NOISE IN HOUSEHOLD REFRIGERATORS: AN EXPERIMENTAL STUDY
Submission Author:
Carlos Boabaid Neto , SC , Brazil
Co-Authors:
Carlos Boabaid Neto, claudio melo, Arcanjo Lenzi
Presenter: Carlos Boabaid Neto
doi://10.26678/ABCM.ENCIT2018.CIT18-0412
Abstract
Among the sources of noise in refrigerators, the expansion noise produced by the flow through the expansion device is one of the least understood. The aim of this study was to investigate experimentally the acoustic excitation generated by the expansion process in a typical household refrigerator equipped with capillary tube, employing direct measurement of the acoustic pressure within the refrigerant flow. A transparent filter-dryer was used in order to visualize the flow pattern at the capillary tube inlet. Tests were carried out under several operating conditions. It was observed that a vortex is formed at the capillary tube inlet under certain conditions. The jet flow at the capillary tube outlet was the dominant source of acoustic excitation associated to the expansion process. A larger diameter capillary tube produced lower levels of acoustic excitation, especially when combined with a higher refrigerant charge. Reducing the speed of the compressor had the effect of reducing the acoustic excitation. The initial period of the operating cycle of the system was the most critical. The acoustic excitation was higher in after-defrost cycles. For the condition of continuous vortex formation, the acoustic excitation showed the lowest levels. The findings bring valuable information to the design of household refrigerators.
Keywords
Household Refrigerator, capillary tube, expansion noise
