Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Numerical simulation of external sweating in a static refrigerator
Submission Author:
Vitor Fiorito , MS
Co-Authors:
Vitor Fiorito, Leandro Salviano
Presenter: Vitor Fiorito
doi://10.26678/ABCM.COBEM2023.COB2023-0753
Abstract
In this paper, a numerical modeling of a commercial refrigerator is developed to examine its external sweating under different environmental conditions. External sweating is a critical malfunction that may occur in these devices, and it is caused by the condensation of wet air at any point below the dew point. For commercial scenario, the liquefied water slips off on the surfaces which may potentially damage the product or even cause other inconveniences to the end user, aside from the restrictions on product exposure at the point of sale. There are numerous experimental and numerical works in the literature that address the physics of this process and focus on the development of hydrophobic surfaces to mitigate the occurrence of this phenomenon. For refrigerators, most studies focus on the assessment of this problem on external surfaces. However, few works were found conducting a full external analysis of the refrigerator. Thus, the present work focused on the appraising of the external temperature profile by the internal flow modeling and the heat transfer through the walls. The main heat transfer mechanism in the refrigerator analyzed is natural convection due to buoyancy differences in the internal flow and conduction through the walls. The phenomena of air movement and stratification are critical for the emergence of this problem. Condensation zones were identified by evaluating the dew point for different ambient conditions (25°C - 60% / 32°C - 65%). The results show relevant condensation zones on the door, back and gasket of the refrigerator and its surroundings. The internal air distribution and cooler construction were out to be crucial factors in both the development and size of these sweating zones. Finally, a parametric study was carried out to investigate the main variables involved in this phenomenon which showed a direct correlation between the phenomenon occurrence and the thermal conductivity level of the insulation material, as opposed to density variation, which has not been shown to be effective.
Keywords
Refrigeration, condensation, Sweating, Computational Fluid Dynamics, Parametric analysis
