Microchannel heat exchangers, although widely used in the automotive and air-conditioning industry, are not usually used in domestic refrigeration especially because of its prohibitive cost. However, with the recent manufacturing processes advance, these heat exchangers have become a tangible option, mainly due to their compact design and high heat transfer rate per unit of volume. This work aims to theoretically and experimentally evaluate the impact of the use of forced-draft microchannel condensers on a specific household refrigerator model. In this context, a mathematical model was developed to predict the heat transfer rate and the air-side pressure drop of microchannel heat exchangers. This model was incorporated to an existing simulation platform for household refrigerators, which allowed correlating the geometry of the heat exchanger with the energy consumption of the appliance. Experiments were carried out in a wind tunnel and in a climatic chamber, which allowed validating both condenser and refrigerator mathematical models. It was observed that the prediction of the heat transfer rate and the air-side pressure drop in the condenser respectively remained within ±10% and ±20% error bands. It was also found that energy consumption was predicted with maximum errors of ±3.5%. Sensitivity analyzes were also performed, pointing to a 13% drop in the energy consumption of the refrigerator with the use of a microchannel condenser with 20 passes, 200mm high, 180mm wide, 72mm deep, 200 fins per meter and 46 rectangular channels of 1.2mm of hydraulic diameter.
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