Comparative Analysis of Different Configuration Domestic Refrigerators: A Computational Fluid Dynamics Approach

摘要

To reduce the tremendous increase in the energy consumption in the residential sector, there is a continuous need to improve the cooling efficiency and reduce running cost in domestic refrigerators. In this regard, three domestic refrigerator configurations have been considered. These configurations, namely, top mounted freezer (TMF), bottom mounted freezer (BMF), and side mounted freezer (SMF), were numerically simulated using ansys fluent 14 code. The refrigerators considered in this paper are air cooled by natural convection mechanism. For improved accuracy, piecewise polynomial function was used to obtain the temperature dependent specific heat capacity, while the discrete ordinate (DO) model was used to account for the radiation energy exchange between the refrigerator walls and cooling air. The effect of refrigerator opening and refrigerator load on the performance of the model refrigerators was also studied. Results show that cabinets that have the same relative position from the base (ground level) in TMF, BMF, and SMF configuration was observed to have similar cooling effectiveness irrespective of the compartment (i.e., freezer or fresh food). Load in the lowest parts of the model refrigerator consistently maintains the highest cooling effectiveness with about 15% more than their respective topmost cabinet. Thus, consumer preference of highly efficient compartment (either freezer or refrigerator) should be considered. After 300 min cooling time, the TMF and BMF cooling load are more than that of SMF by about 8%. This suggests that SMF with better cooling effectiveness will consume less energy and would have a lower running cost.