NUMERICAL MODELING OF REFRIGERATOR COMPARTMENTS

The present study investigated the three dimensional airflow and temperature distribution in the fresh food and freezer compartments of a bottom mount refrigerator using the computational fluid dynamics (CFD) methods. The shelves in the refrigerator were modelled as an obstacle to the flow and as a thermal resistance for the heat transfer. The fan characteristic curve was given as an input in the model to account for the airflow from the fan and the pressure drop across it. The effect of buoyancy forces was considered. The investigations were performed under no load conditions. A steady state analysis was first carried out to study the airflow and thermal uniformity in the compartments. The variation in the air temperature among the shelves of the fresh food compartments was within 3.3 degrees C. The predicted temperature field was validated against in-house experiments. The differences were within 7%. A transient analysis was then performed to study the pull down cycling. The component model was used to obtain the variation in the evaporator tubing temperature with time. The obtained temperature variation was used as a boundary condition in the CFD simulation. The predicted compartment temperature agreed qualitatively with the experimental data. Overall, the presented numerical analysis can assist designers make some preliminary design decisions and comprehensive analysis faster than the experiments.