NUMERICAL INVESTIGATION OF HEAT AND MASS TRANSPORT IN A REFRIGERATED VEGETABLE CRISPER WITH NATURAL CONVECTION

摘要

Heat and mass transport and surface condensation in a refrigerated vegetable crisper having one air inlet and one air outlet were numerically investigated with heat and mass transfer due to food respiration and transpiration. In the numerical model developed, food load and air-flow area within the refrigerated space were taken as two separate control volumes interacting with each other at their boundaries, and timedependent transport equations of each control volume were simultaneously solved. Air inlet velocity was taken as Gr/Re~2 in the crisper being in a range that natural convection conditions arise. In the parametric analyses, effects of the storing temperature and temperature difference between the top surface and other surfaces on momentum, heat and mass transport in the control volumes, moisture loss of the food load due to transpiration, and the amount of surface condensation through the top surface were determined. Weight loss of cucumbers in the situation of 4 K temperature difference between top surface and other boundary surfaces; were calculated to be ～20% more than the weight loss in the situation of 2 K temperature difference.