Numerical Analysis of Air Flow in an Industrial Refrigeration System and Its Effect on Energy Consumption

Abstract

Refrigerated display cabinets as a type of cooling system is preferable commonly in food shops and grocery store to prevent foods from warm air. They do not have much more efficient compared to the cabinets with glass doors because of the interactions between air curtain. This paper presents experimental and numerical methods to seek energy performance of the horizontal refrigerated display cabinets in terms of design parameters. Two geometry with/without airfoil were designed and evaluated the effects of discharge velocity to create more efficient air curtain. 2D Computational Fluid Dynamics (CFD) model was performed to assess the effect of discharge flow on the cooling load performance of the horizontal display cabinet. The results showed that the airfoil design has increased the efficiency of the air curtain with achieving a more effective air curtain, resulted in mitigation of the ambient warm air infiltration into the cabinet. The return air temperature of the cabinet with airfoil decreased from 272.45 K to 270.62 K compared to the one without airfoil due to more effective air curtain. In this way, the cooling capacity of the refrigeration system has been decreased by 3.82% with airfoil usage. It is also concluded that the air temperature inside the cabinet and the cooling capacity have been decreased by 3.5°C and 2.82%, respectively when Case 7 for used the new type airfoil and Case 1 with the same air velocity are compared.