5. Conclusions

Refrigeration slows down the chemical and biological processes in foods, such as the accompanying deterioration and the loss of quality, extending the shelf life of the products.

Food chilling is performed with mechanical refrigeration systems or with ice; the temperature of the product is lowered to 0–8C, depending on the type of food. The chilling medium in mechanically cooled chillers may be air, water, or metal surfaces; batch or continuous operation is possible when using mechanical refrigeration systems, while the batch operation is used in the ice chilling systems.

Retail refrigeration cabinets use cold air, circulated through natural or forced convection. The open front refrigeration cabinets use air curtains in order to prevent the infiltrations of warm air into the cabinet; the proper design of the air curtains imposes an in-depth understanding of the cabinet's fluid dynamics.

CFD simulation was applied as a case study for a refrigeration cabinet. The simulation led to the conclusion that, for the lower shelves, the temperature is at least 4C higher than the one required by standards, while there was a 6C temperature difference between the upper and lower shelves of the cabinet; in the meantime, the simulation showed the non-uniformity of the air curtain in the vicinity of the base air grill. Turbulence intensity and temperature were higher at the back of the cabinet.
