Improving cooling rate in a cold room by using a parametric study coupled with computational fluid dynamics

The cooling dynamics of fruits depend on the flow conditions around the biological material. Computational fluid dynamics (CFD) coupled with a design of experiments (DOE) was implemented to reveal how a design variable (bin open area) and an operational variable (cold air mass flow at the inlet) affect turbulence and therefore the cooling kinetics. The CFD model was first validated against experimental local velocities inside the bins with an error of 14% to later be used in the parametric study (simulated data was consistent with experimental data). A clear non-homogeneity in turbulence distribution (vertical stratification) was found and therefore different local cooling rates. For this cooling room, the bin located in the top are cooling faster (8.1 hour 7/8th cooling time) that the bin located in the bottom (14.7 hours 7/8th cooling time). A 65% reduction in the mass flow rate shows a 21% increment in 7/8th cooling time and 57% increment in the lateral bin open area with a constant the flow rate, shows 9% increments in the 7/8th cooling time but with a 2 hours (7/8th cooling time) reduction in the difference between the bin in the top and the bin in the bottom which implied better homogeneity.