Effects of air discharge modes on airflow organization and temperature uniformity inside automated high-bay cold store

To quantitatively evaluate the influence of air discharge configuration on thermal uniformity and energy performance in automated high-bay cold stores, a three-dimensional CFD (Computational Fluid Dynamics) model was developed to systematically compare the airflow distribution and thermal performance under downward and horizontal air discharge modes of the air cooler. Taking the − 20 ℃ automated high-bay cold store as an example, the mathematical model was validated against measured values. Then, CFD simulations were conducted at four air mass flow rates of 12 kg/s, 24 kg/s, 36 kg/s, and 48 kg/s for the air cooler, and the study focused on evaluating differences in airflow organization efficiency and temperature uniformity between the two air discharge modes. The results demonstrate that downward air discharge fundamentally alters large-scale flow structure formation, suppresses stagnant zones, and enhances global convective heat transfer uniformity. At a lower air mass flow rate of 12 kg/s, the temperature non-uniformity under horizontal air discharge is 3 to 4 times higher than that under downward air discharge, while the latter achieves an average store temperature approximately 2.0 ℃ lower, indicating a pronounced energy-saving potential. With increasing air mass flow rate, temperature uniformity is improved for both modes. However, the downward air discharge mode consistently provides superior temperature gradient control across all operating conditions. This study demonstrates the dominant role of air discharge modes of air cooler in airflow distribution and temperature uniformity inside automated high-bay cold stores and provides quantitative guidance for energy-efficient design.