Experimental investigation of air flow field and cooling heterogeneity in a refrigerated room
Rajkumar Bishnoi, K. R. Aharwal
Abstract
Temperature heterogeneity in the refrigerated cold room promotes food degradation and losses and governs by the airflow field. Achieving the temperature homogeneity of fruits at various locations in the cold room is challenging due to the effect of operating and design variables. This study presents the experimental investigation of airflow field, temperature characteristics (fruits and air), convective heat transfer coefficient, half cooling time and weight loss measurement of fruits loaded in crates inside the cold room. Results showed significant cooling heterogeneity inside the cold room during the cooling period. The maximum cooling heterogeneity identified along the length of the cold room. The crates placed in-front of the air cooling unit observed a higher cooling rate and minimum cooling time in comparison with that placed at the rear-side. During the storage condition, the temperature heterogeneity is varied from 0.87 to 0.97 °C, and the coefficient of temperature heterogeneity ranged from 0.088 to 0.103. The maximum value (79%) of the velocity heterogeneity index obtained at the top plane. This experimental study is beneficial to understand the mechanism of cooling pattern and air distribution in the cold room.