Experimental evaluation of cooling characteristic, airflow distribution and mass transfer in a cold store

Abstract

The cooling characteristics and safety of food products inside the cold room depend on the temperature field and govern by the airflow distribution. The nonuniform air distribution creates variability in the cooling rate and transpiration rate. The volume of products in cold‐store influences the airflow pattern and, therefore, experimental study performed on loaded cold‐room. The experiment includes measuring and estimating temperature, convective heat transfer coefficient, and weight loss to evaluate the heat and mass transfer. The airflow behavior inside the cold room is observed highly nonuniform. In the product‐zone, cooling‐air flow with higher velocities near the floor and flow uniformity decrease with the height of the cold store. The product cooling variability observed along the path of the flow as the product in front zone cooled at a rapid rate compared to that placed in the rear zone. The estimated average transpiration rate ranged from 0.033 to 0.16 gkg−1 h−1 in front zone and in rear zone; it is ranged from 0.038 to 0.2 gkg−1 h−1. The experimental study of loaded cold store presents the factual nature of cooling and storage condition, and the zone‐wise examination of operating variable beneficial for understanding the cooling characteristics included heat and mass transfer. Practical Applications The room air cooling method is the most accepted method to preserve food products, and the preservation (operating) condition of the cold room influences the heat and mass (product weight) transfer phenomenon. The experimental observation of operating conditions (airflow field, temperature change, air relative humidity, convective heat transfer coefficient) is performed at multiple locations and explained. The nonuniformity in operating conditions is observed, which leads the variability in heat and mass transfer process. The theoretical estimation of mass transfer is evaluated and validated with the experimental data. This work is used to provide better insight into the zone‐wise distribution of preservation conditions and its influences on the food product.

Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures

“…At present, the low-temperature transportation conditions of food are often set according to different food types. The wind speed at the cooling air outlet in most cold storage is greater than 6 m/s, while the wind speed at the place where the items are stored in the cold storage space is within the range of 0.5-4 m/s, which is quite different in specific situations ( Bishnoi and Aharwal, 2021 ; McSharry et al., 2021 ). We preliminarily set a wind speed of 3 m/s as the treatment condition and then further analysed the effect of airflow on the viability of SARS-CoV-2 pseudovirus at -18°C.…”

Experimental investigation of effect of ventilation strategies on the performance of cold storage

“…3 The dimensions and arrangements of production stacking, the location and airflow rate of cooling coils, the thickness of structure panels, the volume of produce, air ventilation, and the shape, size, and types of produce all have an impact on cold facility operation. [4][5][6][7][8][9][10] To ensure the food's quality and safety, cold storage facilities keep it chilled (between 0°C and 5°C) or frozen (below −18°C). Ultra-low temperatures (for some fish and specialized foods) or modified environment storage (for fruits and vegetables) are utilized for select specialized products.…”

“…The cooling unit is typically made up of a number of tube bundles through which refrigerant flows and is positioned near the ceiling's top‐end 3 . The dimensions and arrangements of production stacking, the location and airflow rate of cooling coils, the thickness of structure panels, the volume of produce, air ventilation, and the shape, size, and types of produce all have an impact on cold facility operation 4–10 …”