No abstract

No abstract

No abstract

The numerical simulation model of forced-air cooling of strawberries in a clamshell and a box was established by using computational fluid dynamics method. The cooling process of the simulation and the experiment results agreed well in different conditions, indicating that the simulation model was validated. The results showed that the 7/8 cooling time was 180 min, 135 min, 108 min and 100 min and the cooling uniformity coefficients were 0.31, 0.22, 0.24, 0.26 when the diameters of B-vent(the vent on the box) were 30 mm, 40 mm, 50 mm, 60 mm, respectively. The 7/8 cooling time decreased and the cooling uniformity coefficient improved, when the shape of C-vent (the vent on the clamshell) changed from round to rectangular. The 7/8 cooling time also deceased and the cooling uniformity coefficient increased, when the area of C-vent with both round and rectangular shapes increased. These results indicate that both B-vent and C-vent had significant effect on reducing the cooling time and the improving cooling uniformity for strawberries, It is suggested that the optimized vent ratio of B-vent (the diameter is 40 mm) and C-vent (15 mm round or 20 mm × 15 mm rectangular) for the current commercial packaged strawberries were 9.4 % and 8.5 %, respectively.

Forced air pre‐cooling after harvest of fruit was an indispensable part of modern cold chain logistics. A comprehensive thermodynamics evaluation system of forced air pre‐cooling for cherry was established in this paper using the finite volume method and verified with experimental results. The results showed that the 7/8 pre‐cooling time decreased with increasing air velocity. However, when the air velocity was higher than 2 m/s, the 7/8 pre‐cooling time was not significantly shortened. In addition, 7/8 pre‐cooling time and air velocity coincided with the power function: t7/8 = 42.603v−0.687. The energy consumption of forced air pre‐cooling decreased first (0.5–1.5 m/s) and then increased (1.5–3 m/s) with the increase in air velocity, and the largest difference reached 9.30%. Finally, the inhomogeneity of pre‐cooling was also analyzed. The larger the air velocity was, the lower and earlier of the peak value of inhomogeneity in the forced air pre‐cooling process. When the air velocity exceeded 2 m/s, the change rate of the inhomogeneity of 7/8 pre‐cooling time was less than 5%. Practical applications Forced air pre‐cooling after harvest of fruit was an indispensable part of modern cold chain logistics. However it can significantly reduce water loss, fruit wilting and rot during storage. In this paper, the air parameters of cherries 7/8 pre‐cooling time, energy consumption and inhomogeneity of pre‐cooling were analyzed by CFD simulation and experiment. According to the results, we can acquire the explicit relationship between 7/8 pre‐cooling time and air velocity. And the influence of air velocity on energy consumption and the inhomogeneity of pre‐cooling. The purpose was to get optimal air parameters for forced air pre‐cooling of cherries.