Based on computational fluid dynamics (CFD) simulation

the research focused on the influence of different insulation structures and different temperatures of tomatoes on the uniformity

quality

and effect of tomatoes in cold storage. The tomato was used as the test object

and a three-dimensional model of the semiconductor refrigerating box was established to get the temperature field. The test results were verified and analyzed further. When the external temperature was 20 ℃

it took 30 and 35 minutes for the average temperature in the vacuum insulation panel (VIP) combined with polyurethane (PU) box and PU box

respectively

to decrease from 20.7 ℃ to 5 ℃

and the average temperature was 4.58 ℃ and 4.97 ℃

respectively

35 minutes later

with maximum temperature differences of 6.97 ℃ and 8.09 ℃

respectively. Tomatoes that were pre-cooled to 4 ℃

10 ℃ and 15 ℃ in cold storage were put into the two boxes to simulate delivery for 10 hours at 2.5 ℃. With the VIP+PU box and PU box

the final temperatures of these tomatoes were 2.38 ℃

4.29 ℃

5.89 ℃ and 3.33 ℃

5.15 ℃

6.67 ℃

and the uniformity of temperature in tomatoes σ was 0.52

0.44

0.41

0.57

0.47

and 0.43

respectively. The model calculation results are consistent with the experimental results. The results showed that the thermal insulation performance

cooling rate

and cooling uniformity of the VIP+PU box were considerably better than those of the PU box; 4 ℃ was the optimal initial temperature of tomato with 0.08% weight loss rate

minimal change in lightness and chroma

and 5.13% content of total soluble solids under 2.5 ℃ refrigerated environment.