蓝莓预冷箱的设计优化
Design Optimization of Blueberry Pre-cooling Box

本文建立了三维数学模型对3种不同开孔的蓝莓预冷箱体内蓝莓的预冷过程进行模拟，分析了3种预冷箱体内的蓝莓在不同预冷风速下的预冷时间与不均匀度。考虑不同箱体的承载量，提出密度预冷系数来综合评价箱体内的蓝莓质量与预冷时间。模拟结果表明：预冷时间随风速的增加而减小；在相同预冷风速下，箱体3可多承载1/3的蓝莓质量，7/8预冷时间增加低于5 min，预冷不均匀度提升0.2~0.4，密度预冷系数增加最显著，达到3.09 kg/(m3.min)。综合所考察的影响因素，确定蓝莓预冷的最佳风速为1.5 m/s；虽然箱体3的预冷不均匀度有所增加，但可以有效提升预冷库的利用率。
In this study, a three-dimensional mathematical model was established to simulate the pre-cooling process for blueberries in boxes containing three holes. The pre-cooling time and non-uniformity of blueberries with variable wind speeds were analyzed in three types of pre-cooling boxes. Considering the capacity of blueberries in different boxes, a density pre-cooling factor was proposed to evaluate comprehensively the quality of blueberries and the pre-cooling time of the pre-cooling process. The numerical results showed that the pre-cooling time of blueberries decreased with increasing wind speed. At the same pre-cooling wind speed, more than 1/3 of the blueberries could be carried in the No. 3 box, and the 7/8 pre-cooling time increased by less than 5 min. In addition, the unevenness increased by 0.2–0.4, and the density pre-cooling coefficient increased by as much as 3.09 kg/(m3.min). Based on the factors considered, the optimal pre-cooling speed of blueberries was 1.5 m/s. Although the unevenness of cooling increased in the No. 3 box, the utilization rate of pre-cooling storage could be enlarged effectively