果蔬热处理传热过程的数值模拟及验证

    Numerical simulation and experimental verification of heat transfer for fruits and vegetables during heat treatment

    • 摘要: 为了研究果蔬采后热处理过程的传热机理,建立了柱状与球状果蔬热处理的普适传热模型,对模型进行了数值模拟及试验验证。结果表明:所建模型能够准确预测多种边界条件下柱状与球状果蔬热处理时的组织温度变化及动态响应,柱状及球状果蔬的模型预测值与实测值的平均相对误差及均方根误差均低于5%。热水浸泡法与热空气法的对比试验表明:达到相同的热处理效果,伊丽莎白香瓜热水浸泡法的处理时间仅为热空气法的35%~50%;热水浸泡法中香瓜果实的表面换热系数为190~250 W/(m2·℃),而在热空气法中仅为10~30 W/(m2·℃)。所建普适传热模型及相关试验结论可为采后果蔬热处理工艺参数的确定及优化提供参考。

       

      Abstract: In order to investigate the heat transfer mechanism of postharvest fruits and vegetables during heat treatment, a universal heat transfer model suitable for columnar and spherical fruits and vegetables was established. The results showed that the established model could well predict the temperature changes of heat-treated fruits and vegetables, and the relative errors between simulated and measured results were lower than 5%. With the same treatment effect, the heating time of the Elizabeth muskmelon treated by the hot water method was only 35%–50% of the heating time of the Elizabeth muskmelon treated by hot air method. The surface heat transfer coefficients of the muskmelons treated by hot water and hot air were 190–250 and 10–30 W/(m2·℃) respectively. The universal heat transfer model and experimental results can provide guidance for operation and optimization of the heat treatment of postharvest fruits and vegetables.

       

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