In order to solve the problem of cooling nonuniformity in forced air pre-cooling for vegetables and fruits, five vent-hole types were designed, and a physical model and a numerical model were established. The commercial software FLUENT was employed to simulate the cooling process of potatoes with five types of vent-holes, respectively. The simulation results show that the cooling rate was highest and the pre-cooling uniformity was best with 32 non-uniform vent-holes. Our experimental data agree reasonably with the predictions. It is suggested that the aperture ratio near the differential pressure blower should be lower than that far away from the differential pressure blower. Moreover, the aperture diameter at the bottom should be slightly larger than that at the top.%为解决目前果蔬差压预冷的存在的降温不均匀性,设计了五种不同的外部遮挡开孔方式,包括32个均匀孔、32个非均匀孔、28个孔、40个孔及50个孔,建立了物理和数值模型,利用计算流体动力学(CFD)软件对土豆分别进行了五种开孔方式的数值模拟研究.对比分析了五种开孔方式的预冷模拟结果,预冷降温速率最快和均匀性最好的是32个非均匀孔的,并对此进行了实验验证,二者基本吻合.为差压通风预冷的外部遮挡或包装的开孔设计提出了建议:靠近压差风机处的开孔率要低以阻挡靠近差压风机侧气流,远离差压风机处开孔率要高,最底部的孔径应稍大于上部的.
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