准球形葡萄预冷时间的研究

果蔬预冷是冷藏链中一个重要环节，适当的预冷时间能保证果蔬质量。通过对巨峰葡萄在预冷时的传热分析，建立了集总参数法模型来估算葡萄中心温度达到冷库温度时所需要的时间，并通过实验进行了验证。结果表明当冷库内空气流速达到一定时(大于1．1m/s)，采用定性尺寸R，集总参数法能够很好地估算葡萄预冷时间，为农业生产中形状类似于葡萄的果蔬预冷时间提供了依据。

Study on the Definition of Time of the Grape Pre-Cooling

The pre-cooling of fruits and vegetables is an important step in the cold-chain, and a proper pre-cooling time period can assure the quality of fruits and vegetables. Here the lumped parameter method was set up to estimate the required time period after which the center temperature of the grape reaches the air temperature in the cooling store by analyzing the heat transfer of the grape in pre-cooling, and was confirmed by the experiment. The results show that adopting the qualitative size R, the method can estimate the pre-cooling time period of the grape properly when the air velocity in the cooling store is larger than 1.1m/s.