送风温度对苹果差压预冷降温效果的影响

Effect of Air supply Temperature on Cooling Efficiency during Pressure Precooling of Apples

中文关键词: 送风温度  差压预冷；数值模拟  冷却时间；冷却均匀性

英文关键词: air  supply temperature  pressure precooling  numerical simulation  cooling time  cooling uniformity

中文摘要:

      果品采后预冷是现代冷链物流不可缺少的必备环节之一，差压预冷由于其冷却速度快、冷却均匀以及适用性广，近年来已经得到了广泛的应用与发展。以2层箱装红富士苹果为研究对象，建立了考虑其呼吸热与蒸腾热影响的数值模型，利用FLUENT软件模拟在不同送风温度下果品预冷降温过程的温度分布情况。结果表明，预冷初温并不是越低越好，当送风温度低于2℃时，预冷时间没有明显的缩短，而预冷的不均匀性却明显增加，因此建议此规格包装的苹果差压预冷送风温度取2℃较宜。该模拟结果可为合理控制苹果差压预冷时间提供一定的理论依据。

英文摘要:

      Precooling of fruit is one of the indispensable links in modern cold chain logistics because of the rapid cooling speed, cooling uniformity and wide applicability. The pressure precooling has been widely used and developed in recent years. This work established a numerical model for analyzing the temperature distrbution of appales during the process of pressure precooling under different air supply temperaturesby This work takes a two-layer box of red Fuji apple as the research object and considering the effects heat of respiration and transpiration. The results show that the lower the initial precooling temperature is not the lower the better when the air temperature is below 2℃. The precooling time is not significantly reduced, and the non-uniformity of precooling is obviously increased. It suggestes that the optimum air supply temperature is 2℃ . The simulation result provides a theoretical basis for controlling the Precooling time reasonable during pressure precooling of apples.