不同因素对国光苹果差压预冷效果的影响

Effects of Different Factors on Differential Pressure Pre-Cooling of Guoguang Apple

通过搭建果蔬差压预冷试验装置,研究塑料大帐开孔大小、周转箱间距、送风速度和送风温度对国光苹果预冷效果的影响。采用混合正交试验分析上述4个因素对预冷效率及冷却均匀度的影响程度。结果表明:送风温度对预冷速率的影响最为显著,其次为周转箱间距、送风速度、开孔大小;而送风速度对冷却均匀度的影响最显著,其次是送风温度、周转箱间距、开孔大小。正交试验结果表明:大帐开孔越大,预冷速度越快,开孔越小,冷却均匀度越好;周转箱间距越大,预冷速度越快,冷却均匀度越好;送风速度越大,预冷速度越快,冷却均匀度越好;预冷库温度越低,预冷速度越快。优化后的预冷条件为:开孔大小20 mm、周转箱间距100 mm、送风速度1.5 m/s、送风温度–1℃,在此条件下的差压预冷的效率比静止预冷提高了233.33%,冷却均匀度提高了73.92%,失重率降低了64.58%。

By constructing a fruit and vegetable differential pressure pre-cooling test device,the effects of the opening size of the plastic tent,the spacing of the turnover box,the air supply speed and the air supply temperature on the pre-cooling effect of Guoguang apples were studied.The influence of the above four factors on the pre-cooling efficiency and cooling uniformity were analyzed by mixed orthogonal test.The results show that the air supply temperature has the most significant effect on the pre-cooling rate,followed by the turnover box spacing,air supply speed and the size of the opening;while the air supply speed has the most significant effect on the cooling uniformity,followed by the supply air temperature,the turnover box spacing,opening size.The orthogonal test results showed that:The smaller the opening is,the faster the precooling speed is;the larger the opening is,the better the cooling uniformity is;The greater the space between turnover baskets,the faster the precooling speed and the better the cooling uniformity;The higher the air supply speed,the faster the precooling speed and the better the cooling uniformity;The lower the temperature of the precooling warehouse,the faster the precooling speed.The optimized precooling conditions are as follows:the opening size was 20 mm,the spacing between the turnover boxes was 100 mm,the air supply speed was 1.5 m/s,and the air supply temperature was–1℃.Under those condition,the efficiency of differential pressure pre-cooling was increased by 233.33%compared with static pre-cooling,the cooling uniformity was increased by 73.92%,and the weight loss rate was decreased by 64.58%.