To study the effect of different factors on the differential pressure pre-cooling of white radish

we use the Pearson correlation coefficient and the orthogonal experimental method. The absolute value of the Pearson correlation coefficient between temperature and uniformity in differential pressure pre-cooling of white radish was 0.875

and the two were strongly correlated. Based on the orthogonal experimental method

taking cooling rate and cooling uniformity as evaluation indexes

the degree of influence on the cooling rate in decreasing order is porosity

air supply temperature

opening rate

and wind speed; the degree of influence on cooling uniformity in decreasing order is air supply temperature

porosity

wind speed

and opening rate. The orthogonal test results show that the smaller the air supply temperature

the greater the wind speed

opening rate

and porosity

and the greater is the cooling rate；the greater the supply air temperature and porosity

the smaller the wind speed and opening rate

and the smaller is the uniformity. The optimized experimental precooling conditions are as follows: the air supply temperature is 3 ℃

the wind speed is 0.32 m/s

the packing box opening rate is 0.08

and the porosity is 0.48. The application of the orthogonal test method and the reference of Pearson correlation coefficient improve the efficiency of the experiment and the accuracy of variable analysis.