There are many factors which affect supercooling of water. Under the same experimental conditions

supercooling degree of water is not a fixed value. The presence of bead-packed porous structure influences the supercooling of water. Experiments to test supercooling of distilled water and different ball diameters of bead-packed porous structure were conducted thirty two times. And experiments about characteristics of cold storage of distilled water and different ball diameters of bead-packed porous structure were also conducted. Experimental results of supercooling were analyzed using statistical methods

and a CCD camera and a thermal imager were used for observing the phenomenon of supercooling. The average supercooling degree of distilled water under the condition of cooling with large temperature difference was lower than that under the condition of stepped slow cooling. The smaller the ball diameter in bead-packed porous structure

the smaller the average and peak supercooling degree

but there was a special circumstance when ball diameter was 11 mm. The average supercooling degree and the peak value of bead-packed porous structure with 11 mm ball diameter were smaller than that with 8 mm ball diameter. In addition

the presence of a porous solid base greatly reduced storage phase transition time.