To obtain a cooling device, reduced in the deterioration in quality due to the overcooling of vegetables, excellent in cooling capacity and reduced in a using electric power as well as a contract electric power, by a method wherein the cooling of stored matters, in which a freezing chamber temperature is kept within a predetermined temperature width, is constituted of rapid cooling operation and cool keeping operation.
When rapid cooling is required upon the initial period of cooling, a variable speed fan 8 is operated at the full speed thereof to circulate air in a cooling chamber 4 rapidly and supply big amount of cooling air. In this case, midnight electric power can be used. Next, when the temperature t2 of cooling air is stabilized substantially at 5°C, the variable speed fan 8 is operated by the detection of set value of a temperature sensor 9 so that small amount of cooling air is supplied by switching the operation of the same fan 8 from the full-speed operation into slow-speed operation. When the temperature of cooling air becomes 0°C substantially by such a cooling operation, a refrigerating device 1 is operated in accordance with necessity by the set valve detecting command of the temperature sensor 9. Then, brine in a brine tank 7 is cooled and cooling air is kept at 5°C substantially by cooling air, generated by the cooling operation of a cooler 2, through the brine being cooled whereby the cool keeping of the vegetables can be effected.
YOKOYAMA MASASHI
YAMADA KAZUO
ICHINOSE MICHIHIKO
