Pre-cooling is not required for container refrigerated
Many cargo owners prefer to pre-cool the container to a set temperature when packing exported refrigerated (frozen) cargo. This practice is actually unscientific and may have a negative impact on the cargo and the container, and thus cannot guarantee high quality. Container refrigerated (frozen) transportation.
The reason is that if the container is pre-cooled before loading, when the cabinet door is opened to prepare for loading, a large amount of high temperature and high humidity outside air will enter the cabinet and merge with the low humidity and low temperature air, which will make A large number of water droplets condense on the inner wall of the container. These water droplets will not only drip onto the outer packaging of the goods and affect the appearance of the outer packaging, but also affect the operation of the container refrigeration system, which may adversely affect the quality of the goods. Because these condensed water must be removed by the evaporator in the container refrigeration system, and the condensed water will freeze when passing through the evaporator coil, which will make the refrigeration system perform a short defrost process.
On the other hand, the evaporator must also remove the following three parts of heat: the heat that enters the cabinet directly through the cabinet door when loading; the heat that penetrates through the cabinet wall and penetrates into the cabinet; the heat that is constantly generated by the metabolism of fresh and live goods . It is conceivable that if the refrigerated container needs to remove more heat and humidity, the less refrigeration capacity is mainly used to cool the cargo itself.
Therefore, it is best not to pre-cool the container when packing refrigerated (frozen) goods for export. This is especially true when packing in tropical and subtropical regions and the hot summer season. The scientific method for packing refrigerated (frozen) goods should be pre-cooled. Set the temperature, and then quickly load the goods into the container through the insulated passage between the cold storage and the refrigerated container. Of course, when the temperature of the pre-cooled container is the same as the temperature of the cold storage, and there is an insulated passage between the cold storage and the container, the container can be pre-cooled before loading.