The refrigerating vehicle refrigeration unit is pre-cooled, the temperature controller is set at the required temperature, and the pre-cooling is one and a half hours to remove the heat trapped in the compartment. Because refrigerated trucks are generally parked on the side of the road waiting for goods, the temperature of their compartment is close to the ambient temperature. At this time, if the carriage is not pre-cooled, the goods being transported may be damaged due to the ambient temperature.
In addition, the refrigerated truck compartments are loaded without pre-cooling. At this time, there will be varying degrees of temperature difference. Because of the goods, the temperature of the refrigerated truck compartments is unevenly cooled and the goods are damaged.
At the same time, the nature of loading and unloading is the same, and the refrigerated truck refrigeration unit needs to be turned off. The reason is that if the evaporator of the refrigerating unit of a refrigerated truck is always working, the front of the fan has a positive pressure and the back is a negative pressure, and the cold air blows out from the upper part of the car. At this time, the lower part will quickly suck in the hot air from the outside, resulting in a rapid temperature of the car. Rising, if the refrigeration unit is temporarily turned off, the wind pressure inside and outside the car will be the same, and the speed of external hot air entering the car will be correspondingly slower.