I. Working Principle

II. Working Process

1. Trigger Stage: When the sensor detects that the frost thickness on the evaporator is ≥5mm, or the cold storage temperature difference exceeds the set value (e.g., 5℃), the controller starts the defrosting program and shuts down the cold fan.
2. Commutation Stage: The solenoid valve switches to block the refrigerant's path to the condenser and directs the high-temperature refrigerant gas into the evaporator pipeline.
3. Defrosting Stage: The hot gas flows in the evaporator and exchanges heat with the frost layer. The frost layer melts into water, which is discharged through the drain pipe (a proper drainage slope must be ensured to prevent freezing).

4. Reset Stage: After the defrosting duration (usually 5-15 minutes) or when the sensor detects that the frost layer is removed, the solenoid valve resets. The hot gas returns to the condenser, the cold fan restarts, and the system resumes refrigeration.

   
   

5.