What is the function of the capillary in the refrigerator

The capillary is a thin, long copper tube. The inner diameter is generally 0.5 ~ 1mm, and the length is 2 ~ 4m. Copper pipes conduct heat well. Because the pore size of the capillary is relatively small, only a certain amount of high-pressure liquid can pass through it. After the refrigerant exits the capillary tube, it immediately expands into a gas and absorbs heat during the expansion process. This is called refrigeration.

The capillary in the refrigerator has three functions:

1. Keep a certain pressure difference between the refrigerant in the condenser and the refrigerant in the evaporator to ensure that the refrigerant vapor has a higher pressure in the condenser, so that the refrigerant vapor radiates heat and condenses into a liquid in the condenser; ensure The refrigerant liquid has a lower pressure in the evaporator, so that the refrigerant liquid absorbs heat and evaporates into gas in the evaporator.

2. Control the refrigerant flow. If the capillary resistance is large, the refrigerant flow rate is small, the cooling capacity is small, and the evaporation temperature is low; if the capillary resistance is small, the refrigerant flow rate is large, the cooling capacity is large, and the evaporation temperature is high.

3. Throttling and reducing pressure and regulating flow. At the same time, it also has the function of preventing wet compression, liquid shock and abnormal overheating. After passing through the evaporator, the refrigerant absorbs heat and changes from a liquid state to a gas state. After the compressor forces the refrigerant into the condenser, due to the obstruction of capillary tubes, the refrigerant maintains high pressure in the condenser and is compressed from a gas state to a liquid state. After passing through the capillary, the refrigerant has a lower pressure in the evaporator, evaporates from a liquid state to a gas state, absorbs heat, and completes refrigeration. The capillary can also determine the evaporation temperature in the evaporator by adjusting the refrigerant flow.

Bulb and capillary sensor

Post time: Sep-05-2023