Judgment skills of ice blockage, dirty blockage and oil blockage in refrigeration equipment pipeline

System blockage has always been a difficult problem in air conditioning maintenance, which takes time and effort to maintain. Today, we will focus on sharing the types and judgment skills of pipeline system blockage. It should be noted that the following jams are caused by human factors, and the following analysis is for your reference, hoping to bring some help to the future maintenance work.

1. Ice jam

The ice jam is mainly caused by excessive water in the system. With the continuous circulation of refrigerant, the water in the system gradually concentrates at the capillary outlet. Because the temperature at the capillary outlet is the lowest, the water becomes ice and gradually increases. To a certain extent, the capillary is completely blocked and the refrigerant cannot be circulated.

Ice blocking phenomenon:The performance of ice jam in the refrigeration system is that it works normally at the initial stage. With the formation of ice jam, the airflow can be heard gradually weakening and intermittent. When the jam is serious, the airflow sound disappears, the refrigerant circulation is interrupted, and the condenser gradually cools down. The failure of ice blocking in the refrigeration system is due to excessive moisture in the system, so the whole refrigeration system must be dried. After the capillary "ice jam" is determined, the refrigerant in the refrigeration system is discharged first, and then vacuum drying is carried out again.

2. Dirty blockage

The fault is caused by excessive impurities in the refrigeration system. The main sources of impurities in the system are: dust and metal scraps in the manufacturing process of refrigeration equipment, the oxide layer on the inner wall of the pipeline falls off during welding, the inner and outer surfaces of various parts are not cleaned during processing, the pipeline is not tightly sealed, dust enters the pipeline, refrigeration oil and refrigerant contain impurities, and the desiccant powder with poor quality in the filter is dried; In addition, when welding the expansion valve and the drying filter, it is easy to weld the expansion valve nozzle.

After determining that the system is dirty and blocked, high-pressure nitrogen combined with other methods can be used to blow out the dirt of the blocked expansion valve. After the expansion valve is blown through, after cleaning and drying the components in the refrigeration system, it can be reassembled and welded to eliminate the fault. If the expansion valve is seriously blocked, and the above method can't eliminate the fault, replace the expansion valve or the method to eliminate the fault.

3. Oil blockage:

The main cause of oil blockage in refrigeration system is the serious wear of compressor cylinder or the excessive fit clearance between piston and cylinder. The gasoline discharged with the compressor is discharged into the condenser, and then enters the drying filter together with the refrigerant. Because of the high viscosity of the oil, it is blocked by the desiccant in the filter, and when there is too much oil, it forms a blockage at the inlet of the filter, so that the refrigerant cannot circulate normally and does not refrigerate.

The failure of oil blockage indicates that there is too much refrigeration oil left in the refrigeration system, which affects the refrigeration effect and even cannot refrigerate, so the refrigeration oil in the system must be removed. When the filter is blocked, a new filter should be replaced. At the same time, part of the frozen oil accumulated in the condenser should be blown out with high-pressure nitrogen. When nitrogen is introduced, the condenser can be heated with an electric blower. When the filter is blocked, a new filter should be replaced. At the same time, part of the frozen oil accumulated in the condenser should be blown out with high-pressure nitrogen. When nitrogen is introduced, the condenser can be heated with an electric blower.