Why does the refrigeration system experience blockage? How to prevent it?

We all know that the refrigeration system is a general term for the equipment and pipelines through which the refrigerant flows, including compressors, condensers, throttling devices, evaporators, pipelines, and ancillary equipment. It is the main component system of air conditioning equipment, cooling, and refrigeration equipment. There are various forms of blockage faults in refrigeration systems, such as ice blockage, dirty blockage, and oil blockage.
The occurrence of ice blockage faults is mainly due to excessive moisture in the refrigeration system. As the refrigerant continues to circulate, the moisture in the refrigeration system gradually concentrates at the outlet of the expansion valve. Due to the lowest temperature at the outlet of the expansion valve, the water forms ice and gradually increases, completely blocking the expansion valve to a certain extent. The refrigerant cannot circulate and the system no longer fails to cool.
The formation of dirty blockage faults is due to excessive impurities in the refrigeration system. Most of these impurities and powders are removed by the drying filter when passing through it. If there are too many impurities in the system, the drying filter will gradually become clogged. Due to the limited capacity of the filter to filter out dirt and impurities, clogging may occur due to the continuous accumulation of impurities.
In addition, there is also an oil blockage fault. The main reason for the oil blockage in the refrigeration system is that the system did not consider the system flow rate at low loads during design, resulting in insufficient oil return and excessive refrigerant oil filling. When the load increases again, excess refrigerant oil is discharged into the condenser along with the compressor exhaust, and then enters the drying filter together with the refrigerant. Due to the high viscosity of the oil, it is blocked by the desiccant inside the filter. When there is too much oil, it forms a blockage at the inlet of the filter, preventing the refrigerant from circulating properly and cooling.